Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/01/14
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
815 PM MST FRI FEB 28 2014
.SYNOPSIS...
A WELL DEFINED PACIFIC STORM SYSTEM WILL BRING OCCASIONAL SHOWERS TO
SOUTHEAST CALIFORNIA AND SOUTHERN ARIZONA THROUGH THIS EVENING AND
OVERNIGHT. EVEN A FEW ISOLATED THUNDERSTORMS WILL BE POSSIBLE AT
TIMES THROUGH THE WEEKEND...WITH THE MOST CONCENTRATED SHOWER
ACTIVITY OCCURRING LATE TONIGHT THROUGH SATURDAY AFTERNOON.
CONDITIONS WILL GRADUALLY DRY OUT FROM WEST TO EAST SUNDAY WITH HIGH
PRESSURE AND NORMAL TEMPERATURES RETURNING EARLY NEXT WEEK.
&&
.DISCUSSION...
THE MUCH ADVERTISED STORM SYSTEM HAD ITS CENTER PINWHEELING NEAR 35N
127W THIS EVENING...WITH EASTERLY DIRECTIONAL TRAJECTORIES POINTED
DIRECTLY TOWARDS THE LOS ANGELES BASIN. THE PRIMARY LOW/MID LEVEL
MOISTURE PLUME HAS BEEN SHUNTED WELL EAST OF THE MAIN CIRCULATION
CENTER...NOW ARCING FROM THE CNTRL BAJA PENINSULA DIRECTLY NORTH
THROUGH THE COLORADO RIVER VALLEY...WITH OBJECTIVELY ANALYZED PWATS
IN EXCESS OF 1.1 INCHES. AT THE SAME TIME...THE MOST PRONOUNCED
DIFLUENCE...AGEOSTROPHIC FLOW...AND LARGE SCALE DYNAMIC ASCENT WAS
LOCATED TOWARD THE NWRN PERIPHERY OF THIS MOISTURE PLUME ACROSS
CNTRL CALIFORNIA AND SRN NEVADA. ALL TOLD...GIVEN THE POST-MATURE
STATE OF THE CYCLONE...THERE HAS BEEN A SLIGHT DISCONNECT OF SALIENT
ATMOSPHERIC FEATURES LEADING TO A LACK OF MORE ORGANIZED WEATHER AND
IMPACTS WITHIN THE FORECAST AREA THUS FAR THIS EVENING.
THAT SAID...A FRONTAL BOUNDARY ASSOCIATED WITH A DEEP H7-H5 CAA
LAYER HAS ALREADY MOVED ONSHORE...CROSSING THE COAST RANGE EAST OF
SAN DIEGO. AT THE SAME TIME...A STRONG SLY COMPONENT AHEAD OF THIS
BOUNDARY WAS TRANSPORTING MORE ROBUST MOISTURE (AROUND 10 G/KG)
NORTHWARD INTO SE CA/SW AZ CHARACTERIZED BY AN AREA OF DECENT DEEP
MOISTURE CONVERGENCE AND MODEST INSTABILITY. ALSO COINCIDENT WITH
THESE FEATURES WAS A NOTABLE VORTICITY MAXIMUM LIFTING TOWARDS SRN
NEVADA...YIELDING AN INCREASING DIV-Q/VORTICITY ADVECTION FIELD.
BIGGEST QUESTION IS WITH THE SALIENT FORCING MECHANISMS BEING LIFTED
TO THE NORTH...DEFLECTING THROUGH THE WESTERN PART OF THE CWA...HOW
MUCH LARGE SCALE ASCENT CAN BE EXPECTED FOR THE REMAINDER OF THE
NIGHT.
REVIEW OF MODEL OUTPUT CLEARLY INDICATES HRRR AND HIGH RESOLUTION
4KM WRF RUNS (BOTH ARW AND NMM CORES) HAVE OUTPERFORMED OPERATIONAL
MODEL WHICH HAVE GENERALLY BEEN FAR TOO AGGRESSIVE WITH
PRECIPITATION OUTPUT ON THE LEEWARD SIDE OF THE COAST RANGE (SANS
THE NAM12 WHICH HAS SUPPORTED ITS COMPLIMENTARY WRF MEMBERS).
THEREFORE...HAVE GENERALLY DISCOUNTED GLOBAL MODELS...RELYING MORE
ON THE AFOREMENTIONED DIRECT CONVECTIVE ALLOWING MODELS. BOTTOM
LINE...DEEP CONVECTION SHOULD CONTINUE TO PERCOLATE ACROSS THE LOWER
COLORADO RIVER VALLEY...WITH ADDITIONAL UPSLOPE SHOWERS NORTH OF THE
PHOENIX METRO. EVENTUALLY...WITH THE MOISTURE ADVECTION AND CAA
ALOFT BECOMING ALIGNED OVER CNTRL ARIZONA AFTER MIDNIGHT...MORE
LINES OF SHOWERS SHOULD DEVELOP EASTWARD (THOUGH HIGH RES MODELS ARE
NOT PARTICULARLY ENTHUSIASTIC REGARDING COVERAGE). BELIEVE THE BEST
SHOT FOR ORGANIZED SHOWER ACTIVITY WILL BE LATE SATURDAY
MORNING/AFTERNOON WITH SLIGHTLY MORE INSTABILITY REALIZED ALONG WITH
RENEWED DYNAMICAL FORCING ASSOCIATED WITH THE MAIN CIRCULATION
CENTER (ALBEIT DECAY/FILLING AS IT REACHES THE FORECAST AREA).
&&
.PREVIOUS DISCUSSION...
/315 PM MST FRI FEB 28 2014/
THE ATMOSPHERE ACROSS OUR CWA WILL CONTINUE TO RAPIDLY MOISTEN AS
THE LOW SHIFTS FURTHER SOUTH AND EAST. PRECIPITATION PROCESSES WILL
CONTINUE TO BE AIDED BY FAVORABLE UPSLOPE COMPONENT TO THE 700-850MB
WINDS OF 50-60KT THAT WILL GRADUALLY SHIFT EAST INTO SOUTH-CENTRAL
ARIZONA WITH TIME. WHILE EASTERN PORTIONS OF THE FORECAST AREA
REMAIN RELATIVELY DRY THIS AFTERNOON...THE BOUNDARY LAYER WILL
EVENTUALLY SATURATE WITH THE SHIFTING PLUME OF MOISTURE AND WIND...
AND OTHER LOCATIONS CLOSER TO PHOENIX SHOULD START TO SEE SOME
WIDELY SCATTERED LIGHT SHOWERS DURING THE EVENING HOURS...THE PEAK
MOISTURE TRANSPORT AND INCREASING AREAL COVERAGE OF SHOWERS NOW
TIMED TO ARRIVE CLOSER TO MIDNIGHT.
PREVIOUS DISCUSSION...
ALL THE LATEST HI-RES GUIDANCE SUGGEST THE ONSET OF SIGNIFICANT
PRECIPITATION WILL HOLD OFF UNTIL WELL AFTER 00Z AROUND THE PHOENIX
AREA. PER THEIR SOLUTIONS...PRECIP WILL DEVELOP IN THE MOUNTAINS
NORTH/EAST OF PHOENIX FIRST...THEN GRADUALLY BACKFILL OVER THE METRO
AS ADDITIONAL MOISTURE IS IMPORTED INTO THE AREA. FOR BETTER OR
WORSE...BACKFILLING DOESNT TAKE PLACE UNTIL CLOSER TO 12Z
SATURDAY...ABOUT 12 HRS SLOWER THAN PREVIOUSLY THOUGHT. GIVEN THE
VERY STRONG ISENTROPIC LIFT THAT WILL BE OVERHEAD LATE THIS EVENING
ALONG WITH NEARLY 50KT SOUTHERLY 850MB WINDS AND PWATS AROUND
1.2-1.3 INCHES...IM NOT CONVINCED IT WILL STAY DRY ALL THE WAY
THROUGH SATURDAY MORNING. I MADE SLIGHTLY DOWNWARD ADJUSTMENTS TO
POPS ACROSS THE DESERTS FOR THIS EVENING/OVERNIGHT BUT VALUES ARE
STILL RUNNING IN THE 80-90 PERCENT RANGE. THE HIGHER TERRAIN
NORTH/EAST OF PHOENIX IS STILL AT 100 PERCENT AS THEY SHOULD BE THE
FIRST TO SEE PRECIP DEVELOPMENT.
MODELS ARE TRENDING TOWARD SLIGHTLY HIGHER VALUES OF MLCAPE DURING
THE DAY ON SATURDAY...ALONG WITH SLIGHTLY HIGHER VALUES OF 0-1KM
0-3KM AND 0-6KM SHEAR. CONFIDENCE INCREASING THAT THERE WILL INDEED
BE THUNDER AROUND DURING THE DAY ON SATURDAY...BUT WITH QUITE A BIT
OF CLOUD COVER WIDESPREAD SEVERE STILL SEEMS UNLIKELY. PERHAPS A FEW
SHOWERS THAT ARE CAPABLE OF LOCALLY GUSTY WINDS...BUT THATS ABOUT
IT. ACROSS SOUTHEAST CALIFORNIA I THINK THERE COULD BE A FEW SHOWERS
ON SATURDAY BUT ISENTROPIC DOWNGLIDE ON THE 295-310K SURFACES STARTS
BECOMING EVIDENT AS EARLY AS 12-18Z SATURDAY. ACTIVITY MAY END UP
BEING FAIRLY SCATTERED IN NATURE BUT GIVEN THE LARGE SWATH OF
MOISTURE THAT WILL STILL BE IN PLACE...HESITANT TO REDUCE POPS TOO
MUCH.
THE 1.2 INCH PWAT AXIS SHIFTS INTO THE MOUNTAINS EAST OF PHOENIX
SATURDAY EVENING AND A DRYING TREND SHOULD COMMENCE ACROSS THE
ENTIRE FORECAST AREA /EXCLUDING GILA CO/ DURING THE EVENING HOURS.
LINGERING MOISTURE WILL ALLOW FOR A FEW SHOWERS ON SUNDAY BUT THE
VAST MAJORITY OF THESE SHOWERS SHOULD BE IN THE MOUNTAINS WELL EAST
OF PHOENIX. HELD ONTO AT LEAST A SLIGHT CHANCE MENTION OF POPS
SUNDAY INTO SUNDAY AFTERNOON BUT FOR THE DESERTS...RAINFALL SHOULD
BE PRETTY MUCH OVER AND DONE WITH. WHAT DOES THIS MEAN FOR STORM
TOTAL AMOUNTS? A BLEND OF WPC PROVIDED QPF AND GFS/EUROPEAN QPF
YIELDS ABOUT 0.25 TO 0.5 INCHES ACROSS SOUTHEAST CALIFORNIA...AROUND
0.75 TO 1 INCHES AROUND THE PHOENIX AREA...AND UPWARDS OF 1.5 EAST
OF PHOENIX. NATURALLY...HIGHER AMOUNTS ARE EXPECTED WITHIN THE
STRONGER SHOWERS/STORMS BUT OVERALL THESE VALUES FIT IN WELL WITH
CIPS ANALOGS. WILL HOLD OFF ISSUING ANY SORT OF FLOOD WATCHES BUT
NUISANCE FLOODING OF LOW LYING AREAS AND/OR NORMALLY DRY WASHES
CANT BE RULED OUT. SNOWFALL POTENTIAL REMAINS LIMITED AS THIS
SYSTEM WILL CONTINUE TO IMPORT WARM SOUTHERLY AIR INTO THE REGION
UNTIL SUNDAY. SNOW LEVELS WILL DROP TO AROUND 6500FT ON SUNDAY AS
PRECIP IS DRAWING TO A CLOSE. ASIDE FROM THE TOPS OF THE VERY
HIGHEST PEAKS EAST OF PHOENIX...SNOWFALL APPEARS HIGHLY UNLIKELY.
THE WEATHER TURNS MUCH MUCH QUIETER FROM MONDAY ONWARD AS WEAK ZONAL
FLOW TRANSITIONS INTO WEAK RIDGING BY MID WEEK. DRY WEATHER IS A
LOCK FROM MONDAY ONWARD ALONG WITH STEADILY INCREASING TEMPS
EVENTUALLY REACHING THE LOWER 80S TOWARD THE END OF THE WEEK.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SOUTHERLY CROSS WINDS AT KPHX AND KIWA...OCCASIONALLY GUSTING AOA
20KT WILL BE ONE AVIATION CONCERN THROUGH THE ENTIRE NIGHT WITH THE
STRONG PRESSURE GRADIENT NOT ALLOWING WINDS TO RELINQUISH THEIR
GUSTY CHARACTER. INITIAL BANDS OF SHOWERS WILL REMAIN NORTH AND WEST
OF CNTRL ARIZONA TERMINALS THROUGH THE EVENING...WITH BETTER CHANCES
FOR MORE ORGANIZED SHOWERS AFTER 06Z. WHILE CHANCES FOR TS OVERNIGHT
EXIST...PROBABILITIES ARE VERY LOW. THERE IS SOME MODEL INDICATIONS
OF PERSISTENT CIGS FALLING INTO A 4K-5K FT LEVEL SAT MORNING AS SCT
SHOWERS MAY LINGER IN THE VICINITY AFTER SUNRISE. THE BEST CHANCES
FOR MDT/HVY SHOWERS WILL EXIST SAT AFTERNOON...THOUGH CIGS SHOULD
RISE AOA 6K FT.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE AHEAD OF
AN APPROACHING FRONTAL BOUNDARY THIS EVENING...WITH ACTIVITY
EXPECTED TO MOVE EAST AFTER 03Z-06Z. WIND GUSTS TO AOA 25 KT WILL BE
PREVALENT...THOUGH GUSTS APPROACHING 40KT WITH SHIFTING DIRECTION
WILL BE POSSIBLE IN STRONGER SHOWERS. EMBEDDED ISOLD TS WILL ALSO BE
POSSIBLE THIS EVENING. REDEVELOPMENT OF ISOLD/SCT SHOWERS MAY BE
POSSIBLE SAT AFTERNOON...THOUGH CIGS THROUGH THE PERIOD SHOULD
REMAIN AOA 6K FT.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
A LOW PRESSURE SYSTEM WILL EXIT THE FORECAST AREA SUNDAY. THERE WILL
BE A LINGERING CHANCE OF SHOWERS SUNDAY...MAINLY OVER THE HIGHER
TERRAIN OF SOUTH-CENTRAL ARIZONA. TEMPERATURES WILL STILL BE BELOW
NORMAL SUNDAY AND HUMIDITIES WILL BE ELEVATED. HIGH PRESSURE BUILDS
BACK INTO THE REGION MONDAY THROUGH THURSDAY FOR A WARMING TREND
ALONG WITH LESS WIND. HUMIDITIES WILL DECREASE THOUGH OVERNIGHT
RECOVERY WILL REMAIN GOOD.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...WIND ADVISORY UNTIL 10 PM PST THIS EVENING CAZ033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...MO/MEYERS/LEINS
AVIATION...MO
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
1024 AM PST Thu Feb 27 2014
.Synopsis...
Wet weather continues into the weekend. Accumulating mountain
snow will contribute to trans-Sierra travel difficulties today
and also with the next storm wave Friday into Saturday. Isolated
to scattered thunderstorms remain a possibility this morning and
into the early afternoon, then again on Friday. Drivers should be
cautious due to slick roads from snow and rain.
&&
.Discussion...
The shortwave which moved through overnight is splitting, with
energy heading into Oregon and into Nevada. Eastern Pacific
ridging will build in behind, bringing a more stable atmosphere
with warmer air aloft. Some convection is still possible for the
next several hours, though. The HRRR and WRF models are still
showing some CAPE around 100-200 j/kg on the eastern side of the
Sacramento Valley, and into the lower foothills until around 2 pm.
There could be some heavier showers and can`t rule out some isolated
thunderstorms developing in that area before precipitation winds
down in the late afternoon.
Main concern otherwise is snow showers in the mountains through
the rest of the afternoon. A Winter Weather Advisory remains in
effect until 4 pm for the mountains of western Plumas
County/Lassen Park and the northern Sierra above 6000 feet. Snow
amounts so far range from around 4 to 9 inches across interstate
80 from Kingvale eastward to Donner Pass, with chain restrictions
currently still in place. Ski resorts have seen greater amounts,
from around 9 inches up to 19 inches of new snow reported over
some higher peaks. Some additional accumulation of around 1 to 2
inches are possible before the storm ends in the early evening.
After a brief lull tonight, the next storm takes aim at Northern
California. Precipitation amounts at this point look roughly
similar to what we saw with this last storm, although the more
southward track could bring lesser amounts to northern locations
such as in Shasta County mountains. 24 Hour totals (till 4 am)
with this last storm there were around .75 to over 2.50 inches,
and may be about half as much for Friday into early Saturday. The
central and southern Sacramento Valley ranged from low amounts
around Stockton (around .15 inches) to more than an inch, and
Downtown Sacramento had .41 inches as of 4 am. These southerly
Valley spots could see up to an inch or more. Afternoon
thunderstorms are also a concern on Friday. In terms of snow,
motorists should be prepared for wintry driving conditions
returning by early Friday morning. EK
&&
.Extended Discussion (Monday through Thursday)
Nearly zonal flow with weak embedded waves over interior northern
CA Sunday into Monday with a chance for some light showers mainly
over the northern half of the forecast area. A reinforcing wave
impacts northern CA Wednesday and Thursday with a chance of
showers and snow levels around 6000 ft. Expect some breezy
southerly winds ahead of this wave, especially over the Sierra.
JClapp
&&
.Aviation...
Upr trof movg thru this mrng. Flow alf vrs to NWly tda as wk upr
rdg movs thru then backs to SWly ovngt as nxt Pac stm movs thru
Fri into Sat. For Cntrl Vly, mnly VFR tda/tngt exc isold MVFR poss
in shwrs or br. Omtns, areas MVFR/IFR with isold LIFR tda with
impvg conds tngt. Sn lvls 055-065. Conds dtrtg acrs Intr NorCal
aft 10-12z Fri. Lcl Sly sfc wnd gsts up to 30 kts poss in Cntrl
Vly tda and SW-S sfc wnd gsts up to 40 kts ovr hyr mtn trrn.
&&
.STO Watches/Warnings/Advisories...
winter weather advisory until 4 pm pst this afternoon above 6000
feet in the west slope northern sierra nevada...western plumas
county/lassen park.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1004 AM MST THU FEB 27 2014
.UPDATE...
&&
.SHORT TERM...PRECIPITATION SLOW TO DEVELOP AND/OR SPREAD INTO
THE MOUNTAINS...WEB CAMS INDICATING MID LEVEL CLOUDS BEGINNING TO
SPREAD OVER THE AREA. THERE MAY BE SOME LIGHT SNOW OR FLURRIES
OVER THE HIGHER PEAKS. LATEST MODELS...INCLUDING THE RAP AND HRRR
ARE SLOW IN GENERATING THE PRECIPITATION ACROSS THE
MOUNTAINS...UNTIL ABOUT 20Z. SOME PRECIPITATION CURRENTLY ACROSS
THE WEST SLOPE SHOULD BE HEADING INTO THE MOUNTAINS IN THE NEXT
FEW HOURS. WILL DELAY THE HIGHER MOUNTAIN POPS TILL 20Z. REST OF
FORECASTS SEEM ON TRACK AS MOISTURE AND INSTABILITY INCREASE
THROUGH THE AFTERNOON WITH APPROACHING SYSTEM. WILL MAINTAIN THE
ISOLATED THUNDER DUE TO THE INSTABILITY. AND THERE ARE CURRENTLY
SOME STRIKES ACROSS NEVADA INDICATING A FAIRLY UNSTABLE SYSTEM.
CURRENT MOUNTAIN ADVISORY STILL ON TRACK FOR TONIGHT WITH BEST
DYNAMICS...INSTABILITY AND OROGRAPHICS. MODELS STILL SHOW ABOUT 4
TO 8 INCHES THROUGH 5AM FRIDAY. SOME LOCATIONS ALONG WEST FACING
SLOPES COULD RECEIVE HIGHER AMOUNTS. ALSO THE POTENTIAL FOR
BLOWING SNOW WITH GUSTS ABOVE TIMBERLINE INCREASING TO AROUND 60
MPH TONIGHT. DRY CONDITIONS FOR THE PLAINS THROUGH THIS
AFTERNOON...THEN PERHAPS A SLIGHT CHANCE OF RAIN OR SNOW THIS
EVENING WITH INCREASING MID LEVEL ASCENT AND INSTABILITY.
.AVIATION...LATEST MODELS NOW INDICATING WINDS TO WEAKEN BY 19Z AND
BECOME MORE SOUTHEAST AT KDEN AND KAPA AND WEST TO NORTHWEST AT
KBJC WITH THE DEVELOPMENT OF A WEAK CYCLONE NORTH OF DIA. AT THIS
TIME THERE ARE NO SIGNS OF THE CYCLONE DEVELOPING. FOR NOW WILL
CONTINUE THE TREND OF THE CURRENT TAFS WITH A WEST SOUTHWEST
DIRECTION THROUGH TONIGHT. STILL SOME CHANCE OF CEILINGS AROUND
7000 FEET AGL BETWEEN 23Z AND 03Z. NO PRECIPITATION EXPECTED DUE
TO DRIER DOWNSLOPE COMPONENT...THOUGH A FEW RAIN OR SNOW SHOWERS
COULD DEVELOP ALONG THE PALMER DIVIDE SOUTH OF KAPA. ENHANCED
DRAINAGE OVERNIGHT WITH MORE WESTERLY COMPONENT AT KBJC WITH
POSSIBLE GUSTS TO 30 KTS.
&&
.PREV DISCUSSION... /ISSUED 241 AM MST THU FEB 27 2014/
SHORT TERM...THE RIDGE AXIS TO THE WEST OF COLORADO THIS MORNING
WILL FLATTEN OUT AS IT SHIFTS EASTWARD....FOLLOWED BY A WEAK UPPER
LEVEL TROUGH MOVING ACROSS NORTHERN COLORADO TONIGHT. NOT MUCH IN
THE WAY OF SNOWFALL FOR THE MOUNTAINS THIS MORNING...THEN COVERAGE
WILL INCREASE WEST OF THE CONTINENTAL DIVIDE...ESPECIALLY AFTER
21Z. FCST SOUNDINGS SHOW FAIRLY DECENT INSTBY THIS AFTN SO WENT
AHEAD AN ADDED ISOLATED THUNDER IN THE MOUNTAINS AS WELL. THE
URBAN CORRIDOR AND NORTHEAST PLAINS WILL BE QUITE MILD TODAY WITH
HIGHS IN THE 50S. A SURFACE TROUGH WILL BE OVER ERN CO WITH THE
PRESSURE GRADIENT INCREASING ALONG THE FOOTHILLS...WHICH WILL
ENHANCE THE DOWNSLOPE ALONG THE URBAN CORRIDOR AND HELP TO WARM THINGS
UP. MID AND UPPER LEVEL QG ASCENT IS RELATIVELY WEAK WITH THIS
SYSTEM AS IT PASSES ACROSS COLORADO LATE THIS AFTN AND TONIGHT.
THE MDLS TO PAINT SOME QPF ACROSS NERN CO THIS AFTN AND
TONIGHT...MAINLY NORTH AND EAST OF DENVER SO SLGT CHC POPS THERE.
NOT SURE IF DOWNSLOPE OR INSTBY WILL WIN OUT ALONG THE URBAN
CORRIDOR BUT SIDED WITH THE DRY SOLUTION AND NO POPS FOR NOW. IN
THE MOUNTAINS...SPATIAL CROSS-SECTIONS SHOW DEEP MOISTURE AND GOOD
OROGRAPHIC WIND COMPONENT AT 700 MB...25-35KTS. ENOUGH POTENTIAL
FOR SNOW AND WIND TO GO WITH A WINTER WEATHER ADVISORY FOR SNOW
AND BLOWING SNOW FOR ZONES 31..33 AND 34 TONIGHT. SNOW AMOUNTS
GENERALLY 4 TO 6 INCHES BUT SOME AREAS COULD GET 8-10 INCHES.
DOWNSLOPE WINDS DEVELOP AND MID LEVEL SUBSIDENCE INCREASING
FOLLOWING THE PASSAGE OF THE TROUGH AXIS. NO WIND HIGHLIGHTS BUT
WILL ADD AREAS OF BLOWING SNOW WITH GUSTS OF 50-60 MPH ABOVE
TIMBERLINE AND EXPOSED EASTERN SLOPE.
LONG TERM...FRIDAY THROUGH WEDNESDAY...NORTHWEST FLOW ALOFT WILL BE
OVER COLORADO FRIDAY AS A TROUGH MOVES EAST OF THE REGION. COULD BE
SOME LINGERING LIGHT SNOW EARLY FRIDAY OVER THE MOUNTAINS AND FAR
NORTHEAST CORNER. WILL HAVE LOW POPS IN THE FORECAST FOR THIS.
ANOTHER COLD FRONT WILL BACK INTO NORTHEAST COLORADO DURING THE DAY
FRIDAY. IT WILL BE MILD PRIOR TO THE FRONT AND EXPECT HIGHS TO CLIMB
IN TO THE LOWER 50S BEFORE THE FRONTAL PASSAGE.
LARGE PACIFIC LOW WILL MOVE ONTO THE WEST COAST LATE FRIDAY NIGHT. A
MOIST SOUTHWEST FLOW ALOFT WILL TRANSPORT MOISTURE TO COLORADO. WILL
BE ENOUGH MOISTURE TO PRODUCE LIGHT SNOW. HOWEVER...WIND DIRECTION
WILL BE SOUTH-SOUTHWEST...PARALLEL TO THE MOUNTAINS. THIS IS NOT
FAVORABLE FOR OROGRAPHIC LIFT. ALSO THE LACK OF ANY LARGE SCALE
FORCING SHOULD KEEP SNOW LIGHT FRIDAY NIGHT. FOR THE NORTHEAST
PLAINS...AS THE COLD AIR SEEPS INTO THE AREA...MAY SEE LIGHT SNOW OR
FREEZING DRIZZLE LATE FRIDAY NIGHT.
SATURDAY AND SATURDAY NIGHT...LIFT FROM THE TROUGH...JET STREAM AND
INCREASING INSTABILITY WILL CAUSE SNOW TO INCREASE THROUGH THE DAY
AND INTO THE EVENING OVER THE MOUNTAINS. SOME OF THE SNOW COULD
SPREAD ONTO THE PLAINS...ESPECIALLY NORTH. AREAS OF HEAVY MOUNTAIN
SNOW WILL BE POSSIBLE SATURDAY AFTERNOON AND EVENING. THIS WHEN THE
BEST INSTABILITY WILL OCCUR.
TRICKY FORECAST FOR THE FRONT RANGE SATURDAY AND SATURDAY NIGHT...AS
THE COLD AIR DEEPENS...CAN`T RULE OUT A LAYER OF SATURATED AIR NEAR
THE SURFACE THAT COULD PRODUCE FREEZING DRIZZLE. DEPENDING ON HOW
MUCH MOISTURE AND PACIFIC AIR MAKES IT OVER THE MOUNTAINS...SNOW OR
EVEN FREEZING RAIN WILL BE POSSIBLE OVER PARTS OF NORTHEAST
COLORADO. PRECIPITATION TYPE WILL ALSO DEPEND ON SURFACE
TEMPERATURES. FEELING THE MODELS DO NOT HAVE A GOOD HANDLE ON THE
WHERE THE COLD AIR WILL END UP. CLOCKWISE FLOW AROUND A STRONG
SURFACE HIGH OVER THE NORTHERN PLAINS IS EXPECTED TO PRODUCE A
DENVER CYCLONE SATURDAY. DOWNSLOPE SOUTHERLY FLOW OFF THE PALMER
DIVIDER MAY KEEP TEMPERATURES ABOVE FREEZING...WHILE NORTHERLY AND
EASTERLY FLOW DENVER ON NORTH SHOULD PULL IN THE ARCTIC AIR. WILL
HAVE HIGHS FROM AROUND 10 DEGREES OVER THE NORTHEAST CORNER TO MID
40S ALONG THE PALMER DIVIDE. IF ANY MIXED OR FREEZING PRECIPITATION
OCCURS...IT WILL ALL CHANGE TO SNOW BY SATURDAY NIGHT.
ON SUNDAY...SNOW WILL BE ON THE DECREASE SUNDAY AS THE STORM SYSTEM
MOVES EAST OF THE REGION. STRONG ARCTIC HIGH WILL REMAIN EAST OF
COLORADO. THIS WILL KEEP LOW LEVEL FLOW EASTERLY AND PREVENT MUCH
WARMING. LOWERED HIGHS INTO THE TEENS OVER THE FAR NORTHEAST TO MID
30S NEAR THE SOUTHERN FOOTHILLS FOR SUNDAY.
FOR NEXT WEEK...A QUIET WEST TO NORTHWEST FLOW ALOFT WILL PREVAIL.
MODELS SHOWING ENOUGH MOISTURE EMBEDDED IN THE FLOW ALOFT TO KEEP
LOW POPS OVER THE MOUNTAINS. THERE IS A WEAK WAVE PASSING OVER THE
ROCKIES AROUND TUESDAY. NUDGED POPS UPWARDS FOR THIS. EXPECT THE
FRONT RANGE AND EASTERN PLAINS TO REMAIN DRY UNDER THIS PATTERN.
TEMPERATURES WILL BE TRICKY MONDAY AS THE ARCTIC AIR RETREATS.
EVENTUALLY THE COLD AIR WILL BE PUSH OUT OF THE STATE AND
TEMPERATURES WILL BE NEAR NORMAL COME TUESDAY AND WEDNESDAY.
AVIATION...VFR CIGS/VSBYS OVER THE NEXT 24 HOURS. COULD SEE OCNL
BKN CIGS 6-8KFT AGL DEVELOPING 23Z-03Z THIS EVENING...THEN THE
MID LEVEL CLOUDS SHOULD SCT OUT. WSWLY SFC WINDS FOR MUCH OF THE
PERIOD. WINDS MAY SHIFT WEST-NORTHWEST THIS EVENING IS SFC LOW
SHIFTS MORE SOUTH AND EAST. FOR NOW WL STICK WITH WSWLY WINDS
OVER THE NEXT 24 HOURS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 5 AM MST
FRIDAY FOR COZ031-033-034.
&&
$$
SHORT TERM...D-L
LONG TERM....MEIER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS TAUNTON MA
640 AM EST THU FEB 27 2014
.SYNOPSIS...
AN ARCTIC FRONT WILL BRING A CHANCE OF SNOW SHOWERS AND SQUALLS
THURSDAY AFTERNOON FOLLOWED BY BITTER COLD THURSDAY NIGHT INTO
FRIDAY WITH WIND CHILLS DROPPING WELL BELOW ZERO. LIGHT SNOW IS
AGAIN POSSIBLE SATURDAY INTO SUNDAY...FOLLOWED BY A SIGNIFICANT
WINTER STORM CENTERED AROUND MONDAY. UNSEASONABLY COLD AND DRY
CONDITIONS CONTINUE THROUGH THE END OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
7 AM UPDATE...
ECHO SIMILAR SENTIMENTS TO THE PREVIOUS DISCUSSION.
OVER THE PAST FEW DAYS THERE HAVE BEEN INSTANCES IN WHERE THE
NEAR-TERM MESOSCALE GUIDANCE HAS BEEN ROBUST WITH PRECIPITATION
AND RADAR SIMULATION OUTPUT ONLY TO BE OVERDONE DUE TO THE
ABUNDANCE OF DRY AIR ACROSS THE REGION. SUCH GUIDANCE PRESENTLY
HINTS AT STEEP LAPSE-RATES TO H7 UNDERGOING DYNAMIC COOLING AHEAD
OF THE ARCTIC FRONT...SUGGESTING SNOW SHOWERS/SQUALLS INTO THIS
AFTERNOON. SIGNIFICANT CAPE VALUES UP TO AROUND 100 J/KG COUPLED
WITH INVERTED-V PROFILES NEAR THE SURFACE HINT AT THE POTENTIAL OF
VERY GUSTY WINDS.
FEEL A LEVEL OF HESITATION CONCERNING SIGNIFICANT SNOW ACTIVITY.
THE BETTER CHANCES MAY BE E/SE WITH THE SOUTHERLY FETCH OF
MOISTURE OFF THE ATLANTIC /THUS GIVING VALUE TO THE HRRR RADAR
REFLECTIVITY SIMULATIONS/. HAVE HIGH CONFIDENCE THAT LAPSE RATES
WILL STEEPEN ALLOWING FOR THE EFFECTIVE MIX-DOWN OF FASTER
MOMENTUM TO THE SURFACE. EXPECT GUSTY SW WINDS DURING THE DAY.
PREVIOUS DISCUSSION...
MID LEVEL CLOUDS STARTING TO MOVE OVER PORTIONS OF WESTERN
MA...SOUTHERN NH AND NORTHERN CT. TEMPERATURES HAVE SUSPENDED
THEIR FREEFALL AT LOCATIONS BENEATH THESE CLOUDS...AT LEAST FOR
NOW. WILL STILL NEED TO WATCH TEMPERATURES THIS MORNING FOR
FURTHER TWEAKS.
AS FOR THE REST OF TODAY...AM RATHER CONFLICTED OVER THIS
FORECAST. ON ONE HAND...THERE ARE MANY FACTORS WHICH WOULD ARGUE
FOR AT LEAST SCATTERED SNOW SHOWERS...WITH SNOW SQUALLS NOT OUT OF
THE QUESTION. THERE IS PLENTY OF SYNOPTIC LIFT ALONG AND AHEAD OF
AN ARCTIC FRONT WHICH SHOULD CROSS OUR REGION LATER TODAY. THE KEY
MISSING INGREDIENT IS LOW LEVEL MOISTURE.
OBSERVED DEW POINT DEPRESSIONS ARE BETWEEN 10-20 DEGREES
FAHRENHEIT. OF THE 27/00Z GUIDANCE...ONLY THE GFS IS BULLISH
ENOUGH TO MOISTEN THE LOW LEVELS WHERE SIGNIFICANT ACCUMULATING
SNOW BECOMES A REAL POSSIBILITY. GIVEN THE AMOUNT OF LOW LEVEL DRY
AIR...KEPT ONLY SCATTERED SNOW SHOWERS TODAY. STILL EXPECTING
GENERALLY LESS THAN 1 INCH OF SNOW...WHERE IT SNOWS AT ALL. SHOULD
STRONGER SQUALLS DEVELOP...UP TO 2 INCHES OF SNOW WOULD BE
POSSIBLE AT THOSE LOCATIONS.
AN ARCTIC FRONT SHOULD RACE ACROSS SOUTHERN NEW ENGLAND BY LATE
THIS AFTERNOON. THIS WILL MEAN GUSTY SOUTHWEST TO WEST WINDS.
TEMPERATURES SHOULD BE SLIGHTLY LOWER TODAY THAN YESTERDAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
TONIGHT...
A FEW LINGERING FLURRIES OR SNOW SHOWERS POSSIBLE EARLY...THEN
CLEARING SKIES. ARCTIC FRONT CONTINUES TO MOVE OFFSHORE AS STRONG
COLD AIR ADVECTION DEVELOPS. GUSTY WEST WINDS CONTINUE THROUGH
THIS EVENING...THEN DIMINISH. TEMPERATURES WILL NOT QUITE PLUMMET
DUE TO THE STRONGER WINDS. WILL NEED A WIND ADVISORY FOR PORTIONS
OF WESTERN AND CENTRAL MA...MAINLY ACROSS THE HIGHER TERRAIN. WIND
CHILLS WILL BE FAIRLY LOW ACROSS PORTIONS OF SOUTHERN NH AS
WELL...JUST NOT LOW ENOUGH TO MEET THE CRITERIA FOR AN ADVISORY.
VERY IMPRESSIVE FOR THIS LATE IN THE WINTER SEASON.
FRIDAY...
SLIGHT COLD AIR ADVECTION CONTINUES FRIDAY...BUT WILL BE COMPETING
WITH AN INCREASING SUN ANGLE. IT LOOKS LIKE A TOSS-UP... SO STAYED
FAIRLY CLOSE TO THE MOS GUIDANCE. DRY WITH PLENTY OF SUNSHINE.
GUSTY WINDS REDEVELOP FROM MID MORNING INTO MID AFTERNOON.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
*/ HIGHLIGHTS...
- UNSEASONABLY COLD TEMPERATURES PREVAIL THROUGHOUT THE FORECAST
- LIGHT SNOW SHOWERS SATURDAY INTO SUNDAY
- A SIGNIFICANT WINTER STORM LIKELY AROUND MONDAY
- COLD ARCTIC AIR RETURNS FOR THE REMAINDER OF THE WEEK
*/ OVERVIEW AND MODEL PREFERENCE...
UNSEASONABLY COLD CONDITIONS AND AN ACTIVE WEATHER PATTERN THROUGH
THE CONFLUENT FLOW ALONG THE BASE OF THE POLAR LOW ACROSS EASTERN
CANADA PREVAILS OVER THE NORTHEASTERN CONUS THROUGH /PERHAPS/ MID-
MARCH. IT DOES NOT APPEAR CONDITIONS WILL WARM ANYTIME SOON.
27.0Z GUIDANCE EXHIBITS TIGHTER CLUSTERING TOWARDS ENSEMBLE MEANS
FOR THE ANTICIPATED WINTER STORM CENTERED AROUND MONDAY. SENSIBLE
WEATHER DETAILS REMAIN HIGHLY UNCERTAIN ROUGHLY 5-DAYS OUT IN THE
FORECAST...NEVERTHELESS TOOK A CONSENSUS BLEND AND HAVE OUTLINED
CONFIDENCE /IN BROAD TERMS/ THROUGHOUT THE DISCUSSION BELOW.
*/ DAY-TO-DAY DETAILS...
FRIDAY NIGHT INTO SUNDAY...
UNSEASONABLY COLD CONDITIONS CONTINUE. MAIN FORECAST CONCERN IS A
CHANCE OF LIGHT SNOW SHOWERS SATURDAY INTO SUNDAY ALONG A COLD FRONT.
MODERATE CONFIDENCE FORECAST. CLIPPER-LOW AIRMASS WITH CONTINENTAL-
POLAR CHARACTERISTICS. BEST DYNAMICS/LIFT WELL NORTH...PARENT WITH
THE LOW. AS THE FRONT SAGS SOUTH...IT BEGINS TO LATCH INTO SOUTHERN-
STREAM SUB-TROPICAL FLOW. YET LIFT IS LIMITED BY PARALLEL-FLOW ALONG
THE FRONT /LESSER CONVERGENCE/. LOW-LEVEL F-GEN WILL LIKELY BE THE
MAIN FORCING MECHANISM TO YIELD LIGHT SNOW-SHOWER ACTIVITY /PERHAPS
SUPPRESSED ENTIRELY BY THE NEIGHBORING INFLUENCE OF HIGH PRESSURE/.
CHANCE POPS WARRANTED. VERY LIGHT SNOW ACCUMS. DO NOT ANTICIPATE
MUCH IN THE WAY OF IMPACTS.
OTHERWISE...PERHAPS MILD FOR SATURDAY WITH HIGHS AROUND THE LOW- TO
MID-30S AS H85 TEMPS AVERAGE AROUND -5C. MOSTLY CLEAR CONDITIONS
EXPECTED...AND WITH HIGH FEBRUARY SUN-ANGLE IT WILL LIKELY FEEL
SLIGHTLY WARMER. BREEZY SOUTHWEST FLOW AHEAD OF THE FRONT INTO
MIDDAY SUNDAY WHEN ITS PASSAGE IS ANTICIPATED.
SUNDAY NIGHT INTO MONDAY NIGHT...
NORTHERN AND SOUTHERN STREAM IMPULSES CONVERGE /PERHAPS PHASING/ AND
STRETCH THROUGH THE CONFLUENT AND PROGRESSIVE NEAR-ZONAL FLOW ALONG
THE SOUTHERN-PERIPHERY OF THE HUDSON BAY POLAR VORTEX. AN ELONGATED
AREA OF SURFACE LOW PRESSURE IS INVOKED ALONG THE COLD FRONT NOW
STALLED SOUTH OF THE NEW ENGLAND COASTLINE IN REGIONS OF BETTER
BAROCLINICITY RESULTING IN THE LIKELY SETUP OF A SIGNIFICANT WINTER
STORM.
AN OVER-RUNNING EVENT WITH A FRONT-END THUMP CENTERED AROUND MONDAY.
CONSIDERING THE TIGHTER CLUSTERING AND SIMILAR STRENGTH OF 27.0Z
GUIDANCE...INCREASING CONFIDENCE OF STRONG E/NE WINDS OFF THE COLDER
WATERS OF THE GULF OF MAINE COMBINED WITH AGEOSTROPHIC/ISALLOBARIC
UNDERCUTTING DRAINAGE FLOW SOUTHWARD WILL YIELD A VERY TIGHT NORTH-
TO-SOUTH GRADIENT OF SNOW-WINTRY MIX-RAIN. NORTH OF THIS GRADIENT
THE COMBINATION OF ISENTROPIC ASCENT AND H8-6 CONVERGENCE/F-GEN
FORCING OF THE WCB BENEATH STRONG REGIONS OF DIVERGENCE /RRQ OF THE
UPPER-LEVEL JET/ WILL YIELD DEEP-LAYER ASCENT THRU BETTER DENDRITIC
SNOW-GROWTH REGIONS GENERATING ROUGHLY WEST-TO-EAST MESOSCALE SNOW-
BANDING WITH 1-2 INCH PER HOUR SNOWFALL RATES POSSIBLE. WILL HAVE
TO ALSO MONITOR FOR THE POTENTIAL DEVELOPMENT OF A COASTAL FRONT
AS WELL AS THE LONG-FETCH OF THE EASTERLY JET...WHETHER WE WILL
SEE LOCALIZED CONVERGENCE /PERHAPS AGAINST THE HIGHER TERRAIN AS
WELL/.
SOME COASTAL CONCERNS AS TIDES WILL BE NOTABLY HIGH DURING THE TIME
OF STORM PASSAGE. NOON-TIME HIGH TIDE FOR BOSTON ON MONDAY IS AT 11
FEET. THE COMBINATION OF PERHAPS STRONG E/NE FLOW WITH HIGH TIDE
COULD RESULT IN MINOR COASTAL CONCERNS...ALBEIT THE SHORT RESIDENCE
TIME MAY MEAN LITTLE IF ANY IMPACT AT ALL. LOW TIDE MONDAY EVENING
AS THE LOW LIFTS AND DEEPENS ACROSS THE GULF OF MAINE.
STILL CAUTIOUS AS THE ABOVE DISCUSSION IS BROADLY SPEAKING WITH
REGARDS TO TRENDS BASED ON THE TIGHT CLUSTERING OF DETERMINISTIC
SOLUTIONS AS NOTED ABOVE. STILL CONTINUED UNCERTAINTY IN SPECIFIC
SENSIBLE WEATHER DETAILS. THERE IS NOT ENOUGH CONFIDENCE TO STATE
SPECIFICALLY WHERE OR WHEN IMPACTS WILL BE FELT. VARIANCE IN
ENSEMBLE MEMBERS WITH DETERMINISTIC SOLUTIONS LENDS TO SIGNIFICANT
SPATIAL AND TEMPORAL DIFFERENCES. NOTHING IS CERTAIN. SLIGHT WOBBLES
IN BOTH LOW AND FRONTAL POSITIONS IN PROXIMITY TO THE SOUTH-COAST OF
NEW ENGLAND CONTINUE TO EXIST. THERE ARE ALSO PERHAPS ISSUES BETWEEN
THE INTERACTION/PHASING OF NORTHERN- AND SOUTHERN-STREAM IMPULSES.
AS A FINAL NOTE...CIPS ANALOG GUIDANCE BASED ON THE 27.0Z GFS HAS
THE MEAN SNOWFALL BASED ON THE TOP ANALOGS ALONG THE SOUTHERN-TIER
OF NEW ENGLAND STRETCHING BACK INTO PA WITH A GREATER THAN 40
PERCENT CONFIDENCE-LEVEL OF SEEING 6 OR MORE INCHES. THIS ADDS TO
THE OVERALL FORECAST-CONFIDENCE OF A SIGNIFICANT WINTER-STORM
IMPACT.
TUESDAY AND BEYOND...
192- AND 264-HR CIPS ANALOG GUIDANCE ALONG WITH THE 8-DAY CANADIAN
COMPOSITE CONTINUE TO EXHIBIT BELOW-NORMAL CONDITIONS AS A STRONG
NEGATIVE HEIGHT ANOMALY PERSISTS OVER THE HUDSON BAY REGION. BETTER
AGREEMENT IN A STRONG ARCTIC HIGH PRESSURE BUILDING SOUTH INTO NEW
ENGLAND WITH SOME VERY COLD AIR INTO THE END OF THE WEEK.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH FRIDAY/...HIGH CONFIDENCE.
VFR. -SHSN BY THIS AFTERNOON SOME OF WHICH WILL BE MODERATE.
HIGHER CONFIDENCE FOR E/SE SHORELINE TERMINALS. MINOR SNOW ACCUMS.
MAY SEE TEMPO MVFR-IFR IMPACTS. NOT ENOUGH CONFIDENCE THOUGH TO
MENTION IN TAFS AS ACTIVITY WILL BE HIT-OR-MISS. GUSTY SW WINDS UP
TO AROUND 30 KTS ESPECIALLY FOR SOUTH-SHORELINE TERMINALS.
ACTIVITY DIMINISHES OVERNIGHT AS THE ARCTIC FRONT SWEEPS THROUGH
AND WINDS BACK W/NW BECOMING QUIET BY FRIDAY.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. BEST CHANCE FOR SNOW
ACTIVITY IS AROUND 19-23Z.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK...FRIDAY NIGHT THROUGH MONDAY NIGHT...
FRIDAY NIGHT INTO SUNDAY...HIGH CONFIDENCE.
MOSTLY VFR. SOME -SHSN POSSIBLE AHEAD OF A COLD FRONT WHICH WILL
SLIDE THRU THE TERMINALS SUNDAY. BLUSTERY SW WINDS ALONG AND AHEAD
POSSIBLE.
SUNDAY NIGHT INTO MONDAY NIGHT...MODERATE CONFIDENCE.
CONDITIONS DETERIORATING WITH ONSET OF WINTER STORM. IFR-VLIFR
LIKELY. BLUSTERY E/NE POSSIBLE BACKING W/NW WITH STORM DEPARTURE.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
THROUGH FRIDAY...HIGH CONFIDENCE.
GALE WARNINGS POSTED FOR ALL SOUTHERN NEW ENGLAND COASTAL WATERS
EXCEPT BOSTON HARBOR AND NARRAGANSETT BAY. SMALL CRAFT ADVISORIES
POSTED FOR THOSE WATERS. A FREEZING SPRAY ADVISORY CONTINUES.
W/SW WINDS WILL INCREASE THIS AFTERNOON AHEAD OF AN ARCTIC FRONT.
THIS FRONT WILL MOVE EAST OF ALL OF THE WATERS BY LATE THIS
EVENING. GALES ARE LIKELY AS THE COLDER AIRMASS MOVES OVER THE
WATERS. GALE FORCE WINDS GRADUALLY DIMINISH FROM WEST TO EAST
LATE TONIGHT INTO FRIDAY. WILL HAVE TO REPLACE THE GALE WARNINGS
WITH SMALL CRAFT ADVISORIES WHEN THE TIME COMES LATE TONIGHT INTO
FRIDAY.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY NIGHT...
FRIDAY NIGHT INTO SUNDAY...MODERATE CONFIDENCE.
HIGH PRES MOVES OUT AS A COLD FRONT SLIDES SOUTH AND STALLS ACROSS
THE SOUTHERN WATERS SUNDAY. CHANCE OF LIGHT SNOW SHOWERS. PERHAPS
SOME BLUSTERY SW WINDS AHEAD OF THE FRONT...COULD SEE WAVES KICK UP
IN EXCESS OF 5 FEET ON THE OUTER WATERS.
SUNDAY NIGHT INTO MONDAY NIGHT...MODERATE CONFIDENCE.
WINTER STORM. WILL SEE INCREASING E/NE WINDS WITH THE APPROACH OF
THE STORM BACKING W/NW WITH DEPARTURE. SEAS POTENTIALLY BUILDING 10-
12 FEET ON THE OUTER WATERS. IMPACTS DUE TO A MIX OF PRECIPITATION
TYPES.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...WIND CHILL ADVISORY FROM 10 PM THIS EVENING TO 9 AM EST FRIDAY
FOR MAZ002>004-008-009.
NH...NONE.
RI...NONE.
MARINE...FREEZING SPRAY ADVISORY FROM 7 PM THIS EVENING TO 9 AM EST
FRIDAY FOR ANZ231>235-237-250-251-254>256.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 4 AM EST FRIDAY FOR
ANZ231>235-237.
SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 10 AM EST
FRIDAY FOR ANZ230.
SMALL CRAFT ADVISORY FROM NOON TODAY TO 10 AM EST FRIDAY FOR
ANZ236.
GALE WARNING FROM 6 PM THIS EVENING TO 6 AM EST FRIDAY FOR
ANZ250-254.
GALE WARNING FROM 8 PM THIS EVENING TO 4 AM EST FRIDAY FOR
ANZ251.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 6 AM EST FRIDAY FOR
ANZ255-256.
&&
$$
SYNOPSIS...BELK/SIPPRELL
NEAR TERM...BELK/SIPPRELL
SHORT TERM...BELK
LONG TERM...SIPPRELL
AVIATION...BELK/SIPPRELL
MARINE...BELK/SIPPRELL
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1253 PM EST THU FEB 27 2014
.SYNOPSIS...
A COLD FRONT OVER THE EASTERN GREAT LAKES WILL MOVE THROUGH THE
REGION TODAY. AN ARCTIC HIGH PRESSURE SYSTEM WILL BUILD INTO THE
REGION ON FRIDAY AND THEN LIFT NORTHEAST ON SATURDAY. ANOTHER COLD
FRONT WILL MOVE THROUGH THE FORECAST AREA EARLY SUNDAY BEFORE
STALLING TO OUR SOUTH LATER ON SUNDAY. AN ARCTIC HIGH PRESSURE RIDGE
IS FORECAST TO BUILD OVER NEARBY CANADA AS WAVES OF LOW PRESSURE
FORM AND RIDE ALONG THE STALLED FRONTAL BOUNDARY LATER SUNDAY INTO
MONDAY NIGHT. THE ARCTIC HIGH PRESSURE SYSTEM ITSELF WILL THEN
BUILD SOUTHEAST INTO THE NORTHERN PLAINS ON TUESDAY AND THE GREAT
LAKES ON WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A QUICK UPDATE TO ACCOUNT FOR FLURRIES MOVING ACROSS SOUTHERN NJ.
GIVEN DEW POINT DEPRESSIONS OF 15 TO 20 DEGREES, DO NOT EXPECT ANY
ACCUMULATIONS, BUT THE SNOW SHOWERS COULD CONTINUE THROUGH MID DAY.
NO MAJOR CHANGES TO THE NEAR TERM GRIDS WITH THE 830 UPDATE.
EARLIER CLOUD COVER ACROSS DELMARVA AND SOUTHERN NJ IS BEGINNING
TO SCATTER OUT. THE COLD FRONT IS JUST MOVING INTO NORTHWEST PA
NOW. AT IT`S CURRENT SPEED, IT WOULD REACH SE PA BY 4 PM, BUT THIS
IS BASED ON LIMITED SAMPLING, AND IT SHOULD BE SPEEDING UP
THROUGH THE DAY, SO HAVE STAYED CLOSE TO THE PREVIOUS FORECAST FOR
NOW.
PREVIOUS DISCUSSION...ANOTHER COLD FRONT WILL CROSS THE REGION
TODAY AS AN AREA OF LOW PRESSURE MOVES OUT OF THE GREAT LAKES
REGION AND ACROSS THE NORTHEAST AND COULD BRING SCATTERED SNOW
SHOWERS/FLURRIES TO THE AREA. A POTENT SHORT WAVE/VORT MAX WILL
SWING ACROSS THE NORTHERN PART OF THE AREA AROUND MIDDAY TODAY,
WHILE LOW LEVEL LAPSE RATES INCREASE SIGNIFICANTLY, ESPECIALLY
ACROSS THE NORTHERN HALF OF THE AREA. THE LIMITING FACTOR WILL BE
THE MOISTURE AS LOW LEVEL MOISTURE IS RATHER LACKING EXCEPT ACROSS
THE NORTHERN THIRD OF THE AREA. THE GREATEST POTENTIAL FOR SNOW
SHOWERS WILL BE ACROSS THE NORTHERN THIRD OF THE AREA WHERE THE
GREATEST LIFT/INSTABILITY AND MOISTURE CONVERGE, SO WE WILL HAVE
THE GREATEST POPS HERE. WE DECIDED TO INPUT ISOLATED SNOW
SHOWERS/FLURRIES EVEN AS FAR DOWN AS NORTHERN DELMARVA AND
SOUTHERN NEW JERSEY. ANY SNOW SHOWERS THAT DO DEVELOP AND MAKE
THEIR WAY ACROSS THE AREA COULD PUT DOWN A QUICK COATING TO AN
INCH, ESPECIALLY ACROSS THE HIGHER ELEVATIONS ACROSS OUR WESTERN
AND NORTHERN ZONES. THE BEST TIME PERIOD FOR SHOWERS/FLURRIES TO
OCCUR WOULD BE FROM AROUND NOONTIME THROUGH JUST BEFORE SUNSET.
WINDS TODAY WILL BECOME QUITE GUSTY, ESPECIALLY BEHIND THE COLD
FRONT. WINDS AT THE TOP OF THE MIXING LAYER ARE FORECAST AROUND
40-50 KNOTS, BUT THIS IS AROUND 750-800 MB, SO WE ARE NOT CONFIDENT
WE WILL MIX THIS HIGH. HOWEVER, WINDS WITHIN THE LOWEST 2000-3000
FEET ARE STILL AROUND 35 KNOTS, SO WE COULD STILL SEE WIND GUSTS
35-40 MPH. IT IS POSSIBLE THAT AN OCCASIONAL WIND GUST AROUND 45 MPH
COULD OCCUR FOR AN HOUR OR TWO THIS AFTERNOON, BUT CONFIDENCE IN
OCCURRENCE AND FREQUENCY IS NOT HIGH ENOUGH TO WARRANT AN ADVISORY
AT THIS TIME.
TEMPERATURES WILL REMAIN COLD, ABOUT 15-20 DEGREES BELOW NORMAL, AND
WHEN THE WINDS INCREASE DURING THE DAY, IT WILL FEEL A LOT COLDER. A
BLEND OF MAV/MET MOS, MOSGUIDE, AND ECMWF WAS TAKEN FOR DAYTIME
HIGHS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
ANY SHOWERS/FLURRIES THAT OCCUR DURING THE DAY ARE EXPECTED TO
DIMINISH OR MOVE OUT OF THE AREA AS THE FRONT MOVES OFFSHORE AND THE
SHORT WAVE/VORT MAX PULLS AWAY FROM THE AREA THIS EVENING. WINDS
WILL REMAIN GUSTY FOR THE EVENING BEFORE DROPPING OFF OVERNIGHT.
HOWEVER, THERE SHOULD STILL BE A STEADY BREEZE OVERNIGHT.
TEMPERATURES OVERNIGHT ARE EXPECTED TO BECOME QUITE COLD AND WILL BE
20-25 DEGREES BELOW NORMAL. IN FACT, WE COULD BE APPROACHING RECORD
LOWS FOR SOME CLIMATE SITES OVERNIGHT. WIND CHILLS WILL BE LOW
OVERNIGHT INTO FRIDAY MORNING WITH THE LOW TEMPERATURES AND STRONG
WINDS, REACHING INTO THE SINGLE DIGITS TO MINUS SINGLE DIGITS
EVERYWHERE EXCEPT THE POCONOS WHERE WIND CHILLS COULD REACH -15 TO
-20. THEREFORE WE HAVE ISSUED A WIND CHILL ADVISORY FOR CARBON AND
MONROE, PENNSYLVANIA OVERNIGHT THURSDAY INTO FRIDAY MORNING.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AN IMPACTING WINTER WEATHER EVENT IS STILL EXPECTED TO AFFECT OUR
FORECAST AREA FROM SUNDAY INTO MONDAY WITH A PROBABLE 24 HOUR
CONCENTRATION CENTERED AROUND SUNDAY NIGHT AND MONDAY DAY.
CONFIDENCE ABOUT PTYPE REMAINS LOW, BUT CONFIDENCE ABOUT AN EVENT
AFFECTING OUR AREA REMAINS HIGHER THAN AVERAGE AT THIS TEMPORAL FCST
JUNCTURE. THE TWO STRONGEST CIPS ANALOGS OFF THE 12Z GFS RUN BOTH
HAD MIXED PCPN WINTER STORM CRITERIA EVENTS IN OUR CWA. WHILE
NOTHING IS EVER SET IN STONE THIS FAR OUT IN TIME, IT WOULD BE
PRACTICAL FOR ANYONE INVOLVED WITH WINTER WEATHER MITIGATION TO USE
THE NEXT SEVERAL DAYS TO GET PREPARED.
AS FAR AS THE MODELING IS GOING WITH THIS EVENT, THE OPERATION ECMWF
REMAINS THE WARMEST, ALTHOUGH IT DID TREND SLIGHTLY COLDER FROM THE
DAY RUN AND ITS ENSEMBLE MEAN IS SLIGHTLY COLDER BY MONDAY
EVENING. ITS DIFFERENCE FROM THE OTHER MODELS IS A SLIGHTLY
FARTHER NORTH PV IN EASTERN CANADA (LESS OF A NEARBY SFC RIDGE)
AND HANGING BACK MORE ENERGY IN WESTERN CANADA. BOTH PERMIT A
SLIGHTLY STRONGER TROF TO TRAVERSE THE CONUS AND BRING SLIGHTLY
WARMER AIR INTO OUR CWA. THE GFS ENSEMBLE CLUSTERING HAS ABOUT A
40 PERCENT SUPPORT OF THIS WARMER SOLUTION. THE ECMWF HAS DONE A
PRETTY CONSISTENT JOB OF "LOCKING IN" AT ABOUT 96 HOURS AND INWARD
THIS WINTER. THIS WILL MAKE TODAY`S 12Z RUN ONE TO WATCH TO SEE
THERMALLY WHO BLINKS FIRST.
AS FAR AS THE TIMING AND THE SEQUENCE OF EVENTS THEY ARE GETTING
CLOSER. THIS EVENT IS COMPACTING WHICH IS LOGICAL, ITS RARE FOR PCPN
EVENTS TO LAST LONGER THAN 24 HOURS AND IF SO, THERE IS USUALLY AT
LEAST A 6 TO 12 HOUR BREAK BETWEEN WAVES. THE SECOND LOW IN THE
WAVE TRAIN IS TRENDING WEAKER AND NOT A DURATION STRETCHER. WHILE
THERMALLY THE MODELS ARE DIFFERENT, THE SEQUENCE OF EVENTS ARE
SIMILAR, AS COLDER AIR FILTERS SOUTHWARD, PLACES THAT ARE WARM
ENOUGH ALOFT (BECAUSE OF AN 850MB OR SO WARM INTRUSION) FOR NOT
SNOW WOULD/COULD GO FREEZING RAIN TO SLEET AND THEN SNOW. ALL
LOCALES SHOULD END AS SNOW AND OUR FAR NORTHERN CWA COULD LIKELY
REMAIN ALL SNOW. QPF AMOUNTS ARE TRENDING DOWNWARD, BUT OVER ONE
INCH WATER EQUIVALENTS ARE STILL FORECAST WITHIN OUR CWA (NOT THRUT,
THERE IS A NORTH VS SOUTH DIFFERENCE THAT WE DO NOT HAVE THE SKILL
TO CHOOSE AT THIS POINT). WE ALL CAN DO THE MATH AS TO HOW MUCH
SNOW THAT WOULD BE IF ITS THE ONLY PTYPE.
AS FAR AS THE INITIALIZATION GOES, THE PV IN CENTRAL CANADA IS
SLIGHTLY WEST OF THE MODELING SOLUTIONS. WILL THIS ULTIMATELY LEAD
TO THE EURO SOLUTION BEING CLOSER? AT 850MB AND 925MB THERE WERE NO
BIG DISCREPANCIES NOTED.
AS FOR THE PARTICULARS, WE GET THE IMPRESSION THAT ON FRIDAY MANY
PEOPLE METAPHORICALLY WILL BE TELLING METEOROLOGICAL WINTER TO
NOT HAVE THE DOOR HIT IT ON THE WAY OUT. HIGH TEMPERATURES ARE
GOING TO AVERAGE AN ASTONISHING 25 DEGREES LOWER THAN AVERAGE,
COMPARABLE TO THE DEPARTURES WE SAW ON JANUARY 7TH. IF THERE IS
ANY SAVING GRACE, SUNSHINE SHOULD PREVAIL, THE "NORMALS" ARE
HIGHER AND WINDS SHOULD BE RELATIVELY LIGHT. STAT GUIDANCE LOOKS
TOO LOW BASED ON AFTN FCST 925MB TEMPS. THE ONE WAY THEY MIGHT
WORK IS IF WINDS ARE VERY LIGHT AS THE AIR MASS IS WARMING ITS WAY
DOWNWARD.
THE HIGH PRESSURE SYSTEM MOVES OFFSHORE ON FRIDAY NIGHT AND RETURN
FLOW MOISTURE AT MID AND HIGH LEVELS IS FORECAST TO RETURN. THIS
REDUCES THE CONFIDENCE IN MIN TEMPS AND WE HAVE NOT DIFFERED MUCH
FROM CONTINUITY OR STAT GUIDANCE.
KIND OF A DIRTIER MOISTURE DAY ON SATURDAY ACROSS OUR CWA AS
RELATIVELY WARMER AIR RETURNS. COUPLED WITH SOME SHEARING PVA ITS
THE REASON WE KEPT LOW CHANCE POPS. GIVEN LIGHT PCPN INTENSITY IF
IT OCCURS AT ALL, WE HAVE SOME MENTION OF A LIQUID PTYPE.
THEN ON SATURDAY NIGHT POPS ARE MENTIONED JUST FAR NORTHWEST, IN
CLOSER PROXIMITY TO APPROACHING COLD FRONT. CLOUDINESS IS
EXPECTED TO KEEP MIN TEMPERATURES HIGHER.
THE COLD FRONT STARTS MOVING THROUGH OUR CWA ON SUNDAY. HERE THERE A
RE MODELING DIFFERENCES AS TO HOW QUICKLY WILL PCPN ALONG THE WAVE
ARRIVE. GIVEN THE ANTECEDENT WARM BOUNDARY LAYER TEMPS, WE KEPT PCPN
PRIMARILY AS RAIN FROM THE PHL NORTHWEST SUBURBS AND RARITAN VALLEY
SOUTHEAST AND SNOW NORTHWEST. ECMWF MOS IS 10 TO 15 DEGREES WARMER
THAN GFS MOS WITH MAX TEMPS DUE TO BOTH ITS SLOWER CFP AND FASTER
STALLING. WE USED THE UKMET AS THE ARBITRATOR AND HAVE GONE ABOVE
MEXMOS STAT GUIDANCE FOR HIGHS. PRESENT THINKING IS THAT PCPN
THAT DOES OCCUR DURING THIS PERIOD WOULD BE ON THE LIGHTER SIDE.
THEN THE FORECAST BECOMES COMPLICATED AS COLDER AIR SEEPS IN
SOUTHWARD AS THE WAVES OF LOW PRESSURE MOVE CLOSER TO OUR CWA. THE
PRECIPITATION EVENT SHOULD BE INTENSIFYING AS WE GO THROUGH THE
NIGHT AND INTO MONDAY. POPS ARE PEAKED ON MONDAY WHERE ALL THE
MODELS CONVERGE. HERE WE ARE LEANING TOWARD THE COLDER MODELING
SOLUTIONS. SO ITS BASICALLY ALL SNOW FOR OUR NORTHWEST THIRD, SNOW
AND SOME SLEET IN THE PHILADELPHIA SUBURBS INTO THE RARITAN VALLEY,
A RATHER UGLY TRANSITIONAL MIXTURE OF RAIN, FREEZING RAIN TO SLEET
AND SNOW ALONG AND AROUND THE I95 CORRIDOR AND A LATER TRANSITION
NEAR THE COAST. THIS EVENT SHOULD BE ENDING ON MONDAY NIGHT.
TUESDAY AND WEDNESDAY ARE KEPT DRY WITH TEMPERATURES EXPECTED TO
REMAIN WELL BELOW NORMAL. METEOROLOGICAL WINTER STILL CAN NOT
FIND THAT DOOR.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
SCATTERED SHSN CONTINUE ACROSS THE REGION, RESULTING IN BRIEF MVFR
CONDITIONS. A MORE SIGNIFICANT LINE OF SHSN IS CURRENTLY IN
CENTRAL PA SLIDING EAST. IT SHOULD ENTER OUR AREA AROUND 21Z,
HOWEVER HIGH RES MODELS SUCH AS THE HRRR SHOW THE SOUTHERN END OF
THE LINE ERODING AS IT APPROACHES THE REGION. THUS, ONLY EXPECT
ABE AND RDG TO BE AFFECTED AT THIS TIME, BUT WILL BE WATCHING FOR
POSSIBLE IMPACTS TO TTN, PNE, AND PHL. THIS LINE OF SHSN IS WITH
THE COLD FRONT, SO ALSO EXPECT AN ABRUPT SHIFT TO WESTERLY, THEN
NORTHWESTERLY WINDS THROUGH THE SAME TIME PERIOD. WINDS SHOULD
DIMINISH A FEW HOURS AFTER SUNSET AND STAY LIGHT THROUGH THE
REMAINDER OF THE TAF PERIOD. VFR CONDITIONS ARE ALSO EXPECTED
BEHIND THE FRONT THROUGH THE REMAINDER OF THE TAF PERIOD.
OUTLOOK...
FRIDAY AND FRIDAY NIGHT...VFR CONDITIONS EXPECTED.
SATURDAY...VFR CONDITIONS EXPECTED, POSSIBLY MVFR DURING THE
AFTERNOON NW AIRPORTS AND TERMINALS.
SATURDAY NIGHT...MVFR VSBYS EXPECTED AND MVFR TO IFR CIGS EXPECTED.
SUNDAY INTO MONDAY...A PROTRACTED WINTER WEATHER EVENT IS OUTLOOKED
WITH MVFR TO IFR CONDITIONS EXPECTED TO CONTINUE. WHILE CONFIDENCE
ABOUT PCPN TYPE TIMING IS LOW, MOST OF THE AIRPORTS AND TERMINALS
ARE CURRENTLY OUTLOOKED TO BE AFFECTED BY THIS SYSTEM.
&&
.MARINE...
THE GALE WARNING REMAINS IN PLACE ACROSS THE WATERS AS WINDS WILL BE
INCREASING BEHIND A COLD FRONT THAT WILL CROSS THE AREA THIS
AFTERNOON. THE STRONGEST WINDS ARE EXPECTED LATE THIS AFTERNOON INTO
THIS EVENING AND WIND GUSTS COULD RETURN TO ADVISORY LEVELS
OVERNIGHT INTO FRIDAY MORNING. HOWEVER, WE WILL LEAVE THE ENDING
TIME OF 6 AM FRIDAY FOR THE GALE WARNING AND LET LATER SHIFTS
CONVERT THE GALE WARNING TO SMALL CRAFT ADVISORIES WHEN THE TIME
COMES.
WITH THE COLD TEMPERATURES EXPECTED OVERNIGHT INTO FRIDAY MORNING
COMBINED WITH THE GUSTY WINDS, MODERATE FREEZING SPRAY IS EXPECTED
TO DEVELOP. THEREFORE A FREEZING SPRAY ADVISORY HAS BEEN ISSUED FOR
ALL WATERS OVERNIGHT INTO FRIDAY MORNING.
OUTLOOK...
FRIDAY...WINDS AND SEAS WILL DIMINISH THROUGH THE DAY AND FALL BELOW
SMALL CRAFT ADVISORY CRITERIA. SOME MODERATE FREEZING SPRAY IS
LIKELY TO CONTINUE ON FRIDAY MORNING AND IS COVERED IN THE PRESENT
ADVISORY.
FRIDAY NIGHT THROUGH SUNDAY...WINDS AND SEAS ARE EXPECTED TO REMAIN
BELOW SMALL CRAFT ADVISORY CRITERIA.
SUNDAY NIGHT AND MONDAY...SMALL CRAFT ADVISORY CRITERIA CONDITIONS
ARE FORECAST TO RETURN ALONG WITH A WINTRY MIX OF PRECIPITATION.
&&
.FIRE WEATHER...
RELATIVE HUMIDITY LEVELS WILL DROP INTO THE 20S TO NEAR 30 PERCENT
FOR PORTIONS CENTRAL/SOUTHERN NEW JERSEY, EASTERN PENNSYLVANIA, AND
THE DELMARVA REGION THIS AFTERNOON. ALSO WINDS WILL BE VERY WINDY
TODAY. HOWEVER, WITH THE AMOUNT OF PRECIPITATION OUR AREA HAS HAD
THE LAST COUPLE OF WEEKS, FUEL MOISTURE CONTENT SHOULD BE HIGH
ENOUGH TO NEGATE THE NEED FOR ANY RED FLAG HEADLINES, ESPECIALLY
WHERE ANY SNOW COVER REMAINS.
LATEST OBSERVATIONS SHOW DEW POINT TEMPERATURES A BIT HIGHER THAN
PREVIOUSLY FORECAST. THUS, SHOULD APPROACH BUT NOT QUITE MEET THE
RH CRITERION TODAY.
&&
.TIDES/COASTAL FLOODING...
A LOW WATER ADVISORY HAS BEEN ISSUED FOR MARINE AREA WATERS FOR THE
LOW TIDE CYCLE TONIGHT. A SPS WILL ALSO BE ISSUED FOR THE TIDAL
SECTIONS OF THE DELAWARE RIVER FOR THE SAME LOW TIDE CYCLE. GOOD
MODELING CONSENSUS ABOUT BLOW OUT TIDES OCCURRING TONIGHT. THERE IS
DIVERGENCE WITH THE SUBSEQUENT LOW TIDE CYCLE DURING THE SECOND HALF
OF THE DAY ON FRIDAY. BY THEN THE WINDS ARE FORECAST TO BE
RELATIVELY LIGHT FOR AT LEAST SIX HOURS. WE REALIZE THAT THERE IS A
LAGGING EFFECT DUE TO STRONGER WINDS FARTHER OFFSHORE, BUT
CONFIDENCE IS TOO LOW AT THIS POINT TO GO BEYOND THIS LOW TIDE
CYCLE WITH THE ADVISORY.
&&
.CLIMATE...
RECORD LOW TEMPERATURES FOR THE 27TH AND 28TH. IT DOES NOT APPEAR
THAT THESE RECORDS WILL BE IN JEOPARDY TODAY, BUT A FEW LOCATIONS
HAVE A CHANCE ON THE 28TH.
FEBRUARY 28TH
ATLANTIC CITY...2 DEGREES IN 1934
PHILADELPHIA....9 DEGREES IN 1934
WILMINGTON.....-5 DEGREES IN 1934
ALLENTOWN.....-10 DEGREES IN 1934
TRENTON.........1 DEGREE IN 1934
GEORGETOWN......8 DEGREES IN 1950
READING.........3 DEGREES IN 1934
MOUNT POCONO..-15 DEGREES IN 1907
PHILADELPHIA HAD ITS 12TH CALENDAR DAY OF MEASURABLE SNOW SO FAR
THIS SEASON YESTERDAY. THIS TIES THE MOST CALENDAR DAYS WITH AT
LEAST AN INCH OF SNOW SINCE THE WINTER OF 1977-78. THE NEXT ONE
CHRONOLOGICALLY ON THE LIST IS THE RECORD HOLDING WINTER OF
1917-18 WITH 17 DAYS.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WIND CHILL ADVISORY FROM 11 PM THIS EVENING TO 9 AM EST FRIDAY
FOR PAZ054-055.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...LOW WATER ADVISORY FROM 11 PM THIS EVENING TO 4 AM EST FRIDAY
FOR ANZ450>455.
FREEZING SPRAY ADVISORY FROM 11 PM THIS EVENING TO 9 AM EST
FRIDAY FOR ANZ430-431-450>455.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 6 AM EST FRIDAY FOR
ANZ430-431-450>455.
LOW WATER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM EST FRIDAY
FOR ANZ430-431.
&&
$$
SYNOPSIS...GIGI/MEOLA
NEAR TERM...JOHNSON/ROBERTSON
SHORT TERM...ROBERTSON
LONG TERM...GIGI
AVIATION...GIGI/JOHNSON/MEOLA
MARINE...GIGI/ROBERTSON/MEOLA
FIRE WEATHER...
TIDES/COASTAL FLOODING...
CLIMATE...
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
953 PM EST FRI FEB 28 2014
...NOT AS COLD TONIGHT WITH A WARMER WEEKEND...
.UPDATE...
THE NAM12 MODEL BEST DEPICTED THE COASTAL TROUGH OFFSHORE BETWEEN
A HIGH PRESSURE WEDGE EXTENDING OVER SOUTH GA AND A LOW EAST OF
THE S-CENTRAL FL PENINSULA. THE GFS AND ECMWF WERE TOO WEAK WITH
THE PINCHED GRADIENT...AND A BLEND OF THE NAM12 AND RUC WERE USED
FOR THE WIND AND DEW PT FORECAST UPDATE. A SCATTERED BAND OF COASTAL
SHOWERS ON THE WEST SIDE OF THE LOW WAS ORIENTED NE- SW AND MAY SKIRT
OUR OFFSHORE COASTAL WATERS THROUGH MIDNIGHT...WITH SOME WESTWARD
DRIFT THROUGH EARLY SAT MORNING. PATCHY TO AREAS OF FOG ARE POSSIBLE
AS MIN TEMPS COOL INTO THE LOW 40S INLAND TO LOW 50S COAST UNDER
ONSHORE NNE FLOW. CLOUDS WILL INCREASE FROM NORTH WITH PARTLY CLOUDY
TO MOSTLY CLOUDY SKIES EXPECTED OVER SE GA WITH MID/UPPER CLOUDS
FROM THE WEST ASSOCIATED WITH A MID LEVEL SHORT WAVE TROUGH WHILE
LOW CLOUDS WILL CREEP INLAND FORM THE ATLANTIC WITH THE NNE ONSHORE
FLOW. WITH MOSTLY CLEAR OVER NE FL.
&&
.AVIATION...
MVFR TO IFR CIGS POSSIBLE AT SSI...CRG...AND JAX AS LOW STRATUS
BEGINS TO ADVECT ONSHORE THROUGH DAYBREAK.
&&
.MARINE...
UPGRADED THE GA COASTAL WATERS AND THE FL NEARSHORE WATERS TO AN
EXERCISE CAUTION HEADLINE FOR WINDS 15-20 KTS DUE TO THE PINCHED
GRADIENT ALONG THE COASTLINE AND COMBINED SEAS BUILDING TO 5 FT AT
BUOY 41008...WITH 6 FT SEAS LIKELY FARTHER OFFSHORE. THE GRADIENT
WILL RELAX LATE SAT AS FLOW VEERS EASTERLY AS THE COASTAL TROUGH
BREAKS DOWN AND THE LOW DRIFTS FARTHER OFFSHORE OVER THE ATLANTIC.
LINGERING EAST SWELLS MAY SUPPORT AND ELEVATED RIP CURRENT RISK.
RIP CURRENTS: LOW RISK TO MODERATE RISK POSSIBLE ON SAT WITH
INCREASED FLOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 41 68 47 76 / 0 0 0 0
SSI 48 65 53 69 / 10 10 0 10
JAX 43 70 49 76 / 0 0 0 0
SGJ 51 68 55 73 / 10 10 0 0
GNV 43 73 50 78 / 0 0 0 0
OCF 43 76 51 80 / 0 0 0 0
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
ENYEDI/ZIBURA/MCALLISTER
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
400 PM EST THU FEB 27 2014
.SYNOPSIS...
20Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN UPPER LEVEL PATTERN
DOMINATED BY RIDGING OVER THE CONTINENTAL DIVIDE...FOLLOWED
DOWNSTREAM BY A LARGE LONGWAVE TROUGH IN CONTROL OF MUCH OF THE
EASTERN HALF OF THE NATION. A POTENT AND VERY COLD LOBE OF ENERGY
WITHIN THIS TROUGH IS PASSING OVER THE GREAT LAKES WITH H5 HEIGHTS
OF 485-490DM AND 850MB TEMPS AS LOW AS -30. THAT IS COLD FOR THIS
LATE IN FEBRUARY...EVEN FOR THE GREAT LAKES REGION. WE WILL SEE JUST
A QUICK GLANCING COOL DOWN FOR THE NEXT DAY BEFORE A QUICK REBOUND
IN TEMPS OCCURS DURING THE UPCOMING WEEKEND. OUR FORECAST AREA
RESIDES AT THE BASE OF THE EASTERN CONUS TROUGH WITHIN A BROAD
CYCLONIC FLOW REGIME. WV IMAGERY SHOWS A PLUME OF MID/UPPER LEVEL
MOISTURE STREAMING ACROSS THE EASTERN GULF AND OVER FLORIDA AHEAD OF
THE TROUGH AXIS. A SERIES OF WEAK IMPULSES CAN BE SEEN WITHIN THE
FLOW CROSSING THE GULF...AND THIS ENERGY WILL COMPLICATE OUR
FORECAST FOR THE EVENING IN TERMS OF JUST WHERE AND WHEN ANOTHER
ROUND OF SHOWERS WILL OCCUR FOR THE CENTRAL AND SOUTHERN ZONES.
AT THE SURFACE...WEAK COLD FRONT IS ANALYZED OVER SOUTH FLORIDA...
SOUTH OF ALL OUR FORECAST ZONES. TEMPERATURES ARE COOLER THAN WE
HAVE EXPERIENCED OVER THE PAST WEEK OR 2 WITH 50S FAR NORTH RANGING
TO THE LOWER 60S CENTRAL...AND UP TO AROUND 70 FAR SOUTH. REGIONAL
RADAR IS BEGINNING TO PICK UP ON AN EXPANDING AREA OF SHOWERS OFF
THE WEST-CENTRAL/SOUTHWEST FLORIDA COAST WHICH IS EXPECTED TO EXPAND
TOWARD THE COAST THE NEXT COUPLE OF HOURS.
&&
.SHORT TERM (TONIGHT THROUGH SUNDAY)...
TONIGHT...
FORECAST DILEMMA FOR THE FIRST HALF OF THE NIGHT IS JUST HOW FAR
NORTH THE INFLUENCE OF THE APPROACHING SHORTWAVE IMPULSES WILL
ALLOW FOR SHOWERS. THE RAP/HRRR GUIDANCE ALONG WITH LOCAL HIRES
GUIDANCE HAS BEEN INSISTENT ALL DAY ON A FINAL BATCH OF RAIN/SHOWERS
ARRIVING LATE AFTERNOON INTO THE EVENING OVER THE SOUTHERN HALF OF
THE AREA. WE SAW THE COOLING COLD TOPS ON SATELLITE OUT OVER THE
CENTRAL GULF THE PAST FEW HOURS...AND NOW FINALLY THIS DEVELOPMENT
IS COMING INTO RANGE OF THE LAND BASED RADARS. LOOKING MORE AND MORE
LIKE THE GUIDANCE MENTIONED ABOVE IS ON THE RIGHT TRACK...AND A
SHOWERY EVENING APPEARS ON TAP FOR THE SOUTHERN HALF OF THE AREA.
THE QUESTION IS WHETHER OR NOT THE TAMPA BAY AREA EASTWARD ALONG THE
I-4 CORRIDOR WILL GET INTO THIS BATCH OF SHOWERS OR IF THE CUT-OFF
WILL BE AROUND MANATEE/HARDEE COUNTIES. WILL KEEP AT LEAST A LOW END
CHANCE FOR SHOWERS INTO PINELLAS/HILLSBOROUGH/NORTHERN POLK FOR THE
EVENING HOURS...WITH HIGHER RAIN CHANCES FURTHER SOUTH. INITIAL
FORECAST WAS FOR HIGH END CHANCE 50% POPS FOR THESE SOUTHERN ZONES
WITH SOME UNCERTAINTY AS TO JUST HOW MUCH SYNOPTIC SUPPORT THE
SHORTWAVES WOULD PROVIDE. NOW THAT THERE INFLUENCE IS BECOMING MORE
CERTAIN...WILL BE RAISING POPS TO LIKELY THIS EVENING SOUTH OF THE
BAY AREA.
BY THE SECOND HALF OF TONIGHT...MOST OF THE SYNOPTIC SUPPORT FOR
LIFT ALONG WITH THE BEST COLUMN MOISTURE DEPARTS TO THE EAST OF THE
FORECAST AREA. WILL SHOW ANY LINGERING SHOWER CHANCES ENDING OVER
THE SOUTHERN ZONES BEFORE DAWN. SURFACE HIGH PRESSURE WILL BE
BUILDING IN FROM THE NORTH WITH A COOL AND DRY AIRMASS BECOMING
STRONGLY ESTABLISHED FROM TAMPA BAY NORTHWARD. A FAVORABLE DRAINAGE
FLOW PATTERN LOOKS TO BRING ENOUGH COLD AIR SOUTHWARD THAT WE ARE
CONCERNED WITH TEMPS LATE NIGHT APPROACHING...OR EVEN DROPPING BELOW
FREEZING FOR A FEW HOURS ACROSS PARTS OF LEVY COUNTY. AS A RESULT
THE FREEZE WATCH HAS BEEN UPGRADE TO A FREEZE WARNING. IN TERMS OF
FROST...THE DEWPOINT DEPRESSION IN THE MOS GUIDANCE IS ALMOST TOO
LARGE (5-7 DEGREES) TO SUPPORT MUCH FROST FORMATION ACROSS LEVY
COUNTY. HOWEVER...NORMALLY THIS DEPRESSION IS LESS RIGHT AT GROUND
LEVEL AND WILL ALLOW FOR FROST DEVELOPMENT IN THE GRIDS TO GO ALONG
WITH THE FREEZE. SLIGHTLY BETTER CONDITIONS FOR AREAS OF FROST MAY
ACTUALLY EXIST SOUTH OF THE FREEZE WARNING ACROSS CITRUS/SUMTER AND
HERNANDO COUNTIES WHERE TEMPS ARE EXPECTED TO ACTUALLY STAY JUST
ABOVE FREEZING...BUT WHERE THE DRY AIR INTRUSION WILL BE LESS.
YES...IT IS POSSIBLE TO HAVE FROST WITH 2-M TEMPS ABOVE FREEZING. A
FROST ADVISORY HAS BEEN ISSUED FOR CITRUS AND HERNANDO COUNTIES FOR
LATE TONIGHT. THE REST OF THE FORECAST AREA WILL SEE LOW TEMPS IN
THE 40S ACROSS CENTRAL FLORIDA AND INTO THE LOWER/MID 50S DOWN
TOWARD CHARLOTTE/LEE COUNTIES.
FRIDAY/FRIDAY NIGHT...
A PLEASANT LATE FEBRUARY DAY IN STORE FOR THE FINAL DAY OF THE WORK
WEEK. EXPECTING PLENTY OF SUNSHINE AND LIGHT WINDS AS COLUMN
MOISTURE CONTINUES TO DECREASE AND SURFACE RIDGING BECOMES FIRMLY
ESTABLISHED FROM THE NORTH. STILL WILL SEE A FEW PASSING IMPULSES
ALOFT...BUT WITH VERY LITTLE LEFT OVER MOISTURE...HAVE NO RAIN
CHANCES IN THE FORECAST. TEMPERATURES WILL WARM AFTER THE COOL START
INTO THE 70S FOR MOST LOCATIONS. ONLY EXCEPTIONS WILL BE OVER THE
FAR NORTHERN ZONES...AND ALONG THE COAST FROM MANATEE COUNTY
NORTHWARD WHERE DEVELOPING AFTERNOON SEA-BREEZES WILL BRING COOLER
AIR OFF THE SHELF WATERS BACK ONSHORE. LOW TEMPS WILL STILL BE COOL
FRIDAY NIGHT...BUT DO NOT HAVE ANY CONCERNS FOR FREEZES OR FROST FOR
ANY OF OUR ZONES. GENERALLY LOOKING FOR LOWER TO MIDDLE 40S NORTH OF
I-4...AND UPPER 40S TO LOWER 50S FURTHER SOUTH.
SATURDAY/SUNDAY...
THE WARMING TREND CONTINUES. HEIGHTS WILL BE RISING THROUGH THE DAY
ON SATURDAY WITH MORE ABUNDANT SUNSHINE. LOCATIONS AWAY FROM THE
COAST FROM I-4 SOUTHWARD WILL BE FLIRTING WITH 80 DEGREES WHILE
FURTHER NORTH 70S WILL BE COMMON. ONCE AGAIN...TEMPERATURES MAY FALL
BACK THROUGH THE 70S DURING THE AFTERNOON ALONG THE IMMEDIATE COAST
WITH WINDS BECOMING LOCALLY ONSHORE. MORE OF THE SAME FOR SUNDAY. A
VERY NICE LOOKING WEEKEND IN TERMS OF SENSIBLE WEATHER IN STORE.
&&
.LONG TERM (MONDAY THROUGH NEXT THURSDAY)...
MEDIUM RANGE GUIDANCE IS IN FAIRLY GOOD AGREEMENT THROUGH THE LONG
TERM PERIOD. HIGH PRESSURE WILL HOLD IN PLACE ACROSS THE AREA
THROUGH MONDAY. A WEAKENING COLD FRONT WILL THEN SHIFT SOUTHWARD
THROUGH THE REGION MONDAY NIGHT WITH HIGH PRESSURE THEN BUILDING
NORTH OF THE STATE TUESDAY THROUGH WEDNESDAY. MODEL SOLUTIONS THEN
BEGIN TO DIVERGE SLIGHTLY WITH RESPECT TO THE TIMING OF THE NEXT
STORM SYSTEM...WHICH COULD POTENTIALLY BE A STRONG ONE...FOR THE END
OF THE UPCOMING WORK WEEK. AS FOR FORECAST DETAILS...WILL SHOW RAIN
CHANCES MONDAY NIGHT AND TUESDAY IN ASSOCIATION WITH THE WEAKENING
COLD FRONT MOVING THROUGH. WILL ALSO INDICATE RAIN CHANCES WEDNESDAY
THROUGH THURSDAY ASSOCIATED WITH THE NEXT STORM SYSTEM THAT WILL
MOVE INTO THE AREA. TEMPERATURES ARE EXPECTED TO RUN NEAR TO
SLIGHTLY ABOVE NORMAL LEVELS THROUGH THE PERIOD.
&&
.AVIATION...
MVFR CIGS ACROSS TERMINALS CONTINUE TO LINGER OVER THE CENTRAL
PENINSULA. DRIER IS SLOWLY FILTERING SOUTH...BUT WILL NOT REACH THE
NORTHERN SITES UNTIL LATE THIS EVENING. ADDITIONALLY...GUIDANCE
CONTINUES TO HINT AT SHOWERS PUSHING INLAND FROM THE GULF BY THIS
EVENING AFFECTING SITES FROM SRQ SOUTHWARD THROUGH AROUND 04Z. WILL
UPDATE WITH PREVAILING/TEMPO -RA OR RA GROUPS AS NEEDED BUT FOR THE
18Z FORECAST WILL ONLY MENTION VCSH. DRIER AIR EXPECTED TO PUSH
THROUGH THE REGION BY TOMORROW MORNING WITH VFR PREVAILING.
&&
.MARINE...
HIGH PRESSURE WILL BUILD OVER THE EASTERN GULF OF MEXICO TONIGHT AND
REMAIN IN PLACE THROUGH THE UPCOMING WEEKEND. WINDS AND SEAS SHOULD
REMAIN BELOW HEADLINE CRITERIA THROUGH THE PERIOD. WINDS WILL SHIFT
ONSHORE NEAR THE COAST EACH OF THE NEXT SEVERAL AFTERNOONS AS LOCAL
SEA-BREEZES DEVELOP. THE NEXT COLD FRONT AND POTENTIAL FOR
CAUTIONARY OR ADVISORY LEVEL WINDS AND SEAS IS NOT EXPECTED TO
ARRIVE UNTIL NEXT TUESDAY OR TUESDAY NIGHT.
&&
.FIRE WEATHER...
PERIODS OF SHOWERS OVER THE CENTRAL AND SOUTHERN ZONES WILL END
OVERNIGHT AS A MUCH DRIER AIRMASS ARRIVES FROM THE NORTH. THIS DRIER
AIRMASS WILL COMBINE WITH MODERATING TEMPERATURES ON FRIDAY TO
PRODUCE WIDESPREAD RELATIVE HUMIDITY VALUES AT OR BELOW CRITICAL
LEVELS FOR THE AFTERNOON HOURS. ALTHOUGH THE RELATIVE HUMIDITY WILL
BE LOW...ERC VALUES AND WINDS WILL BE BELOW CRITICAL THRESHOLDS AND
NO RED FLAG CONDITIONS ARE ANTICIPATED. INLAND AREAS MAY ONCE AGAIN
BRIEFLY APPROACH CRITICAL LEVELS OF RELATIVE HUMIDITY ON SATURDAY
AFTERNOON ONCE AGAIN...BUT LIGHT WINDS AND LOW ERC VALUES SHOULD
PREVENT ANY RED FLAG CONDITIONS. LOCATIONS ALONG AND CLOSE TO THE
COAST SHOULD EXPECT A WIND SHIFT TO THE WEST OR NORTHWEST EACH
AFTERNOON THE NEXT SEVERAL DAYS AS LOCAL SEA BREEZES DEVELOP.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 46 69 52 75 / 30 0 0 0
FMY 55 75 55 80 / 60 10 0 0
GIF 48 72 51 78 / 30 0 0 0
SRQ 48 69 51 74 / 60 0 0 0
BKV 35 71 42 77 / 10 0 0 0
SPG 52 69 55 74 / 30 0 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...FROST ADVISORY FROM 2 AM TO 8 AM EST FRIDAY FOR COASTAL
CITRUS-COASTAL HERNANDO-INLAND CITRUS-INLAND HERNANDO.
FREEZE WARNING FROM 2 AM TO 8 AM EST FRIDAY FOR COASTAL
LEVY-INLAND LEVY.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM...JELSEMA
AVIATION...BARRON
AREA FORECAST DISCUSSION
NWS MIAMI FL
956 AM EST THU FEB 27 2014
.UPDATE...
NO CHANGES WERE NECESSARY TO CURRENT FORECAST. CLOUDY SKIES WILL
PREVAIL TODAY AS THE FRONTAL BOUNDARY CONTINUES MOVING SOUTH. AT THIS
MOMENT...IT IS LOCATED ACROSS THE LAKE OKEECHOBEE REGION. A FEW
SPOTTY AND WEAK SHOWERS ARE DEVELOPING MAINLY ACROSS THE LOCAL
ATLANTIC AND GULF WATERS. THIS TREND WILL CONTINUE THROUGH THE
DAY. LATEST HRRR RUN CONTINUES TO SHOW THIS ACTIVITY AND AN
INCREASE IN PRECIPITATION TOWARDS THE EVENING AS A MOISTURE SURGE
LOCATED ACROSS THE GULF MOVES THROUGH SOUTH FLORIDA.
&&
.PREV DISCUSSION... /ISSUED 627 AM EST THU FEB 27 2014/
AVIATION...
THE TAF SITES WILL SEE THE WINDS SLOWLY SWING FROM WEST EARLY THIS
MORNING TO NORTHWEST AS THE MORNING PROGRESSES AND THE COLD FRONT
MOVES THROUGH THE AREA. KAPF ALREADY NW AND SHOULD REMAIN THAT WAY
ALL DAY, WITH KMIA AREA SITES BECOMING NW BY MIDDAY. WIND SPEEDS
WILL REMAIN 10-12 KNOTS TODAY. MVFR CEILINGS WILL PREVAIL BOTH
AHEAD AND BEHIND THE FRONT TODAY, WITH THE POTENTIAL FOR CEILINGS
BELOW 2000 FT AFTER 16Z BEHIND THE FRONT AS PLENTY OF DEEP
MOISTURE REMAINS. SHOWER ACTIVITY WILL BE LIMITED THIS MORNING
THROUGH MIDDAY, WITH SCATTERED SHOWERS POSSIBLE AGAIN THIS
AFTERNOON. NOT ENOUGH CONFIDENCE TO PUT IN TAF OTHER THAN A VCSH
MENTION. BAXTER/MOLLEDA
PREV DISCUSSION... /ISSUED 312 AM EST THU FEB 27 2014/
.BRIEF INTERRUPTION IN OUR NICE WEATHER TODAY, BUT SUNSHINE
RETURNS FOR THE WEEKEND AHEAD; CONTINUED SEASONABLY WARM...
DISCUSSION...A WEAKENING COLD FRONT JUST NORTH OF LAKE
OKEECHOBEE WILL SAG SOUTHEASTWARD ACROSS OUR LOCAL AREA LATE THIS
AFTERNOON-EVENING. SURFACE WINDS ARE CURRENTLY SOUTHWESTERLY AHEAD
OF THE FRONT, SO LITTLE CONVERGENCE WILL OCCUR WITH ITS PASSAGE.
SEA BREEZES WON`T HELP EITHER, AS LOW LEVEL WINDS WILL BE TOO
STRONG AND HEATING WILL BE LESS COMPARED TO RECENT. GIVEN THIS
AND LIMITED INSTABILITY DUE TO EXTENSIVE CLOUDINESS, ALONG WITH
CURRENT RADAR TRENDS, HAVE LOWERED POPS TO SCATTERED CATEGORY
TODAY-TONIGHT. HAVE ALSO REMOVED TSTORMS FROM THE FORECAST GIVEN
THE ABOVE AND THIS IS IN LINE WITH SPC.
FRIDAY LOOKS TO BE A DAY OF GRADUAL IMPROVEMENT FROM NW TO SE AS
DRIER AIR SLOWLY SPREADS IN FROM THE NW. THE HIGHEST SHOWER
CHANCES WILL BE SOUTHEAST, BUT THE LATEST CONSENSUS SHOWS IT DRY
FROM THE GULF COAST TO THE LAKE OKEECHOBEE REGION.
TEMPS WILL BE SLIGHTLY COOLER TODAY-FRIDAY, ALONG WITH DECREASING
HUMIDITY. DEWPOINTS ARE STILL AROUND 70F ACROSS SOUTH FL, BUT
HAVE FALLEN OFF TO AROUND 60F AT TAMPA. THIS DRIER AIR WILL SPREAD
INTO SOUTH FLORIDA TODAY-FRIDAY, ALLOWING FOR NOTICEABLY COOLER
NIGHTS. DAYTIME HIGHS WILL BE IN THE 70S AT MOST LOCALES TODAY-
FRIDAY BEFORE WARMING BACK INTO THE 80S THIS WEEKEND AND INTO
EARLY NEXT WEEK. HIGH PRESSURE BUILDING IN AT ALL LEVELS ALONG
WITH SUFFICIENTLY LOW RH`S THROUGH THE COLUMN SUGGESTS THAT
SUNSHINE WILL BE IN FULL FORCE THIS WEEKEND INTO EARLY NEXT WEEK.
BOTH GFS AND ECMWF SHOW A FAIRLY WEAK COLD FRONT MOVING ACROSS
SOUTH FL DURING THE MIDDLE PART OF NEXT WEEK, BUT SOMETHING TO
WATCH FOR LATE NEXT WEEK IS A STRONG SHORTWAVE SHOWN BY BOTH
GFS/ECMWF INTO THE GULF OF MEXICO, WHICH EVENTUALLY SPAWNS
AN INTENSE OCEAN STORM OVER THE ATLANTIC. THIS COULD RESULT IN AN
ACTIVE COLD FRONT MOVING ACROSS THE FLORIDA PENINSULA...SOMETHING
TO WATCH FOR TSTORM POTENTIAL DOWN THE ROAD.
MARINE...SW WINDS HAVE INCREASED OVER THE MARINE AREA WITH WINDS
PREVAILING AT 15-20 KT. WINDS PEAK THIS MORNING THEN GRADUALLY
SUBSIDE. NWPS SHOWS SEAS SIG WAVE HEIGHTS PEAKING AT 4 FT TODAY.
WINDS/SEAS THEN SUBSIDE FRIDAY AND INTO THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 77 57 78 61 / 50 40 20 -
FORT LAUDERDALE 79 62 76 65 / 50 40 40 -
MIAMI 80 62 78 66 / 50 40 40 -
NAPLES 73 54 74 59 / 40 30 10 -
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...17/ERA
AVIATION/RADAR...59/RM
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
905 AM EST THU FEB 27 2014
.UPDATE (REST OF TODAY AND TONIGHT)...
14Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN UPPER LEVEL PATTERN
DOMINATED BY RIDGING OVER THE CONTINENTAL DIVIDE...FOLLOWED
DOWNSTREAM BY A LARGE LONGWAVE TROUGH IN CONTROL OF MUCH OF THE
EASTERN HALF OF THE NATION. A POTENT AND VERY COLD LOBE OF ENERGY
WITHIN THIS TROUGH IS PASSING OVER THE GREAT LAKES THIS MORNING WITH
H5 HEIGHTS OF 485-490DM AND 850MB TEMPS AS LOW AS -30. THAT IS COLD
FOR THIS LATE IN FEBRUARY...EVEN FOR THE GREAT LAKES REGION. WE WILL
SEE JUST A QUICK GLANCING COOL DOWN THE NEXT DAY OR 2 BEFORE A QUICK
REBOUND IN TEMPS DURING THE UPCOMING WEEKEND.
AT THE SURFACE...WEAK COLD FRONT IS NOW ANALYZED OVER SOUTH
FLORIDA...THROUGH ALL OF OUR FORECAST ZONES. WINDS HAVE SHIFTED
NORTH AND NORTHWEST ACROSS THE ENTIRE REGION WITH A COOLER AIRMASS
FILTERING SOUTHWARD. TEMPERATURES ARE CURRENTLY IN THE 40S TO THE
NORTH OF I-4...RANGING TO THE 50S THROUGH CENTRAL FLORIDA AND IN THE
60S DOWN TOWARD FORT MYERS. COLD AIR ADVECTION AND ABUNDANT CLOUD
COVER WILL SLOW THE DIURNAL TEMP RISE AND MAKE TODAY THE COOLEST DAY
OF THE WEEK FOR MOST LOCATIONS.
OUR REGION RESIDES ON THE SOUTHERN PERIPHERY OF THE LONGWAVE TROUGH
WITHIN A FAST WESTERLY FLOW CONTAINING SEVERAL WEAK IMPULSES
STREAMING ACROSS THE GULF OF MEXICO. PLENTY OF LEFT OVER COLUMN
MOISTURE WILL ALLOW THESE IMPULSES ALONG WITH A FAVORABLE DIVERGENT
UPPER JET STRUCTURE TO PROVIDE A FEW PERIODS LIGHT SHOWERS THROUGH
THIS EVENING TO THE FORECAST AREA. THE FIRST IMPULSE THIS MORNING
WILL ALIGN WITH THIS JET TO PROVIDE THE BEST CHANCES FOR LIGHT
SHOWERS TO THE NORTH OF THE I-4 CORRIDOR...WITH THE SUBSEQUENT
FOLLOWING IMPULSES TRENDING MAINLY SOUTH OF THE TAMPA BAY AREA BY
THE EVENING HOURS ALONG WITH THE MORE EFFICIENT UPPER DIVERGENCE.
THIS TREND IS SHOWN BY THE LATEST RAP/HRRR GUIDANCE...ALONG WITH THE
GLOBAL GFS/ECMWF GUIDANCE. DUE TO THIS CONSENSUS AND SUPPORTING
SATELLITE TRENDS...THE FORECAST HAS BEEN TRENDED TOWARD THIS
PHILOSOPHY. THE WEAKNESS OF EACH IMPULSE...MEANS THAT THEIR SYNOPTIC
INFLUENCES WILL BE HIGHLY DEPENDENT ON JUST HOW WELL EACH OF THE NWP
GUIDANCE MEMBERS INITIALIZE. WILL BE WATCHING CLOSELY THROUGH THE
DAY TO FIND THOSE MEMBERS INITIALIZING THE CENTRAL GULF REGION THE
BEST...AND CONTINUE TO TREND TIMING/LOCATION OF THE SHOWER BATCHES
THROUGH THE NEXT 12-18 HOURS.
BY THE SECOND HALF OF TONIGHT...MOST OF THE SYNOPTIC SUPPORT FOR
LIFT ALONG WITH THE BEST COLUMN MOISTURE DEPARTS TO THE EAST OF
THE FORECAST AREA. WILL SHOW ANY LINGERING SHOWER CHANCES ENDING
OVER THE SOUTHERN ZONES. SURFACE HIGH PRESSURE WILL BE BUILDING IN
FROM THE NORTH WITH A COOL AND DRY AIRMASS BECOMING STRONGLY
ESTABLISHED FROM TAMPA BAY NORTHWARD. A FAVORABLE DRAINAGE FLOW
PATTERN LOOKS TO BRING ENOUGH COLD AIR SOUTHWARD THAT WE ARE
CONCERNED WITH TEMPS LATE NIGHT APPROACHING...OR EVEN DROPPING BELOW
FREEZING FOR A FEW HOURS ACROSS PARTS OF LEVY COUNTY. A FREEZE WATCH
IS CURRENTLY UP FOR LEVY COUNTY...AND WILL BE LOOKING CLOSELY AT THE
12Z GUIDANCE LATER THIS MORNING TO DETERMINE IF THE LIKELIHOOD OF
SUB-FREEZING TEMPS IS HIGH ENOUGH TO WARRANT AND UPGRADE TO A FREEZE
WARNING. IN TERMS OF FROST...THE DEWPOINT DEPRESSION IN THE MOS
GUIDANCE IS ALMOST TOO GREAT (5-7 DEGREES) TO SUPPORT MUCH FROST
FORMATION ACROSS LEVY COUNTY. HOWEVER...IF WE END UP DE-COUPLING THE
BOUNDARY LAYER LATE AT NIGHT...THEN THIS DIFFERENCE MAY END UP BEING
LESS. SLIGHTLY BETTER CHANCES FOR PATCHY FROST MAY ACTUALLY EXIST
SOUTH OF THE FREEZE WATCH ACROSS CITRUS/SUMTER AND HERNANDO COUNTIES
WHERE TEMPS ARE EXPECTED TO STAY JUST ABOVE FREEZING...BUT THE DRY
AIR INTRUSION WILL BE LESS. WILL ALSO LOOK AT THIS POTENTIAL...AND
WILL LIKELY ADD FROST INTO THE GRIDS FURTHER SOUTH THAN IS CURRENTLY
FORECAST WITH THE AFTERNOON PACKAGE. THE REST OF THE FORECAST AREA
WILL SEE LOW TEMPS IN THE 40S ACROSS CENTRAL FLORIDA AND INTO THE
LOWER/MID 50S DOWN TOWARD CHARLOTTE/LEE COUNTIES.
AFTER THE COOL START...FRIDAY WILL BEGIN A SEVERAL DAY STRETCH OF
FAIR WEATHER AND QUICKLY MODERATING TEMPERATURES. A GREAT LOOKING
WEEKEND IN TERMS OF SENSIBLE WEATHER APPEARS IN STORE.
&&
.AVIATION...
EXPECT LINGERING MVFR CIGS THROUGH THE MORNING ACROSS ALL TERMINALS.
WITH A SOME LIGHT SHOWERS MOVING SOUTH TODAY TERMINALS SOUTH OF SRQ
COULD SEE PERIODS OF MVFR CIGS EXTEND THROUGH THIS AFTERNOON. LIGHT
RAIN MAY PERSIST SOUTH OF TAMPA BAY THROUGH THE EVENING HOURS.
&&
.MARINE...
WINDS SHOULD GRADUALLY DIMINISH BELOW HEADLINE CRITERIA FOR ALL
AREAS INTO THE AFTERNOON AND EVENING HOURS. HIGH PRESSURE BUILDING
IN FROM THE NORTH TONIGHT AND FRIDAY WILL SET UP A PERIOD OF
GENERALLY LIGHT WINDS AND SEAS FOR THE UPCOMING WEEKEND. THE NEXT
POTENTIAL FOR A FRONTAL PASSAGE AND STRONGER WINDS/SEAS LOOKS TO
ARRIVE DURING NEXT TUESDAY AND TUESDAY NIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 63 47 69 56 / 30 10 0 0
FMY 73 56 75 57 / 30 20 10 0
GIF 66 48 73 55 / 30 10 0 0
SRQ 65 48 68 53 / 30 10 0 0
BKV 62 37 70 44 / 30 10 0 0
SPG 63 53 69 60 / 30 10 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...FREEZE WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING FOR
COASTAL LEVY-INLAND LEVY.
GULF WATERS...NONE.
&&
$$
UPDATE/MARINE...MROCZKA
AVIATION...BARRON
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
324 AM EST THU FEB 27 2014
.UPDATE...
THE SYNOPSIS...NEAR TERM...AND SHORT TERM SECTIONS HAVE BEEN UPDATED
BELOW.
&&
.SYNOPSIS...
ISSUED AT 324 AM EST THU FEB 27 2014
A COLD FRONT WILL USHER IN ANOTHER ROUND OF ARCTIC AIR TODAY.
ANOTHER FRONT WILL BRING CHANCES FOR SNOW FRIDAY NIGHT INTO
SATURDAY...BUT A MORE POTENT SYSTEM WILL BRING A WINTRY MIX OF
PRECIPITATION SATURDAY NIGHT INTO MONDAY. TEMPERATURES WILL BE BELOW
AVERAGE FOR THE NEXT WEEK.
&&
.NEAR TERM /TODAY/...
ISSUED AT 324 AM EST THU FEB 27 2014
COLD FRONT REMAINS TO THE WEST AT THIS MOMENT AND TEMPERATURES
ACROSS CENTRAL INDIANA ARE RISING AHEAD OF THE FRONT. FRONT WILL BE
THROUGH THE AREA BY THE START OF THE TODAY PERIOD /7 AM/...BUT THE
QUESTION IS HOW MUCH OF THE COLD AIR WILL HAVE LOWERED TEMPERATURES
FROM THEIR RELATIVELY HIGHER LEVELS AT THE MOMENT.
FEEL THAT A BLEND OF MODELS CAPTURES CURRENT TRENDS BEST AND WILL
USE FOR TEMPERATURE FORECASTS TODAY. TEMPERATURES WILL FALL SOME
THIS MORNING IN THE STRONG COLD ADVECTION BEFORE REBOUNDING SOME
THIS AFTERNOON WITH SOME SUNSHINE EXPECTED. USING THE MODEL BLEND
FOR HIGHS ENDS UP CLOSE TO THE MET MOS.
THERE ARE SOME CLOUDS NEAR THE FRONT ITSELF AND BEHIND THE FRONT IN
THE COLD ADVECTION. THESE WILL DIMINISH THROUGH THE DAY AS CORE OF
COLD AIR BEGINS TO MOVE OFF TO THE EAST. PARTLY TO MOSTLY SUNNY WILL
COVER IT.
GUSTY WINDS AND A FEW FLURRIES ACCOMPANY THE FRONT. FLURRIES SHOULD
BE OUT OF THE AREA BY 12Z...BUT GUSTY WINDS WILL CONTINUE TODAY
ESPECIALLY THIS MORNING.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 324 AM EST THU FEB 27 2014
FOCUS IS ON PRECIPITATION CHANCES THROUGH THE PERIOD. MODELS ARE
CLOSE ENOUGH THAT A BLEND CAN BE USED.
HIGH PRESSURE WILL PROVIDE MOSTLY CLEAR SKIES TONIGHT ALONG WITH
LIGHT /BUT NOT CALM/ WINDS. THESE WILL ALLOW A COLD NIGHT...BUT FEEL
THAT MAV MOS IS JUST TOO COLD WITH NO SNOW COVER AND SOME LIGHT
WINDS. WENT CLOSER TO MET MOS.
CLOUDS WILL INCREASE ON FRIDAY AHEAD OF THE NEXT SYSTEM. MOST AREAS
WILL REMAIN DRY AS FORCING DOES NOT ARRIVE UNTIL LATE IN THE DAY.
TRIMMED BACK SLIGHT CHANCE POPS TO JUST THE FAR SOUTHWEST FORECAST
AREA...AND ONLY WENT WITH THEM AFTER 21Z. WENT WARMER THAN THE
CONTINUED COLD MAV MOS...CLOSER TO THE MET.
FORCING FRIDAY NIGHT DOES NOT LOOK AS GOOD TODAY AS IT DID
YESTERDAY. BETTER FORCING LOOKS TO BE CLOSER TO AN UPPER TROUGH THAT
MOVES ACROSS KENTUCKY AND TENNESSEE. THUS CUT POPS BACK TO CHANCE
CATEGORY NORTH WHILE KEEPING LOW LIKELY POPS SOUTH. WENT SNOW AS
PRECIPITATION TYPE...BUT WOULD NOT BE SURPRISED TO SEE A LITTLE RAIN
AT ONSET ACROSS THE FAR SOUTH.
ON SATURDAY A COLD FRONT WILL MOVE INTO THE AREA...BUT LITTLE
FORCING IS AROUND WITH IT. THUS CONTINUED THE SLIGHT CHANCE POPS.
COLD AIR WILL NOT MOVE IN RIGHT BEHIND THE FRONT...SO READINGS WILL
HAVE A CHANCE TO GET RELATIVELY WARM. WENT WITH A MODEL BLEND.
GOOD FRONTOGENETICAL FORCING DEVELOPS BEHIND THE FRONT SATURDAY
NIGHT ALONG WITH FORCING FROM AN UPPER JET. WENT LIKELY POPS ALL
AREAS. PRECIPITATION TYPE COMES INTO QUESTION WITH WARMER AIR AT THE
SURFACE INITIALLY FOLLOWED BY HOW MUCH WARM AIR WORKS IN ALOFT
OVERNIGHT. WITH PLENTY OF UNCERTAINTY AROUND...DECIDED TO KEEP
MAINLY SNOW NORTH...AND MIX OF FREEZING RAIN AND SNOW SOUTH.
/SREF SHOWS A GOOD EXAMPLE OF THIS UNCERTAINTY. 03Z SREF MEAN SHOWS
SURFACE TEMPERATURES ABOVE 32 THROUGH MUCH OF THE NIGHT ACROSS MUCH
OF CENTRAL INDIANA. OTHER MODELS ARE COLDER AND LOOK REASONABLE
GIVEN EXPECTED LOCATION OF UPPER JET ENTRANCE REGION AND
FRONTOGENETICAL FORCING/.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
ISSUED AT 212 AM EST THU FEB 27 2014
MODELS ARE ACTUALLY FAIRLY CLOSE ON THE SYNOPTIC SCALE AND ALLBLEND
INITIALIZATIONS REFLECT WELL THE TRENDS OF THE LARGE SYSTEM
PROJECTED TO MOVE THROUGH THE REGION SUNDAY AND SUNDAY NIGHT.
THE FOCUS OF THIS PERIOD COMES DOWN TO PRECIPITATION TYPE SUNDAY
AND SUNDAY NIGHT AND IT COMES DOWN TO TEMPERATURES/THICKNESSES
WHICH AS OF LATE HAVE BEEN TRENDING COLDER. AS OF THIS MODEL RUN
THIS MEANS BETTER CHANCES FOR SNOW AS OPPOSED TO FREEZING RAIN OR
SLEET. BEST CHANCE FOR SNOW LIES ACROSS THE NORTHERN HALF OF THE
COUNTY WARNING AREA...BUT A WARM INTRUSION TO OUR SOUTH COULD STILL
BRING CHANCES FOR SLEET AND FREEZING RAIN (SOUTH OF I-70) INTO THE
FORECAST.
DEVELOPED FORECAST TOWARD THIS COLDER TREND HOWEVER WITHOUT
COMPLETELY FLIP-FLOPPING BACK AND FORTH BETWEEN FREEZING RAIN AND
SNOW. THE NORTHERN COUNTIES LOOK LIKE AN ALL SNOW EVENT...WHILE
AROUND I-70 APPEARS SNOW WILL BE THE MAIN PRECIP-TYPE WITH CHANCES
FOR SLEET OR FREEZING RAIN POSSIBLE AT TIMES. AND THEN FOR THE
SOUTHERN TIER OF COUNTIES SLEET OR FREEZING RAIN WITH POSSIBLY SOME
CHANCES FOR SNOW LOOK TO BE THE PRECIP-TYPE.
THIS EVENT SHOULD BE WINDING DOWN ON MONDAY...WITH ONLY LOW CHANCES
FOR SNOW POSSIBLE BY THEN AS IT LOOKS EVEN COLDER. TUESDAY AND
WEDNESDAY LOOK DRY AS COLD HIGH PRESSURE BUILDS BACK OVER THE
REGION. WEDNESDAY NIGHT INTO THURSDAY A WEAK UPPER WAVE LOOKS TO
MOVE ACROSS THE REGION WITH SMALL CHANCES FOR SNOW POSSIBLE.
&&
.AVIATION /DISCUSSION FOR 270600Z TAF ISSUANCE/...
ISSUED AT 320 AM EST THU FEB 27 2014
0820Z UPDATE...NO CHANGES NEEDED AT THIS TIME. PREVIOUS DISCUSSION
FOLLOWS.
VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD.
INITIAL IMPACTS WILL COME AS A SHARP COLD FRONT TRACKS THROUGH THE
FORECAST AREA LATE TONIGHT. RAP MODEL SOUNDINGS CONTINUE TO SUPPORT
A BRIEF PERIOD OF LOW LEVEL WIND SHEAR PRIOR TO THE FRONTAL PASSAGE
AS A LOW LEVEL JET ROTATES THROUGH THE REGION. THE FRONT WILL CROSS
THE TERMINALS BETWEEN 08Z AND 11Z FROM NORTHWEST TO SOUTHEAST...WITH
NORTHWEST WIND GUSTS COMMENCING IMMEDIATELY BEHIND THE FRONT AS COLD
ADVECTION ESTABLISHES. TIMING OF THE STRONGEST WIND GUSTS...POSSIBLY
AS HIGH AS 35KT...WILL BE IN THE COUPLE OF HOURS DIRECTLY BEHIND THE
FRONTAL PASSAGE ROUGHLY BETWEEN 09-13Z. MOISTURE IS LIMITED WITH THE
FRONT...BUT MODEL SOUNDINGS AND RH PROGS DO FAVOR SOME VFR STRATOCU
ACCOMPANYING THE BOUNDARY. POTENTIAL EVEN EXIST FOR A FEW FLURRIES.
STRONG HIGH PRESSURE WILL BRING A RETURN TO MOSTLY CLEAR SKIES
SHORTLY AFTER DAYBREAK. WINDS WILL CONTINUE TO GUST AT 25 TO 30KT
THROUGH MIDDAY...SLOWLY DIMINISHING DURING THE AFTERNOON AS THE
SURFACE PRESSURE GRADIENT RELAXES. OTHER THAN SOME PASSING
CIRRUS...CLEAR SKIES WILL CONTINUE INTO THURSDAY NIGHT AS THE HIGH
SETTLES OVER THE REGION.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....SMF
AVIATION...RYAN/SMF
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
321 AM EST THU FEB 27 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 227 PM EST WED FEB 26 2014
AN INACTIVE COLD FRONT IS EXPECTED TO MOVER THROUGH THE AREA LATE
TONIGHT. IN THE WAKE OF THIS FRONT...HIGH PRESSURE WILL BUILD INTO
THE AREA INTO FRIDAY. AN UPPER DISTURBANCE IS EXPECTED TO MOVE
THROUGH FRIDAY NIGHT INTO SATURDAY. A STRONGER SYSTEM WILL AFFECT
THE AREA LATE IN THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 956 PM EST WED FEB 26 2014
UPSTREAM OBSERVATIONS SUGGEST WE CAN EXPECT A PERIOD OF STRONGER
WIND GUSTS AT LEAST IN THE 20-30KT RANGE LATER TONIGHT AS THE
FRONT MOVES THROUGH THE AREA IF NOT SLIGHTLY STRONGER. HAVE ADDED
THIS AS WELL AS A ZONE OF INCREASED CLOUD COVER AS THE FRONT
PASSES THROUGH THE AREA.
SOME SNOW SHOWERS OBSERVED UPSTREAM BUT MAJORITY OF DATA SUGGESTS
THESE WILL LARGELY STAY TO THE NORTH OF THE FORECAST AREA. PERHAPS
SOME FLURRIES COULD OCCUR BUT EXPECT LITTLE MORE THAN THAT.
PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 227 PM EST WED FEB 26 2014
COLD FRONT CURRENTLY DROPPING SOUTHEAST THROUGH THE NORTHERN PLAINS
IS EXPECTED TO MOVE INTO THE LOCAL AREA DURING THE EARLY MORNING
HOURS OF THURSDAY. AIR MASS IS QUITE DRY...SO FRONT SHOULD BE
INACTIVE FOR THE MOST PART...ALTHOUGH THERE COULD BE A NARROW AREA
OF LOWER CLOUD IN THE VICINITY OF THE FRONT.
WARM ADVECTION AHEAD OF THE FRONT LOOKS PRETTY STRONG...SO NOT
EXPECTING MUCH OF A TEMPERATURE FALL UNTIL THE FRONT PASSES DURING
THE PRE DAWN HOURS OF THURSDAY. THE GFS MOS LOWS TONIGHT LOOK
REASONABLE OVER THE NORTHWEST ZONES...BUT WILL RAISE THE LOWS SOME
ELSEWHERE DUE TO THE LATE ARRIVAL OF THE FRONT.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
ISSUED AT 227 PM EST WED FEB 26 2014
MODEL DATA INDICATE THE UPPER FLOW IS EXPECTED TO FLATTEN OUT DURING
THIS PERIOD...WITH HEIGHTS RISING QUITE A BIT BY SATURDAY AS RIDGING
DEVELOP OVER THE GULF COAST STATES IN RESPONSE TO TROUGHING
DEVELOPING OVER THE WESTERN PARTS OF THE COUNTRY.
MAIN ITEM OF INTEREST DURING THIS PERIOD IS AN UPPER DISTURBANCE
THAT IS EXPECTED TO MOVE ACROSS THE LOCAL AREA AROUND FRIDAY NIGHT.
OPERATIONAL MODELS SUGGEST THE MAIN PRECIPITATION THREAT WILL HOLD
OFF UNTIL FRIDAY NIGHT...ALTHOUGH THERE ARE QUITE A FEW ENSEMBLES
THAT SUGGEST THIS MAY BE TOO SLOW. WILL BRING IN SOME CHANCE POPS TO
THE WEST CENTRAL AND SOUTHWEST ZONES BY FRIDAY AFTERNOON TO COVER
THE POTENTIAL FOR THE FASTER SOLUTIONS.
LIKELY POPS STILL LOOK OK FOR FRIDAY NIGHT...GIVEN THE 40-45 KT LOW
LEVEL JET OVERHEAD. QPF SHOULD BE FAIRLY LIGHT AS THERE DOESN/T SEEM
TO BE A LOT OF MOISTURE ADVECTION.
MOST OF THE PRECIPITATION THREAT LOOKS TO BE OVER BY SUNRISE
SATURDAY AT THIS TIME...BUT WITH A WAVY FRONTAL SYSTEM
NEARBY...HESITANT TO KEEP SATURDAY DRY. WILL GO WITH SMALL CHANCE
POPS ON SATURDAY.
GIVEN THE STRONG WARM ADVECTION ALOFT WITH THE LOW LEVEL
JET...LEANING MORE TOWARDS A MIXED PRECIPITATION EVENT FRIDAY NIGHT
INTO SATURDAY RATHER THAN JUST SNOW.
PROGGED LOW LEVEL THICKNESSES SUGGEST THE GFS MOS TEMPERATURES
GUIDANCE IS PROBABLY TOO COLD BY FRIDAY AND FRIDAY NIGHT. WILL NUDGE
UP THE GUIDANCE ABOUT A CATEGORY IN THOSE PERIODS. OTHER PERIODS
LOOK OK.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
ISSUED AT 212 AM EST THU FEB 27 2014
MODELS ARE ACTUALLY FAIRLY CLOSE ON THE SYNOPTIC SCALE AND ALLBLEND
INITIALIZATIONS REFLECT WELL THE TRENDS OF THE LARGE SYSTEM
PROJECTED TO MOVE THROUGH THE REGION SUNDAY AND SUNDAY NIGHT.
THE FOCUS OF THIS PERIOD COMES DOWN TO PRECIPITATION TYPE SUNDAY
AND SUNDAY NIGHT AND IT COMES DOWN TO TEMPERATURES/THICKNESSES
WHICH AS OF LATE HAVE BEEN TRENDING COLDER. AS OF THIS MODEL RUN
THIS MEANS BETTER CHANCES FOR SNOW AS OPPOSED TO FREEZING RAIN OR
SLEET. BEST CHANCE FOR SNOW LIES ACROSS THE NORTHERN HALF OF THE
COUNTY WARNING AREA...BUT A WARM INTRUSION TO OUR SOUTH COULD STILL
BRING CHANCES FOR SLEET AND FREEZING RAIN (SOUTH OF I-70) INTO THE
FORECAST.
DEVELOPED FORECAST TOWARD THIS COLDER TREND HOWEVER WITHOUT COMPLETELY
FLIP-FLOPPING BACK AND FORTH BETWEEN FREEZING RAIN AND SNOW. THE
NORTHERN COUNTIES LOOK LIKE AN ALL SNOW EVENT...WHILE AROUND I-70
APPEARS SNOW WILL BE THE MAIN PRECIP-TYPE WITH CHANCES FOR SLEET
OR FREEZING RAIN POSSIBLE AT TIMES. AND THEN FOR THE SOUTHERN TIER
OF COUNTIES SLEET OR FREEZING RAIN WITH POSSIBLY SOME CHANCES FOR
SNOW LOOK TO BE THE PRECIP-TYPE.
THIS EVENT SHOULD BE WINDING DOWN ON MONDAY...WITH ONLY LOW CHANCES
FOR SNOW POSSIBLE BY THEN AS IT LOOKS EVEN COLDER. TUESDAY AND
WEDNESDAY LOOK DRY AS COLD HIGH PRESSURE BUILDS BACK OVER THE
REGION. WEDNESDAY NIGHT INTO THURSDAY A WEAK UPPER WAVE LOOKS TO
MOVE ACROSS THE REGION WITH SMALL CHANCES FOR SNOW POSSIBLE.
&&
.AVIATION /DISCUSSION FOR 270600Z TAF ISSUANCE/...
ISSUED AT 320 AM EST THU FEB 27 2014
0820Z UPDATE...NO CHANGES NEEDED AT THIS TIME. PREVIOUS DISCUSSION
FOLLOWS.
VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD.
INITIAL IMPACTS WILL COME AS A SHARP COLD FRONT TRACKS THROUGH THE
FORECAST AREA LATE TONIGHT. RAP MODEL SOUNDINGS CONTINUE TO SUPPORT
A BRIEF PERIOD OF LOW LEVEL WIND SHEAR PRIOR TO THE FRONTAL PASSAGE
AS A LOW LEVEL JET ROTATES THROUGH THE REGION. THE FRONT WILL CROSS
THE TERMINALS BETWEEN 08Z AND 11Z FROM NORTHWEST TO SOUTHEAST...WITH
NORTHWEST WIND GUSTS COMMENCING IMMEDIATELY BEHIND THE FRONT AS COLD
ADVECTION ESTABLISHES. TIMING OF THE STRONGEST WIND GUSTS...POSSIBLY
AS HIGH AS 35KT...WILL BE IN THE COUPLE OF HOURS DIRECTLY BEHIND THE
FRONTAL PASSAGE ROUGHLY BETWEEN 09-13Z. MOISTURE IS LIMITED WITH THE
FRONT...BUT MODEL SOUNDINGS AND RH PROGS DO FAVOR SOME VFR STRATOCU
ACCOMPANYING THE BOUNDARY. POTENTIAL EVEN EXIST FOR A FEW FLURRIES.
STRONG HIGH PRESSURE WILL BRING A RETURN TO MOSTLY CLEAR SKIES
SHORTLY AFTER DAYBREAK. WINDS WILL CONTINUE TO GUST AT 25 TO 30KT
THROUGH MIDDAY...SLOWLY DIMINISHING DURING THE AFTERNOON AS THE
SURFACE PRESSURE GRADIENT RELAXES. OTHER THAN SOME PASSING
CIRRUS...CLEAR SKIES WILL CONTINUE INTO THURSDAY NIGHT AS THE HIGH
SETTLES OVER THE REGION.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/NIELD
SHORT TERM...JAS
LONG TERM....SMF
AVIATION...SMF
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
218 AM EST THU FEB 27 2014
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 227 PM EST WED FEB 26 2014
AN INACTIVE COLD FRONT IS EXPECTED TO MOVER THROUGH THE AREA LATE
TONIGHT. IN THE WAKE OF THIS FRONT...HIGH PRESSURE WILL BUILD INTO
THE AREA INTO FRIDAY. AN UPPER DISTURBANCE IS EXPECTED TO MOVE
THROUGH FRIDAY NIGHT INTO SATURDAY. A STRONGER SYSTEM WILL AFFECT
THE AREA LATE IN THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 956 PM EST WED FEB 26 2014
UPSTREAM OBSERVATIONS SUGGEST WE CAN EXPECT A PERIOD OF STRONGER
WIND GUSTS AT LEAST IN THE 20-30KT RANGE LATER TONIGHT AS THE
FRONT MOVES THROUGH THE AREA IF NOT SLIGHTLY STRONGER. HAVE ADDED
THIS AS WELL AS A ZONE OF INCREASED CLOUD COVER AS THE FRONT
PASSES THROUGH THE AREA.
SOME SNOW SHOWERS OBSERVED UPSTREAM BUT MAJORITY OF DATA SUGGESTS
THESE WILL LARGELY STAY TO THE NORTH OF THE FORECAST AREA. PERHAPS
SOME FLURRIES COULD OCCUR BUT EXPECT LITTLE MORE THAN THAT.
PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 227 PM EST WED FEB 26 2014
COLD FRONT CURRENTLY DROPPING SOUTHEAST THROUGH THE NORTHERN PLAINS
IS EXPECTED TO MOVE INTO THE LOCAL AREA DURING THE EARLY MORNING
HOURS OF THURSDAY. AIR MASS IS QUITE DRY...SO FRONT SHOULD BE
INACTIVE FOR THE MOST PART...ALTHOUGH THERE COULD BE A NARROW AREA
OF LOWER CLOUD IN THE VICINITY OF THE FRONT.
WARM ADVECTION AHEAD OF THE FRONT LOOKS PRETTY STRONG...SO NOT
EXPECTING MUCH OF A TEMPERATURE FALL UNTIL THE FRONT PASSES DURING
THE PRE DAWN HOURS OF THURSDAY. THE GFS MOS LOWS TONIGHT LOOK
REASONABLE OVER THE NORTHWEST ZONES...BUT WILL RAISE THE LOWS SOME
ELSEWHERE DUE TO THE LATE ARRIVAL OF THE FRONT.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
ISSUED AT 227 PM EST WED FEB 26 2014
MODEL DATA INDICATE THE UPPER FLOW IS EXPECTED TO FLATTEN OUT DURING
THIS PERIOD...WITH HEIGHTS RISING QUITE A BIT BY SATURDAY AS RIDGING
DEVELOP OVER THE GULF COAST STATES IN RESPONSE TO TROUGHING
DEVELOPING OVER THE WESTERN PARTS OF THE COUNTRY.
MAIN ITEM OF INTEREST DURING THIS PERIOD IS AN UPPER DISTURBANCE
THAT IS EXPECTED TO MOVE ACROSS THE LOCAL AREA AROUND FRIDAY NIGHT.
OPERATIONAL MODELS SUGGEST THE MAIN PRECIPITATION THREAT WILL HOLD
OFF UNTIL FRIDAY NIGHT...ALTHOUGH THERE ARE QUITE A FEW ENSEMBLES
THAT SUGGEST THIS MAY BE TOO SLOW. WILL BRING IN SOME CHANCE POPS TO
THE WEST CENTRAL AND SOUTHWEST ZONES BY FRIDAY AFTERNOON TO COVER
THE POTENTIAL FOR THE FASTER SOLUTIONS.
LIKELY POPS STILL LOOK OK FOR FRIDAY NIGHT...GIVEN THE 40-45 KT LOW
LEVEL JET OVERHEAD. QPF SHOULD BE FAIRLY LIGHT AS THERE DOESN/T SEEM
TO BE A LOT OF MOISTURE ADVECTION.
MOST OF THE PRECIPITATION THREAT LOOKS TO BE OVER BY SUNRISE
SATURDAY AT THIS TIME...BUT WITH A WAVY FRONTAL SYSTEM
NEARBY...HESITANT TO KEEP SATURDAY DRY. WILL GO WITH SMALL CHANCE
POPS ON SATURDAY.
GIVEN THE STRONG WARM ADVECTION ALOFT WITH THE LOW LEVEL
JET...LEANING MORE TOWARDS A MIXED PRECIPITATION EVENT FRIDAY NIGHT
INTO SATURDAY RATHER THAN JUST SNOW.
PROGGED LOW LEVEL THICKNESSES SUGGEST THE GFS MOS TEMPERATURES
GUIDANCE IS PROBABLY TOO COLD BY FRIDAY AND FRIDAY NIGHT. WILL NUDGE
UP THE GUIDANCE ABOUT A CATEGORY IN THOSE PERIODS. OTHER PERIODS
LOOK OK.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
ISSUED AT 212 AM EST THU FEB 27 2014
MODELS ARE ACTUALLY FAIRLY CLOSE ON THE SYNOPTIC SCALE AND ALLBLEND
INITIALIZATIONS REFLECT WELL THE TRENDS OF THE LARGE SYSTEM
PROJECTED TO MOVE THROUGH THE REGION SUNDAY AND SUNDAY NIGHT.
THE FOCUS OF THIS PERIOD COMES DOWN TO PRECIPITATION TYPE SUNDAY
AND SUNDAY NIGHT AND IT COMES DOWN TO TEMPERATURES/THICKNESSES
WHICH AS OF LATE HAVE BEEN TRENDING COLDER. AS OF THIS MODEL RUN
THIS MEANS BETTER CHANCES FOR SNOW AS OPPOSED TO FREEZING RAIN OR
SLEET. BEST CHANCE FOR SNOW LIES ACROSS THE NORTHERN HALF OF THE
COUNTY WARNING AREA...BUT A WARM INTRUSION TO OUR SOUTH COULD STILL
BRING CHANCES FOR SLEET AND FREEZING RAIN (SOUTH OF I-70) INTO THE
FORECAST.
DEVELOPED FORECAST TOWARD THIS COLDER TREND HOWEVER WITHOUT COMPLETELY
FLIP-FLOPPING BACK AND FORTH BETWEEN FREEZING RAIN AND SNOW. THE
NORTHERN COUNTIES LOOK LIKE AN ALL SNOW EVENT...WHILE AROUND I-70
APPEARS SNOW WILL BE THE MAIN PRECIP-TYPE WITH CHANCES FOR SLEET
OR FREEZING RAIN POSSIBLE AT TIMES. AND THEN FOR THE SOUTHERN TIER
OF COUNTIES SLEET OR FREEZING RAIN WITH POSSIBLY SOME CHANCES FOR
SNOW LOOK TO BE THE PRECIP-TYPE.
THIS EVENT SHOULD BE WINDING DOWN ON MONDAY...WITH ONLY LOW CHANCES
FOR SNOW POSSIBLE BY THEN AS IT LOOKS EVEN COLDER. TUESDAY AND
WEDNESDAY LOOK DRY AS COLD HIGH PRESSURE BUILDS BACK OVER THE
REGION. WEDNESDAY NIGHT INTO THURSDAY A WEAK UPPER WAVE LOOKS TO
MOVE ACROSS THE REGION WITH SMALL CHANCES FOR SNOW POSSIBLE.
&&
.AVIATION /DISCUSSION FOR 270600Z TAF ISSUANCE/...
ISSUED AT 1128 PM EST WED FEB 26 2014
VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD.
INITIAL IMPACTS WILL COME AS A SHARP COLD FRONT TRACKS THROUGH THE
FORECAST AREA LATE TONIGHT. RAP MODEL SOUNDINGS CONTINUE TO SUPPORT
A BRIEF PERIOD OF LOW LEVEL WIND SHEAR PRIOR TO THE FRONTAL PASSAGE
AS A LOW LEVEL JET ROTATES THROUGH THE REGION. THE FRONT WILL CROSS
THE TERMINALS BETWEEN 08Z AND 11Z FROM NORTHWEST TO SOUTHEAST...WITH
NORTHWEST WIND GUSTS COMMENCING IMMEDIATELY BEHIND THE FRONT AS COLD
ADVECTION ESTABLISHES. TIMING OF THE STRONGEST WIND GUSTS...POSSIBLY
AS HIGH AS 35KT...WILL BE IN THE COUPLE OF HOURS DIRECTLY BEHIND THE
FRONTAL PASSAGE ROUGHLY BETWEEN 09-13Z. MOISTURE IS LIMITED WITH THE
FRONT...BUT MODEL SOUNDINGS AND RH PROGS DO FAVOR SOME VFR STRATOCU
ACCOMPANYING THE BOUNDARY. POTENTIAL EVEN EXIST FOR A FEW FLURRIES.
STRONG HIGH PRESSURE WILL BRING A RETURN TO MOSTLY CLEAR SKIES
SHORTLY AFTER DAYBREAK. WINDS WILL CONTINUE TO GUST AT 25 TO 30KT
THROUGH MIDDAY...SLOWLY DIMINISHING DURING THE AFTERNOON AS THE
SURFACE PRESSURE GRADIENT RELAXES. OTHER THAN SOME PASSING
CIRRUS...CLEAR SKIES WILL CONTINUE INTO THURSDAY NIGHT AS THE HIGH
SETTLES OVER THE REGION.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/NIELD
SHORT TERM...JAS
LONG TERM....SMF
AVIATION...RYAN
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1128 PM EST WED FEB 26 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 227 PM EST WED FEB 26 2014
AN INACTIVE COLD FRONT IS EXPECTED TO MOVER THROUGH THE AREA LATE
TONIGHT. IN THE WAKE OF THIS FRONT...HIGH PRESSURE WILL BUILD INTO
THE AREA INTO FRIDAY. AN UPPER DISTURBANCE IS EXPECTED TO MOVE
THROUGH FRIDAY NIGHT INTO SATURDAY. A STRONGER SYSTEM WILL AFFECT
THE AREA LATE IN THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 956 PM EST WED FEB 26 2014
UPSTREAM OBSERVATIONS SUGGEST WE CAN EXPECT A PERIOD OF STRONGER
WIND GUSTS AT LEAST IN THE 20-30KT RANGE LATER TONIGHT AS THE
FRONT MOVES THROUGH THE AREA IF NOT SLIGHTLY STRONGER. HAVE ADDED
THIS AS WELL AS A ZONE OF INCREASED CLOUD COVER AS THE FRONT
PASSES THROUGH THE AREA.
SOME SNOW SHOWERS OBSERVED UPSTREAM BUT MAJORITY OF DATA SUGGESTS
THESE WILL LARGELY STAY TO THE NORTH OF THE FORECAST AREA. PERHAPS
SOME FLURRIES COULD OCCUR BUT EXPECT LITTLE MORE THAN THAT.
PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 227 PM EST WED FEB 26 2014
COLD FRONT CURRENTLY DROPPING SOUTHEAST THROUGH THE NORTHERN PLAINS
IS EXPECTED TO MOVE INTO THE LOCAL AREA DURING THE EARLY MORNING
HOURS OF THURSDAY. AIR MASS IS QUITE DRY...SO FRONT SHOULD BE
INACTIVE FOR THE MOST PART...ALTHOUGH THERE COULD BE A NARROW AREA
OF LOWER CLOUD IN THE VICINITY OF THE FRONT.
WARM ADVECTION AHEAD OF THE FRONT LOOKS PRETTY STRONG...SO NOT
EXPECTING MUCH OF A TEMPERATURE FALL UNTIL THE FRONT PASSES DURING
THE PRE DAWN HOURS OF THURSDAY. THE GFS MOS LOWS TONIGHT LOOK
REASONABLE OVER THE NORTHWEST ZONES...BUT WILL RAISE THE LOWS SOME
ELSEWHERE DUE TO THE LATE ARRIVAL OF THE FRONT.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
ISSUED AT 227 PM EST WED FEB 26 2014
MODEL DATA INDICATE THE UPPER FLOW IS EXPECTED TO FLATTEN OUT DURING
THIS PERIOD...WITH HEIGHTS RISING QUITE A BIT BY SATURDAY AS RIDGING
DEVELOP OVER THE GULF COAST STATES IN RESPONSE TO TROUGHING
DEVELOPING OVER THE WESTERN PARTS OF THE COUNTRY.
MAIN ITEM OF INTEREST DURING THIS PERIOD IS AN UPPER DISTURBANCE
THAT IS EXPECTED TO MOVE ACROSS THE LOCAL AREA AROUND FRIDAY NIGHT.
OPERATIONAL MODELS SUGGEST THE MAIN PRECIPITATION THREAT WILL HOLD
OFF UNTIL FRIDAY NIGHT...ALTHOUGH THERE ARE QUITE A FEW ENSEMBLES
THAT SUGGEST THIS MAY BE TOO SLOW. WILL BRING IN SOME CHANCE POPS TO
THE WEST CENTRAL AND SOUTHWEST ZONES BY FRIDAY AFTERNOON TO COVER
THE POTENTIAL FOR THE FASTER SOLUTIONS.
LIKELY POPS STILL LOOK OK FOR FRIDAY NIGHT...GIVEN THE 40-45 KT LOW
LEVEL JET OVERHEAD. QPF SHOULD BE FAIRLY LIGHT AS THERE DOESN/T SEEM
TO BE A LOT OF MOISTURE ADVECTION.
MOST OF THE PRECIPITATION THREAT LOOKS TO BE OVER BY SUNRISE
SATURDAY AT THIS TIME...BUT WITH A WAVY FRONTAL SYSTEM
NEARBY...HESITANT TO KEEP SATURDAY DRY. WILL GO WITH SMALL CHANCE
POPS ON SATURDAY.
GIVEN THE STRONG WARM ADVECTION ALOFT WITH THE LOW LEVEL
JET...LEANING MORE TOWARDS A MIXED PRECIPITATION EVENT FRIDAY NIGHT
INTO SATURDAY RATHER THAN JUST SNOW.
PROGGED LOW LEVEL THICKNESSES SUGGEST THE GFS MOS TEMPERATURES
GUIDANCE IS PROBABLY TOO COLD BY FRIDAY AND FRIDAY NIGHT. WILL NUDGE
UP THE GUIDANCE ABOUT A CATEGORY IN THOSE PERIODS. OTHER PERIODS
LOOK OK.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ISSUED AT 152 PM EST WED FEB 26 2014
ON THE SYNOPTIC SCALE THE MODELS ARE FAIRLY CLOSE. REGIONAL
INITIALIZATION NOT BAD FOR TEMPS AND POPS.
FORECAST PROBLEM IS PRECIPITATION TYPE THIS WEEKEND. UNCERTAINTY
VERY GREAT. MODEL ERRORS THAT ARE SMALL OBJECTIVELY WOULD HAVE HUGE
IMPACT.
MODELS HAVE SLOWLY BEEN GETTING COLDER FROM ONE RUN TO THE NEXT.
CONSIDERING THIS AND LATEST TEMPERATURE CROSS
SECTIONS...NORTHERN COUNTIES SHOULD SEE ONLY SNOW.
SAME METHODOLOGY MAKES SNOW SINGLE MOST LIKELY SINGLE ELEMENT
CENTRAL COUNTIES. HOWEVER...CERTAINLY A CHANCE OF FREEZING RAIN
THERE.
IN THE SOUTH WITH ITS STRONGER WARM INTRUSION WILL SAY FREEZING RAIN
OR SNOW. VERY POSSIBLE SAME SPOT COULD GET BOTH IN SAME PERIOD
DEPENDING ON EXACT DEVELOPMENT OF THE INTRUSION.
WONT HAVE SLEET ANYWHERE. IT COULD CERTAINLY HAPPEN. BUT FOR A HIGH
LEAD TIME INCLUDING SLEET WITH FREEZING RAIN AND SNOW INCREASES
COMPLICATION WITHOUT ADDING MUCH VALUE.
&&
.AVIATION /DISCUSSION FOR 270600Z TAF ISSUANCE/...
ISSUED AT 1128 PM EST WED FEB 26 2014
VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD.
INITIAL IMPACTS WILL COME AS A SHARP COLD FRONT TRACKS THROUGH THE
FORECAST AREA LATE TONIGHT. RAP MODEL SOUNDINGS CONTINUE TO SUPPORT
A BRIEF PERIOD OF LOW LEVEL WIND SHEAR PRIOR TO THE FRONTAL PASSAGE
AS A LOW LEVEL JET ROTATES THROUGH THE REGION. THE FRONT WILL CROSS
THE TERMINALS BETWEEN 08Z AND 11Z FROM NORTHWEST TO SOUTHEAST...WITH
NORTHWEST WIND GUSTS COMMENCING IMMEDIATELY BEHIND THE FRONT AS COLD
ADVECTION ESTABLISHES. TIMING OF THE STRONGEST WIND GUSTS...POSSIBLY
AS HIGH AS 35KT...WILL BE IN THE COUPLE OF HOURS DIRECTLY BEHIND THE
FRONTAL PASSAGE ROUGHLY BETWEEN 09-13Z. MOISTURE IS LIMITED WITH THE
FRONT...BUT MODEL SOUNDINGS AND RH PROGS DO FAVOR SOME VFR STRATOCU
ACCOMPANYING THE BOUNDARY. POTENTIAL EVEN EXIST FOR A FEW FLURRIES.
STRONG HIGH PRESSURE WILL BRING A RETURN TO MOSTLY CLEAR SKIES
SHORTLY AFTER DAYBREAK. WINDS WILL CONTINUE TO GUST AT 25 TO 30KT
THROUGH MIDDAY...SLOWLY DIMINISHING DURING THE AFTERNOON AS THE
SURFACE PRESSURE GRADIENT RELAXES. OTHER THAN SOME PASSING
CIRRUS...CLEAR SKIES WILL CONTINUE INTO THURSDAY NIGHT AS THE HIGH
SETTLES OVER THE REGION.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/NIELD
SHORT TERM...JAS
LONG TERM...JK
AVIATION...RYAN
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
217 PM EST THU FEB 27 2014
.SYNOPSIS...
HIGH PRESSURE BUILDS IN TONIGHT SERVING UP A COLD NIGHT. THE NEXT
UPPER LEVEL DISTURBANCE BRINGS SNOW SHOWERS SATURDAY. LOW PRESSURE
RIDING UP THE OHIO VALLEY WILL PRODUCE ACCUMULATING SNOW SUNDAY INTO
MONDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
SNOW SHOWERS...SQUALLS...AND WINDS WILL SLOWLY DECREASE THIS
AFTERNOON AS MID LEVEL ENERGY EXITS E. RADAR SHOULD BE PCPN FREE
BEFORE 0Z. IF YOU BELIEVE THE LATEST HRRR SIMULATED REFLECTIVITY
BETWEEN 22-23Z.
A COLD NIGHT ON TAP FOR THE REGION. WIND CHILL VALUES FALL INTO
ADVISORY RANGE /-10 TO -20F/ BY THIS EVENING. H8 TEMPS DROP TO -24C
BY 12Z FRIDAY WITH HIGH PRESSURE BUILDING IN FROM THE GREAT LAKES.
WITH JUXTAPOSITION OF SFC ANTICYCLONE AND CONTINUED SNOWPACK ACROSS
NORTHERN COUNTIES WOULD NOT BE SURPRISED TO SEE MIN T FALL CLOSE TO
-10 ACROSS JEFFERSON WWRD TO FOREST. RIGHT NOW...SIDED WITH VALUES
AROUND -5F PER WINDS WILL STAY UP MOST OF THE NIGHT AND NOT BECOMING
LIGHT UNTIL AFTER MIDNIGHT.
BL TEMPS UNDERGO STRONG WARM ADVECTION /+10C IN 12HRS/ WHICH ALLOWS
FOR A NICE RECOVERY FROM SUB ZERO MORNING READINGS. WITH H8 TEMPS
AROUND -8C TO -14C COUPLED WITH FULL SUNSHINE WE STILL WON`T MANAGE
TO GET ABOVE 30F ANYWHERE. COMMUNITIES ALONG AND NORTH OF I-80 WILL
REMAIN IN THE TEENS. NOT THE BEST WAY TO CLOSE OUT FEBRUARY...BUT
GIVEN WE WERE -4F BELOW NORMAL FOR THE MONTH...THIS SHOULD NOT BE A
SURPRISE. IT APPEARS WE WON/T MAKE THE TOP 20 COLDEST FEBRUARY/S
AT PITTSBURGH BASED ON AVERAGE MEAN TEMPERATURE.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
BENIGN WEATHER FRIDAY NIGHT HOWEVER MID AND UPPER LEVEL MOISTURE
WILL BE APPROACHING FROM THE WEST AHEAD OF THE NEXT SHORT WAVE
TROUGH. STILL EXPECT A LIGHT QPF EVENT SAT WITH AREA OF HIGHEST
POPS CONFINED ACROSS I-80 WHERE DYNAMICS ARE BETTER FOR INCREASED
SNOW SHOWER COVERAGE. NOT EXPECTING MORE THAN AN INCH OF
ACCUMULATION IN THE AFOREMENTIONED AREA.
BAROCLINIC ZONE STALLS OUT ALONG THE OHIO RIVER E ALONG THE MASON
DIXON LINE AS STEERING FLOW ALOFT ORIENTS PARALLEL TO IT. LOT OF
CLOUDS ARE PREDICTED THROUGH THE WEEKEND AS MOISTURE TRAIN EXISTS IN
THE WSW FLOW ALL THE WAY BACK TO THE SOUTHERN PLAINS. ANY PCPN SUN
MORNING WILL BE FLURRIES OR LIGHT SNOW SHOWERS...HOWEVER AS THE DAY
PROGRESSES MODEST ISENTROPIC UPGLIDE AND POSITIVE PRESSURE ADVECTION
WILL INCREASE AREAL COVERAGE OF SNOW AND INTENSITY. ECMWF SEEMS
HIGH WITH QPF AND SIDED MORE WITH GFS WHICH IS ALIGNED WITH
PREVIOUS FORECAST. ANY ACCUMULATIONS WILL BE LIGHT WITH A FEW
INCHES POSSIBLE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
QUESTIONS REMAIN REGARDING THE MUCH ASKED AND MUCH HYPED WINTER
STORM POISED TO AFFECT THE AREA EARLY NEXT WEEK. DIFFERENCES REMAIN
AMONGST NCEP SUITE WITH SLIGHT WOBBLING WITHIN ENSEMBLE MEANS.
GREATEST CERTAINTY AT THIS POINT IS SNOW NORTH OF I-70 WHERE THERMAL
PROFILES REMAIN COLD ENOUGH. EVEN NORTHERN MOST TRACK KEEPS PTYPE
ALL SNOW. FARTHER SOUTH IT REMAINS IFFY GIVEN PLACEMENT OF SURFACE
CYCLONE. LATEST RUN OF 12Z ECMWF HAS ARRIVED COOLER WITH SOUTHWARD
PLACEMENT OF LOW PRESSURE. IN SITUATIONS LIKE THIS SLIGHT
ADJUSTMENTS ARE PRUDENT TO KEEP FORECAST CONSISTENCY. GIVEN THIS
WINTER MOST WEATHER SYSTEMS HAVE OVER ACHIEVED AND TRENDED COLDER AS
THE EVENT DREW CLOSER...OUR CURRENT PROJECTION OF MOSTLY SNOW LOOKS
GOOD. DID ADD A PERIOD OF SNOW AND SLEET ACROSS THE FAR SOUTHERN
ROW OF COUNTIES SUNDAY NIGHT SINCE WARM LAYER ALOFT TEMPERATURE FROM
BOTH GFS AND ECMWF SUPPORT THIS.
DETERMINISTIC MODELS PULL PRECIP FROM THE FORECAST BY MONDAY
NIGHT...HAVE KEPT IN CHANCE POPS MONDAY NIGHT INTO TUESDAY MORNING
WITH ENSEMBLES INDICATING SNOW MAY HANG AROUND A BIT LONGER.
HIGH PRESSURE WILL MOVE OVER THE WESTERN GREAT LAKES BY TUESDAY...AND
SLOWLY DRIFT TO THE EAST ON WEDNESDAY...ALLOWING FOR DRY
CONDITIONS. A RETURN TO NORMAL TEMPERATURES IS NOT SEEN IN THE
EXTENDED FORECAST...WITH READINGS REMAINING 15 TO 20 DEGREES BELOW
NORMAL.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
SNOW SQUALLS CONTINUE TO IMPACT MOST...IF NOT ALL...OF THE TAF
SITES THIS AFTERNOON AS THE ARCTIC FRONT CROSSES. EXPECT RAPID
FLUCTUATIONS FROM MVFR TO LIFR IN THESE BANDS AND HAVE TRIED TO
HANDLE THESE WITH TEMPO GROUPS THROUGH THE NEXT COUPLE OF HOURS
BASED OFF OF THE RADAR. A GRADUAL IMPROVEMENT SHOULD BE SEEN TO
MVFR AND VFR THROUGH THE LATE AFTERNOON ALTHOUGH CEILINGS MAY HOLD
ON A BIT LONGER WITH SUCH STRONG COLD ADVECTION TAKING PLACE. NONE
OF THE MODELS CARRY MVFR BEYOND 21Z BUT THIS MAY NEED TO BE
ADJUSTED.
IN ADDITION TO THE SNOW...WIND GUSTS WILL CONTINUE TO BE IN THE
30-35KT RANGE THROUGH THIS AFTERNOON WITH THIS FRONTAL
PASSAGE...DECREASING TOWARDS SUNSET TONIGHT AS HIGH PRESSURE
BEGINS TO BUILD TO THE EAST. HIGH PRESSURE SHOULD HELP TO SCATTER
OUT CLOUDS AND RETURN VFR CONDITIONS TO MOST LOCATIONS OVERNIGHT
TONIGHT AND FOR FRIDAY.
.OUTLOOK..../THURSDAY NIGHT THROUGH TUESDAY/...
MULTIPLE DISTURBANCES ARE EXPECTED TO SPAWN WIDESPREAD
RESTRICTIONS SATURDAY THROUGH MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST FRIDAY
FOR MDZ001.
OH...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST FRIDAY
FOR OHZ040-041.
PA...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST FRIDAY
FOR PAZ007>009-013>016-022-023-074-076.
WV...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST FRIDAY
FOR WVZ023-041.
&&
$$
.SYNOPSIS...34
.NEAR TERM...98
.SHORT TERM...98
.LONG TERM...98/33
.AVIATION...34
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
657 PM EST FRI FEB 28 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 341 PM EST FRI FEB 28 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW ARCTIC BRANCH WNW
FLOW ALF OVER THE UPR LKS TO THE S OF CORE OF ARCTIC AIRMASS/CLOSED
LO CENTERED OVER SRN HUDSON BAY. 12Z H5 TEMP WAS AS LO AS AN
IMPRESSIVE -50C OVER NRN QUEBEC...AND -30C OR LOWER H85 TEMPS WERE
PRESENT WITHIN THE CORE OF COLDEST AIR. A FAIRLY STRONG SHRTWV
EMBEDDED IN THE ARCTIC BRANCH IS CURRENTLY JUST W OF LK WINNIPEG...
WITH SUPPORTING AXIS OF STRONGER H3 WINDS AOA 100KT STRETCHING FM
JUST S OF THE SHRTWV ACRS THE UPR LKS INTO NEW ENGLAND. SOME
ENHANCED CLDS ARE PRESENT OVER THE NRN PLAINS INTO MN IN WHAT
APPEARS TO BE THE RRQ OF SPEED MAX SUPPORTING THE LK WINNIPEG
SHRTWV. THIS AREA IS ALSO EXPERIENCING GENERAL WAD/ISENTROPIC ASCENT
IN THE SW FLOW AHEAD OF ACCOMPANYING H85 LO CENTER JUST S OF LK
WINNIPEG. DESPITE QUITE A BIT OF VERY DRY LLVL AIR SHOWN ON LOCAL
12Z RAOBS...H925 DEWPT DEPRESSION WAS AS HI AS 26C AT MPX AT 12Z...
SOME PATCHY LGT SN HAS BROKEN OUT OVER NE MN WHERE LATEST RUC
ANALYSIS INDICATES SHARPER ISENTROPIC ASCENT/MOISTENING ON THE
270-280K SFCS /ABOUT H85-7/. DESPITE WHAT APPEARS TO BE FAIRLY
EXTENSIVE ICE COVER ON VSBL STLT IMAGE OVER THE N PORTION OF LK
MI...A BAND OF -SHSN IN THE LLVL SSW WIND UP THE LENGTH OF LK MOVED
AS FAR N AS INTO MANISTIQUE BY LATE IN THE MRNG. ANOTHER BAND OF SN
UNDER AXIS OF SHARPER MID LVL FGEN IS STREAKING ENEWD THRU WI TOWARD
SCENTRAL UPR MI. OTRW...SFC TEMPS OVER UPR MI HAVE RECOVERED ABV
ZERO FM THE RECORD COLD OBSVD THIS MRNG DESPITE THE THICKENING WAD
CLDS. THE LOWEST TEMP REPORTED WAS -41F AT NEWBERRY CITY.
MAIN FCST CONCERNS IN THE SHORT TERM WL BE SN TRENDS/POPS/GOING
HEADLINES ASSOCIATED WITH SHRTWV/SFC LO NOW NEAR LK WINNIPEG. FOCUS
FOR LATER TNGT INTO SAT TURNS TO TEMPS ONCE DRIER AIR RETURNS ALF
AND ENDS THE PCPN. PER NCEP GUIDANCE AND ITS CONSISTENT HANDLING OF
APRCHG DISTURBANCE...GENERALLY FOLLOWED THE 12Z GFS FOR FCST PREP.
LATE THIS AFTN/TNGT...AREA OF DEEP LYR QVECTOR CNVGC/ISENTROPIC
ASCENT ASSOCIATED WITH UPSTREAM SHRWTV IS FCST TO OVERSPREAD THE UPR
LKS BY THIS EVNG BEFORE PUSHING OFF TO THE EAST AFT MIDNGT WITH
VIGOROUS MID LVL DRYING/DEEP LYR QVECTOR DVGC FOLLOWING. EXPECT THE
PATCHY LGT SN IN NRN MN EARLY THIS AFTN TO OVERSPREAD MOST OF UPR MI
BY LATE AFTN. MODELS CONTINUE TO INDICATE THE WAD PCPN WL BE
ENHANCED A BIT BY SOME UPR DVGC IN RRQ OF 120KT H3 JET MAX THAT IS
SUPPORTING THE ENHANCED CLDS NOW OVER MN AND WHICH WL BE STREAKING
EWD ACRS LK SUP AND INTO SE ONTARIO AFTER 00Z. LOOKS LIKE THE
HEAVIEST PCPN WL FALL OVER THE SE HALF OF THE CWA CLOSER TO AXIS OF
SHARPEST MID LVL FGEN AND WHERE THERE WL BE SOME ENHANCEMENT WITH
LLVL SSW FLOW UP THE LENGTH OF LK MI...INCLUDING THE OPEN WATERS S
OF THE LATITUDE OF MENOMINEE WHERE LES BAND WAS QUITE APRNT ON VSBL
STLT IMAGERY BEFORE THE ARRIVAL OF HIER CLDS OBSCURED THIS FEATURE.
THE ARRIVAL OF THE MID LVL DRYING/DEEP LYR QVECTOR DVGC WL END
OVERALL LIGHTER PCPN OVER THE W EARLY THIS EVNG AND OVER THE E SOON
AFT 06Z. AS FOR SN TOTALS...H7 SPECIFIC HUMIDITY IS FCST TO INCRS TO
1.5-2.0 G/KG OVER THE SE CWA AT 00Z. WITH A 6HR PERIOD OF SYNOPTIC
SN AT MOST LOCATIONS...THAT WOULD EQUATE TO UP TO 2 INCHES OF ACCUM.
BUT FCST SDNGS CONT TO EXHIBIT A DEEP DGZ THAT IS 10K FT OR EVEN
DEEPER. WITH FVRBL SN/WATER RATIOS THAT MAY BE AS HI AS 25-30:1...
EXPECT UP TO 4 INCHES SN TOTAL OVER MUCH OF THE SE CWA WHERE DYNAMIC
SUPPORT WL BE GREATEST. WITH SOME ENHANCEMENT OFF LK MI THAT MIGHT
ADD AN ADDITIONAL INCH OR 2 TO THE SN TOTALS...GOING ADVYS FOR
DELTA/SRN SCHOOLCRAFT COUNTIES STILL SEEM ON TARGET. AFTER THE PCPN
ENDS...A DVLPG NW FLOW IN THE WAKE OF THE SFC LO CENTER TRACKING
ACRS LK SUP WL ADVECT COLDER AIR BACK INTO THE UPR LKS...DROPPING
H85 TEMPS TO ARND -25C OVER THE NW BY 12Z SAT. WITH EXTENSIVE ICE
COVER ON LK SUP...ANY LK EFFECT SHSN IN THE NW WIND SN BELTS SHOULD
BE NO MORE THAN ISOLD. SO MAINTAINED ONLY SCHC POPS IN THESE
LOCATIONS. THE REST OF THE CWA WL BE DRY AFT THE EVNG PCPN EXITS.
ONE CONCERN IS THE POTENTIAL FOR ADVY LVL WIND CHILLS OVER THE W
LATER ON. PREFER THE SOMEWHAT STRONGER WINDS SHOWN BY THE FAVORED
GFS...WHICH HAS CONSISTENTLY SHOWN A DEEPER SFC LO TRACKING ACRS LK
SUP. BUT EVEN THE HIER GFS NW WINDS AND FCST MIN TEMPS CLOSE TO -10F
OVER THE W RESULT IN ONLY MARGINAL WIND CHILLS NEAR -25F LATE TNGT
INTO SAT MRNG. SO OPTED TO HOLD OFF ON ADVY FOR NOW.
SAT...THE CWA WL BE DOMINATED BY COLD...ACYC NW FLOW E OF ARCTIC HI
PRES BLDG INTO THE NRN PLAINS. H85 TEMPS ON SAT ARE FCST TO FALL TO
-29C OVER THE NW TO -25C OVER THE SE CWA BY 00Z SUN. OVERALL ACYC
FLOW AND NEAR ABSENCE OF OPEN WATER OVER LK SUP SHOULD RESTRICT LES
POPS TO NO HIER THAN LO CHC. GUSTY NW WINDS WITH UNSTABLE LLVL LAPSE
RATES UP TO INVRN BASE NEAR H85 WL ALLOW FOR SOME BLSN MAINLY IN
OPEN AREAS NEAR LK SUP DOWNWIND OF SNOW COVERED ICE THAT HAVE BEEN
PLAGUED BY THESE EVENTS THRU THIS COLD WINTER. BUT SINCE LTL IF ANY
SN WL BE FALLING...SUSPECT THERE WL BE NO SGNFT ISSUES. GIVEN THE
ANOMALOUSLY COLD H85 TEMPS...TENDED TOWARD THE LOWER END OF GUIDANCE
FOR MAX TEMPS...WHICH ARE SUPPORTED BY MIXING TO H85 ON THE GFS FCST
SDNGS. WITH DISTURBANCE STREAKING E TOWARD THE LOWER LKS...NOT OUT
OF THE QUESTION THE NRN FRINGE OF -SN SHIELD COULD BRUSH THE FAR
SCNTRL LATE IN THE DAY. RETAINED SCHC POPS THERE.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 436 PM EST FRI FEB 28 2014
BY EARLY NEXT WEEK...MODELS POINT TOWARD A BREAK IN THE HIGHLY
AMPLIFIED WEST COAST/ERN PACIFIC RIDGE AND BROAD DOWNSTREAM TROUGH
PATTERN WHICH HAS CHARACTERIZED MUCH OF OUR RECORD COLD WINTER.
MODELS INDICATE THAT THE NRN END OF THE WRN RIDGE IS FCST TO CLOSE
OFF AND RETROGRADE TO SIBERIA...ALLOWING PACIFIC FLOW TO STRENGTHEN
INTO THE CONUS. THIS WILL BRING ABOUT A SLOW MODERATION IN TEMPS FOR
NEXT WEEK. HOWEVER...MEDIUM RANGE GUIDANCE CONTINUES TO SHOW A
TENDENCY FOR SOME DEGREE OF WRN RIDGING WHICH SHOULD ENSURE
GENERALLY BELOW NORMAL TEMPS PERSIST ACROSS UPPER MI FOR THE FIRST
COUPLE OF WEEKS OF MARCH. SYNOPTIC PCPN APPEARS TO BE MININAL IN
THIS PATTERN WITH THE BEST CHANCE FOR PCPN MID TO LATE WEEK AS A
SERIES OF SHORTWAVES MOVE ONSHORE FROM THE PACIFIC AND TRACK E
ACROSS THE NRN CONUS IN A MORE LOWER AMPLITUDE MORE PROGRESSIVE
FLOW. LINGERING COLD AIRMASS FOR LATE THIS WEEKEND INTO EARLY NEXT
WEEK WOULD NORMALLY RESULT IN LES OFF LAKE SUPERIOR IN NW FLOW...
BUT GIVEN NEAR 100PCT ICE COVER...LES MAY BE SHUTDOWN THRU THIS FCST
PERIOD.
SAT NIGHT INTO MONDAY...A HIGH PRES RIDGE STRETCHING FROM THE SFC
HIGH CENTER OVER THE NRN PLAINS INTO THE UPPER LAKES WILL ENSURE A
PERIOD OF DRY...BUT STILL VERY COLD WEATHER SAT NIGHT INTO SUNDAY
NIGHT. FORECASTING TEMPS WILL BE A CHALLENGE FOR SAT NIGHT INTO
EARLY NEXT WEEK AS MIN TEMPS COULD BE VERY COLD EACH NIGHT (WELL BLO
LOWEST GUIDANCE) UNDER LINGERING BUT GRADUALLY MODERATING ARCTIC AIR
MASS. HIGH CLOUDS ON THE NRN FRINGE OF DISTURBANCE PASSING TO THE S
OF THE AREA MAY LIMIT COOLING SOME SAT NIGHT. OTHERWISE...CLOUD
COVER MAY NOT BE THAT MUCH OF AN ISSUE THRU EARLY NEXT WEEK AS
BUILDING HIGH PRESSURE SHOULD ENSURE MOSTLY CLEAR SKIES AND THERE
SHOULD BE LITTLE IF ANY STRATOCU OFF WHAT SHOULD BE A TOTALLY ICE
COVERED LAKE SUPERIOR. EXPECT WINDS TO BE MOSTLY LIGHT EACH NIGHT AS
SFC HIGH PRES DOMINATES SO WILL CONTINUE TO FAVOR MIN TEMPS
GENERALLY AT OR BLO THE LOWEST GUIDANCE SAT NIGHT AND SUN
NIGHT...ESPECIALLY FOR TRADITIONAL COLD SPOTS. WITH MODELS TRENDING
FARTHER SOUTH WITH SHORTWAVE NOW FCST TO MOVE THROUGH THE NORTHERN
PLAINS AND LOWER MIDWEST...CLOUDS MAY NOT BE AS MUCH OF A FACTOR AS
PREV THOUGHT SO HAVE TRENDED COLDER WITH MIN TEMPS FOR MON
NIGHT...CLOSER TO GEM-NH BIAS CORRECTED VALUES. INCREASINGLY
HIGHER SUN ANGLE AT THIS TIME OF YEAR WORKING ON LOWER ALBEDO
FORESTED TERRAIN WILL HELP TEMPS REBOUND INTO THE SINGLE DIGITS AND
LOWER TEENS ABOVE ZERO FROM FRIGID OVERNIGHT LOWS EACH DAY...THOUGH
MAX TEMPS WILL STILL BE WELL BLO NORMAL.
12Z MODELS NOW SHOWING BIGGER DISCREPANCIES FOR MID TO LATE NEXT
WEEK. BOTH THE GEM-NH AND ECMWF AND TO A LESSER EXTENT THE UKMET
SHOW A SHORTWAVE ROTATING DOWN FM HUDSON BAY BRINGING ANOTHER PUSH
OF ARCTIC AIR INTO THE REGION. THE GEM-NH IS DEEPER AND SLOWER WITH
THIS FEATURE THAN THE ECMWF AND EVENTUALLY FORMS A CLOSED LOW BY 12Z
THU OVER THE WRN GREAT LAKES. MEANWHILE THE GFS SHOWS THIS SHORTWAVE
STAYING WELL NE AND NOT IMPACTING THE GREAT LAKES. GIVEN
UNCERTAINTY...FEEL INCLINED TO FOLLOW ALONG WITH THE ECMWF WHICH IS
MORE OF A COMPROMISE BETWEEN THE GFS AND MORE EXTREME GEM-NH SOLN.
THIS WILL KEEP MORE OF AN ARCTIC AIRMASS OVER THE AREA FOR ONE MORE
DAY WITH DOUBLE DIGIT BELOW ZERO TEMPS POSSIBLE AGAIN ON TUE NIGHT
BEFORE AIRMASS BEGINS TO MODERATE ON WEDNESDAY. MODELS STILL SHOW A
PACIFIC SHORTWAVE COMING INTO THE AREA TOWARD THE END OF THE WEEK
WITH SIGNIFICANT TIMING ISSUES. THE GFS IS MUCH MORE PROGRESSIVE
BRINGING THE SHORTWAVE AND ASSOC FRONT THROUGH THU AFTERNOON AND
EVENING WHILE THE ECMWF DOES NOT BRING IT THROUGH UNTIL LATE THU
NIGHT AND FRI. FOR NOW WILL FOLLOW CONSENSUS MODEL GUIDANCE RESULTING
IN 30 TO 40 PCT POPS FOR LIGHT SNOW MAINLY THU NIGHT INTO FRI. TEMPS
BY THE END OF THE WEEK WILL MODERATE INTO THE 20S AND MAY EVEN
APPROACH 30F AT A FEW SITES ALONG THE WI BORDER.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 657 PM EST FRI FEB 28 2014
A PERIOD OF IFR VSBY WITH SNOW EARLY THIS EVENING AT SAW/CMX WILL
DIMINISH BY LATE EVENING AS THE ARRIVAL OF DRIER AIR ALOFT ENDS THE
PCPN FROM WEST TO EAST. HOWEVER...EXPECT PREDOMINANT MVFR CIGS TO
LINGER THROUGH SAT MRNG AT IWD/CMX WITH STEADY...UPSLOPE NW FLOW OF
COLDER AIR. EXTENSIVE ICE COVER OVER LAKE SUPERIOR WILL LIMIT THE
POTENTIAL FOR HEAVIER LES THAT WOULD NORMALLY BE A PROBLEM AT THESE
LOCATIONS. DOWNSLOPE NW FLOW SHOULD RESULT IN A TREND TOWARD VFR
CONDITIONS AT SAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 436 PM EST FRI FEB 28 2014
EXPECT S WINDS UP TO 20-25 KTS AHEAD OF LO PRES CROSSING LAKE
SUPERIOR THIS EVENING TO SHIFT TO THE NW LATE TONIGHT ONCE THE LO
SHIFTS INTO SE ONTARIO AND THEN INCREASE UP TO 25-30 KTS INTO SAT
UNDER SHARPENING PRES GRADIENT BETWEEN THE DEPARTING LO AND HI PRES
BUILDING INTO THE NORTHERN PLAINS. A RIDGE BUILDING ACROSS THE GREAT
LAKES FROM THE N PLAINS AND S CENTRAL CANADA SATURDAY THROUGH MONDAY
WILL ENSURE LIGHT WINDS. HIGH PRESSURE AND GENERALLY LIGHT WINDS WILL
CONTINUE TO DOMINATE THE UPPER GREAT LAKES INTO THE MIDDLE OF NEXT
WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 1 AM EST SATURDAY FOR MIZ013-014.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...VOSS
AVIATION...JLB
MARINE...KC/VOSS
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
1148 PM CST WED FEB 26 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 220 PM CST WED FEB 26 2014
MAIN FORECAST CONCERN IN THE SHORT TERM IS STRONG WINDS AND THE
RESULTING BLOWING/DRIFTING SNOW EXPECTED ACROSS THE AREA THROUGH
THIS EVENING. LATEST SURFACE ANALYSIS AND OBS SHOW THE COLD FRONT
MOVING THROUGH THE NORTH HALF OF THE FORECAST AREA AT THE CURRENT
TIME... WITH A NICE WIND SHIFT FROM SOUTHWEST TO NORTHWEST BEHIND
THE FRONT. WE/RE SEEING STRONG SOUTHWEST WINDS... SUSTAINED NEAR
20KT WITH GUSTS TO AROUND 30KT AHEAD OF THE FRONT... AND NORTHWEST
WINDS OF AROUND 25KT WITH GUSTS OF 35KT IMMEDIATELY BEHIND THE
FRONT. HOWEVER... FORECAST SOUNDINGS FROM THE RAP AND NAM CONTINUE
TO SUGGEST THE BEST MIXING WITH POST FRONTAL COLD ADVECTION AND
SUBSIDENCE WILL OCCUR DURING THE EARLY EVENING ACROSS MOST OF THE
AREA... WITH 00-05Z LOOKING LIKE PRIME TIME FOR STRONG WINDS AND
POTENTIAL BLIZZARD CONDITIONS. THE HOPWRF MATCHES UP WITH THIS
TIMING QUITE WELL... AND HAS ENSEMBLE MEAN SUSTAINED WINDS OF
AROUND 30 MPH AND GUSTS WELL IN EXCESS OF 40 MPH FOR A PERIOD OF
SEVERAL HOURS. LOCATIONS WHICH WILL SEE THE GREATEST IMPACT STILL
LOOK TO BE THE OPEN AREAS OVER THE WESTERN AND SOUTHERN PART OF
THE AREA... WHERE THE COMBINATION OF DEEP SNOW... STRONG WINDS...
AND FAVORABLE TERRAIN SHOULD LEAD TO WIDESPREAD LOW VISIBILITY AND
SIGNIFICANT DRIFTING SNOW. SOME LIGHT SNOW AND FLURRIES WILL SLIP
THROUGH THE NORTH/NORTHEAST PORTION OF THE AREA THROUGH THIS
EVENING... BUT ANY ACCUMULATION WILL BE VERY MINOR GIVEN THE
EXTREMELY LIMITED MOISTURE AHEAD OF THE SHORTWAVE AND COLD FRONT.
THE PRESSURE GRADIENT LOOKS TO QUICKLY RELAX OVERNIGHT INTO
THURSDAY MORNING... SO WE SHOULD SEE THE BLOWING/DRIFTING SETTLE
DOWN FAIRLY QUICKLY AFTER MIDNIGHT. WILL KEEP THE GOING HEADLINES
IN PLACE... AS WELL AS THE TIMING... WHICH STILL LOOKS TO
ENCAPSULATE THE ENTIRETY OF THE EVENT. HOWEVER... WIND CHILLS WILL
BE PLUMMETING OVERNIGHT AS COLDER AIR ARRIVES. ALTHOUGH WINDS WILL
BE DYING OFF... THEY WILL STILL BE SUFFICIENT TO PRODUCE VERY COLD
WIND CHILLS... WHICH WILL PERSIST INTO THE DAY ON THURSDAY. THE
NORTHERN COUNTIES LOOK LIKE THEY WILL SEE WIDESPREAD WIND CHILLS
OF -35 TO -45... WHILE THE CENTRAL AND SOUTHERN PORTION OF THE
AREA WILL MAINLY BE IN THE -25 TO -35 RANGE. SO... ALTHOUGH THE
HEADLINES FOR BLOWING/DRIFTING SNOW WILL END OVERNIGHT... THEY
WILL BE REPLACED BY WIND CHILL HEADLINES THROUGH THURSDAY MORNING.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 220 PM CST WED FEB 26 2014
LONGER TERM TRENDS CONTINUE TO REMAIN COLD. TEMPERATURES ARE
EXPECTED TO REMAIN FAR BELOW NORMAL THROUGH THE ENTIRE PERIOD.
STANDARDIZED ANOMALIES FROM THE NAM AND GEFS CONTINUE TO SHOW H85
TEMPERATURES AROUND 2 TO 3 STANDARD DEVIATIONS BELOW
NORMAL...WHICH SHOULD CONTINUE TO YIELD 30 TO 40 DEGREES BELOW
NORMAL THROUGH MOST OF THE PERIOD. SOME INDICATIONS AT THE END OF
THE PERIOD...INTO NEXT WEEK...THE UPPER FLOW PATTERN MAY FLATTEN A
BIT OVER THE NORTHERN CONUS...ALLOWING SOME MODIFIED PACIFIC TYPE
AIR TO INTRUDE ACROSS THE NORTHERN PLAINS. THAT IS PRETTY FAR IN
THE FUTURE AND THE 12Z ECMWF IS THE MODEL MOST PROMINENT WITH THIS
OVERALL DEVELOPMENT.
A COUPLE OF SNOW CHANCES COME INTO PLAY...NAMELY FRIDAY AND
SATURDAY/SATURDAY NIGHT. MODELS TREND AN INVERTED TROUGH EAST
ACROSS THE CWA ON FRIDAY. BEST FORCING IS FOUND OVER THE SOUTHERN
CWA. WILL CONTINUE TO MENTION LIKELY POPS FOR THE SOUTHERN
THIRD OF THE AREA THEN. WILL HAVE TO MONITOR FOR DEVELOPMENT ON
THE NORTH END OF THE TROUGH AS WELL...BUT CONTINUE CHANCE POPS
THERE. THIS WOULD GENERATE AN INCH OR TWO OF ACCUMULATION TO THE
SOUTH BY FRIDAY EVENING. SHOULD BE A FLUFFY SNOW AND WINDS DO
INCREASE SOME IN THE WAKE OF THE TROUGH. AT THE PRESENT TIME THEY
DO NOT APPEAR TO BE STRONG ENOUGH TO GENERATE SIGNIFICANT
BLOWING/DRIFTING SNOW CONCERNS.
THE NEXT SNOW THREAT ARRIVES FOR SATURDAY AND SATURDAY NIGHT.
MODELS IN SOME DISAGREEMENT AS TO HOW FAR AND SNOW THREAT WOULD
BE AS LARGE COLD ARCTIC HIGH BUILDS SOUTHEAST OVER THE AREA INTO HE
WEEKEND. AT THE MOMENT THE BEST AGREEMENT REMAINS OVER FAR SOUTHERN
MINNESOTA FOR MEASURABLE SNOW AND WILL MENTION LIKELY POPS IN THAT
AREA.
WIND CHILL CONCERNS WILL CONTINUE INTO THE WEEKEND BUT WINDS
SHOULD GRADUALLY DIMINISH AS THE ARCTIC HIGH SETTLES CLOSE TO THE
CWA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1144 PM CST WED FEB 26 2014
BLOWING SNOW CONCERNS ARE WANING AS WINDS ARE SUBSIDING. VFR
EXPECTED FOR THE REST OF THE PERIOD WITH NORTHWEST WINDS BECOMING
5-10 KT EARLY THURSDAY MORNING...LIGHT/VARIABLE IN THE AFTERNOON...
THEN SOUTH/SOUTHEAST 5 KT THURSDAY EVENING.
KMSP...VFR. DIMINISHING NORTHWEST WINDS WILL BECOME SOUTH/SOUTHEAST
BY LATE THURSDAY AFTERNOON.
/OUTLOOK FOR KMSP/
FRI...CHC MVFR WITH -SN. S WIND 5-10 KT BCMG NW.
SAT...VFR. NNW WIND 10 KT.
SUN...VFR. NW WIND 5 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR MNZ047-
048-054>070-073>078-082>085-091>093.
BLIZZARD WARNING UNTIL 3 AM CST THURSDAY FOR MNZ041-042-048-049-
055>059-065>069-073>077-082>085-091>093.
WIND CHILL WARNING FROM 3 AM TO NOON CST THURSDAY FOR MNZ041>045-
049>053.
WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR MNZ043>045-
047-050>054-060>064-070-078.
WI...WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR
WIZ023>028.
WIND CHILL WARNING FROM 3 AM TO NOON CST THURSDAY FOR WIZ014>016.
WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR WIZ014>016-
023>028.
&&
$$
SHORT TERM...TRH
LONG TERM...DWE
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
817 PM CST Fri Feb 28 2014
.UPDATE:
Issued at 817 PM CST Fri Feb 28 2014
Going forecast looks on track. Radar continues to show weak
returns over central and southeast Missouri with high dewpoint
depressions and no precipitation reports on the surface
observations. Will maintain slight chances for rain and snow for
these returns which are being forced by weak moisture convergence
that shows up well in the RAP. RAP also shows that precipitation
now over northwestern MO will continue to move east and reach the
northern CWA after midnight.
Britt
&&
.SHORT TERM: (Through Late Tonight)
Issued at 351 PM CST Fri Feb 28 2014
(Tonight)
System currently over the south-central United States and its attendant
precipitation shield is forecast to continue to weaken as it slowly
travels to the north and east. Main impact across our CWFA will be
increasing mid/high level cloudiness. Did keep slow low chc PoPs in case
some light rain showers do hold together over portions of south-central
and southeastern Missouri early this evening. Also kept chc PoPs over
portions of northeastern Missouri and west-central Illinois roughly along
arctic baroclinic zone. For temperatures...leaned warmer ahead of boundary
overnight tonight due to expected cloud cover and southerly component to
winds.
Gosselin
.LONG TERM: (Saturday through Next Friday)
Issued at 351 PM CST Fri Feb 28 2014
Saturday through Monday: Upper shortwave ridging moves across the
area tomorrow, ensuring quiet conditions through at least the
morning hours and probably for most of the afternoon as well.
Attention then turns to a potentially high-impact late winter
storm which is expected to bring a veritable cornucopia of
precipitation types to the LSX CWA this weekend, especially from
Saturday night through Sunday night.
The overall thinking remains similar to previous forecast packages:
snow in the north (including KUIN/KHAE), freezing rain in the south
(including KFAM), a band of mixed precip in the middle (including
KCOU, KSTL, KSLO), and a gradual changeover with time from mixed
ptypes to pure snow after colder air moves into the region. The
primary forecast issues are precipitation types and amounts,
although forecasting these details is difficult since neither the
main system nor its leading shortwaves have been sampled by the
upper air network. Regardless, all guidance suggests that the
specific amounts of each precipitation type are far less important
than the cumulative effects of a widespread and prolonged wintry
mix over the region. No changes were made to the ongoing Winter
Storm Watch at this time due to continued uncertainty regarding
precipitation types and amounts.
Atmospheric features that will affect ptypes and amounts during
this event include 1) a sharpening baroclinic zone to the south of
the CWA, 2) an Arctic air mass spreading across the area from the
north, 3) a warm nose aloft associated with a LLJ, 4) several
hours where the maximum lift occurs just below or within the DGZ
in an environment which is saturated WRT ice, and 5) a secondary
DGZ which develops below 5000 ft on Sunday and may re-introduce
ice crystals at low levels. This forecast package reflects a blend
of several models excluding the SREF, which was discounted because
it was much warmer and farther north than any other guidance.
Precipitation will probably begin as snow in the north and rain or
freezing rain farther south, depending on surface temperatures. A
prolonged period of sleet (occasionally mixing with rain, freezing
rain, and/or snow depending on the location) is expected across a
broad part of the CWA. One of the factors contributing to the
prolonged period of sleet is that as the depth of the surface cold
layer gradually increases to 3000-4000 ft, the strength of the
warm nose aloft will become less important since partially or
fully melted snowflakes will have plenty of time and distance to
refreeze into ice pellets. In general, precipitation types should
change from ZR -> ZR/IP -> IP -> IP/SN -> SN. Isolated thunder is
possible on Sunday, which would tend to increase precipitation
rates.
The greatest snow accumulations are expected across northeast
MO/west central IL and the greatest ice accumulations are expected
across southern and southeastern MO into southern IL.
1020-1030 hPa surface high builds into the region on Monday
behind the departing system with unseasonably cold air returning
to the area.
Kanofsky
Tuesday through Friday: Very cold ams in the wake of the weekend
storm will mean more unusually cold early March weather lingering
into Tuesday. All of the latest raw model output and MOS-based
guidance are indicating single digits lows in the offing for the
entire CWA on Tuesday morning, with highs rebounding into the
lower 20s to lower 30s during the afternoon hours.
Heading into the latter half of the week, mean UA flow over the
CONUS takes on a much more zonal look, which should translate into
moderating temperatures. Operational GFS is forecasting a very big
warmup by Thursday, however the ECMWF, GEM, and to a lesser extent
the GFS ensemble keep heights much lower over the northeast U.S.,
which in turn keeps surface ridge entrenched from the Great Lakes
into the mid Mississippi Valley and slows the ewd erosion of the
cold air. Given the snow cover that should be blanketing much of the
region, as well as the cold track record of this winter, have used
with model consensus and gone with a slower warming trend, with
temps finally rebounding to near normal levels by Friday.
Precipitation threat looks fairly low for much of the extended
period. All medium range models to forecast shortwave to pass over
the area Wed-Wed night, but with surface ridge nosing into area
moisture should be modest so have kept PoPs in the slight chance
range for now.
Truett
&&
.AVIATION: (For the 00z TAFs through 00z Saturday Evening)
Issued at 503 PM CST Fri Feb 28 2014
Low level cloud cover around 3000-5000 ft over wrn MO should
advect ewd this evng into the taf sites. S-sely surface winds will
weaken this evng, and gradually veer around to a swly direction as
a cold front approaches. This cold front will drop sewd through
UIN and COU late tgt, and through the St Louis metro area around
12z Saturday with the wind veering around to a n-nwly direction
and strengthening after fropa. The cloud ceiling will lower into
the MVFR catagory after fropa as well.
Specifics for KSTL: S-sely surface winds will weaken this evng and
veer around to a swly direction late tgt. The surface wind will
continue to veer around to a n-nwly direction early Saturday mrng
after fropa and strengthen through the day and into Saturday evng.
VFR, low level clouds will advect into STL later this evng, and
lower into the MVFR catagory Saturday mrng after fropa.
Precipitation should move into the STL area by late Saturday evng
as a s-swly low level jet brings strong low-mid level warm air
advection and increasing low level moisture to the region.
Precipitation type is uncertain but should initially be freezing
rain and sleet.
GKS
&&
.CLIMATE:
Issued at 351 PM CST Fri Feb 28 2014
Potentially historically cold arctic air is forecast to move into
the region beginning on Sunday and lasting into Tuesday. Several
records are in jeopardy of being broken at our three official
climate sites which can be seen below:
St. Louis, MO (1874-present):
Date Record low Record low maximum
3/2 2 (1980) 19 (1943)
3/3 1 (1943) 19 (2002)
3/4 -1 (1978) 15 (1960)
Columbia, MO (1890-present):
Date Record low Record low maximum
3/2 -5 (1890) 17 (1943)
3/3 1 (1900) 16 (2002)
3/4 -5 (1978) 12 (1960)
Quincy, IL (1901-present):
Date Record low Record low maximum
3/2 -2 (1980) 21 (1960)
3/3 -1 (1913) 14 (2002)
3/4 -8 (1978) 11 (1960)
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...WINTER STORM WATCH from Saturday evening through late Sunday
night FOR Audrain MO-Boone MO-Callaway MO-Cole MO-Crawford
MO-Franklin MO-Gasconade MO-Iron MO-Jefferson MO-Knox MO-
Lewis MO-Lincoln MO-Madison MO-Marion MO-Moniteau MO-Monroe
MO-Montgomery MO-Osage MO-Pike MO-Ralls MO-Reynolds MO-
Shelby MO-St. Charles MO-St. Francois MO-St. Louis City MO-
St. Louis MO-Ste. Genevieve MO-Warren MO-Washington MO.
IL...WINTER STORM WATCH from Saturday evening through late Sunday
night FOR Adams IL-Bond IL-Brown IL-Calhoun IL-Clinton IL-
Fayette IL-Greene IL-Jersey IL-Macoupin IL-Madison IL-
Marion IL-Monroe IL-Montgomery IL-Pike IL-Randolph IL-St.
Clair IL-Washington IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
315 PM MST THU FEB 27 2014
.SHORT TERM...VALID FOR FRI AND SAT...
INGREDIENTS CONTINUE TO COME TOGETHER FOR A DANGEROUS WINTER
STORM TONIGHT THROUGH SAT NIGHT. AT 21Z...ARCTIC FRONT WAS SURGING
S THROUGH SOUTHERN ALBERTA. MOISTURE MOVING INTO THE AREA FROM W
MT WAS GENERATING LIGHT SHOWERS OVER AREAS W AND N OF KBIL PER
RADAR IMAGERY AND OBSERVATIONS. MODELS WERE IN GOOD AGREEMENT IN
BRINGING THE FRONT INTO THE AREA EARLY THIS EVENING AND SLIDING IT
S THROUGH THE AREA TONIGHT. A BAND OF STRONG FRONTOGENESIS WILL
ACCOMPANY THE FRONT AND ISENTROPIC LIFT WILL DEVELOP OVER THE
WESTERN ZONES. SNOW WILL OVERSPREAD THE AREA FROM W TO E TONIGHT.
NOTED THE HRRR AND SREF HINTED AT SOME POSSIBLE FREEZING RAIN
EARLY IN THE EVENING BEFORE A CHANGEOVER TO SNOW...BUT RAP
SOUNDINGS SHOWED A QUICK WET BULB DOWN ONCE THE PRECIPITATION
BEGINS SO WILL NOT INCLUDE IT IN THE FORECAST AT THIS TIME. ALSO
SOUNDINGS SUPPORTED ICE DEVELOPMENT IN THE CLOUDS SO RESULT SHOULD
BE A RATHER QUICK CHANGEOVER TO SNOW THIS EVENING. GOOD DENDRITIC
GROWTH WILL ACCOMPANY THE LIFT AND MOISTURE RESULTING IN SEVERAL
INCHES OF SNOW ACCUMULATION OVERNIGHT WEST OF ROSEBUD COUNTY. IT
WILL BECOME WINDY OVERNIGHT DUE TO THE FRONTAL PASSAGE AND AREAS
LIKE JUDITH GAP AND KLVM COULD SEE NEAR WHITEOUT CONDITIONS.
TEMPERATURES BY FRI MORNING WILL BE IN THE SINGLE DIGITS ABOVE AND
BELOW ZERO.
STRONG ISENTROPIC LIFT WILL OVERSPREAD THE REGION FRIDAY AND
CONTINUE THROUGH SAT...BEFORE DIMINISHING SAT NIGHT. SHORTWAVE
ENERGY PASSING BY TO THE S OF THE AREA WILL AID IN GENERATING
THE ISENTROPIC LIFT. THE FRONTOGENESIS BAND WILL BE ALONG THE
MOUNTAINS AND FOOTHILLS ON FRI AND WILL MOVE S OF THE AREA FRI
NIGHT. STRONG JET DIVERGENCE WILL AID THE LIFT OVER THE AREA FRI
INTO SAT AS WELL. EXPECT AREAS OF BLOWING SNOW OVER THE REGION ON
FRI DUE TO WINDY CONDITIONS. THE BEST DENDRITIC GROWTH WILL SINK S
AND SW DURING THE DAY ON FRI AND WILL BE OVER THE FAR SW FRI NIGHT
AND SAT. SEVERAL INCHES OF SNOW WILL CONTINUE W OF ROSEBUD COUNTY
ON FRI WITH HIGHER ACCUMULATIONS IN THE MOUNTAINS. FRI NIGHT AND
SAT WILL HAVE SIMILAR ACCUMULATIONS. WINDS WILL BE LOWER FOR FRI
NIGHT AND SAT WITH LESS OF A THREAT OF BLOWING SNOW. SNOW WILL
WIND DOWN SAT NIGHT AS LIFT DECREASES OVER THE AREA.
HIGHS WILL BE IN THE SINGLE DIGITS AND TEENS ON FRI AND LOWS WILL
BE IN THE TEENS BELOW ZERO FRI NIGHT. TEMPERATURES WILL NOT RISE
ABOVE ZERO FOR SAT AND WILL BE VERY COLD SAT NIGHT AS 850 MB
TEMPERATURES APPROACH -30 DEGREES C. EXPECT DANGEROUS WIND CHILLS
ACROSS THE AREA FROM FRI ONWARD.
WILL CONTINUE THE WARNING FOR AREAS W OF ROSEBUD COUNTY FOR
MULTIPLE STORM IMPACTS...AND WILL ISSUE AN ADVISORY FOR THE
EASTERN ZONES...EXCEPT FOR FALLON COUNTY WHERE SNOW AMOUNTS WILL
BE LIGHT. ARTHUR
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
BITTERLY COLD TEMPERATURES AND WIND CHILLS WILL CONTINUE SUNDAY
INTO MONDAY BEFORE A MODERATION IN TEMPERATURES ARRIVES TUESDAY.
MODELS ARE IN FAIRLY GOOD AGREEMENT IN KEEPING A 500MB UPPER LOW
AND ASSOCIATED VORTICITY AREA OVER BRITISH COLUMBIA SUNDAY AND
MONDAY. THIS WILL RESULT IN AN UPPER LEVEL FLOW FROM THE
WEST/NORTHWEST KEEPING A MOIST PACIFIC FLOW ACROSS THE FORECAST
AREA. AT THE SURFACE...A STRONG BAROCLINIC ZONE WILL BE SITUATED
ACROSS THE ENTIRE EASTERN SLOPES OF THE ROCKY MOUNTAINS. ALTHOUGH
THE STRONG DYNAMICS FROM THIS CURRENT STORM WILL MAINLY BE OUT OF
THE AREA THERE WILL STILL BE CHANCES FOR SNOW SHOWERS BOTH DAYS.
TEMPERATURES WILL REMAIN BELOW ZERO DURING THE DAY SUNDAY BUT A
SLIGHT MODERATION WILL BE POSSIBLE MONDAY.
MODELS TRY TO QUICKLY RETREAT THE ARCTIC AIR BY TUESDAY WITH
READINGS WELL UP INTO THE 40S. HOWEVER...GIVEN EXPECTED SNOW COVER
WILL KEEP READINGS IN THE 20S AND 30S ACROSS THE AREA. HIGH
TEMPERATURES THIS TIME OF YEAR CAN BE DIFFICULT...ESPECIALLY WITH
SNOW COVER...AS STRONG EARLY MARCH SUN ANGLE CAN QUICKLY BOOST
TEMPERATURES FOR A FEW HOURS. IN ADDITION... WILL NEED TO WATCH
THE POSSIBILITY OF BLOWING SNOW AS SOME BRIEF GAP AND/OR DRAINAGE
WINDS MAY BE GUSTY AS THE ARCTIC RETREATS. AFTER SUNDAY...NO
STRONG STORM SYSTEM LOOKS TO IMPACT THE FORECAST AREA UNTIL NEAR
THE END OF NEXT WEEK AS MODELS BRING THE POSSIBILITY OF MORE SNOW.
HOOLEY
&&
.AVIATION...
SNOW WILL BEGIN ALONG AND WEST OF A KSHR-KBIL-ROUNDUP LINE BY 06Z
AND AREAS EAST BETWEEN 06Z AND 12Z. VFR FLIGHT CONDITIONS WILL
PREVAIL EARLY THIS EVENING BUT WILL BEGIN TO DETERIORATE BY MID
EVENING AS A STRONG ARCTIC FRONT MOVES THROUGH THE FORECAST AREA.
SNOW...HEAVY AT TIMES...WILL RESULT IN WIDESPREAD IFR TO LIFR
CONDITIONS AFTER 06Z. THESE CONDITIONS WILL CONTINUE THROUGH
SATURDAY. THE MOUNTAINS WILL BE OBSCURED. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
FRI SAT SUN MON TUE WED THU
-----------------------------------------------------------
BIL 008/009 912/909 917/905 916/015 007/032 015/037 023/030
++/S ++/S 73/S 33/S 23/S 32/S 22/S
LVM 010/015 908/903 914/006 912/024 013/035 017/039 027/036
++/S ++/S 74/S 43/S 33/S 42/S 33/S
HDN 007/012 913/905 919/901 918/014 002/030 013/034 020/029
++/S ++/S 73/S 33/S 22/S 32/S 22/S
MLS 002/005 915/909 920/902 919/008 000/026 011/031 017/023
66/S 77/S 52/S 22/S 12/S 22/S 22/S
4BQ 004/010 910/903 919/002 918/011 003/027 013/035 017/027
77/S 9+/S 62/S 22/S 12/S 21/B 12/S
BHK 902/002 917/908 921/901 920/005 903/022 015/031 012/022
45/S 56/S 42/S 22/S 12/S 21/B 12/S
SHR 014/015 909/901 914/005 915/019 008/035 016/039 020/035
9+/S ++/S 73/S 32/S 22/S 32/S 12/S
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER STORM WARNING IN EFFECT UNTIL 6 AM MST SUNDAY FOR
ZONES 28>30-34-35-39>42-57-63>65-67-68.
WINTER WEATHER ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO 6
AM MST SUNDAY FOR ZONES 31-32-36-37.
WINTER STORM WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 6 AM
MST SUNDAY FOR ZONES 38-58.
WINTER STORM WARNING IN EFFECT FROM 9 PM THIS EVENING TO 6 AM
MST SUNDAY FOR ZONES 56-66.
WY...WINTER STORM WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 6 AM
MST SUNDAY FOR ZONES 98-99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
753 PM CST FRI FEB 28 2014
.UPDATE...
ISSUED AT 748 PM CST FRI FEB 28 2014
FIRST BATCH OF PRECIPITATION WAS MOVING OUT OF THE FA WITH A
LINGERING FREEZING RAIN/SNOW MIX THROUGH ABOUT 03Z FAR SERN
COUNTIES...WITH A FEW TRAILING FLURRIES/SNOW SHOWERS AN HR OR SO
LONGER. THIS WAS HANDLED WITH UPDATE A BIT AGO. OTHERWISE 18Z AND
LATEST SHORT-TERM HRRR MODELS SUGGESTED THE ONSET OF THE NEXT
ROUND OF SNOW WILL BE A BIT SLOWER. THUS PUSHED BACK START TIME OF
WINTER WEATHER ADVISORY 3 TO 6 HRS. NO OTHER SIGNIFICANT CHANGES
AT THIS TIME.
&&
.SHORT TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 305 PM CST FRI FEB 28 2014
WHAT A WAY TO START THE MONTH OF MARCH...SOME OF THE COLDEST AIR
OF THE SEASON IS EXPECTED TO SETTLE OVER THE AREA THIS WEEKEND
WITH THE POTENTIAL TO SMASH LOW TEMPERATURE RECORDS FOR THE DATES.
THE COLD FRONT THAT WILL USHER IN THE ARCTIC AIR WAS MOVING INTO
SOUTHEAST NEBRASKA AND SOUTHWEST IOWA AT 20Z WITH RADAR SHOWING A
FRONTOGENETIC BAND OF LIGHT PRECIP OVER EAST CENTRAL NEBRASKA.
EXPECT THE MAJORITY OF THIS PRECIP TO BE EAST OF THE MISSOURI
RIVER AT THE START OF THE PERIOD AND SHOULD SEE A PERIOD OF
LIGHT SNOW EARLY THIS EVENING IN PARTS OF SOUTHWEST IOWA AS THE
COLD AIR DEEPENS IN THE LOW LEVELS BEFORE MOVING OFF TO THE EAST.
A SECOND ROUND OF LIGHT SNOW IS EXPECTED TO DEVELOP TONIGHT NEAR
THE NEBRASKA SOUTH DAKOTA BORDER AND SPREAD EAST INTO NORTHWEST
PARTS OF THE FORECAST AREA AFTER MIDNIGHT. THE FRONTOGENETIC
FORCING ASSOCIATED WITH THIS BAND OF SNOW PUSHES SOUTH ACROSS
THE REST OF THE AREA DURING THE DAY ON SATURDAY AND INTO KANSAS
AND NORTHERN MISSOURI SATURDAY NIGHT WHERE STRONGER FORCING IS
INDICATED ALONG THE 850MB FRONT. EXPECT SNOW RATIOS TO BE RATHER
HIGH WITH THIS EVENT DUE TO THE EXTREMELY COLD AIR SO SNOWFALL IN
THE 4 TO 6 INCH RANGE IS POSSIBLE ACROSS EASTERN NEBRASKA AND
SOUTHWEST IOWA WITH ISOLATED 6+ IN FAR SOUTHEAST NEBRASKA. THE
MAJORITY OF SNOWFALL FOR THE FORECAST AREA IS EXPECTED DURING THE
DAY ON SATURDAY WITH ADDITIONAL AMOUNTS IN THE SOUTH SATURDAY
NIGHT. SNOW MAY LINGER OVER THE FAR SOUTH INTO SUNDAY WITH SOME
LIGHT ACCUMULATION BEFORE ENDING SUNDAY AFTERNOON.
WITH THE ADDITION OF FRESH SNOW COVER...RECORD COLD TEMPERATURES
LOOK LIKELY WITH FORECAST HIGHS WELL BELOW CURRENT RECORD LOW
MAXIMUMS AT ALL THREE CLIMATE STATIONS ON SATURDAY AND SUNDAY.
RECORD LOW MINIMUMS ARE ALSO POSSIBLE AT SEVERAL SITES.
WIND CHILL HEADLINES ARE LIKELY TO REPLACE WINTER WEATHER
HEADLINES AFTER THEIR EXPIRATION SATURDAY NIGHT AND SUNDAY AS THE
ARCTIC HIGH PRESSURE WORKS SOUTH INTO THE LOWER MISSOURI VALLEY
SUNDAY NIGHT AND MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 305 PM CST FRI FEB 28 2014
MONDAY NIGHT THROUGH NEXT FRIDAY...THIS FORECAST PERIOD IS
CHARACTERIZED BY A WARMING TREND THROUGH THE WORK WEEK AND MEAGER
PRECIPITATION CHANCES THROUGHOUT.
MONDAY NIGHT WILL BE COLD...BUT NOT NEARLY AS COLD AS THE PREVIOUS
NIGHT. TEMPERATURES REBOUND A BIT WITH LOWS STAYING ABOVE
ZERO...NOWHERE NEAR RECORD TERRITORY. BY TUESDAY AFTERNOON WE BEGIN
A GRADUAL WARM-UP AS 850MB TEMPERATURES FINALLY RISE ABOVE ZERO
CELSIUS. THIS WARMING TREND CONTINUES THROUGH THE WORK WEEK WITH
850MB TEMPERATURES PUSHING 10 CELSIUS BY THURSDAY AND THURSDAY
NIGHT. GIVEN THIS AMOUNT OF WARMTH...DAYTIME HIGHS WILL LIKELY
EXCEED 50 DEGREES THURSDAY AND MAYBE EVEN FRIDAY DEPENDING ON THE
TIMING OF THE WEEKEND SYSTEM.
PRECIPITATION-WISE THE FORECAST IS GENERALLY DRY. A COUPLE DIFFERENT
SHORTWAVES EMBEDDED IN THE MID-LEVEL NORTHWEST FLOW WILL TRANSLATE
THROUGH THE FORECAST AREA. HOWEVER MEAGER MOISTURE PROFILES ONLY
POINT TO A SLIGHT CHANCE OF PRECIPITATION ON WEDNESDAY...OTHERWISE
WE ANTICIPATE DRY WEATHER THROUGH THURSDAY NIGHT AS UPPER LEVEL
RIDGING DOMINATES. BY FRIDAY THE UPPER LEVEL RIDGE BREAKS DOWN AND
THE NEXT WEATHER MAKER ENTERS THE PICTURE. AT THIS TIME MODEL
GUIDANCES POINTS TO AN INCREASED POTENTIAL FOR
PRECIPITATION...LIKELY A RAIN/SNOW MIX...BY FRIDAY NIGHT AND
CONTINUING INTO THE WEEKEND.
&&
.AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 525 PM CST FRI FEB 28 2014
A BAND OF MAINLY SNOW WILL WORK ACROSS THE KLNK/KOMA SITES
THROUGH EARLY EVENING...ALTHOUGH A BRIEF MIX POSSIBLE AT KLNK.
SOME VSBYS HAVE DROPPED TO 1/2SM OR LESS IN THIS BAND. ALTHOUGH
THE HEAVIEST SNOW/LOWEST VSBYS SHOULD REMAIN MOSTLY N OF KOMA AND
KLNK...A PERIOD OF 1SM OR LESS IS LIKELY AT BOTH SITES. AFTER THIS
FIRST BAND OF SNOW EXITS THE REGION EARLY THIS EVENING...CIGS WERE
EXPECTED TO LIFT ABOVE FL030 UNTIL ANOTHER ROUND OF SNOW FORECAST
TO SPREAD INTO ERN NEBRASKA SATURDAY MORNING/EARLY AFTERNOON.
CONDITIONS WILL LIKELY DROP INTO IFR CATEGORY AT ALL
SITES...ESPECIALLY SAT AFTN.
&&
.CLIMATE...
ISSUED AT 305 PM FRI FEB 28 2014
COLD MAX TEMP AND RECORD MIN TEMP RECORDS FOR THE FIRST FEW DAYS
IN MARCH. ASTERISK VALUES INDICATE POTENTIAL BROKEN RECORDS BASED
ON CURRENT FORECAST.
3/1 3/2 3/3
OMAHA 12*/-9 13*/-4* 10*/-5*
LINCOLN 16*/-6 14*/-7 10/-10
NORFOLK 11*/-11 10*/-15* 6/-10*
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY FROM 9 AM SATURDAY TO 6 AM CST SUNDAY
FOR NEZ034-043>045-050>053-065>067-078.
WINTER WEATHER ADVISORY FROM NOON SATURDAY TO NOON CST SUNDAY
FOR NEZ068-088>093.
WINTER WEATHER ADVISORY FROM 3 AM SATURDAY TO MIDNIGHT CST
SATURDAY NIGHT FOR NEZ011-012-015>018-030>033-042.
IA...WINTER WEATHER ADVISORY FROM 9 AM SATURDAY TO 6 AM CST SUNDAY
FOR IAZ043-055-056-069-079-080.
WINTER WEATHER ADVISORY FROM NOON SATURDAY TO NOON CST SUNDAY
FOR IAZ090-091.
&&
$$
UPDATE...CHERMOK
SHORT TERM...FOBERT
LONG TERM...PEARSON
AVIATION...CHERMOK
CLIMATE...FOBERT
AREA FORECAST DISCUSSION
NWS ELKO NV
811 AM PST THU FEB 27 2014
.SYNOPSIS...THE RUMBLE OF THUNDER WILL BE POSSIBLE AS TWO
SEPARATE PACIFIC STORM SYSTEMS BRING MUCH NEEDED RAIN AND SNOW TO
NEVADA...THE FIRST ONE TODAY...AND THE SECOND ONE FRIDAY THROUGH
SATURDAY.
&&
.UPDATE...DID A QUICK UPDATE THIS MORNING WITH REGARDS TO SNOW
LEVEL...QPF...SNOW AMOUNTS...AND WEATHER GRIDS. 3KM HRRR AND NEW
SNOW SQUALL TOOL ARE PINGING AREAS OF LIGHT TO MODERATE SNOW SHOWERS
ACROSS PORTIONS OF CENTRAL AND EAST-CENTRAL NEVADA THIS
MORNING...AS WELL AS FURTHER NORTH IN PORTIONS OF ELKO COUNTY.
HAVE LOWERED SNOW LEVELS SLIGHTLY AND INCREASED QPF AND SNOW
AMOUNTS TO REFLECT QUICK HITTING SNOW SHOWERS THROUGH 18Z THIS
MORNING. SNOW LEVELS APPEAR TO BE AROUND THE 55000 TO 6000 FOOT
MARK...WITH ACCUMULATIONS OF AN INCH POSSIBLE IN LOCALIZED AREAS. TEXT
PRODUCTS WILL BE SENT SHORTLY...ALL OTHER GRIDS LOOK GOOD.
&&
.PREV DISCUSSION... /ISSUED AT 207 AM /
SHORT TERM...TODAY THROUGH SATURDAY. MOISTURE IS ATTACKING THE
SIERRAS AT THIS TIME WITH A COUPLE STRONG CONVECTIVE RAIN BANDS
ON THE SACRAMENTO SIDE NOTED ON RADAR. SHOWERS BEGAN TO SPILL
OVER THE SIERRA EAST SIDE AROUND MIDNIGHT DENOTED BY LIGHT RAIN AT
RENO FALLON AND LOVELOCK. EXPECTED TIME OF ARRIVAL AT ELKO IS
BETWEEN 3AM AND 4AM. AS OF 2 AM PST...TEMPERATURES ARE VERY WARM
IN THE 40S ALL AROUND AND ONLY CLOUD BANDING EAST OF BATTLE
MOUNTAIN. TWO DISTINCT SHORTWAVES WILL SPIN OFF THE PARENT PACIFIC
UPPER LOW FEATURE AND AFFECT THE GREAT BASIN. THE FIRST WILL
AFFECT THE STATE TODAY AND TONIGHT TO PROVIDE MUCH NEEDED
RAINFALL IN THE VALLEYS WITH MOUNTAIN SNOW ESSENTIALLY TIED UP
ABOVE 6000 FEET. NO MAJOR IMPACTS EXPECTED. THE SECOND SYSTEM
WILL ENTER THE GREAT BASIN DOMAIN FRIDAY AND LAST LONGER WHICH
WILL ALLOW COLDER AIR TO SLIDE IN FROM THE NORTH BEFORE THE
PRECIPITATION EXITS. THERE IS POTENTIAL FOR SOME IMPACTS FROM THIS
SYSTEM AS THE WEEKEND PROGRESSES.
TODAY. PRECIPITATION WILL SPREAD TO ALL PARTS OF THE STATE...WITH
LESSER CHANCES FOR PRECIPITATION FOR AREAS EAST OF THE RUBY
MOUNTAINS UNTIL THE AFTERNOON. ONCE THE UPPER LOW MOVES ONSHORE
EARLY THIS MORNING...THE CENTER OF THE LOW WILL SKIP THROUGH NORTHERN
CALIFORNIA AND OREGON AND MELD NORTHEAST INTO THE NORTHERN FLOW. THE
SPEED OF THE PASSING LOW WILL PROVIDE A ROBUST SOUTHWEST FLOW FOR
THE LKN CWFA AND THUNDERSTORM ACTIVITY WILL BE POSSIBLE AS THE
TROUGH AXIS PASSES OVER THE STATE EARLY IN THE AFTERNOON. MODEL QPF IS
GENEROUS HOWEVER THERE WILL BE SIERRA SHADOWING EFFECT TO DEAL
WITH. AREAS TO THE NORTH MAY NOT RECEIVE AS MUCH PRECIPITATION
EARLY. THERE MAY BE SOME RUMBLES OF THUNDER NEAR TONOPAH LATE IN
THE MORNING HOWEVER THE MOIST CORE AND INSTABILITY FAVORS EAST
CENTRAL NEVADA IN THE AFTERNOON. RAIN MAY MIX WITH SNOW IN THE
AFTERNOON AS SNOW LEVELS WILL BE LOWERING FROM 7000 FEET DOWN TO
AROUND 6000 FEET. LITTLE SNOW ACCUMULATION IS EXPECTED BELOW 6000
FEET HOWEVER AREAS AROUND 6500 FEET MAY RECEIVE UP TO 4 INCHES OF
SNOW ALL TOTAL TODAY. GUSTY WINDS TO 30 MPH ARE EXPECTED ACROSS
MUCH OF THE GREAT BASIN. HIGH TEMPERATURES WILL BE IN THE 50S.
TONIGHT. A WEAK HIGH PRESSURE RIDGE WILL BEGIN TO MOVE ACROSS THE
GREAT BASIN. SHOWERS WILL BE TAPERING OFF SOUTH TO NORTH AS
ANOTHER WEATHER MAKER GATHERS STRENGTH OUT OVER THE PACIFIC. SNOW
LEVELS WILL BE DROPPING TO AROUND 5500 FEET HOWEVER LITTLE SNOW
ACCUMULATION IS EXPECTED WITH THE EXPECTED DIMINISHING OF THE
SHOWER ACTIVITY. LOW TEMPERATURES WILL RANGE FROM THE MID 20S TO
THE MID 30S.
FRIDAY THROUGH SATURDAY. ANOTHER TROUGH OF LOW PRESSURE WILL MOVE
DOWN THE COAST OF CALIFORNIA FRIDAY AND MOVE ONSHORE OVER SOUTHERN
CALIFORNIA SATURDAY AFTERNOON. THE TRACK OF THIS LOW IS MUCH
FARTHER SOUTH THAN THE PREVIOUS ONE AND AS EARLY AS FRIDAY
MORNING...EXTREME AMOUNTS OF MOISTURE WILL BE SPREADING INTO
SOUTHERN CALIFORNIA AND BANKING UP AGAINST ALL MOUNTAIN RANGES
NEAR THE CALIFORNIA BORDER WITH NEVADA. THE MORE SOUTHERN
TRAJECTORY WILL ALLOW A STRONG INFLUX OF MOISTURE INTO CENTRAL
NEVADA WITH THE POTENTIAL FOR STRONG FLASH-FLOOD PRODUCING
THUNDERSTORMS SOUTH OF HIGHWAY 50. THERE MAY BE SOME RUMBLES OF
THUNDER NEAR TONOPAH LATE IN THE MORNING HOWEVER THE MOIST CORE
AND INSTABILITY AGAIN FAVORS EAST CENTRAL NEVADA IN THE AFTERNOON.
SNOW WILL BEGIN SPREADING ACROSS WESTERN NEVADA AROUND DAYBREAK
FRIDAY AND SPREAD TO ALL PARTS OF THE STATE BY FRIDAY AFTERNOON.
IMPACTS WILL BE GREATEST FOR AREAS SOUTH OF HIGHWAY 50 FROM FRIDAY
AFTERNOON THROUGH FRIDAY EVENING...FOLLOWED BY NORTHERN NEVADA
FRIDAY MIDNIGHT THROUGH SATURDAY MORNING. ELEVATIONS ABOVE 6000
FEET COULD RECEIVE ONE HALF FOOT OF SNOW. SNOW LEVELS WILL BE
DIPPING DOWN TO AROUND 5500 FEET EARLY SATURDAY SO SEVERAL INCHES
OF SNOW IS POSSIBLE AT THAT LEVEL...ESPECIALLY ACROSS NORTHEAST
NEVADA. LOW TEMPERATURES WILL BE IN THE 30S. HIGH TEMPERATURES
WILL RANGE FROM THE MID 40S TO AROUND 50.
LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY. WEAK TROF WITH SEVERAL
EMBEDDED SHORTWAVES OVER NEVADA WILL KEEP SHOWERS CONTINUING ACROSS
THE CWA SATURDAY NIGHT. MODELS HAVE A WEAK DIRTY RIDGE FOR ZONAL
FLOW OVER THE CWA SUNDAY THROUGH TUESDAY. WITH DOWNSLOPE CONDITIONS
DUE TO THE STRONG WESTERLY FLOW ALOFT...EXPECT SHOWERS WILL BE
MAINLY CONFINED TO THE WEST FACING SLOPES OF THE MOUNTAINS. THEN BY
WEDNESDAY...MODELS IN GENERAL AGREEMENT WITH BUILDING A RIDGE OVER
NEVADA AHEAD OF THE NEXT DIGGING UPSTREAM SYSTEM...THUS PUSHING THE
LOW LEVEL MOISTURE BRIEFLY NORTH OF NEVADA. WITH THE CWA UNDER A
ZONAL WESTERLY FLOW...TEMPERATURES WILL REMAIN 5 TO 10 DEGREES ABOVE
NORMAL THROUGH THE PERIOD.
AVIATION...RAIN SHOWERS...HEAVY AT TIMES...ARE EXPECTED TO
DEVELOP AT KWMC AND KTPH AROUND 11Z SPREADING ACROSS THE ENTIRE
AREA BY LATE THURSDAY MORNING. EXPECT POSSIBLE MVFR CONDITIONS IN
HEAVY SHOWERS FROM LOWERED CIGS/VIS. GUSTY WINDS TO 30 MPH WILL
DEVELOP BY THIS AFTERNOON.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
86/96
AREA FORECAST DISCUSSION
NWS TULSA OK
1132 PM CST WED FEB 26 2014
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
CLEAR SKIES AND LIGHT WINDS WILL REMAIN COMMON ACROSS EASTERN
OKLAHOMA AND NORTHWEST ARKANSAS OVERNIGHT TONIGHT AND INTO THE
AFTERNOON HOURS THURSDAY. A FRONTAL BOUNDARY IS EXPECTED TO MOVE
INTO THE REGION DURING THE DAY THURSDAY...WITH VARIABLE WIND
DIRECTIONS INTO THE AFTERNOON HOURS BEFORE A SOUTH SOUTHEASTERLY
WIND DEVELOPS. SCATTERED/BROKEN HIGHS CLOUDS LOOK TO MOVE IN
TOWARD THE END OF THE TAF PERIOD. VFR CONDITIONS ARE SHOULD
CONTINUE THROUGH THE PERIOD AT ALL TAF SITES.
&&
.PREV DISCUSSION... /ISSUED 941 PM CST WED FEB 26 2014/
DISCUSSION...
WITH CLEAR SKIES AND LIGHT WINDS...TEMPERATURES HAVE ALREADY
FALLEN TO NEAR THE FORECAST LOWS IN SOME PLACES. THE LATEST RUNS
OF THE HRRR HAVE SHOWN THIS TREND WELL...AND THEY SUGGEST THAT
TEMPERATURES WILL HOLD NEARLY STEADY FOR MUCH OF THE REST OF THE
NIGHT. A LIGHT WEST TO SOUTHWEST WIND MAY HOLD THE OFFICIAL
TEMPERATURE AT TUL UP SOME MOST OF THE NIGHT...BUT A WIND SHIFT TO
THE NORTH MAY ALLOW FOR A QUICK FALL AT SUNRISE TO THE FORECAST
LOWS. AS A RESULT...THE CURRENT FORECAST LOOKS GOOD AND NO UPDATE
IS NEEDED AT THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 21 50 38 58 / 0 0 20 40
FSM 21 51 33 53 / 0 0 10 40
MLC 19 53 40 62 / 0 0 10 30
BVO 16 49 31 53 / 0 0 20 40
FYV 14 45 29 48 / 0 0 10 50
BYV 19 44 28 45 / 0 0 0 50
MKO 19 50 34 58 / 0 0 10 40
MIO 18 45 30 49 / 0 0 10 50
F10 21 50 37 60 / 0 0 10 30
HHW 20 51 37 65 / 0 0 10 30
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...20
AREA FORECAST DISCUSSION
NWS NORMAN OK
1056 PM CST WED FEB 26 2014
.DISCUSSION...
06 TAF DISCUSSION BELOW.
&&
.AVIATION...
VFR CONDITIONS THROUGHOUT THE TAF PERIOD WITH HIGH AND MID CLOUDS
INCREASING THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 1003 PM CST WED FEB 26 2014/
DISCUSSION...
MINIMUM TEMPERATURES WERE LOWERED SLIGHTLY BASED ON THE RUC TO
BETTER REFLECT LOCAL CONDITIONS ON A DRY, LIGHT-WIND NIGHT.
OTHERWISE THE BIG WARM-UP TOMORROW AND FRIDAY IS UNCHANGED.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 16 54 37 67 / 0 0 10 10
HOBART OK 17 55 36 69 / 0 0 10 10
WICHITA FALLS TX 19 57 39 77 / 0 0 10 10
GAGE OK 20 55 36 64 / 0 0 10 10
PONCA CITY OK 15 46 32 59 / 0 0 20 20
DURANT OK 21 54 36 69 / 0 0 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
09/25/25
AREA FORECAST DISCUSSION
NWS PORTLAND OR
252 AM PST THU FEB 27 2014
.SYNOPSIS...A WEAK UPPER LOW JUST OFF THE SOUTH OREGON COAST EARLY
THIS MORNING WILL CONTINUE TO WEAKEN DURING THE DAY. A NARROW UPPER
LEVEL RIDGE DEVELOPS OVER THE FORECAST AREA TONIGHT. A COMPLEX
PATTERN DEVELOPS FRIDAY...WITH AN UPPER LOW OFF THE CENTRAL
CALIFORNIA COAST AND A COLD UPPER TROUGH IN CANADA. SOME OF THE COLD
CANADIAN AIR WILL SEEP SOUTH FROM THE CENTRAL WASHINGTON COLUMBIA
BASIN...REACHING THE COLUMBIA GORGE AND SOUTH WASHINGTON CASCADES
FRIDAY NIGHT. THIS COLD AIR LINGERS SATURDAY...FOR A THREAT OF
WINTER-TYPE PRECIPITATION TO THE CENTRAL COLUMBIA GORGE AND UPPER
HOOD RIVER VALLEY. MILDER WEST FLOW ALOFT FORCES THE COLD AIR EAST
BEGINNING SUNDAY. A WETTER AND MILDER PATTERN IS EXPECTED EARLY NEXT
WEEK.
&&
.SHORT TERM...THURSDAY THROUGH SATURDAY...LARGE-SCALE PATTERN EARLY
THIS MORNING INCLUDES A NARROW 500 MB RIDGE AXIS EXTENDING FROM
ALASKA THROUGH NWRN WA AND INTO NERN NV. THERE IS ALSO AN UPPER LOW
NEARING THE SRN OREGON COAST AND ANOTHER DEVELOPING LOW OUT AROUND
40N 150W. WATER VAPOR IMAGERY WOULD SUGGEST THAT THERE ARE TWO LOW
PRES CENTERS ASSOCIATED WITH THE TROUGH OFF THE SRN OREGON AND
CALIFORNIA COAST. STRONG JET WRAPPING AROUND AN APPARENT LOW CENTER
IN N CENTRAL CALIFORNIA...WITH ANOTHER CIRCULATION NEAR K4BK. DESPITE
DEEP SLY DIFFLUENT FLOW ALOFT PRECIP ACROSS THE FORECAST AREA HAS
BEEN RATHER MEAGER. KRTX DUAL-POL DOPPLER RADAR AT 10Z SHOWED A FEW
SHOWERS MOVING THROUGH THE SRN PART OF THE FORECAST AREA...PRIMARILY
THE CENTRAL OREGON COAST RANGE AND THE CENTRAL CASCADES AND
FOOTHILLS. THE 03Z HRRR COMPOSITE REFLECTIVITY LOOP VALID 10Z SEEMED
TO HAVE THE RIGHT IDEA BUT APPEARS TO BE A LITTLE OVERDONE.
MODELS STILL INSIST SOME SORT OF DEFORMATION ZONE WILL SET UP OVER
THE AREA THIS MORNING. THE UPPER LOW STALLS ALONG THE S OREGON COAST
TODAY AND FILLS. PRECIP WANES THIS AFTERNOON AND EVENING AS THE
DEFORMATION ZONE LOSES DEFINITION AND 500 MB HIGH PRES REBOUNDS. LEFT
CHANCE POPS 00Z-06Z FRI...WITH THE BEST CHANCES TO THE NORTH CLOSEST
TO WHATEVER IS LEFT OF THE DEFORMATION ZONE. COMPLICATED UPPER AIR
PATTERN EVOLVES LATER TONIGHT. GFS AND ECMWF HAVE A FAIRLY DEEP UPPER
LOW SITUATED NEAR 37N 132W AND A LARGE ELONGATED COLD UPPER TROUGH
OVER CENTRAL CANADA...WITH THE FORECAST AREA CAUGHT BETWEEN THESE TWO
FEATURES. COLD AIR ASSOCIATED WITH AN ARCTIC BOUNDARY ALONG THE
SLOPES OF THE ROCKIES STARTS TO SEEP INTO THE CENTRAL WASHINGTON
COLUMBIA BASIN LATE TONIGHT...BUT MORE SO FRI. ECMWF BRINGS MORE OF
THE COLD AIR SOUTHWARD ALONG THE ERN WA CASCADE SLOPES AND INTO THE
COLUMBIA GORGE. BY 00Z SAT THE ECMWF 0C 850 MB ISOTHERM IS NEAR KDLS
WHILE THE 0C GFS 850 ISOTHERM IS A LITTLE MORE NORTH.
ALL IN ALL...MUCH OF FRI WILL BE DRY. MOISTURE ASSOCIATED WITH THE
NRN CAL LOW STARTS TO WORK ITS WAY NORTHWARD LATE FRI AFTERNOON FOR A
MENTION OF SLIGHT CHANCE POPS ACROSS THE FAR SOUTH. THE PRIMARY
SHORT-TERM CONCERN WILL BE THE FRI NIGHT THROUGH SAT NIGHT PERIOD.
BOTH THE GFS AND ECMWF BRING A LITTLE MORE OF THE ARCTIC AIR THROUGH
THE COLUMBIA GORGE...WITH THE ECMWF A LITTLE MORE AGRESSIVE. THE
ECMWF HAS ABOUT -6C 850 MB TEMPS AT KDLS 12Z SAT WHILE THE GFS IS -2
TO -4C. BELIEVE THE NAM IS WAY TOO COLD AS A MODEL SOUNDING FOR KPDX
INDICATES SNOW SAT MORNING THEN TRANSITIONING TO -FZRA IN THE
AFTERNOON. GFS SOUNDING SEEMS MORE REALISTIC WITH POSSIBLY SOME
RAIN/SNOW MIX SAT MORNING THEN GOING TO ALL RAIN IN THE AFTERNOON.
NOT LOOKING AT MUCH IN THE WAY OF QPF FRI NIGHT AND SAT. TROUBLE
AREAS WILL BE FROM KCZK-K4S2 AND THE UPPER HOOD RIVER VALLEY.
WEISHAAR
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...ECMWF HANGS ON TO THE
COLD AIR MUCH LONGER THAN THE GFS. BY SUN MORNING THE GFS HAS THE
COLD AIR RETREATING TO THE EAST IN RESPONSE TO STRONG WLY FLOW ALOFT
TRYING TO PUSH INTO THE AREA. EVEN IF THE GFS IS TOO FAST ERADICATING
THE COLD AIR...BELIEVE THE SNOW AND ICE THREAT FOR THE CENTRAL GORGE
AND UPPER HOOD RIVER VALLEY ENDS LATE SUN OR SUN EVENING.
HOWEVER...PLENTY OF UNCERTAINTY WITH THIS PATTERN...BUT LATEST MODEL
TRENDS ARE SUGGESTING WHAT COLD AIR MAKES IT INTO THE GORGE WILL NOT
AS COLD OR PERSISTENT AS PREVIOUS RUNS DEPICTED. GUSTY EAST WIND WILL
CONTINUE TO FUNNEL THE COLD AIR FROM THE COLUMBIA BASIN EAST OF THE
CASCADES THROUGH THE GORGE LATE SATURDAY THROUGH SUN NIGHT. THE GFS
AND ECMWF HAVE MAJOR DISCREPANCIES REGARDING THE LOCATION OF THE MILD
WESTERLIES AND WHAT HAPPENS WITH THE COLD CANADIAN LOW. THE ECMWF
SHOWS THE COLD UPPER LOW RETROGRADING FURTHER WEST TO JUST N OF
VANCOUVER ISLAND BY 18Z MON WHILE THE GFS ATTEMPTS TO HAVE A FLAT
UPPER RIDGE BUILD OVER THE REGION. BIGGEST QUESTION IS HOW FAST THE
WESTERLIES BREAK THROUGH. ABOUT THE ONLY CONFIDENT DETAIL IS THAT THE
FIRST PART OF NEXT WEEK LOOKS RATHER WET. WEISHAAR
.AVIATION...12Z TAFS...FRONTAL SYSTEM APPROACHING FROM SOUTH IS
ONLY PRODUCING SPOTTY LIGHT RAIN AT THIS POINT...MAINLY NEAR KEUG.
AS A RESULT VFR CONDITIONS PREVAIL WITH CIGS GENERALLY ABOVE 5000
FEET. AREA OF STEADIER LIGHT RAIN IS EXPECTED TO SPREAD NORTH
ACROSS THE FORECAST AREA THIS MORNING...POSSIBLY RESULTING IN
BRIEF MVFR CONDITIONS. EAST WINDS CONTINUE TO GUST 20-30 KT NEAR
KTTD...THIS SHOULD COME TO AN END AS THE OCCLUDED FRONT PUSHES
NORTH ACROSS THE PDX METRO. AFTER THAT...LIGHT S-SW FLOW MAY HAVE
ENOUGH ONSHORE COMPONENT TO RESULT IN AREAS IFR ALONG THE COAST.
OTHERWISE RESIDUAL MOISTURE AND WEAK INSTABILITY WILL LEAD TO
AREAS OF MVFR INLAND THIS AFTERNOON WITH SCATTERED -SHRA...
TAPERING OFF THIS EVENING.
KPDX AND APPROACHES...VFR LIKELY TO PREVAIL THROUGH 16Z-18Z...
THEN INCREASING ODDS OF MVFR IN AREAS OF MORNING -RA AND SCATTERED
SHOWERS IN THE AFTERNOON. GUSTY EAST WINDS NEAR THE WEST END OF
THE COLUMBIA GORGE WILL EASE THROUGHOUT THE DAY. WEAGLE
&&
.MARINE...LOW PRESSURE OFF THE NORTHERN CALIFORNIA COAST CONTINUES
TO FILL AS IT DRIFTS NORTH INTO THE OREGON WATERS. LIGHT TO
MODERATE EAST WINDS WILL SHIFT SOUTHERLY BEHIND AN OCCLUDED FRONT
THIS MORNING...BUT WINDS SHOULD REMAIN MODERATE BEHIND THE FRONT.
THERE MAY BE A GUST OR TWO TO 25 KT...BUT LIKELY NOT WIDESPREAD
ENOUGH TO WARRANT A SMALL CRAFT ADVISORY. SEAS WILL BE A BIT
CONFUSED TODAY...WITH A COMBINATION OF LONGER PERIOD WESTERLY
SWELL AND SHORTER PERIOD SOUTHERLY SWELL. HOWEVER COMBINED SEA
HEIGHTS ARE EXPECTED TO REMAIN BELOW 10 FEET. SMALL CRAFT ADVISORY
FOR ROUGH BAR THIS AFTERNOON...MAINLY DUE TO THE VERY STRONG EBB
CURRENT ASSOCIATED WITH THE NEW MOON.
IN THE LONGER TERM...THE VERY ACTIVE PACIFIC STORM TRACK WILL
CONTINUE TO FOCUS ON CALIFORNIA. EVENTUALLY W-SW SWELL FROM ALL
THIS ACTIVITY WILL AFFECT OUR WATERS...LATER IN THE WEEKEND AND
INTO EARLY NEXT WEEK. WEAGLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM
1 PM TO 5 PM PST THIS AFTERNOON.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
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 STATE COLLEGE PA
517 PM EST THU FEB 27 2014
.SYNOPSIS...
A REINFORCING THE ARCTIC AIR MASS WILL SPREAD OVER PENNSYLVANIA
TONIGHT WITH BITTERLY COLD WIND CHILLS OVER MUCH OF CENTRAL PA
THROUGH FRIDAY MORNING. SOME MODERATION IS EXPECTED ON SATURDAY
AS HIGH PRESSURE MOVES EAST OF THE REGION...AND THE FRONT LIFTS
NORTHWARD. IT WILL WAGGLE SOUTH AGAIN ON SUNDAY AHEAD OF A
MOIST SOUTHERN STREAM STORM SYSTEM THAT IS EXPECTED TO MOVE SOUTH
OF PA ON MONDAY. SIGNIFICANT WINTRY PRECIPITATION IS EXPECTED
ACROSS THE REGION SUNDAY INTO MONDAY...FOLLOWED BY FAIR AND
CONTINUED COLD WEATHER FOR TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
MOST INTENSE/ORGANIZED SNOW SQUALL ACTIVITY HAS RAPIDLY LIFTED
INTO THE POCONO PLATEAU AND TOWARD THE CATSKILLS REGION NY BY MID
AFTERNOON...BUT NUMEROUS SNOW SHOWERS WITH BRIEF SNOW BURSTS
CONTINUE ACROSS CENTRAL PA THANKS TO STEEP LOW LEVEL LAPSE RATES
AND SFC BASED CAPES UP TO 200 J/KG. RUC13 AND NAM12 DIAGNOSTICS
INDICATE RAPID DISSIPATION OF SNOW SHOWERS THROUGH 21/22Z FOLLOWED
BY CLEARING FOR MUCH OF CENTRAL AND SOUTH CENTRAL PA AS HIGH
PRESSURE BUILDS IN FROM THE OHIO VALLEY. LAKE CLOUDS SHOULD HANG
INTO EARLY FRIDAY MORNING ACROSS THE NORTH AND ESPECIALLY NORTHWEST.
MAIN CONCERN TONIGHT IS FOR DANGEROUS WIND CHILLS...AS STRONG
WINDS COMBINE WITH FALLING TEMPS DURING THIS AFTERNOON AND
EVENING. GOING WIND CHILL ADVISORY IN GOOD SHAPE TONIGHT INTO
TOMORROW. BUFKIT SOUNDINGS SUPPORT GUSTS UP TO 40KTS.
MIN TEMPS TONIGHT WILL DROP WELL BELOW ZERO UP NORTH...WITH -10F
TO -15F EXPECTED. SINGLE DIGITS BELOW ZERO WILL AFFECT THE LAUREL
HIGHLANDS...CENTRAL MOUNTAINS...ENDLESS MOUNTAINS AND LYCOMING
VALLEY...ZERO TO 5 ABOVE ELSEWHERE ACROSS SOUTH CENTRAL MOUNTAINS
AND LOWER SUSQ. EXTREMELY COLD FOR THIS TIME OF YEAR...BUT NO
RECORD LOWS EXPECTED DUE TO A FRIGID MORNING BACK IN 1934.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
ARCTIC SFC HIGH PRESSURE WILL REMAIN THE MAIN PLAYER FRIDAY AND
FRIDAY NIGHT FOR PA...WITH THE SFC HIGH MOVING WELL OFFSHORE BY
SATURDAY MORNING INTRODUCING A BRIEF MODERATING SPELL FOR SATURDAY.
MOSTLY SUNNY SKIES WITH LIGHT SFC WINDS ARE EXPECTED ON SATURDAY...
WHICH WILL BE MUCH MORE TOLERABLE TO FRIDAY CONDITIONS.
ENSEMBLE MEAN 925TEMPS OF ARND -15C WILL SUPPORT MAX TEMPS NO
BETTER THAN THE TEENS TO NR 20F...ARND 25F BELOW NORMAL FOR LATE
FEBRUARY.
FRIDAY NIGHT SHOULD REMAIN DRY...BUT WITH SOME INCREASING HIGH
CLOUDS LATE IN THE RETURN FLOW AROUND THE DEPARTING OFFSHORE SFC
HIGH. RESULTING MIN TEMPS WILL BE SOME 15 TO AS MUCH AS 20F WARMER
SATURDAY MORNING.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
ON SAT...STORM OF INTEREST FOR LATE WEEKEND/EARLY NEXT WEEK WILL
BEGIN WORKING ITS WAY FROM THE CALIF COAST EASTWARD. OVER PA...
FAST AND NEARLY ZONAL FLOW ALOFT AS SPOKES OF COLDER AIR ROTATING
AROUND A LOW ANCHORED NEAR HUDSON BAY GET SHUNTED TO OUR NORTH.
ONE NOTABLE SHORTWAVE SLIDING EASTWARD ACROSS S CANADA WILL DRAG A
SURFACE COLD FRONT THROUGH PA SAT NIGHT. AHEAD OF THAT...SOME
MILDER AIR WILL WORK INTO THE STATE ALONG WITH PLENTY OF CLOUDS.
A BIT OF LIGHT SNOW ALSO POSS...EMPHASIS ON LIGHT AS QPF AT BEST
IS JUST A FEW HUNDREDTHS...AND CONFINED TO THE NW MTNS AS SW FLOW
OVERRUNS RETREATING ARCTIC AIR MASS.
NORTHERN STREAM SHORTWAVE PASSING N OF THE GRT LKS WILL PUSH A
DYING COLD FRONT THRU CENTRAL PA SAT NIGHT. SCT LIGHT SNOW MAY
ACCOMPANY PASSAGE OF THIS FRONT MAINLY OVR THE N MTNS...WHILE AIR
MASS ACTUALLY BECOMES MILD ENOUGH FOR EITHER -SHRA OR -SHSN OVER
SOUTH. QPF AGAIN REMAINS LIGHT...A TENTH OF AN INCH OR LESS AT
BEST ALONG NY BORDER. ERODING FRONTAL BOUNDARY BECOMES STATIONARY
NEAR THE MASON DIXON LINE...ALLOWING MILDER AIR TO REMAIN IN PLACE
SOUTH OF IT ACROSS PORTIONS OF S PA...WITH READINGS ONLY FALLING
TO ARND 32F IN THE LOWER SUSQ.
REMNANTS OF THIS OLD FRONTAL BOUNDARY COMBINED WITH SOUTHERN
STREAM ENERGY WILL BECOME THE FOCUS FOR MID RANGE. MODEL GUIDANCE
IN QUITE GOOD AGREEMENT ON A SOUTHERN STREAM DISTURBANCE LIFTING
TOWARD PA LATE IN THE WEEKEND. CONFIDENCE CONTINUES TO INCREASE IN
A SIGNIFICANT BOUT OF WINTRY PRECIP FOR MUCH OF CENTRAL PA LATER
SUNDAY INTO MONDAY...AS PLUME OF GULF OF MEX MOISTURE OVERRUNS A
QUASI-STATIONARY BNDRY JUST S OF THE MASON DIXON. BOTH GEFS AND
OPER EC/CMC CONTINUE TO SUGGEST THERE WILL BE A NARROW SWATH OF
GREATER THAN AN INCH PRECIP ACROSS CENTRAL OR SOUTHERN PA...MAYBE
SLIDING JUST A BIT FURTHER SOUTH THAN PREV RUNS. BEST CHC FOR
SIGNIFICANT SNOW APPEARS TO BE ACROSS CENTRAL/PARTS OF NORTHERN
PA...WITH A GREATER CHC OF A WINTRY MIX OR EVEN A PERIOD OF RAIN
IN THE SOUTH /AND MUCH LOWER SNOW ACCUMS/...BEFORE COLDER AIR
AT LOWER LEVELS BEGINS TO SLIDE IN FROM THE NORTH TOWARD THE END
OF THE EVENT BRINGING BETTER CHANCES FOR PRECIP TO END AS A PERIOD
OF SNOW ON MONDAY.
MIDWEEK WILL BRING FAIR AND COLD WX /AROUND 15F BELOW NORMAL ALONG
WITH MORNING LOWS BACK INTO SINGLE DIGITS/ AS LARGE SFC HIGH PRES
SYSTEM BUILDS SE TOWARDS PA FROM CENTRAL CANADA. LATE WEEK LOOKS
TO BRING A BIT OF RELIEF FROM THE VERY CHILLY WEATHER AS COLDER
AIR RETREATS BACK TO THE NORTH AS WARMER SOUTHWEST FLOW HELPS TO
NUDGE TEMPS BACK TOWARD...YET STILL SLIGHTLY BELOW...NORMAL.
HEADING INTO NEXT WEEKEND...GFS/ECMWF SUGGESTING ANOTHER SOUTHERN
STREAM WAVE PROGGED TO IMPACT MAINLY SOUTHEAST STATES BEFORE
SLIDING OFF CAROLINA COAST.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
AS EXPECTED...RATHER ACTIVE SNOW SHOWERS MADE IT INTO THE LOWER
SUSQUEHANNA VALLEY THIS AFT...JUST TOOK A LITTLE LONGER TO GET
THERE.
MAIN CHANGE TO 21Z TAF PACKAGE WAS TO KEEP MENTION OF SNOW SHOWERS
AND GUSTY WINDS FURTHER OUT TO 01Z NOW...INSTEAD OF 23Z.
MOST OF THE HEAVIER SNOW SHOWERS NOW ACROSS THE SOUTHERN PART OF
THE STATE.
EARLIER DISCUSSION BELOW.
SNOW SHOWERS WILL CONTINUE TO DISSIPATE THIS AFTERNOON AND EVENING
AS INSTABILITY DECREASES. GUSTY WINDS WILL PERSIST INTO EARLY
EVENING...CONDITIONS WILL IMPROVE SIGNIFICANTLY BY 00Z. DOWNSLOPE
FLOW IN THE WAKE OF THE FRONT SHOULD BRING ALL SITES E OF THE MTS
BACK TO VFR WHILE MVFR CIGS/OCNL -SHSN LINGER ACRS WRN SXNS.
SFC HIGH PRES BUILDS INTO THE REGION TNGT ALLOWING WINDS TO
SUBSIDE INTO FRI MORNING.
OUTLOOK...
SAT...VFR TRENDING LOWER INTO SAT NGT IN -SN.
SUN-MON...MVFR/IFR LKLY IN SN AND/OR MIXED PCPN.
TUE-WED...MVFR POSS NW...VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM EST FRIDAY FOR PAZ004>006-
010>012-017-018-024-033-037-041-042.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/RXR
AVIATION...DEVOIR/MARTIN/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
437 PM EST THU FEB 27 2014
.SYNOPSIS...
A REINFORCING THE ARCTIC AIR MASS WILL SPREAD OVER PENNSYLVANIA
TONIGHT WITH BITTERLY COLD WIND CHILLS OVER MUCH OF CENTRAL PA
THROUGH FRIDAY MORNING. SOME MODERATION IS EXPECTED ON SATURDAY
AS HIGH PRESSURE MOVES EAST OF THE REGION...AND THE FRONT LIFTS
NORTHWARD. IT WILL WAGGLE SOUTH AGAIN ON SUNDAY AHEAD OF A
MOIST SOUTHERN STREAM STORM SYSTEM THAT IS EXPECTED TO MOVE SOUTH
OF PA ON MONDAY. SIGNIFICANT WINTRY PRECIPITATION IS EXPECTED ACROSS
THE REGION SUNDAY INTO MONDAY...FOLLOWED BY FAIR AND CONTINUED
COLD WEATHER FOR TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
MOST INTENSE/ORGANIZED SNOW SQUALL ACTIVITY HAS RAPIDLY LIFTED
INTO THE POCONO PLATEAU AND TOWARD THE CATSKILLS REGION NY BY MID
AFTERNOON...BUT NUMEROUS SNOW SHOWERS WITH BRIEF SNOW BURSTS
CONTINUE ACROSS CENTRAL PA THANKS TO STEEP LOW LEVEL LAPSE RATES
AND SFC BASED CAPES UP TO 200 J/KG. RUC13 AND NAM12 DIAGNOSTICS
INDICATE RAPID DISSIPATION OF SNOW SHOWERS THROUGH 21/22Z FOLLOWED
BY CLEARING FOR MUCH OF CENTRAL AND SOUTH CENTRAL PA AS HIGH
PRESSURE BUILDS IN FROM THE OHIO VALLEY. LAKE CLOUDS SHOULD HANG
INTO EARLY FRIDAY MORNING ACROSS THE NORTH AND ESPECIALLY NORTHWEST.
MAIN CONCERN TONIGHT IS FOR DANGEROUS WIND CHILLS...AS STRONG
WINDS COMBINE WITH FALLING TEMPS DURING THIS AFTERNOON AND
EVENING. GOING WIND CHILL ADVISORY IN GOOD SHAPE TONIGHT INTO
TOMORROW. BUFKIT SOUNDINGS SUPPORT GUSTS UP TO 40KTS.
MIN TEMPS TONIGHT WILL DROP WELL BELOW ZERO UP NORTH...WITH -10F
TO -15F EXPECTED. SINGLE DIGITS BELOW ZERO WILL AFFECT THE LAUREL
HIGHLANDS...CENTRAL MOUNTAINS...ENDLESS MOUNTAINS AND LYCOMING
VALLEY...ZERO TO 5 ABOVE ELSEWHERE ACROSS SOUTH CENTRAL MOUNTAINS
AND LOWER SUSQ. EXTREMELY COLD FOR THIS TIME OF YEAR...BUT NO RECORD
LOWS EXPECTED DUE TO A FRIGID MORNING BACK IN 1934.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
ARCTIC SFC HIGH PRESSURE WILL REMAIN THE MAIN PLAYER FRIDAY AND
FRIDAY NIGHT FOR PA...WITH THE SFC HIGH MOVING WELL OFFSHORE BY
SATURDAY MORNING INTRODUCING A BRIEF MODERATING SPELL FOR SATURDAY.
MOSTLY SUNNY SKIES WITH LIGHT SFC WINDS ARE EXPECTED ON SATURDAY...
WHICH WILL BE MUCH MORE TOLERABLE TO FRIDAY CONDITIONS.
ENSEMBLE MEAN 925TEMPS OF ARND -15C WILL SUPPORT MAX TEMPS NO
BETTER THAN THE TEENS TO NR 20F...ARND 25F BELOW NORMAL FOR LATE
FEBRUARY.
FRIDAY NIGHT SHOULD REMAIN DRY...BUT WITH SOME INCREASING HIGH
CLOUDS LATE IN THE RETURN FLOW AROUND THE DEPARTING OFFSHORE SFC
HIGH. RESULTING MIN TEMPS WILL BE SOME 15 TO AS MUCH AS 20F WARMER
SATURDAY MORNING.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
ON SAT...STORM OF INTEREST FOR LATE WEEKEND/EARLY NEXT WEEK WILL
BEGIN WORKING ITS WAY FROM THE CALIF COAST EASTWARD. OVER PA...
FAST AND NEARLY ZONAL FLOW ALOFT AS SPOKES OF COLDER AIR ROTATING
AROUND A LOW ANCHORED NEAR HUDSON BAY GET SHUNTED TO OUR NORTH.
ONE NOTABLE SHORTWAVE SLIDING EASTWARD ACROSS S CANADA WILL DRAG A
SURFACE COLD FRONT THROUGH PA SAT NIGHT. AHEAD OF THAT...SOME
MILDER AIR WILL WORK INTO THE STATE ALONG WITH PLENTY OF CLOUDS.
A BIT OF LIGHT SNOW ALSO POSS...EMPHASIS ON LIGHT AS QPF AT BEST
IS JUST A FEW HUNDREDTHS...AND CONFINED TO THE NW MTNS AS SW FLOW
OVERRUNS RETREATING ARCTIC AIR MASS.
NORTHERN STREAM SHORTWAVE PASSING N OF THE GRT LKS WILL PUSH A
DYING COLD FRONT THRU CENTRAL PA SAT NIGHT. SCT LIGHT SNOW MAY
ACCOMPANY PASSAGE OF THIS FRONT MAINLY OVR THE N MTNS...WHILE AIR
MASS ACTUALLY BECOMES MILD ENOUGH FOR EITHER -SHRA OR -SHSN OVER
SOUTH. QPF AGAIN REMAINS LIGHT...A TENTH OF AN INCH OR LESS AT
BEST ALONG NY BORDER. ERODING FRONTAL BOUNDARY BECOMES STATIONARY
NEAR THE MASON DIXON LINE...ALLOWING MILDER AIR TO REMAIN IN PLACE
SOUTH OF IT ACROSS PORTIONS OF S PA...WITH READINGS ONLY FALLING
TO ARND 32F IN THE LOWER SUSQ.
REMNANTS OF THIS OLD FRONTAL BOUNDARY COMBINED WITH SOUTHERN
STREAM ENERGY WILL BECOME THE FOCUS FOR MID RANGE. MODEL GUIDANCE
IN QUITE GOOD AGREEMENT ON A SOUTHERN STREAM DISTURBANCE LIFTING
TOWARD PA LATE IN THE WEEKEND. CONFIDENCE CONTINUES TO INCREASE IN
A SIGNIFICANT BOUT OF WINTRY PRECIP FOR MUCH OF CENTRAL PA LATER
SUNDAY INTO MONDAY...AS PLUME OF GULF OF MEX MOISTURE OVERRUNS A
QUASI-STATIONARY BNDRY JUST S OF THE MASON DIXON. BOTH GEFS AND
OPER EC/CMC CONTINUE TO SUGGEST THERE WILL BE A NARROW SWATH OF
GREATER THAN AN INCH PRECIP ACROSS CENTRAL OR SOUTHERN PA...MAYBE
SLIDING JUST A BIT FURTHER SOUTH THAN PREV RUNS. BEST CHC FOR
SIGNIFICANT SNOW APPEARS TO BE ACROSS CENTRAL/PARTS OF NORTHERN
PA...WITH A GREATER CHC OF A WINTRY MIX OR EVEN A PERIOD OF RAIN
IN THE SOUTH /AND MUCH LOWER SNOW ACCUMS/...BEFORE COLDER AIR
AT LOWER LEVELS BEGINS TO SLIDE IN FROM THE NORTH TOWARD THE END
OF THE EVENT BRINGING BETTER CHANCES FOR PRECIP TO END AS A PERIOD
OF SNOW ON MONDAY.
MIDWEEK WILL BRING FAIR AND COLD WX /AROUND 15F BELOW NORMAL ALONG
WITH MORNING LOWS BACK INTO SINGLE DIGITS/ AS LARGE SFC HIGH PRES
SYSTEM BUILDS SE TOWARDS PA FROM CENTRAL CANADA. LATE WEEK LOOKS
TO BRING A BIT OF RELIEF FROM THE VERY CHILLY WEATHER AS COLDER
AIR RETREATS BACK TO THE NORTH AS WARMER SOUTHWEST FLOW HELPS TO
NUDGE TEMPS BACK TOWARD...YET STILL SLIGHTLY BELOW...NORMAL.
HEADING INTO NEXT WEEKEND...GFS/ECMWF SUGGESTING ANOTHER SOUTHERN
STREAM WAVE PROGGED TO IMPACT MAINLY SOUTHEAST STATES BEFORE
SLIDING OFF CAROLINA COAST.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
SNOW SHOWERS WILL CONTINUE TO DISSIPATE THIS AFTERNOON AND EVENING
AS INSTABILITY DECREASES. GUSTY WINDS WILL PERSIST INTO EARLY
EVENING...CONDITIONS WILL IMPROVE SIGNIFICANTLY BY 00Z. DOWNSLOPE
FLOW IN THE WAKE OF THE FRONT SHOULD BRING ALL SITES E OF THE MTS
BACK TO VFR WHILE MVFR CIGS/OCNL -SHSN LINGER ACRS WRN SXNS.
SFC HIGH PRES BUILDS INTO THE REGION TNGT ALLOWING WINDS TO
SUBSIDE INTO FRI MORNING.
OUTLOOK...
FRI...VFR.
SAT...VFR TRENDING LOWER INTO SAT NGT IN -SN.
SUN-MON...MVFR/IFR LKLY IN SN AND/OR MIXED PCPN.
TUE-WED...MVFR POSS NW...VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM EST FRIDAY FOR PAZ004>006-
010>012-017-018-024-033-037-041-042.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/RXR
AVIATION...DEVOIR/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
303 PM EST THU FEB 27 2014
.SYNOPSIS...
A REINFORCING THE ARCTIC AIR MASS WILL SPREAD OVER PENNSYLVANIA
TONIGHT WITH BITTERLY COLD WIND CHILLS OVER MUCH OF CENTRAL PA
THROUGH FRIDAY MORNING. SOME MODERATION IS EXPECTED ON SATURDAY
AS HIGH PRESSURE MOVES EAST OF THE REGION...AND THE FRONT LIFTS
NORTHWARD. IT WILL WAGGLE SOUTH AGAIN ON SUNDAY AHEAD OF A
MOIST SOUTHERN STREAM STORM SYSTEM THAT IS EXPECTED TO MOVE SOUTH
OF PA ON MONDAY. SIGNIFICANT WINTRY PRECIPITATION IS EXPECTED ACROSS
THE REGION SUNDAY INTO MONDAY...FOLLOWED BY FAIR AND CONTINUED
COLD WEATHER FOR TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
MOST INTENSE/ORGANIZED SNOW SQUALL ACTIVITY HAS RAPIDLY LIFTED
INTO THE POCONO PLATEAU AND TOWARD THE CATSKILLS REGION NY BY MID
AFTERNOON...BUT NUMEROUS SNOW SHOWERS WITH BRIEF SNOW BURSTS
CONTINUE ACROSS CENTRAL PA THANKS TO STEEP LOW LEVEL LAPSE RATES
AND SFC BASED CAPES UP TO 200 J/KG. RUC13 AND NAM12 DIAGNOSTICS
INDICATE RAPID DISSIPATION OF SNOW SHOWERS THROUGH 21/22Z FOLLOWED
BY CLEARING FOR MUCH OF CENTRAL AND SOUTH CENTRAL PA AS HIGH
PRESSURE BUILDS IN FROM THE OHIO VALLEY. LAKE CLOUDS SHOULD HANG
INTO EARLY FRIDAY MORNING ACROSS THE NORTH AND ESPECIALLY NORTHWEST.
MAIN CONCERN TONIGHT IS FOR DANGEROUS WIND CHILLS...AS STRONG
WINDS COMBINE WITH FALLING TEMPS DURING THIS AFTERNOON AND
EVENING. GOING WIND CHILL ADVISORY IN GOOD SHAPE TONIGHT INTO
TOMORROW. BUFKIT SOUNDINGS SUPPORT GUSTS UP TO 40KTS.
MIN TEMPS TONIGHT WILL DROP WELL BELOW ZERO UP NORTH...WITH -10F
TO -15F EXPECTED. SINGLE DIGITS BELOW ZERO WILL AFFECT THE LAUREL
HIGHLANDS...CENTRAL MOUNTAINS...ENDLESS MOUNTAINS AND LYCOMING
VALLEY...ZERO TO 5 ABOVE ELSEWHERE ACROSS SOUTH CENTRAL MOUNTAINS
AND LOWER SUSQ. EXTREMELY COLD FOR THIS TIME OF YEAR...BUT NO RECORD
LOWS EXPECTED DUE TO A FRIGID MORNING BACK IN 1934.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
ARCTIC SFC HIGH PRESSURE WILL REMAIN THE MAIN PLAYER FRIDAY AND
FRIDAY NIGHT FOR PA...WITH THE SFC HIGH MOVING WELL OFFSHORE BY
SATURDAY MORNING INTRODUCING A BRIEF MODERATING SPELL FOR SATURDAY.
MOSTLY SUNNY SKIES WITH LIGHT SFC WINDS ARE EXPECTED ON SATURDAY...
WHICH WILL BE MUCH MORE TOLERABLE TO FRIDAY CONDITIONS.
ENSEMBLE MEAN 925TEMPS OF ARND -15C WILL SUPPORT MAX TEMPS NO
BETTER THAN THE TEENS TO NR 20F...ARND 25F BELOW NORMAL FOR LATE
FEBRUARY.
FRIDAY NIGHT SHOULD REMAIN DRY...BUT WITH SOME INCREASING HIGH
CLOUDS LATE IN THE RETURN FLOW AROUND THE DEPARTING OFFSHORE SFC
HIGH. RESULTING MIN TEMPS WILL BE SOME 15 TO AS MUCH AS 20F WARMER
SATURDAY MORNING.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
DEEP UPPER TROF IS PROGGED TO RAPIDLY LIFT OUT BY SATURDAY...
ALLOWING MILDER AIR TO WORK INTO THE STATE. PLENTY OF CLOUDS
SHOULD ACCOMPANY THE RETURN OF MILDER WX SAT AND PERHAPS A BIT OF
VERY LGT SNOW...AS SOUTHERLY FLOW OVERRUNS RETREATING ARCTIC AIR
MASS. BLEND OF LATEST MED RANGE QPF SUGGEST ANY ACCUMS WOULD BE
VERY LIGHT AND CONFINED TO THE NW MTNS.
NORTHERN STREAM SHORTWAVE PASSING N OF THE GRT LKS WILL PUSH A
DYING COLD FRONT THRU CENTRAL PA SAT NIGHT. A FEW -SHSN MAY
ACCOMPANY PASSAGE OF THIS FRONT OVR THE N MTNS...WHILE AIR MASS
ACTUALLY BECOMES MILD ENOUGH FOR EITHER -SHRA OR -SHSN OVER SOUTH.
CONSALL AND OPER EC BOTH SUPPORT MILD TEMPS SAT NIGHT ACROSS
SOUTHERN PA...WITH READINGS ONLY FALLING TO ARND 32F.
FOCUS OF THE MED RANGE FCST REMAINS ON SOUTHERN STREAM DISTURBANCE
LIFTING TOWARD PA LATE IN THE WEEKEND. CONFIDENCE CONTINUES TO
INCREASE IN A SIGNIFICANT BOUT OF WINTRY PRECIP FOR MUCH OF
CENTRAL PA SUNDAY INTO MONDAY...AS PLUME OF GULF OF MEX MOISTURE
OVERRUNS A QUASI-STATIONARY BNDRY JUST S OF THE MASON DIXON. BOTH
GEFS AND OPER EC/CMC SUGGEST THERE WILL BE A NARROW SWATH OF
GREATER THAN AN INCH PRECIP ACROSS CENTRAL OR SOUTHERN PA. BEST
CHC FOR SIGNIFICANT SNOW STILL APPEARS TO BE ACROSS CENTRAL/NORTHERN
PA...WITH A GREATER CHC OF A WINTRY MIX OR RAIN IN THE SOUTH.
BULK OF MED RANGE GUIDANCE INDICATES FAIR AND COLD WX TUE/WED...AS
LG SFC HIGH PRES SYSTEM BUILDS SE TOWARDS PA FROM CENTRAL CANADA.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
SNOW SHOWERS WILL CONTINUE TO DISSIPATE THIS AFTERNOON AND EVENING
AS INSTABILITY DECREASES. GUSTY WINDS WILL PERSIST INTO EARLY
EVENING...CONDITIONS WILL IMPROVE SIGNIFICANTLY BY 00Z. DOWNSLOPE
FLOW IN THE WAKE OF THE FRONT SHOULD BRING ALL SITES E OF THE MTS
BACK TO VFR WHILE MVFR CIGS/OCNL -SHSN LINGER ACRS WRN SXNS.
SFC HIGH PRES BUILDS INTO THE REGION TNGT ALLOWING WINDS TO
SUBSIDE INTO FRI MORNING.
OUTLOOK...
FRI...VFR.
SAT...VFR TRENDING LOWER INTO SAT NGT IN -SN.
SUN-MON...MVFR/IFR LKLY IN SN AND/OR MIXED PCPN.
TUE-WED...MVFR POSS NW...VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM EST FRIDAY FOR PAZ004>006-
010>012-017-018-024-033-037-041-042.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD
AVIATION...DEVOIR/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
657 AM EST THU FEB 27 2014
.SYNOPSIS...
A SHARP COLD FRONT WILL SWEEP THROUGH THE AREA TODAY...REINFORCING
THE ARCTIC AIR MASS OVER PENNSYLVANIA. A SOUTHERN STREAM
SHORTWAVE WILL LIFT TOWARD PA LATE THIS WEEKEND. THE ASSOCIATED
SFC LOW WILL LIKELY TRACK JUST SOUTH OF PA...PRODUCING SIGNIFICANT
WINTRY PRECIPITATION ACROSS THE REGION SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NEAR TERM MDL DATA INDICATES A BIT OF LIGHT SNOW WILL WORK INTO
THE NW MTNS BY ARND DAWN...IN RESPONSE TO ARRIVAL OF SWRLY LL JET
AND ASSOC WEAK WAA. A SHARP UPPER TROF AND REINFORCING SHOT OF
ARCTIC AIR WILL BLAST THRU THE AREA LATER TODAY...ACCOMPANIED BY
SNOW SHOWERS AND SQUALLS...MAINLY OVR NORTHERN PA. STEEP LOWER
TROPOSPHERIC LAPSE RATES ALONG WITH A GOOD ISALLOBARIC COMPONENT
AND SFC BASED CAPES UP TO 150 J/KG POINT TOWARD THE LIKELIHOOD OF
SNOW SQUALLS LATE THIS MORNING AND AFTERNOON ACROSS THE NORTHERN
HALF OF THE STATE. LATEST RAP AND NAMPARA SIMULATED REFLECTIVITY
NOW PICKING UP ON THE SQUALL THREAT WITH A NARROW BAND OF HIGHER
RETURNS ALONG THE COLD FRONT...WHICH SHOULD ARRIVE OVER THE NW
MTNS BY LATE MORNING AND EXIT THE EASTERN COUNTIES BY 21Z. SFC
TEMPS SHOULD BE WELL BELOW FREEZING...SO THREAT OF A FLASH FREEZE
APPEARS MINIMAL. HOWEVER...LOW VISIBILITIES AND A QUICK INCH OR SO
OF ACCUMULATION IS LIKELY OVER AREAS ESPECIALLY NORTH OF I80.
THE OTHER CONCERN WILL BE DANGEROUS WCHILLS...AS STRONG WINDS
COMBINE WITH FALLING TEMPS DURING THE AFTN. STRONG SUBSIDENCE AND
SFC PRES RISES INDICATED DURING THE AFTN...WHEN BUFKIT SOUNDINGS
SUPPORT GUSTS TO NEAR 40KTS. HAVE ISSUED WIND CHILL ADVISORY FOR
THE ALLEGHENY PLATEAU STARTING LATE THIS AFTN...WHEN APPARENT
TEMPS BEGIN TO APPROACH -15F. MDL SOUNDINGS DO INDICATE THE
LIKELIHOOD OF A FEW GUSTS THIS AFTN IN EXCESS OF 40KTS...MAINLY
OVR THE LAURELS/SC MTNS. HOWEVER...BIG STORY WILL BE THE COLD...SO
WILL INCLUDE MENTION OF WGUSTS IN THE WCHILL ADV AND NOT ISSUE A
SEPARATE WIND ADV ATTM.
MAX TEMPS THIS AFTERNOON SHOULD RANGE FROM ONLY 10 ABOVE ACROSS
THE NW MTNS TO THE MID TO UPPER 20S SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CORE OF THE COLDEST AIR ROTATES THRU CENTRAL PA TONIGHT WITH 8H
TEMPS DIPPING TO BTWN -20C AND -24C. THIS BONE DRY ARCTIC AIR MASS
WILL GATHER LITTLE MOISTURE FROM THE MOSTLY FROZEN GRT LKS.
THUS...EXPECT VERY LITTLE IN THE WAY OF POST-FRONTAL SNOW
SHOWERS. HAVE INCLUDED ONLY A SLGHT CHC OF MEASURABLE SNOW THIS
EVENING ACROSS WARREN CO. THIS ARCTIC AIR MASS WILL BE ACCOMPANIED
BY A GUSTY NW WIND DURING THE EVENING. HOWEVER...ARRIVAL OF HIGH
PRES TOWARDS DAWN SHOULD CAUSE THE WIND TO RELENT. THE DIMINISHING
WIND...CLEARING SKIES AND SNOW COVER SHOULD ALLOW TEMPS TO FALL
WELL BLW ZERO ACROSS THE ALLEGHENY PLATEAU AND TO NEAR ZERO ACROSS
THE SUSQ VALLEY. NO RECORD LOWS EXPECTED DUE TO A FRIGID MORNING
BACK IN 1934.
MSUNNY SKIES AND LGT WIND ASSOC WITH SFC HIGH PRESSURE SYSTEM WILL
MAKE CONDITIONS FEEL LESS HARSH ON FRIDAY. HOWEVER...ENSEMBLE MEAN
925TEMPS OF ARND -15C SHOULD SUPPORT MAX TEMPS NO BETTER THAN THE
TEENS TO NR 20F...ARND 25F BELOW NORMAL FOR LATE FEBRUARY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
DEEP UPPER TROF IS PROGGED TO RAPIDLY LIFT OUT BY SATURDAY...ALLOWING
MILDER AIR TO WORK INTO THE STATE. PLENTY OF CLOUDS SHOULD
ACCOMPANY THE RETURN OF MILDER WX SAT AND PERHAPS A BIT OF VERY
LGT SNOW...AS SOUTHERLY FLOW OVERRUNS RETREATING ARCTIC AIR MASS.
BLEND OF LATEST MED RANGE QPF SUGGEST ANY ACCUMS WOULD BE VERY
LIGHT AND CONFINED TO THE NW MTNS.
NORTHERN STREAM SHORTWAVE PASSING N OF THE GRT LKS WILL PUSH A
DYING COLD FRONT THRU CENTRAL PA SAT NIGHT. A FEW -SHSN MAY
ACCOMPANY PASSAGE OF THIS FRONT OVR THE N MTNS...WHILE AIR MASS
ACTUALLY BECOMES MILD ENOUGH FOR EITHER -SHRA OR -SHSN OVER SOUTH.
CONSALL AND OPER EC BOTH SUPPORT MILD TEMPS SAT NIGHT ACROSS
SOUTHERN PA...WITH READINGS ONLY FALLING TO ARND 32F.
FOCUS OF THE MED RANGE FCST REMAINS ON SOUTHERN STREAM DISTURBANCE
LIFTING TOWARD PA LATE IN THE WEEKEND. CONFIDENCE CONTINUES TO
INCREASE IN A SIGNIFICANT BOUT OF WINTRY PRECIP FOR MUCH OF
CENTRAL PA SUNDAY INTO MONDAY...AS PLUME OF GULF OF MEX MOISTURE
OVERRUNS A QUASI-STATIONARY BNDRY JUST S OF THE MASON DIXON. BOTH
GEFS AND OPER EC/CMC SUGGEST THERE WILL BE A NARROW SWATH OF
GREATER THAN AN INCH PRECIP ACROSS CENTRAL OR SOUTHERN PA. BEST
CHC FOR SIGNIFICANT SNOW STILL APPEARS TO BE ACROSS CENTRAL/NORTHERN
PA...WITH A GREATER CHC OF A WINTRY MIX OR RAIN IN THE SOUTH.
BULK OF MED RANGE GUIDANCE INDICATES FAIR AND COLD WX TUE/WED...AS
LG SFC HIGH PRES SYSTEM BUILDS SE TOWARDS PA FROM CENTRAL CANADA.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
27/12Z...ARCTIC FRONT MOVG THRU NW OH WILL CONT TO SURGE EWD ACRS
THE AIRSPACE BY LATE THIS AFTN. -SHSN BREAKING OUT NOW ACRS NWRN PA
WITH VIS RUNNING BTWN 1-3SM. FINAL CHANGES FOR THE 12Z SCHEDULED
ISSUANCE INCLUDED INC WND GUSTS AND ADDING 15/16Z TEMPO FOR SNSQ
AT BFD..DROPPING VIS TO 1/4SM. THIS MAY OCCUR AT OTHER WRN/CNTRL
STIES BTWN 16-19Z.
27/09Z...VERY MINOR CHANGES TO TIMING OF SHSN/SNSQ ASSOCD WITH
ARCTIC FROPA...WHICH IS CURRENTLY NEAR DTW. MVFR CIGS INVADING
BFD WITH WINDS PICKING UP ACRS WRN SXNS.
27/06Z...VFR CONDITIONS EXPECTED THRU 12Z. ARCTIC FROPA WILL BLAST
THRU THE AIRSPACE BTWN 13-21Z ACCOMPANIED BY SNOW SHOWERS AND
LCL/BRIEF +SHSN/SNSQ. REDUCTIONS TO VIS /IFR CATG OR LOWER/ ARE
LKLY OVR THE WRN/CNTRL TAF SITES WITH THE LOWER VISBYS PERSISTING
THE LONGEST AT JST/BFD INTO THE AFTN. STRONG GUSTY WND SHFT FROM
WSW TO WNW WILL ALSO OCCUR WITH PEAK GUSTS AROUND 30KTS...WHICH
COULD CONTRIBUTE TO LOWER VIS IN AREAS OF BLSN. KEPT VIS AT MVFR
INTO THE MDT/LNS VCNTY BUT GIVEN SHARPNESS/INSTABILITY ALONG THE
REINFORCING ARCTIC FRONT..CANT RULE OUT A BRIEF IFR RESTRICTION
HERE. DOWNSLOPE FLOW IN THE WAKE OF THE FRONT SHOULD BRING ALL
SITES E OF THE MTS BACK TO VFR WHILE MVFR CIGS/OCNL -SHSN LINGER
ACRS WRN SXNS. SFC HIGH PRES BUILDS INTO THE REGION TNGT ALLOWING
WINDS TO SUBSIDE INTO FRI MORNING.
OUTLOOK...
FRI...VFR.
SAT...VFR TRENDING LOWER INTO SAT NGT IN -SN.
SUN-MON...MVFR/IFR LKLY IN SN AND/OR MIXED PCPN.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 3 PM THIS AFTERNOON TO 10 AM EST
FRIDAY FOR PAZ004>006-010>012-017-018-024-033-037-041-042.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
619 AM EST THU FEB 27 2014
.SYNOPSIS...
A SHARP COLD FRONT WILL SWEEP THROUGH THE AREA TODAY...REINFORCING
THE ARCTIC AIR MASS OVER PENNSYLVANIA. A SOUTHERN STREAM
SHORTWAVE WILL LIFT TOWARD PA LATE THIS WEEKEND. THE ASSOCIATED
SFC LOW WILL LIKELY TRACK JUST SOUTH OF PA...PRODUCING SIGNIFICANT
WINTRY PRECIPITATION ACROSS THE REGION SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NEAR TERM MDL DATA INDICATES A BIT OF LIGHT SNOW WILL WORK INTO
THE NW MTNS BY ARND DAWN...IN RESPONSE TO ARRIVAL OF SWRLY LL JET
AND ASSOC WEAK WAA. A SHARP UPPER TROF AND REINFORCING SHOT OF
ARCTIC AIR WILL BLAST THRU THE AREA LATER TODAY...ACCOMPANIED BY
SNOW SHOWERS AND SQUALLS...MAINLY OVR NORTHERN PA. STEEP LOWER
TROPOSPHERIC LAPSE RATES ALONG WITH A GOOD ISALLOBARIC COMPONENT
AND SFC BASED CAPES UP TO 150 J/KG POINT TOWARD THE LIKELIHOOD OF
SNOW SQUALLS LATE THIS MORNING AND AFTERNOON ACROSS THE NORTHERN
HALF OF THE STATE. LATEST RAP AND NAMPARA SIMULATED REFLECTIVITY
NOW PICKING UP ON THE SQUALL THREAT WITH A NARROW BAND OF HIGHER
RETURNS ALONG THE COLD FRONT...WHICH SHOULD ARRIVE OVER THE NW
MTNS BY LATE MORNING AND EXIT THE EASTERN COUNTIES BY 21Z. SFC
TEMPS SHOULD BE WELL BELOW FREEZING...SO THREAT OF A FLASH FREEZE
APPEARS MINIMAL. HOWEVER...LOW VISIBILITIES AND A QUICK INCH OR SO
OF ACCUMULATION IS LIKELY OVER AREAS ESPECIALLY NORTH OF I80.
THE OTHER CONCERN WILL BE DANGEROUS WCHILLS...AS STRONG WINDS
COMBINE WITH FALLING TEMPS DURING THE AFTN. STRONG SUBSIDENCE AND
SFC PRES RISES INDICATED DURING THE AFTN...WHEN BUFKIT SOUNDINGS
SUPPORT GUSTS TO NEAR 40KTS. HAVE ISSUED WIND CHILL ADVISORY FOR
THE ALLEGHENY PLATEAU STARTING LATE THIS AFTN...WHEN APPARENT
TEMPS BEGIN TO APPROACH -15F. MDL SOUNDINGS DO INDICATE THE
LIKELIHOOD OF A FEW GUSTS THIS AFTN IN EXCESS OF 40KTS...MAINLY
OVR THE LAURELS/SC MTNS. HOWEVER...BIG STORY WILL BE THE COLD...SO
WILL INCLUDE MENTION OF WGUSTS IN THE WCHILL ADV AND NOT ISSUE A
SEPARATE WIND ADV ATTM.
MAX TEMPS THIS AFTERNOON SHOULD RANGE FROM ONLY 10 ABOVE ACROSS
THE NW MTNS TO THE MID TO UPPER 20S SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CORE OF THE COLDEST AIR ROTATES THRU CENTRAL PA TONIGHT WITH 8H
TEMPS DIPPING TO BTWN -20C AND -24C. THIS BONE DRY ARCTIC AIR MASS
WILL GATHER LITTLE MOISTURE FROM THE MOSTLY FROZEN GRT LKS.
THUS...EXPECT VERY LITTLE IN THE WAY OF POST-FRONTAL SNOW
SHOWERS. HAVE INCLUDED ONLY A SLGHT CHC OF MEASURABLE SNOW THIS
EVENING ACROSS WARREN CO. THIS ARCTIC AIR MASS WILL BE ACCOMPANIED
BY A GUSTY NW WIND DURING THE EVENING. HOWEVER...ARRIVAL OF HIGH
PRES TOWARDS DAWN SHOULD CAUSE THE WIND TO RELENT. THE DIMINISHING
WIND...CLEARING SKIES AND SNOW COVER SHOULD ALLOW TEMPS TO FALL
WELL BLW ZERO ACROSS THE ALLEGHENY PLATEAU AND TO NEAR ZERO ACROSS
THE SUSQ VALLEY. NO RECORD LOWS EXPECTED DUE TO A FRIGID MORNING
BACK IN 1934.
MSUNNY SKIES AND LGT WIND ASSOC WITH SFC HIGH PRESSURE SYSTEM WILL
MAKE CONDITIONS FEEL LESS HARSH ON FRIDAY. HOWEVER...ENSEMBLE MEAN
925TEMPS OF ARND -15C SHOULD SUPPORT MAX TEMPS NO BETTER THAN THE
TEENS TO NR 20F...ARND 25F BELOW NORMAL FOR LATE FEBRUARY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
DEEP UPPER TROF IS PROGGED TO RAPIDLY LIFT OUT BY SATURDAY...ALLOWING
MILDER AIR TO WORK INTO THE STATE. PLENTY OF CLOUDS SHOULD
ACCOMPANY THE RETURN OF MILDER WX SAT AND PERHAPS A BIT OF VERY
LGT SNOW...AS SOUTHERLY FLOW OVERRUNS RETREATING ARCTIC AIR MASS.
BLEND OF LATEST MED RANGE QPF SUGGEST ANY ACCUMS WOULD BE VERY
LIGHT AND CONFINED TO THE NW MTNS.
NORTHERN STREAM SHORTWAVE PASSING N OF THE GRT LKS WILL PUSH A
DYING COLD FRONT THRU CENTRAL PA SAT NIGHT. A FEW -SHSN MAY
ACCOMPANY PASSAGE OF THIS FRONT OVR THE N MTNS...WHILE AIR MASS
ACTUALLY BECOMES MILD ENOUGH FOR EITHER -SHRA OR -SHSN OVER SOUTH.
CONSALL AND OPER EC BOTH SUPPORT MILD TEMPS SAT NIGHT ACROSS
SOUTHERN PA...WITH READINGS ONLY FALLING TO ARND 32F.
FOCUS OF THE MED RANGE FCST REMAINS ON SOUTHERN STREAM DISTURBANCE
LIFTING TOWARD PA LATE IN THE WEEKEND. CONFIDENCE CONTINUES TO
INCREASE IN A SIGNIFICANT BOUT OF WINTRY PRECIP FOR MUCH OF
CENTRAL PA SUNDAY INTO MONDAY...AS PLUME OF GULF OF MEX MOISTURE
OVERRUNS A QUASI-STATIONARY BNDRY JUST S OF THE MASON DIXON. BOTH
GEFS AND OPER EC/CMC SUGGEST THERE WILL BE A NARROW SWATH OF
GREATER THAN AN INCH PRECIP ACROSS CENTRAL OR SOUTHERN PA. BEST
CHC FOR SIGNIFICANT SNOW STILL APPEARS TO BE ACROSS CENTRAL/NORTHERN
PA...WITH A GREATER CHC OF A WINTRY MIX OR RAIN IN THE SOUTH.
BULK OF MED RANGE GUIDANCE INDICATES FAIR AND COLD WX TUE/WED...AS
LG SFC HIGH PRES SYSTEM BUILDS SE TOWARDS PA FROM CENTRAL CANADA.
&&
.AVIATION /11Z THURSDAY THROUGH MONDAY/...
27/09Z...VERY MINOR CHANGES TO TIMING OF SHSN/SNSQ ASSOCD WITH
ARCTIC FROPA...WHICH IS CURRENTLY NEAR DTW. MVFR CIGS INVADING
BFD WITH WINDS PICKING UP ACRS WRN SXNS.
27/06Z...VFR CONDITIONS EXPECTED THRU 12Z. ARCTIC FROPA WILL BLAST
THRU THE AIRSPACE BTWN 13-21Z ACCOMPANIED BY SNOW SHOWERS AND
LCL/BRIEF +SHSN/SNSQ. REDUCTIONS TO VIS /IFR CATG OR LOWER/ ARE
LKLY OVR THE WRN/CNTRL TAF SITES WITH THE LOWER VISBYS PERSISTING
THE LONGEST AT JST/BFD INTO THE AFTN. STRONG GUSTY WND SHFT FROM
WSW TO WNW WILL ALSO OCCUR WITH PEAK GUSTS AROUND 30KTS...WHICH
COULD CONTRIBUTE TO LOWER VIS IN AREAS OF BLSN. KEPT VIS AT MVFR
INTO THE MDT/LNS VCNTY BUT GIVEN SHARPNESS/INSTABILITY ALONG THE
REINFORCING ARCTIC FRONT..CANT RULE OUT A BRIEF IFR RESTRICTION
HERE. DOWNSLOPE FLOW IN THE WAKE OF THE FRONT SHOULD BRING ALL
SITES E OF THE MTS BACK TO VFR WHILE MVFR CIGS/OCNL -SHSN LINGER
ACRS WRN SXNS. SFC HIGH PRES BUILDS INTO THE REGION TNGT ALLOWING
WINDS TO SUBSIDE INTO FRI MORNING.
OUTLOOK...
FRI...VFR.
SAT...VFR TRENDING LOWER INTO SAT NGT IN -SN.
SUN-MON...MVFR/IFR LKLY IN SN AND/OR MIXED PCPN.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 3 PM THIS AFTERNOON TO 10 AM EST
FRIDAY FOR PAZ004>006-010>012-017-018-024-033-037-041-042.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
532 AM EST THU FEB 27 2014
.SYNOPSIS...
A SHARP COLD FRONT WILL SWEEP THROUGH THE AREA TODAY...REINFORCING
THE ARCTIC AIR MASS OVER PENNSYLVANIA. A SOUTHERN STREAM
SHORTWAVE WILL LIFT TOWARD PA LATE THIS WEEKEND. THE ASSOCIATED
SFC LOW WILL LIKELY TRACK JUST SOUTH OF PA...PRODUCING SIGNIFICANT
WINTRY PRECIPITATION ACROSS THE REGION SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NEAR TERM MDL DATA INDICATES A BIT OF LIGHT SNOW WILL WORK INTO
THE NW MTNS BY ARND DAWN...IN RESPONSE TO ARRIVAL OF SWRLY LL JET
AND ASSOC WEAK WAA. A SHARP UPPER TROF AND REINFORCING SHOT OF
ARCTIC AIR WILL BLAST THRU THE AREA LATER TODAY...ACCOMPANIED BY
SNOW SHOWERS AND SQUALLS...MAINLY OVR NORTHERN PA. STEEP LOWER
TROPOSPHERIC LAPSE RATES ALONG WITH A GOOD ISALLOBARIC COMPONENT
AND SFC BASED CAPES UP TO 150 J/KG POINT TOWARD THE LIKELIHOOD OF
SNOW SQUALLS LATE THIS MORNING AND AFTERNOON ACROSS THE NORTHERN
HALF OF THE STATE. LATEST RAP AND NAMPARA SIMULATED REFLECTIVITY
NOW PICKING UP ON THE SQUALL THREAT WITH A NARROW BAND OF HIGHER
RETURNS ALONG THE COLD FRONT...WHICH SHOULD ARRIVE OVER THE NW
MTNS BY LATE MORNING AND EXIT THE EASTERN COUNTIES BY 21Z. SFC
TEMPS SHOULD BE WELL BELOW FREEZING...SO THREAT OF A FLASH FREEZE
APPEARS MINIMAL. HOWEVER...LOW VISIBILITIES AND A QUICK INCH OR SO
OF ACCUMULATION IS LIKELY OVER AREAS ESPECIALLY NORTH OF I80.
THE OTHER CONCERN WILL BE DANGEROUS WCHILLS...AS STRONG WINDS
COMBINE WITH FALLING TEMPS DURING THE AFTN. STRONG SUBSIDENCE AND
SFC PRES RISES INDICATED DURING THE AFTN...WHEN BUFKIT SOUNDINGS
SUPPORT GUSTS TO NEAR 40KTS. HAVE ISSUED WIND CHILL ADVISORY FOR
THE ALLEGHENY PLATEAU STARTING LATE THIS AFTN...WHEN APPARENT
TEMPS BEGIN TO APPROACH -15F. MDL SOUNDINGS DO INDICATE THE
LIKELIHOOD OF A FEW GUSTS THIS AFTN IN EXCESS OF 40KTS...MAINLY
OVR THE LAURELS/SC MTNS. HOWEVER...BIG STORY WILL BE THE COLD...SO
WILL INCLUDE MENTION OF WGUSTS IN THE WCHILL ADV AND NOT ISSUE A
SEPARATE WIND ADV ATTM.
MAX TEMPS THIS AFTERNOON SHOULD RANGE FROM ONLY 10 ABOVE ACROSS
THE NW MTNS TO THE MID TO UPPER 20S SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CORE OF THE COLDEST AIR ROTATES THRU CENTRAL PA TONIGHT WITH 8H
TEMPS DIPPING TO BTWN -20C AND -24C. THIS BONE DRY ARCTIC AIR MASS
WILL GATHER LITTLE MOISTURE FROM THE MOSTLY FROZEN GRT LKS.
THUS...EXPECT VERY LITTLE IN THE WAY OF POST-FRONTAL SNOW
SHOWERS. HAVE INCLUDED ONLY A SLGHT CHC OF MEASURABLE SNOW THIS
EVENING ACROSS WARREN CO. THIS ARCTIC AIR MASS WILL BE ACCOMPANIED
BY A GUSTY NW WIND DURING THE EVENING. HOWEVER...ARRIVAL OF HIGH
PRES TOWARDS DAWN SHOULD CAUSE THE WIND TO RELENT. THE DIMINISHING
WIND...CLEARING SKIES AND SNOW COVER SHOULD ALLOW TEMPS TO FALL
WELL BLW ZERO ACROSS THE ALLEGHENY PLATEAU AND TO NEAR ZERO ACROSS
THE SUSQ VALLEY. NO RECORD LOWS EXPECTED DUE TO A FRIGID MORNING
BACK IN 1934.
MSUNNY SKIES AND LGT WIND ASSOC WITH SFC HIGH PRESSURE SYSTEM WILL
MAKE CONDITIONS FEEL LESS HARSH ON FRIDAY. HOWEVER...ENSEMBLE MEAN
925TEMPS OF ARND -15C SHOULD SUPPORT MAX TEMPS NO BETTER THAN THE
TEENS TO NR 20F...ARND 25F BELOW NORMAL FOR LATE FEBRUARY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
DEEP UPPER TROF IS PROGGED TO RAPIDLY LIFT OUT BY SATURDAY...ALLOWING
MILDER AIR TO WORK INTO THE STATE. PLENTY OF CLOUDS SHOULD
ACCOMPANY THE RETURN OF MILDER WX SAT AND PERHAPS A BIT OF VERY
LGT SNOW...AS SOUTHERLY FLOW OVERRUNS RETREATING ARCTIC AIR MASS.
BLEND OF LATEST MED RANGE QPF SUGGEST ANY ACCUMS WOULD BE VERY
LIGHT AND CONFINED TO THE NW MTNS.
NORTHERN STREAM SHORTWAVE PASSING N OF THE GRT LKS WILL PUSH A
DYING COLD FRONT THRU CENTRAL PA SAT NIGHT. A FEW -SHSN MAY
ACCOMPANY PASSAGE OF THIS FRONT OVR THE N MTNS...WHILE AIR MASS
ACTUALLY BECOMES MILD ENOUGH FOR EITHER -SHRA OR -SHSN OVER SOUTH.
CONSALL AND OPER EC BOTH SUPPORT MILD TEMPS SAT NIGHT ACROSS
SOUTHERN PA...WITH READINGS ONLY FALLING TO ARND 32F.
FOCUS OF THE MED RANGE FCST REMAINS ON SOUTHERN STREAM DISTURBANCE
LIFTING TOWARD PA LATE IN THE WEEKEND. CONFIDENCE CONTINUES TO
INCREASE IN A SIGNIFICANT BOUT OF WINTRY PRECIP FOR MUCH OF
CENTRAL PA SUNDAY INTO MONDAY...AS PLUME OF GULF OF MEX MOISTURE
OVERRUNS A QUASI-STATIONARY BNDRY JUST S OF THE MASON DIXON. BOTH
GEFS AND OPER EC/CMC SUGGEST THERE WILL BE A NARROW SWATH OF
GREATER THAN AN INCH PRECIP ACROSS CENTRAL OR SOUTHERN PA. BEST
CHC FOR SIGNIFICANT SNOW STILL APPEARS TO BE ACROSS CENTRAL/NORTHERN
PA...WITH A GREATER CHC OF A WINTRY MIX OR RAIN IN THE SOUTH.
BULK OF MED RANGE GUIDANCE INDICATES FAIR AND COLD WX TUE/WED...AS
LG SFC HIGH PRES SYSTEM BUILDS SE TOWARDS PA FROM CENTRAL CANADA.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
27/09Z...VERY MINOR CHANGES TO TIMING OF SHSN/SNSQ ASSOCD WITH
ARCTIC FROPA...WHICH IS CURRENTLY NEAR DTW. MVFR CIGS INVADING
BFD WITH WINDS PICKING UP ACRS WRN SXNS.
27/06Z...VFR CONDITIONS EXPECTED THRU 12Z. ARCTIC FROPA WILL BLAST
THRU THE AIRSPACE BTWN 13-21Z ACCOMPANIED BY SNOW SHOWERS AND
LCL/BRIEF +SHSN/SNSQ. REDUCTIONS TO VIS /IFR CATG OR LOWER/ ARE
LKLY OVR THE WRN/CNTRL TAF SITES WITH THE LOWER VISBYS PERSISTING
THE LONGEST AT JST/BFD INTO THE AFTN. STRONG GUSTY WND SHFT FROM
WSW TO WNW WILL ALSO OCCUR WITH PEAK GUSTS AROUND 30KTS...WHICH
COULD CONTRIBUTE TO LOWER VIS IN AREAS OF BLSN. KEPT VIS AT MVFR
INTO THE MDT/LNS VCNTY BUT GIVEN SHARPNESS/INSTABILITY ALONG THE
REINFORCING ARCTIC FRONT..CANT RULE OUT A BRIEF IFR RESTRICTION
HERE. DOWNSLOPE FLOW IN THE WAKE OF THE FRONT SHOULD BRING ALL
SITES E OF THE MTS BACK TO VFR WHILE MVFR CIGS/OCNL -SHSN LINGER
ACRS WRN SXNS. SFC HIGH PRES BUILDS INTO THE REGION TNGT ALLOWING
WINDS TO SUBSIDE INTO FRI MORNING.
OUTLOOK...
FRI...VFR.
SAT...VFR TRENDING LOWER INTO SAT NGT IN -SN.
SUN-MON...MVFR/IFR LKLY IN SN AND/OR MIXED PCPN.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 3 PM THIS AFTERNOON TO 10 AM EST
FRIDAY FOR PAZ004>006-010>012-017-018-024-033-037-041-042.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
527 AM EST THU FEB 27 2014
.SYNOPSIS...
A SHARP COLD FRONT WILL SWEEP THROUGH THE AREA TODAY...REINFORCING
THE ARCTIC AIR MASS OVER PENNSYLVANIA. A SOUTHERN STREAM
SHORTWAVE WILL LIFT TOWARD PA LATE THIS WEEKEND. THE ASSOCIATED
SFC LOW WILL LIKELY TRACK JUST SOUTH OF PA...PRODUCING SIGNIFICANT
WINTRY PRECIPITATION ACROSS THE REGION SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NEAR TERM MDL DATA INDICATES A BIT OF LIGHT SNOW WILL WORK INTO
THE NW MTNS BY ARND DAWN...IN RESPONSE TO ARRIVAL OF SWRLY LL JET
AND ASSOC WEAK WAA. A SHARP UPPER TROF AND REINFORCING SHOT OF
ARCTIC AIR WILL BLAST THRU THE AREA LATER TODAY...ACCOMPANIED BY
SNOW SHOWERS AND SQUALLS...MAINLY OVR NORTHERN PA. STEEP LOWER
TROPOSPHERIC LAPSE RATES ALONG WITH A GOOD ISALLOBARIC COMPONENT
AND SFC BASED CAPES UP TO 150 J/KG POINT TOWARD THE LIKELIHOOD OF
SNOW SQUALLS LATE THIS MORNING AND AFTERNOON ACROSS THE NORTHERN
HALF OF THE STATE. LATEST RAP AND NAMPARA SIMULATED REFLECTIVITY
NOW PICKING UP ON THE SQUALL THREAT WITH A NARROW BAND OF HIGHER
RETURNS ALONG THE COLD FRONT...WHICH SHOULD ARRIVE OVER THE NW
MTNS BY LATE MORNING AND EXIT THE EASTERN COUNTIES BY 21Z. SFC
TEMPS SHOULD BE WELL BELOW FREEZING...SO THREAT OF A FLASH FREEZE
APPEARS MINIMAL. HOWEVER...LOW VISIBILITIES AND A QUICK INCH OR SO
OF ACCUMULATION IS LIKELY OVER AREAS ESPECIALLY NORTH OF I80.
THE OTHER CONCERN WILL BE DANGEROUS WCHILLS...AS STRONG WINDS
COMBINE WITH FALLING TEMPS DURING THE AFTN. STRONG SUBSIDENCE AND
SFC PRES RISES INDICATED DURING THE AFTN...WHEN BUFKIT SOUNDINGS
SUPPORT GUSTS TO NEAR 40KTS. HAVE ISSUED WIND CHILL ADVISORY FOR
THE ALLEGHENY PLATEAU STARTING LATE THIS AFTN...WHEN APPARENT
TEMPS BEGIN TO APPROACH -15F. MDL SOUNDINGS DO INDICATE THE
LIKELIHOOD OF A FEW GUSTS THIS AFTN IN EXCESS OF 40KTS...MAINLY
OVR THE LAURELS/SC MTNS. HOWEVER...BIG STORY WILL BE THE COLD...SO
WILL INCLUDE MENTION OF WGUSTS IN THE WCHILL ADV AND NOT ISSUE A
SEPARATE WIND ADV ATTM.
MAX TEMPS THIS AFTERNOON SHOULD RANGE FROM ONLY 10 ABOVE ACROSS
THE NW MTNS TO THE MID TO UPPER 20S SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CORE OF THE COLDEST AIR ROTATES THRU CENTRAL PA TONIGHT WITH 8H
TEMPS DIPPING TO BTWN -20C AND -24C. THIS BONE DRY ARCTIC AIR MASS
WILL GATHER LITTLE MOISTURE FROM THE MOSTLY FROZEN GRT LKS.
THUS...EXPECT VERY LITTLE IN THE WAY OF POST-FRONTAL SNOW
SHOWERS. HAVE INCLUDED ONLY A SLGHT CHC OF MEASURABLE SNOW THIS
EVENING ACROSS WARREN CO. THIS ARCTIC AIR MASS WILL BE ACCOMPANIED
BY A GUSTY NW WIND DURING THE EVENING. HOWEVER...ARRIVAL OF HIGH
PRES TOWARDS DAWN SHOULD CAUSE THE WIND TO RELENT. THE DIMINISHING
WIND...CLEARING SKIES AND SNOW COVER SHOULD ALLOW TEMPS TO FALL
WELL BLW ZERO ACROSS THE ALLEGHENY PLATEAU AND TO NEAR ZERO ACROSS
THE SUSQ VALLEY. NO RECORD LOWS EXPECTED DUE TO A FRIGID MORNING
BACK IN 1934.
MSUNNY SKIES AND LGT WIND ASSOC WITH SFC HIGH PRESSURE SYSTEM WILL
MAKE CONDITIONS FEEL LESS HARSH ON FRIDAY. HOWEVER...ENSEMBLE MEAN
925TEMPS OF ARND -15C SHOULD SUPPORT MAX TEMPS NO BETTER THAN THE
TEENS TO NR 20F...ARND 25F BELOW NORMAL FOR LATE FEBRUARY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
DEEP UPPER TROF IS PROGGED TO RAPIDLY LIFT OUT BY SATURDAY...ALLOWING
MILDER AIR TO WORK INTO THE STATE. PLENTY OF CLOUDS SHOULD
ACCOMPANY THE RETURN OF MILDER WX SAT AND PERHAPS A BIT OF VERY
LGT SNOW...AS SOUTHERLY FLOW OVERRUNS RETREATING ARCTIC AIR MASS.
BLEND OF LATEST MED RANGE QPF SUGGEST ANY ACCUMS WOULD BE VERY
LIGHT AND CONFINED TO THE NW MTNS.
NORTHERN STREAM SHORTWAVE PASSING N OF THE GRT LKS WILL PUSH A
DYING COLD FRONT THRU CENTRAL PA SAT NIGHT. A FEW -SHSN MAY
ACCOMPANY PASSAGE OF THIS FRONT OVR THE N MTNS...WHILE AIR MASS
ACTUALLY BECOMES MILD ENOUGH FOR EITHER -SHRA OR -SHSN OVER SOUTH.
CONSALL AND OPER EC BOTH SUPPORT MILD TEMPS SAT NIGHT ACROSS
SOUTHERN PA...WITH READINGS ONLY FALLING TO ARND 32F.
FOCUS OF THE MED RANGE FCST REMAINS ON SOUTHERN STREAM DISTURBANCE
LIFTING TOWARD PA LATE IN THE WEEKEND. CONFIDENCE CONTINUES TO
INCREASE IN A SIGNIFICANT BOUT OF WINTRY PRECIP FOR MUCH OF
CENTRAL PA SUNDAY INTO MONDAY...AS PLUME OF GULF OF MEX MOISTURE
OVERRUNS A QUASI-STATIONARY BNDRY JUST S OF THE MASON DIXON. BOTH
GEFS AND OPER EC/CMC SUGGEST THERE WILL BE A NARROW SWATH OF
GREATER THAN AN INCH PRECIP ACROSS CENTRAL OR SOUTHERN PA. BEST
CHC FOR SIGNIFICANT SNOW STILL APPEARS TO BE ACROSS CENTRAL/NORTHERN
PA...WITH A GREATER CHC OF A WINTRY MIX OR RAIN IN THE SOUTH.
BULK OF MED RANGE GUIDANCE INDICATES FAIR AND COLD WX TUE/WED...AS
LG SFC HIGH PRES SYSTEM BUILDS SE TOWARDS PA FROM CENTRAL CANADA.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
27/06Z...VFR CONDITIONS EXPECTED THRU 12Z. ARCTIC FROPA WILL BLAST
THRU THE AIRSPACE BTWN 13-21Z ACCOMPANIED BY SNOW SHOWERS AND
LCL/BRIEF +SHSN/SNSQ. REDUCTIONS TO VIS /IFR CATG OR LOWER/ ARE
LKLY OVR THE WRN/CNTRL TAF SITES WITH THE LOWER VISBYS PERSISTING
THE LONGEST AT JST/BFD INTO THE AFTN. STRONG GUSTY WND SHFT FROM
WSW TO WNW WILL ALSO OCCUR WITH PEAK GUSTS AROUND 30KTS...WHICH
COULD CONTRIBUTE TO LOWER VIS IN AREAS OF BLSN. KEPT VIS AT MVFR
INTO THE MDT/LNS VCNTY BUT GIVEN SHARPNESS/INSTABILITY ALONG THE
REINFORCING ARCTIC FRONT..CANT RULE OUT A BRIEF IFR RESTRICTION
HERE. DOWNSLOPE FLOW IN THE WAKE OF THE FRONT SHOULD BRING ALL
SITES E OF THE MTS BACK TO VFR WHILE MVFR CIGS/OCNL -SHSN LINGER
ACRS WRN SXNS. SFC HIGH PRES BUILDS INTO THE REGION TNGT ALLOWING
WINDS TO SUBSIDE INTO FRI MORNING.
OUTLOOK...
FRI...VFR.
SAT...VFR TRENDING LOWER INTO SAT NGT IN -SN.
SUN-MON...MVFR/IFR LKLY IN SN AND/OR MIXED PCPN.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 3 PM THIS AFTERNOON TO 10 AM EST
FRIDAY FOR PAZ004>006-010>012-017-018-024-033-037-041-042.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
624 AM EST THU FEB 27 2014
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH FRIDAY...BEFORE AN
UPPER LEVEL DISTURBANCE CROSSES THE FROM THE WEST ON SATURDAY. ANOTHER
WARMING AREA OF HIGH PRESSURE WILL BUILD INTO THE AREA LATE SATURDAY
AND LINGER UNTIL A COLD FRONT APPROACHES ON MONDAY AND BRINGS
WIDESPREAD PRECIPITATION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM EST...SFC FRONT HAS PUSHED WELL SOUTH OF THE CWFA
BRINGING DEWPOINTS INTO THE LOWER 20S AND TEENS AT MOST OBS SITES.
VALUES HAVE BEEN STEADY OVER THE PAST COUPLE HOURS BUT SHOULD DROP
ONCE AGAIN AFTER DAYBREAK WITH MIXING GETTING UNDERWAY.
PATCHY LOW STRATUS ARE PRESENT OVER THE ERN UPSTATE AND THE SE SIDE
OF THE CHARLOTTE METRO...BUT ARE BEING FORCED SOUTH/EAST BY THE
DRYING COMING FROM THE NORTH AND THE LIGHT SWLY LLVL FLOW. THESE
HAVE BEEN REASONABLY WELL HANDLED BY THE HRRR OVERNIGHT...AND THIS
MODEL INDICATES THEY WILL DIMINISH RAPIDLY AFTER SUNRISE.
WATER VAPOR IMAGERY SHOWS BROAD TROUGH HAS DIPPED THRU THE AREA WITH
VERY DRY MID-UPPER LEVELS. THIS WILL RESULT IN CLEAR SKIES LASTING
THRU THE DAY. AS THIS WILL COMBINE WITH SOME DEGREE OF
DOWNSLOPING...HAVE LEANED TEMPS IN FAVOR OF BIAS CORRECTED MOS BOTH
TODAY AND TONIGHT.
06Z MODELS FAVOR SLIGHTLY LIGHTER WINDS TODAY WHICH LEADS THEM TO
ALSO FAVOR SLIGHTLY WARMER TEMPERATURES...BUT I THINK CURRENT VALUES
LOOK GOOD BEING ON THE WARM END ALREADY. THE IMPACT ON THE FIRE WX
FCST WOULD BE MINIMAL ANYWAY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 200 AM EST THURSDAY...SFC HIGH PRESSURE WILL BUILD ACROSS THE
DELMARVA REGION DURING THE DAY ON FRIDAY...WITH A PRONOUNCED WEDGE
RIDGE EXTENDED SOUTHWEST ALONG THE EAST SLOPES OF THE BLUE RIDGE. AS
THE AIRMASS WILL BE VERY DRY OVER THE REGION...NO CLOUD COVER IS
EXPECTED TO ACCOMPANY THE COLD AIR DAMMING DURING THE DAY ON
FRIDAY...THOUGH THERE WILL BE SOME INCREASING HIGH CLOUDS LATE IN
THE DAY ASSOCIATED WITH AN APPROACHING SHORT WAVE. EVEN WITH SUNNY
SKIES...HIGH TEMPERATURES SHOULD RUN AROUND 10 DEGREES BELOW NORMAL.
A COMPACT...STRONGLY ADVECTIVE SHORT WAVE WILL CROSS THE REGION
FRIDAY NIGHT AND EARLY SATURDAY. THE MID LEVEL ASCENT AND FORCING
WITH THE WAVE IS IMPRESSIVE...THOUGH THE BAND OF FORCING IS RATHER
NARROW. THE DRY LLVLS WILL TAKE A WHILE TO SATURATE. HOWEVER...
STRONG LLVL UPGLIDE WILL DEVELOP OVERNIGHT OVER THE NE PIEDMONT OF
SC AND THE WRN PIEDMONT OF NC. THIS WILL HELP TO SATURATE THE LLVLS
AND WILL LIKELY CONTRIBUTE TO HIGHER PCPN AMOUNTS IN THIS AREA. EVEN
SO...THE SREF MEAN FOR THE PIEDMONT ZONES IS AROUND A TENTH OF AN
INCH OF LIQUID. THE NC MTNS SHOULD ALSO SEE MORE PCPN FOR THE SIMPLE
FACT THAT THEY ARE HIGHER AND THERE WON/T BE AS MUCH DRY LLVL AIR TO
OVERCOME.
THE PCPN SHOULD FALL AS LIGHT SNOW INITIALLY OVER THE NC MTNS AND
NORTH OF I-40...TRANSITIONING TO A PERIOD OF FREEZING RAIN BEFORE
ENDING AROUND SUNRISE. MUCH LIKE THE PREVIOUS SHIFT...MY SNOW
AMOUNTS ARE BELOW ADVISORY CRITERIA OVER THE NC MTNS AND WRN
FOOTHILLS. FREEZING RAIN ACCUMULATIONS REMAIN QUITE
LIGHT...GENERALLY A COUPLE HUNDREDTHS OF AN INCH ACROSS THE CENTRAL
NC MTNS AND THE NC FOOTHILLS AND THE PIEDMONT ZONES NORTH OF
CHARLOTTE. AS THE PCPN AMOUNTS ARE LOOKING A LITTLE HEAVIER OVER THE
ERN ZONES...IT IS POSSIBLE THAT A FREEZING RAIN OR WINTER WX
ADVISORY MAY BE NEEDED FRI NIGHT FOR ICY SPOTS PRIMARILY ON ELEVATED
SFCS. SINCE MY CONFIDENCE OF AN ADVISORY IS IN THE 30 PERCENT
RANGE...I/LL ADD A MENTION OF THIS TO THE HWO.
FINALLY...WITH HIGH PRESSURE OVERHEAD SATURDAY NIGHT AND A MOIST
BOUNDARY LAYER...BUFKIT SOUNDINGS STRONGLY IMPLY THAT FOG WILL
DEVELOP ACROSS MUCH OF THE REGION.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 2 AM EST THURSDAY...THE MEDIUM RANGE FCST PICKS UP AT 12Z ON
SUNDAY WITH UPPER RIDGING OVER THE GULF OF MEXICO AND SE CONUS AND A
SOUTHERN STREAM UPPER TROF OVER THE SW CONUS. AS WE MOVE INTO
MONDAY...HEIGHTS BEGIN TO LOWER AGAIN AS THE UPPER TROF APPROACHES
THE FCST AREA AND EVENTUALLY PHASES BACK WITH THE NORTHERN STREAM BY
LATE MONDAY. THE MODELS INDICATE THAT SOME DEGREE OF UPPER TROFINESS
WILL MAINTAIN ITSELF OVER THE REGION THRU TUES AND INTO WED WITH THE
LATEST 00Z RUN OF THE GFS BEING SLOWER TO LIFT THE TROF ON WED AND
MAINTAINING A MORE AMPLIFIED SYSTEM COMPARED TO THE ECMWF. THE NEXT
FEATURE OF INTEREST APPEARS TO BE ANOTHER SOUTHERN STREAM H5
SHORTWAVE THAT APPROACHES THE CWFA BY THE END OF THE MEDIUM RANGE
NEXT THURS.
AT THE SFC...THE MODELS APPEAR TO BE COMING INTO BETTER AGREEMENT
WITH REGARDS TO THE EVOLUTION OF THE SYNOPTIC PATTERN ESPECIALLY FOR
THE LATTER HALF OF THE MEDIUM RANGE. WEAK BERMUDA HIGH PRESSURE WILL
BE CENTERED TO OUR EAST ON SUN WITH WEAK AND WARMING SLY LOW LVL
FLOW. BY EARLY MON...THE MODELS SPIN UP A LOW OVER THE SOUTHERN MISS
RIVER VALLEY AND MOVE IT OVER THE CWFA BY MON AFTERNOON AND THEN
WELL OFFSHORE BY EARLY TUES. IN THE LOWS WAKE...DRIER CANADIAN HIGH
PRESSURE SPREADS OVER THE REGION ON TUES AND REMAINS IN PLACE THRU
WED. TEMPS WILL START OUT WELL ABOVE NORMAL ON SUNDAY WITH HIGHS IN
THE UPPER 60S FOR THE LOWER ELEVATIONS AND UPPER 50S TO MID 60S FOR
THE HIGHER TERRAIN. BY WED...I ANTICIPATE VALUES WILL COOL BACK DOWN
BELOW CLIMATOLOGY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AT KCLT...LOW VFR STRATUS ARE EXPECTED TO QUICKLY DISSIPATE ONCE THE
SUN FALLS ON THE CLOUDS AND MIXING GETS GOING...WITH ALL TRACE OF
THEM GONE BY 15Z. MAIN CONCERN OTHERWISE IS WINDS...ALSO BEING
AFFECTED BY THE LEE TROF TODAY. WINDS STARTING OUT NE EARLY THIS
MRNG WOULD THEN FAVOR NW QUADRANT AFTER DIURNAL MIXING BEGINS...BUT
THE TROF IS LIKELY TO KEEP THEM BACKED TO WNW...POSSIBLY GOING WSW
AT TIMES AROUND MIDDAY. THEY SHOULD VEER TO NORTHERLY AGAIN TONIGHT.
ELSEWHERE...SKC EXCEPT FOR STRATUS OVER THE LOWER PIEDMONT WHICH
WILL DISSIPATE BY MID MORNING. WINDS WILL PREVAIL N TO NW THIS MRNG
BUT STAND TO BE AFFECTED BY LEE TROF OVER THE PIEDMONT
TODAY...BRINGING THEM SWLY FOR A TIME. FREQUENT GUSTS OF 25-30 KT
LIKELY AT HIGH MTN ELEVATIONS. SOME GUSTING LIKELY AT KAVL/KHKY
ALSO...THOUGH REMAINING MORE MODERATE AND LESS FREQUENT. GUSTS WOULD
FAVOR NWLY AT ALL SITES. LIGHTER NORTHERLY WINDS WILL RETURN THIS
EVENING.
OUTLOOK...VFR THRU FRIDAY. PRECIPITATION AND SOME RESTRICTIONS ARE
POSSIBLE BEGINNING LATE FRIDAY NIGHT...WITH A LIGHT WINTRY MIX
RESULTING MAINLY OVER WRN NC SATURDAY. VFR CONDITIONS SHOULD RETURN
SUNDAY...BUT A FRONTAL SYSTEM WILL LIKELY BRING WIDESPREAD SHOWERS
AND SOME RESTRICTIONS MONDAY.
CONFIDENCE TABLE...
11-17Z 17-23Z 23-05Z 05-11Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.FIRE WEATHER...
FIRE DANGER STATEMENT WILL REMAIN IN EFFECT TODAY WITH RH VALUES
DIPPING WELL INTO THE TEENS AND MODERATE WINDS THROUGHOUT THE AREA.
WINDS ARE PARTICULARLY CONCERNING ONLY IN THE NRN MTNS...WHERE 850MB
FLOW IS A BIT STRONGER. RIDGETOPS MIGHT SEE SUSTAINED SPEEDS 30-35
MPH...WITH GUSTS TO THAT RANGE EVEN IN LOWER ELEVATIONS. SOME
GUSTING LIKELY THROUGHOUT THE MTNS/FOOTHILLS...UP TO AROUND 20 MPH.
COORDINATION WITH FIRE AGENCIES BY DAY SHIFT TODAY MAY RESULT IN RED
FLAG WARNING BEING ISSUED...ESPECIALLY ALONG THE BLUE RIDGE NORTH OF
THE FRENCH BROAD VALLEY.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...WIMBERLEY
SHORT TERM...MCAVOY
LONG TERM...JPT
AVIATION...WIMBERLEY
FIRE WEATHER...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
315 AM EST THU FEB 27 2014
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH FRIDAY...BEFORE AN
UPPER LEVEL DISTURBANCE CROSSES THE FROM THE WEST ON SATURDAY. ANOTHER
WARMING AREA OF HIGH PRESSURE WILL BUILD INTO THE AREA LATE SATURDAY
AND LINGER UNTIL A COLD FRONT APPROACHES ON MONDAY AND BRINGS
WIDESPREAD PRECIPITATION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM EST...SFC FRONT HAS NOW PUSHED SOUTH OF THE CWFA
WITH DEWPOINTS HAVING DROPPED INTO THE TEENS OVER MOST OF OUR OBS
SITES...AND CONTINUING TO DROP SLOWLY. WATER VAPOR IMAGERY SHOWS THE
BROAD TROUGH HAS ALSO DIPPED THRU THE AREA WITH VERY DRY MID-UPPER
LEVELS. FOR THE MOST PART THIS WILL RESULT IN CLEAR SKIES LASTING
THRU THE DAY. COMBINED WITH SOME DEGREE OF DOWNSLOPING...HAVE LEANED
TEMPS IN FAVOR OF BIAS CORRECTED MOS.
HOWEVER...EARLY THIS MORNING A PATCH OF LOW STRATUS HAVE FORMED OVER
THE PIEDMONT NEAR CHARLOTTE POSSIBLY DUE TO LLVL CONVERGENCE DUE TO
THE SFC FRONT AND/OR WEAK LEE TROUGH. THIS IS BEING BEST HANDLED BY
THE HRRR RUNS...WHICH BASICALLY SHOW THE CLOUDS EXPANDING MAINLY
EAST/SOUTH FROM THEIR INITIAL SIZE IN LLVL SWLY FLOW AND WITH DRIER
AIR FILTERING IN FROM THE NORTH. PLACEMENT ON THE HRRR OR RAP IS NOT
PERFECT SO I DREW IN SOME CLOUDS AND TIMED THE MOVEMENT/DISSIPATION
BASED ON THE MODELS. THEY APPEAR TO BE RAPIDLY DISSOLVED BY SOLAR
WARMING AND MIXING AFTER SUNRISE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 200 AM EST THURSDAY...SFC HIGH PRESSURE WILL BUILD ACROSS THE
DELMARVA REGION DURING THE DAY ON FRIDAY...WITH A PRONOUNCED WEDGE
RIDGE EXTENDED SOUTHWEST ALONG THE EAST SLOPES OF THE BLUE RIDGE. AS
THE AIRMASS WILL BE VERY DRY OVER THE REGION...NO CLOUD COVER IS
EXPECTED TO ACCOMPANY THE COLD AIR DAMMING DURING THE DAY ON
FRIDAY...THOUGH THERE WILL BE SOME INCREASING HIGH CLOUDS LATE IN
THE DAY ASSOCIATED WITH AN APPROACHING SHORT WAVE. EVEN WITH SUNNY
SKIES...HIGH TEMPERATURES SHOULD RUN AROUND 10 DEGREES BELOW NORMAL.
A COMPACT...STRONGLY ADVECTIVE SHORT WAVE WILL CROSS THE REGION
FRIDAY NIGHT AND EARLY SATURDAY. THE MID LEVEL ASCENT AND FORCING
WITH THE WAVE IS IMPRESSIVE...THOUGH THE BAND OF FORCING IS RATHER
NARROW. THE DRY LLVLS WILL TAKE A WHILE TO SATURATE. HOWEVER...
STRONG LLVL UPGLIDE WILL DEVELOP OVERNIGHT OVER THE NE PIEDMONT OF
SC AND THE WRN PIEDMONT OF NC. THIS WILL HELP TO SATURATE THE LLVLS
AND WILL LIKELY CONTRIBUTE TO HIGHER PCPN AMOUNTS IN THIS AREA. EVEN
SO...THE SREF MEAN FOR THE PIEDMONT ZONES IS AROUND A TENTH OF AN
INCH OF LIQUID. THE NC MTNS SHOULD ALSO SEE MORE PCPN FOR THE SIMPLE
FACT THAT THEY ARE HIGHER AND THERE WON/T BE AS MUCH DRY LLVL AIR TO
OVERCOME.
THE PCPN SHOULD FALL AS LIGHT SNOW INITIALLY OVER THE NC MTNS AND
NORTH OF I-40...TRANSITIONING TO A PERIOD OF FREEZING RAIN BEFORE
ENDING AROUND SUNRISE. MUCH LIKE THE PREVIOUS SHIFT...MY SNOW
AMOUNTS ARE BELOW ADVISORY CRITERIA OVER THE NC MTNS AND WRN
FOOTHILLS. FREEZING RAIN ACCUMULATIONS REMAIN QUITE
LIGHT...GENERALLY A COUPLE HUNDREDTHS OF AN INCH ACROSS THE CENTRAL
NC MTNS AND THE NC FOOTHILLS AND THE PIEDMONT ZONES NORTH OF
CHARLOTTE. AS THE PCPN AMOUNTS ARE LOOKING A LITTLE HEAVIER OVER THE
ERN ZONES...IT IS POSSIBLE THAT A FREEZING RAIN OR WINTER WX
ADVISORY MAY BE NEEDED FRI NIGHT FOR ICY SPOTS PRIMARILY ON ELEVATED
SFCS. SINCE MY CONFIDENCE OF AN ADVISORY IS IN THE 30 PERCENT
RANGE...I/LL ADD A MENTION OF THIS TO THE HWO.
FINALLY...WITH HIGH PRESSURE OVERHEAD SATURDAY NIGHT AND A MOIST
BOUNDARY LAYER...BUFKIT SOUNDINGS STRONGLY IMPLY THAT FOG WILL
DEVELOP ACROSS MUCH OF THE REGION.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 2 AM EST THURSDAY...THE MEDIUM RANGE FCST PICKS UP AT 12Z ON
SUNDAY WITH UPPER RIDGING OVER THE GULF OF MEXICO AND SE CONUS AND A
SOUTHERN STREAM UPPER TROF OVER THE SW CONUS. AS WE MOVE INTO
MONDAY...HEIGHTS BEGIN TO LOWER AGAIN AS THE UPPER TROF APPROACHES
THE FCST AREA AND EVENTUALLY PHASES BACK WITH THE NORTHERN STREAM BY
LATE MONDAY. THE MODELS INDICATE THAT SOME DEGREE OF UPPER TROFINESS
WILL MAINTAIN ITSELF OVER THE REGION THRU TUES AND INTO WED WITH THE
LATEST 00Z RUN OF THE GFS BEING SLOWER TO LIFT THE TROF ON WED AND
MAINTAINING A MORE AMPLIFIED SYSTEM COMPARED TO THE ECMWF. THE NEXT
FEATURE OF INTEREST APPEARS TO BE ANOTHER SOUTHERN STREAM H5
SHORTWAVE THAT APPROACHES THE CWFA BY THE END OF THE MEDIUM RANGE
NEXT THURS.
AT THE SFC...THE MODELS APPEAR TO BE COMING INTO BETTER AGREEMENT
WITH REGARDS TO THE EVOLUTION OF THE SYNOPTIC PATTERN ESPECIALLY FOR
THE LATTER HALF OF THE MEDIUM RANGE. WEAK BERMUDA HIGH PRESSURE WILL
BE CENTERED TO OUR EAST ON SUN WITH WEAK AND WARMING SLY LOW LVL
FLOW. BY EARLY MON...THE MODELS SPIN UP A LOW OVER THE SOUTHERN MISS
RIVER VALLEY AND MOVE IT OVER THE CWFA BY MON AFTERNOON AND THEN
WELL OFFSHORE BY EARLY TUES. IN THE LOWS WAKE...DRIER CANADIAN HIGH
PRESSURE SPREADS OVER THE REGION ON TUES AND REMAINS IN PLACE THRU
WED. TEMPS WILL START OUT WELL ABOVE NORMAL ON SUNDAY WITH HIGHS IN
THE UPPER 60S FOR THE LOWER ELEVATIONS AND UPPER 50S TO MID 60S FOR
THE HIGHER TERRAIN. BY WED...I ANTICIPATE VALUES WILL COOL BACK DOWN
BELOW CLIMATOLOGY.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
AT KCLT...LOW VFR OR HIGH MVFR STRATUS WILL LIKELY PERSIST THRU
SUNRISE IN LLVL CONVERGENCE ZONE RESULTING FROM LEE TROFING AND
FRONTAL BDY TO THE SOUTH...QUICKLY DISSIPATING ONCE THE SUN FALLS ON
THE CLOUDS. MAIN CONCERN OTHERWISE IS WINDS...ALSO BEING AFFECTED BY
THE LEE TROF TODAY. WINDS STARTING OUT NE EARLY THIS MRNG WOULD THEN
FAVOR NW QUADRANT AFTER DIURNAL MIXING BEGINS...BUT THE TROF IS
LIKELY TO KEEP THEM BACKED TO WNW...POSSIBLY EVEN TO WSW BRIEFLY
AROUND MIDDAY. THEY SHOULD VEER TO NORTHERLY AGAIN TONIGHT.
ELSEWHERE...SKC EXCEPT WHERE LOW STRATUS LINGERS THRU DAYBREAK.
WINDS WILL PREVAIL N TO NW THIS MRNG BUT STAND TO BE AFFECTED BY LEE
TROF OVER THE PIEDMONT TODAY...BRINGING THEM SWLY FOR A TIME.
FREQUENT GUSTS OF 25-30 KT LIKELY AT HIGH MTN ELEVATIONS. SOME
GUSTING LIKELY AT KAVL/KHKY ALSO...THOUGH REMAINING MORE MODERATE
AND LESS FREQUENT. GUSTS WOULD FAVOR NWLY AT ALL SITES. LIGHTER
NORTHERLY WINDS WILL RETURN THIS EVENING.
OUTLOOK...VFR THRU FRI. PRECIPITATION AND SOME RESTRICTIONS ARE
POSSIBLE BEGINNING LATE FRI NIGHT...WITH A LIGHT WINTRY MIX POSSIBLE
MAINLY OVER WRN NC. VFR CONDITIONS SHOULD RETURN SUNDAY...BUT A
FRONTAL SYSTEM WILL LIKELY BRING WIDESPREAD SHOWERS AND SOME
RESTRICTIONS MONDAY.
CONFIDENCE TABLE...
08-14Z 14-20Z 20-02Z 02-08Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.FIRE WEATHER...
FIRE DANGER STATEMENT WILL REMAIN IN EFFECT TODAY WITH RH VALUES
DIPPING WELL INTO THE TEENS AND MODERATE WINDS THROUGHOUT THE AREA.
WINDS ARE PARTICULARLY CONCERNING ONLY IN THE NRN MTNS...WHERE 850MB
FLOW IS A BIT STRONGER. RIDGETOPS MIGHT SEE SUSTAINED SPEEDS 30-35
MPH...WITH GUSTS TO THAT RANGE EVEN IN LOWER ELEVATIONS. SOME
GUSTING LIKELY THROUGHOUT THE MTNS/FOOTHILLS...UP TO AROUND 20 MPH.
COORDINATION WITH FIRE AGENCIES BY DAY SHIFT TODAY MAY RESULT IN RED
FLAG WARNING BEING ISSUED...ESPECIALLY ALONG THE BLUE RIDGE NORTH OF
THE FRENCH BROAD VALLEY.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...WIMBERLEY
SHORT TERM...MCAVOY
LONG TERM...JPT
AVIATION...WIMBERLEY
FIRE WEATHER...WIMBERLEY
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1039 PM EST FRI FEB 28 2014
.DISCUSSION...HOURLY TEMPS AND DEW POINT TEMPS DRIFTING SEVERAL
DEGREES OFF THE FORECAST GRIDS. SOME LIGHT PRECIPITATION (PCPN)
MOVING EAST THROUGH MAINLY SRN MIDDLE TN AND NRN AL AT LATE
EVENING. THE 01/00Z NAM AND LATEST RUC MODELS DON`T DEVELOP THIS
PCPN MUCH AFTER IT PASSES ACROSS SE TN...SO MIGHT SEE TRACE TO A
COUPLE HUNDREDTHS OF AN INCH BY EARLY MORNING SOUTH OF I-40.
CURRENT GRIDS HAVE CHANCE POPS FOR THOSE AREAS...SO DID NOT MAKE
ANY CHANGES TO POP OR WEATHER GRIDS FOR REST OF THE NIGHT. SO FAR
BNA HAS ONLY REPORTED TRACE AMOUNTS.
OTHERWISE...UPDATED HOURLY GRIDS AND ALL PRODUCTS...AND NUDGED MIN
TEMPS UP GENERALLY OR OPENED A WIDER RANGE OF MINS.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 38 59 43 69 41 / 30 10 10 20 80
KNOXVILLE MCGHEE TYSON AIRPORT, TN 34 58 40 66 41 / 20 10 10 10 80
OAK RIDGE, TN 33 57 41 64 39 / 20 10 10 30 90
TRI CITIES AIRPORT, TN 28 55 35 62 41 / 10 20 10 20 80
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
747 PM CST FRI FEB 28 2014
.UPDATE...RECENTLY RECEIVED SOME REPORTS OF SLEET FROM OUR
SOUTHERN COUNTIES AND RUC SOUNDINGS INDICATE THAT SLEET WILL
REMAIN A POSSIBILITY ALONG THE LEADING EDGE OF THE PRECIP BAND AS
IT TRAVERSES OUR AREA TONIGHT. LOOKS LIKE TEMPS AND DEW POINTS
WARM SUFFICIENTLY ALONG THE LAGGING PART OF THE BAND, SO THAT
PRECIP WILL LIKELY CHANGE BACK TO ALL RAIN BEFORE ENDING. THUS,
HAVE ADDED A BRIEF PERIOD FOR THE POSSIBILITY OF SLEET INTO THE
OVERNIGHT FORECAST. OTHERWISE, NO CHANGE.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
19
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
939 PM CST FRI FEB 28 2014
.UPDATE...
ADDED FOG TO THE FORECAST FOR LATE TONIGHT INTO SATURDAY MORNING
ACROSS ALL BUT THE FAR SOUTHWEST TX PANHANDLE. LOW-LEVEL EASTERLY UPSLOPE
FLOW APPEARS CONDUCIVE TO FOG DEVELOPMENT...AND MODEL LOW-LEVEL RH
PROGS...SREF VSBY PROBS...AND HRRR VSBY PROGS ALL SUPPORT THIS. MAY
SEE A FETCH OF LOWER SFC DEWPOINTS WORK INTO THE CENTRAL AND EASTERN
OK PANHANDLE...LIMITING THE FOG THREAT AND SUPPORTING MORE OF A LOW
CLOUD SCENARIO IN THESE AREAS /AND STILL CANNOT RULE OUT SOME PATCHY
DZ OR FZDZ TOWARD DAYBREAK IF THE LOW-LEVEL MOIST LAYER DEEPENS
ENOUGH IN THIS FAR NORTHEAST PORTION OF THE CWA/. FARTHER SOUTH
HOWEVER...FOG LOOKS LIKE A BETTER BET ACROSS ALL BUT THE FAR
SOUTHWEST TX PANHANDLE. TEMPS ARE EXPECTED TO FALL A LITTLE BELOW
FREEZING ACROSS THE NORTHERN PANHANDLES...BUT WARM GROUND TEMPS FROM
THE RECENT WARM STRETCH SHOULD PREVENT ANY REAL ICING PROBLEMS ON
ROADWAYS. NOT TO MENTION...THE GREATER PROBABILITIES OF DENSER FOG
APPEAR TO BE FARTHER SOUTH WHERE TEMPS WILL BE MAINLY ABOVE FREEZING.
KB
&&
.PREV DISCUSSION... /ISSUED 558 PM CST FRI FEB 28 2014/
AVIATION...
00Z TAFS...A COLD FRONT WILL BACK SOUTHWEST INTO THE PANHANDLES
TONIGHT...BEFORE EVENTUALLY STALLING ACROSS THE AREA. LOW CLOUDS ARE
EXPECTED TO FILL IN BEHIND THE FRONT...LIKELY BRINGING IFR CIGS TO
KGUY BEGINNING AROUND 09Z AND LASTING THROUGH LATE SATURDAY MORNING.
IT LOOKS LIKE THE EDGE OF THE LOW CLOUDS WILL BE SOMEWHERE VERY NEAR
KDHT AND KAMA...BUT WHETHER THEY MAKE IT INTO THESE TWO TERMINALS OR
STAY JUST TO THE EAST IS A VERY TOUGH CALL AT THIS POINT. WILL
MENTION FEW-SCT LOW CLOUDS AT BOTH SITES FROM 10Z TO 15-16Z AT THIS
TIME UNTIL CONFIDENCE INCREASES ONE WAY OR THE OTHER. IF THE LOW
CLOUDS MAKE IT IN...IFR OR LOWER CONDITIONS WILL BE POSSIBLE. VFR
CONDITIONS ARE EXPECTED FROM LATE SATURDAY MORNING THROUGH THE END
OF THE TAF PERIOD AT BOTH KAMA AND KDHT AS GUSTY SOUTHWEST WINDS
DEVELOP...SCOURING OUT THE LOW CLOUDS. HOWEVER KGUY WILL LIKELY
REMAIN BEHIND THE COLD FRONT ON SATURDAY. THUS THE LOW CLOUDS WILL
LIKELY PERSIST INTO THE LATE MORNING HOURS. SHOULD SEE A BRIEF PERIOD
OF VFR CONDITIONS AT KGUY SATURDAY AFTERNOON...BEFORE THE FRONT AND
LOW CLOUDS SURGE BACK SOUTHWEST BY EARLY EVENING. PRECIPITATION
CHANCES WILL INCREASE JUST BEYOND THE END OF THIS TAF PERIOD.
KB
PREV DISCUSSION... /ISSUED 401 PM CST FRI FEB 28 2014/
SHORT TERM...
THROUGH TONIGHT: AN ARCTIC FRONT WILL OOZE ITS WAY INTO THE
PANHANDLES LATE TONIGHT BEFORE STALLING. BEHIND THE FRONT, LOW
CLOUDS WILL RAPIDLY DEVELOP, ESPECIALLY ACROSS THE NORTHERN AND
EASTERN PANHANDLES. ISENTROPIC ASCENT MAY DEEPEN LOW-LEVEL MOISTURE
JUST ENOUGH TO WARRANT A MENTION OF PATCHY DRIZZLE/FREEZING DRIZZLE
DEPENDING ON SURFACE TEMPERATURES. IF THE DRIZZLE IS IN THE FROZEN
FORM, IT SHOULDN`T CAUSE ANY TRAVEL PROBLEMS AS GROUND TEMPERATURES
HAVE BEEN RATHER WARM LATELY. NONETHELESS, IT COULD STICK TO
ELEVATED AND METAL SURFACES.
SATURDAY-SUNDAY NIGHT: THE ARCTIC FRONT WILL PLAY HAVOC WITH
TEMPERATURES TOMORROW, AND WE`RE A LITTLE CONCERNED THE FRONT COULD
SEEP FARTHER SOUTH AND WEST THAN WE`RE CURRENTLY FORECASTING. LIKE
THE PREVIOUS SHIFT MENTIONED, IF THIS SCENARIO OCCURS, HIGH
TEMPERATURES WILL BE FAR TOO WARM OVER THE SOUTHWEST HALF OF THE
FORECAST AREA. THE THERMAL GRADIENT WILL BE VERY IMPRESSIVE ALONG
THE FRONT SUCH THAT TEMPERATURES MAY VARY BY NEARLY 40 DEGREES
WITHIN A 50-MILE DISTANCE. LARGE SCALE FORCING FOR ASCENT WILL
GRADUALLY BEGIN INCREASING TOMORROW AFTERNOON FROM WEST TO EAST.
EXPECT TO SEE SOME HIGH-BASED SHOWERS, POSSIBLY EVEN A THUNDERSTORM,
MOVE OUT OF NORTHEAST NEW MEXICO INTO OUR NORTHWEST AREAS AFTER 2
PM. THESE HIGH-BASED SHOWERS COULD PRODUCE LOCALLY GUSTY WINDS UP TO
45 MPH BENEATH THEM, BUT NO SEVERE WEATHER IS EXPECTED. BY SATURDAY
NIGHT AND SUNDAY MORNING, FORCING FOR ASCENT STRENGTHENS WITH THE
APPROACH OF THE MAIN UPPER TROUGH. AS THE COLD FRONT SETTLES
SOUTHWARD, ARCTIC AIR WILL GRADUALLY DEEPEN WITH TIME FROM NORTHEAST
TO SOUTHWEST. AS THIS OCCURS IN CONJUNCTION WITH THE UPPER FORCING,
PRECIPITATION WILL INCREASE IN COVERAGE, ESPECIALLY FOR LOCATIONS
NORTH AND WEST OF THE HIGHWAY 60 CORRIDOR. PRECIPITATION TYPE IS
VERY DIFFICULT AS THE NAM REMAINS THE FASTEST AND DEEPEST WITH THE
ARCTIC AIR. IN FACT, IF THE NAM IS CORRECT, SNOW WILL BE THE
PREDOMINANT TYPE OF PRECIPITATION AS THE BOUNDARY LAYER ESSENTIALLY
BECOMES THE DENDRITIC GROWTH ZONE, ESPECIALLY LATE SATURDAY NIGHT
AND SUNDAY. HOWEVER, ALL OTHER MODELS ARE NOT AS DEEP AND FAST WITH
THE COLD AIR, MAKING FOR A MESSY PRECIPITATION TYPE FORECAST. AS A
RESULT, WE THINK WE`LL INITIALLY SEE RAIN CHANGE TO FREEZING RAIN
AND THEN FINE SNOW GRAINS AS THE COLD AIR DEEPENS. ACROSS THE
SOUTHWESTERN TEXAS PANHANDLE, FREEZING RAIN AND RAIN WILL BE THE
PREDOMINANT PRECIPITATION TYPES. THE PRECIPITATION TYPE WILL BECOME
PREDOMINANTLY SNOW FOR THE SOUTHWEST TEXAS PANHANDLE AS THE ARCTIC
AIR MASS BECOMES FULLY ENTRENCHED, BUT A BRIEF PERIOD OF SLEET CAN`T
BE RULED OUT SUNDAY MORNING. THE PRECIPITATION IS EXPECTED TO BEGIN
TAPERING OFF FROM WEST TO EAST LATE SUNDAY AFTERNOON. VERY COLD
TEMPERATURES ARE EXPECTED ON SUNDAY WITH HIGHS RANGING FROM NEAR 40
IN THE SOUTHWEST (NEAR SUNRISE) TO THE MID TEENS IN THE NORTHEAST.
THE HIGHEST SNOWFALL AMOUNTS ARE EXPECTED TO OCCUR ACROSS THE
NORTHERN HALF OF THE PANHANDLES WHERE 1 TO 3 INCHES OF SNOW MAY
OCCUR. ICE ACCUMULATIONS FROM FREEZING RAIN WILL MAINLY IMPACT THE
TEXAS PANHANDLE WITH AMOUNTS EXPECTED TO REMAIN LESS THAN 0.10 OF AN
INCH. HOWEVER, A WINTER WEATHER ADVISORY WILL LIKELY BE REQUIRED FOR
PART OR ALL OF THE AREA SATURDAY NIGHT AND SUNDAY. BLOWING SNOW
COULD ALSO LEAD TO REDUCED VISIBILITIES AND SOME DRIFTING.
LONG TERM...
THE GFS IS DEPICTING SOME POSSIBILITY OF LOCALIZED FREEZING
FOG/FREEZING DRIZZLE ACROSS THE EASTERN OKLAHOMA AND NORTHEASTERN
TEXAS PANHANDLES EARLY MONDAY MORNING, BUT CONFIDENCE REMAINS A
LITTLE LOW TO INSERT INTO THE FORECAST CURRENTLY.
MONDAY NIGHT A WEAK SHORTWAVE IS DEPICTED TO MOVE ACROSS THE
PANHANDLES. MODELS AGREE THAT THIS SHORTWAVE SHOULD MOVE THROUGH DRY
AS LOW LEVEL MOISTURE WILL BE LIMITED. HOWEVER SOME PRECIP MAY BE
POSSIBLE A BIT NORTH OF THE OKLAHOMA PANHANDLE WHERE THE FORCING
FROM THE SHORTWAVE AND THE ENTRANCE REGION OF THE SPLIT FLOW JET
OVERLAP.
ZONAL FLOW ALOFT WILL IS EXPECTED TO PREVAIL TUESDAY AND MOST OF
WEDNESDAY. WEDNESDAY NIGHT A BROAD TROUGH WILL DROP ACROSS THE
PANHANDLES. MEDIUM RANGE MODELS DISAGREE ON WHERE THERE WILL BE
SUFFICIENT DYNAMICS AND MOISTURE FOR PRECIP TO OCCUR. THE ECMWF IS
MORE FAVORABLE FOR PRECIP WHILE THE GFS IS A LITTLE LESS FAVORABLE.
THE FORECAST LEANS CLOSER TO THE DRY GFS.
NORTHERLY TO NORTHWESTERLY FLOW ALOFT IS EXPECTED FOR THURSDAY WHICH
WILL ALLOW TEMPERATURES TO WARM NICELY BACK INTO THE MID TO UPPER
60S. PREVIOUS MODEL RUNS HINTED AT SOME PRECIP CHANCES FOR FRIDAY BUT
THESE CHANCES HAVE BEEN PUSHED BACK TO FRIDAY NIGHT FOR THE GFS AND
INTO SATURDAY FOR THE ECMWF.
FIRE WEATHER...
ELEVATED FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS THE
SOUTHWESTERN TEXAS PANHANDLE SATURDAY AFTERNOON AS RELATIVE
HUMIDITIES DROP TO 18 TO 20 PERCENT. TWENTY FOOT WINDS ARE EXPECTED
TO INCREASE INTO THE 17 TO 25 MPH RANGE BY THE EARLY AFTERNOON FROM
A SOUTHERLY TO SOUTH-SOUTHWESTERLY DIRECTION. FROM SATURDAY NIGHT
THROUGH WEDNESDAY OF THIS COMING WEEK...NEITHER ELEVATED NOR
CRITICAL FIRE WEATHER CONDITIONS ARE ANTICIPATED AT THIS TIME.
ELEVATED FIRE WEATHER WILL BE POSSIBLE THURSDAY AFTERNOON ACROSS THE
WESTERN AND CENTRAL PORTIONS OF THE TEXAS AND OKLAHOMA PANHANDLES.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
08/19
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
556 PM CST FRI FEB 28 2014
.UPDATE...
WINDS CONTINUE TO GRADUALLY DECREASE EARLY THIS EVENING BRINGING
AN END TO THE CRITICAL FIRE WEATHER CONDITIONS FOR THE SOUTH
PLAINS REGION. THUS...THE RED FLAG WARNING WILL BE ALLOWED TO
EXPIRE AS SCHEDULED AT 00Z.
&&
.AVIATION...
GUSTY WINDS AT KLBB WILL QUICKLY DIMINISH OVER THE NEXT HOUR OR
SO...WITH LIGHT WINDS EXPECTED THROUGH THE REMAINDER OF THE NIGHT.
A FRONT WILL MOVE THROUGH KCDS EARLY THIS EVENING WITH LIGHT
NORTHEAST TO EASTERLY WINDS IN ITS WAKE. THIS FRONT MAY BRIEFLY
EDGE THROUGH KLBB BY 10-12Z WITH AN EASTERLY WIND SHIFT...BUT
GUSTY SOUTHWESTERLY WINDS SHOULD RETURN TO THE TERMINAL BY AROUND
MIDDAY ON SATURDAY. AT KCDS...EASTERLY WINDS WILL WILL LIKELY
PERSIST THROUGH THE PERIOD. IN ADDITION...THERE WILL BE A CHANCE
OF LOW CLOUDS DEVELOPING AT KCDS BY AROUND 12Z. IF CLOUDS DO
FORM...THEY COULD PERSIST THROUGH MUCH OF THE MORNING BEFORE
LIFTING AND SCATTERING OUT. CURRENTLY HAVE INDICATED A MVFR DECK
AT KCDS...BUT THERE IS A CHANCE THE CLOUDS COULD BE LOWER...IN THE
IFR TO LIFR CATEGORY. AT KLBB...VFR CONDITIONS SHOULD PREVAIL
THROUGH THE TAF CYCLE.
&&
.PREV DISCUSSION... /ISSUED 348 PM CST FRI FEB 28 2014/
SHORT TERM...
FOLLOWING A COMPACT S/W TROUGH THAT GENERATED TSTORMS IN PARTS OF
THE TX PANHANDLE LAST NIGHT...THE AXIS OF STRONG WESTERLY WINDS HAVE
SINCE EXITED THE FORECAST AREA ON SCHEDULE. THESE WINDS DID RESULT
IN A BIT MORE DRAMA THAN EXPECTED THANKS TO A 59 MPH GUST AS
MEASURED BY THE GRAHAM WEST TX MESONET...BUT AS A WHOLE THE BLOWING
DUST THIS MORNING WAS NOTHING UNUSUAL FOR THE HARDY RESIDENTS THAT
FREQUENT THESE PARTS.
ALREADY BY SUNSET...A WEAK COLD FRONT WILL BE EDGING SOUTHWEST
ACROSS THE EASTERN PANHANDLE WELL AHEAD OF A BROODING ARCTIC HIGH
STILL POISED IN THE WESTERN CANADIAN PRAIRIES. DO BELIEVE THE
NON-RUC GUIDANCE IS TOO CONSERVATIVE WITH THIS FRONT/S PROGRESS
TONIGHT...SO HAVE EDGED LOW TEMPS DOWN A BIT ESPECIALLY NORTHEAST
OF THE HIGHWAY 84 CORRIDOR WHERE THE RUC HAS THIS BOUNDARY ROUGHLY
STALLING BY DAYBREAK. THIS BOUNDARY HOWEVER WILL RETREAT BY LATE
MORNING AS WINDS ALOFT BACK SWLY AND AMPLIFY MODESTLY AHEAD OF
SUNDAY/S UPPER TROUGH. AS WE SAW TODAY...EARLIER MODELS WERE MUCH
TOO MOIST WITH 2M DEWPOINTS...BUT THIS WAS EXPECTED IN PRIOR
FORECASTS AND WE CONTINUE TO EMPLOY THIS RATIONALE WITH TOMORROW/S
SETUP BEHIND THE RETREATING FRONT. NUDGED HIGHS UP A FEW DEGREES ON
THE CAPROCK WHERE THE DRIEST AIR WILL BE FOUND AND THIS WILL ALSO
RESULT IN SOME FIRE WX CONCERNS...ALTHOUGH NOT TO THE DEGREE THAT WE
SAW TODAY.
LONG TERM...
BROAD SOUTHWESTERLY FLOW WILL BE IN PLACE BY LATE SATURDAY. WHAT IS
CURRENTLY A WOUND-UP SPIRAL OFF THE COAST WILL BECOME AN OPEN TROUGH
FROM THE GREAT BASIC TO BAJA. NORTH OF THE BORDER...A COMPLEX
ELONGATED LOW SPANNING MUCH OF CANADA IS LATITUDINALLY ORIENTED
AROUND 55N. MODEL GUIDANCE IS FAIRLY CONSISTENT WITH THE SYNOPTIC
SCALE FEATURES OVER THE NEXT 7 DAYS. THE WEST COAST TROUGH IS
EXPECTED TO APPROACH ON SUNDAY FOLLOWED BY A MORE SUBTLE EMBEDDED
TROUGH INTO MONDAY. ON WEDNESDAY...YET ANOTHER TROUGH AXIS
APPROACHES AND STARTS TO DEEPEN BEFORE DIVING INTO THE GULF COAST
SATES LATE WEEK. OUR FINAL TROUGH OF THE EXTENDED APPROACHES ON
FRIDAY.
YET ANOTHER BACK DOOR COLD FRONT SNEAKS INTO THE AREA ON SUNDAY
MAKING FCST HIGHS QUITE TRICKY AS THE BOUNDARY HANGS UP FOR SEVERAL
HOURS ACROSS THE CWFA. THEN...WITH THE FALL OF NIGHT...THE COLDER
AIR SHOULD FILTER INTO THE REGION. OVERNIGHT BUT NOT BEFORE THERE
IS SOME OPPORTUNITY FOR PRECIPITATION.
MONDAY SHOULD REMAIN DRY AND QUITE COOL BEFORE RETURN FLOW SETS UP
ON TUESDAY QUICKLY REBOUNDING TEMPERATURES THOUGH PERHAPS REMAINING
A FEW DEGREES SHY OF CLIMATOLOGICAL AVERAGES. ANOTHER COLD FRONT
ENTERS THE REGION WEDNESDAY MORNING HELPING TO HOLD TEMPS DOWN ONE
MORE DAY BEFORE SOUTHWESTERLY SURFACE FLOW PICKS UP FOR THURSDAY
WITH THE POTENTIAL FOR ANOTHER BOUT OF FIRE WEATHER LATE NEXT WEEK.
YET ANOTHER PUSH OF COLD AIR ENTERS FOR SEVERE WEATHER AWARENESS DAY.
FIRE WEATHER...
WIDESPREAD RED FLAG CONDITIONS CONTINUE THIS AFTERNOON ACROSS THE
SOUTH PLAINS AND MUCH OF THE ROLLING PLAINS. THE STRONGEST WINDS
HAVE SINCE DEPARTED THE REGION...BUT 20-FOOT SPEEDS OF 20-25 MPH
WILL CONTINUE UNTIL 6 PM AT WHICH POINT THE RED FLAG WARNING SHOULD
BE ALLOWED TO EXPIRE.
BY THIS EVENING AND OVERNIGHT...A LIGHT NORTHEAST WIND SHIFT WILL
PUSH SOUTHWEST ACROSS THE ROLLING PLAINS AND EASTERN SOUTH PLAINS
BEFORE RETREATING NORTHEAST BY LATE SATURDAY MORNING. ELEVATED TO
MARGINALLY CRITICAL FIRE WEATHER IS POSSIBLE BY SATURDAY AFTERNOON
ON THE CAPROCK AS SOUTHWEST WINDS RISE TO 15 TO 25 MPH WITH MIN RH
VALUES FALLING INTO THE LOWER-TO-MID TEENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 36 75 32 34 12 / 0 0 20 30 10
TULIA 37 75 25 29 10 / 0 0 20 20 10
PLAINVIEW 39 77 27 32 11 / 0 0 10 20 10
LEVELLAND 39 80 33 45 15 / 0 0 10 20 10
LUBBOCK 38 80 29 40 14 / 0 0 10 20 10
DENVER CITY 44 79 36 54 20 / 0 0 10 20 10
BROWNFIELD 42 80 34 46 18 / 0 0 10 20 10
CHILDRESS 37 68 24 25 10 / 0 0 10 20 10
SPUR 39 80 25 34 13 / 0 0 10 20 10
ASPERMONT 39 83 25 31 12 / 0 0 20 20 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: TXZ021>023-027>031-033>044.
&&
$$
23/33/23
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1247 PM CST THU FEB 27 2014
.DISCUSSION...OVERCAST CLOUD DECK CONTINUES TO EXPAND EASTWARD AND
IS SHOWING NO SIGNS OF ERODING YET. UPDATED CLOUD COVER ACROSS
CENTRAL AND WESTERN AREAS FOR AFTERNOON AND LOWERED TEMPS A
CATEGORY ACROSS THIS AREA.
&&
.PREV DISCUSSION... /ISSUED 1128 AM CST THU FEB 27 2014/
DISCUSSION...UPDATE FOR 18Z AVIATION.
AVIATION...OVC DECK RANGING FROM 3000-4000 FEET ALONG AND WEST OF
A BKS-ALI-COT LINE. RUC13 AND NAM12 SOUNDINGS SHOWING A GRADUAL
ERODING OF THIS DECK LATER IN THE AFTERNOON...POSSIBLY BECOMING
SCT. OTHERWISE ACROSS EASTERN AREAS MAINLY CLR SKIES. NE TO E
WINDS 5-12 KTS ACROSS EASTERN AREAS BECOMING SE THIS AFTERNOON.
BKN MVFR DECK MAY DEVELOP ACROSS EASTERN AREAS EARLY FRI MORNING.
IN ADDITION...MAY BE SOME PATCHY FOG RESULTING IN IFR TO MVFR
VISIBILITIES FROM ALI-VCT TOWARDS SUNRISE FRI MORNING.
PREV DISCUSSION... /ISSUED 923 AM CST THU FEB 27 2014/
DISCUSSION...OVERCAST CLOUD DECK AROUND 2500-3000 FEET PERSISTS
OUT ACROSS THE WESTERN BRUSH COUNTRY AND RIO GRANDE PLAINS. NAM12
AND GFS TIME SERIES INDICATE THE OVERCAST LAYER IS THIN...AND BOTH
INSIST THE DECK WILL SCATTER OUT LATE THIS AFTERNOON. UNTIL THIS
HAPPENS...INCREASED CLOUD IN THE FORECAST THROUGH THE REMAINDER OF
THE MORNING AND EARLY AFTERNOON ACROSS THIS REGION...THEN SHOWED
PARTLY CLOUDY TO MOSTLY CLEAR SKIES DEVELOPING LATE AFTERNOON INTO
THE EVENING. ALSO LOWERED FORECAST HIGHS BY A COUPLE OF DECREES.
REST OF THE FORECAST ACROSS EASTERN AREAS LOOKS IN GOOD SHAPE AND
NO CHANGES WERE MADE.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 57 51 80 66 80 / 0 10 10 10 10
VICTORIA 57 46 76 64 79 / 0 10 10 10 10
LAREDO 58 55 85 64 89 / 0 0 10 10 10
ALICE 58 49 84 64 84 / 0 10 10 10 10
ROCKPORT 54 52 75 65 75 / 0 10 10 10 10
COTULLA 57 46 82 60 85 / 0 0 10 10 10
KINGSVILLE 58 50 83 66 83 / 0 10 10 10 10
NAVY CORPUS 54 52 74 65 76 / 0 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
JR/76...SHORT TERM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1128 AM CST THU FEB 27 2014
.DISCUSSION...UPDATE FOR 18Z AVIATION.
&&
.AVIATION...OVC DECK RANGING FROM 3000-4000 FEET ALONG AND WEST OF
A BKS-ALI-COT LINE. RUC13 AND NAM12 SOUNDINGS SHOWING A GRADUAL
ERODING OF THIS DECK LATER IN THE AFTERNOON...POSSIBLY BECOMING
SCT. OTHERWISE ACROSS EASTERN AREAS MAINLY CLR SKIES. NE TO E
WINDS 5-12 KTS ACROSS EASTERN AREAS BECOMING SE THIS AFTERNOON.
BKN MVFR DECK MAY DEVELOP ACROSS EASTERN AREAS EARLY FRI MORNING.
IN ADDITION...MAY BE SOME PATCHY FOG RESULTING IN IFR TO MVFR
VISIBILITIES FROM ALI-VCT TOWARDS SUNRISE FRI MORNING.
&&
.PREV DISCUSSION... /ISSUED 923 AM CST THU FEB 27 2014/
DISCUSSION...OVERCAST CLOUD DECK AROUND 2500-3000 FEET PERSISTS
OUT ACROSS THE WESTERN BRUSH COUNTRY AND RIO GRANDE PLAINS. NAM12
AND GFS TIME SERIES INDICATE THE OVERCAST LAYER IS THIN...AND BOTH
INSIST THE DECK WILL SCATTER OUT LATE THIS AFTERNOON. UNTIL THIS
HAPPENS...INCREASED CLOUD IN THE FORECAST THROUGH THE REMAINDER OF
THE MORNING AND EARLY AFTERNOON ACROSS THIS REGION...THEN SHOWED
PARTLY CLOUDY TO MOSTLY CLEAR SKIES DEVELOPING LATE AFTERNOON INTO
THE EVENING. ALSO LOWERED FORECAST HIGHS BY A COUPLE OF DECREES.
REST OF THE FORECAST ACROSS EASTERN AREAS LOOKS IN GOOD SHAPE AND
NO CHANGES WERE MADE.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 57 51 80 66 80 / 0 10 10 10 10
VICTORIA 57 46 76 64 79 / 0 10 10 10 10
LAREDO 62 55 85 64 89 / 0 0 10 10 10
ALICE 60 49 84 64 84 / 0 10 10 10 10
ROCKPORT 54 52 75 65 75 / 0 10 10 10 10
COTULLA 61 46 82 60 85 / 0 0 10 10 10
KINGSVILLE 60 50 83 66 83 / 0 10 10 10 10
NAVY CORPUS 54 52 74 65 76 / 0 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
JR/76...AVIATION
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1131 PM CST WED FEB 26 2014
.AVIATION...
/06Z TAFS/
CLEARING CONTINUES OVERNIGHT AS DRIER AIR FROM THE NORTH SPREADS
ACROSS SOUTH CENTRAL TEXAS. WINDS WILL BE LIGHT WITH A NORTHERLY
COMPONENT OVER THE EASTERN TWO-THIRDS OF SOUTH CENTRAL TEXAS. OVER
THE RIO GRANDE...LIGHT SOUTHERLY WINDS WILL PREVAIL THROUGH THURSDAY.
UPPER END MVFR CONDITIONS ARE EXPECTED ACROSS KSAT AND KSSF
OVERNIGHT THROUGH EARLY THURSDAY MORNING DUE VISIBILITY OF 5SM.
OTHERWISE...VFR CONDITIONS EXPECTED FOR MUCH OF THE FORECAST PERIOD.
SOUTHERLY FLOW RETURNS THURSDAY AFTERNOON ACROSS THE REGION AS
SURFACE HIGH PRESSURE SYSTEM OVER EAST TEXAS MOVES PUSHES EASTWARD.
&&
.PREV DISCUSSION... /ISSUED 903 PM CST WED FEB 26 2014/
UPDATE...
WE HAVE UPDATED THE FORECAST TO REMOVE THE MENTION OF
PRECIPITATION THROUGH THE REMINDER OF TONIGHT. RADAR ECHOES
CONTINUE TO DECREASE ACROSS SOUTH CENTRAL TEXAS THIS EVENING AS
DRIER AIR IN THE LOW-LEVELS AND MID-LEVEL SUBSIDENCE SPREAD INTO
THE REGION. WE HAVE ALSO REDUCED CLOUD COVER ACROSS MOST AREAS...
ALTHOUGH LOW CLOUDS MAY PERSIST THROUGH TONIGHT ALONG THE RIO
GRANDE. WE HAVE LOWERED TEMPERATURES A FEW DEGREES ACROSS PORTIONS
OF THE HILL COUNTRY AND ADJACENT I-35 CORRIDOR AS DEW POINTS WILL
DROP INTO THE TEENS OVERNIGHT. WE/LL NEED TO MONITOR LLANO...
BURNET AND WILLIAMSON COUNTIES AS THE RUC13 SUGGESTS LOWS MAY DROP
INTO THE MID 20S. WE HAVE ALSO LOWERED TEMPERATURES A DEGREE OR
TWO ALONG THE HIGHWAY 77 CORRIDOR AS DRIER AIR...LIGHT WINDS AND
DECREASING CLOUD COVER ARE EXPECTED OVER THIS REGION. OTHERWISE...
MINOR CHANGES WERE MADE TO THE WINDS AND DEW POINTS BASED ON THE
LATEST OBSERVATIONAL TRENDS.
PREV DISCUSSION... /ISSUED 527 PM CST WED FEB 26 2014/
AVIATION...
AN AREA OF DRIZZLE/LIGHT RAIN MAINLY ALONG AND SOUTH OF HIGHWAY 90...
WILL CONTINUE TO PUSH TO THE SOUTHEAST THROUGH THIS EVENING. BY
00Z THURSDAY...THIS ACTIVITY SHOULD BE PUSHING OVER THE COASTAL
PLAINS AREA...WHILE NORTHERLY LOW LEVEL WINDS BRING DRIER AIR TO
THE REGION. SURFACE HIGH PRESSURE SYSTEM OVER EAST TEXAS LATE THIS
AFTERNOON/EARLY EVENING WILL PUSH TO THE SOUTHEAST LATE TONIGHT
INTO THURSDAY. THIS WILL RESULT IN THE RETURN OF SOUTHERLY FLOW
ACROSS THE RIO GRANDE PLAINS WITH NORTH/NORTHEASTERLY WINDS ACROSS
THE EASTERN TWO-THIRDS OF SOUTH CENTRAL TEXAS OVERNIGHT AND EARLY
THURSDAY. SOUTHERLY WINDS ARE EXPECTED TO DOMINATE THE AREA
THURSDAY AFTERNOON AS SURFACE HIGH PUSHES TO THE EAST. COULD SEE
UPPER END MVFR CONDITIONS ACROSS KSAT AND KSSF OVERNIGHT DUE TO
CEILINGS OF 5 KFT. OTHERWISE...VFR EXPECTED ACROSS THE ENTIRE FORECAST
AREA BY 12Z THURSDAY THROUGH THE REMAINDER OF THE FORECAST CYCLE.
PREV DISCUSSION... /ISSUED 320 PM CST WED FEB 26 2014/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...
THE UPPER LEVEL PATTERN THIS MORNING SHOWED A LARGE AMPLITUDE
TROUGH EXTENDING FROM THE GREAT LAKES TO NORTHEAST TEXAS AND A
SECOND TROUGH MOVING ACROSS NORTHERN MEXICO. THIS SECOND FEATURE
IS PULLING MID-LEVEL MOISTURE FROM THE TROPICS ACROSS MEXICO INTO
TEXAS. THE 700 TO 300 MB FLOW ACROSS TEXAS IS SLIGHTLY ANTICYCLONIC.
AT THE SURFACE THE COLD FRONT HAS MOVED SOUTH OF TEXAS AND WINDS
ARE FROM THE NORTH. COLDER...DRIER AIR IS DROPPING INTO OUR CWA.
PRECIPITATION WILL BE ENDING THIS EVENING FROM NORTHWEST TO
SOUTHEAST. WHERE THERE IS PRECIPITATION THIS EVENING..TEMPERATURES
WILL BE ABOVE FREEZING AND IT SHOULD BE ALL RAIN. LOW TEMPERATURES
OVERNIGHT WILL DROP TO FREEZING OR BELOW OVER THE HILL COUNTRY AND
ADJACENT AREAS FROM CONCAN TO LA GRANGE. MOST OF THE SAN ANTONIO
METRO AREA WILL BE ABOVE FREEZING WITH ONLY THE EXTREME NORTHERN
PORTION OF THE AREA DROPPING TO OR BELOW 32. A WARMING TREND WILL
BEGIN THURSDAY WITH THE SURFACE WINDS TURNING TO THE SOUTHEAST BY
THE AFTERNOON.
LONG TERM (FRIDAY THROUGH WEDNESDAY)...
AN UPPER LEVEL RIDGE WILL BUILD OVER THE SOUTHERN PLAINS FOR THE
END OF THE WEEK. THE LOW LEVEL FLOW WILL REMAIN FROM THE SOUTHEAST
MAKING FRIDAY AND SATURDAY QUITE WARM. SATURDAY MORNING THE
SOUTHEASTERLY FLOW MAY PRODUCE PATCHY DRIZZLE ACROSS THE THE
SOUTHEASTERN PART OF THE CWA AS FAR NORTH AS I-35. SUNDAY ANOTHER
COLD FRONT WILL MOVE THROUGH BRINGING A CHANCE FOR SHOWERS AND
THUNDERSTORMS SUNDAY AND MONDAY. IT WILL ALSO BRING ANOTHER ROUND
OF COLD AIR WITH FREEZING TEMPERATURES POSSIBLE AGAIN IN THE HILL
COUNTRY TUESDAY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 32 63 46 78 59 / - 0 - - -
AUSTIN BERGSTROM INTL AIRPORT 28 60 41 76 55 / - 0 - - -
NEW BRAUNFELS MUNI AIRPORT 32 61 42 76 57 / - 0 - - -
BURNET MUNI AIRPORT 27 60 42 77 53 / - 0 - - -
DEL RIO INTL AIRPORT 36 65 45 81 56 / - - 0 - -
GEORGETOWN MUNI AIRPORT 28 60 42 75 55 / - 0 - - -
HONDO MUNI AIRPORT 34 64 42 81 54 / - 0 - - -
SAN MARCOS MUNI AIRPORT 31 60 42 75 57 / - 0 - - -
LA GRANGE - FAYETTE REGIONAL 30 58 44 72 60 / - - 10 - -
SAN ANTONIO INTL AIRPORT 33 65 47 80 60 / - 0 - - -
STINSON MUNI AIRPORT 35 64 45 79 58 / - 0 - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...17
SYNOPTIC/GRIDS...24
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
330 PM CST THU FEB 27 2014
.TONIGHT - CONFIDENCE...MEDIUM
MAIN CONCERN IS EXTENT OF TEMP DROPOFF BEFORE CLOUDS INCREASE LATER
IN THE NIGHT. VERY DRY AIRMASS IS SETTLING ACROSS SRN WI. DEW POINTS
INTO THE MINUS TEENS. 2 METER TEMPS...ESP THE GFS...HAVE REALLY
BACKED OFF ON THE LOWS. MEANWHILE THE RAP WITH A STRONG INVERSION IS
A LOW OF -31 AT KMSN. MEANWHILE THE NAM SHOWS MORE OF AN ISOTHERMAL
SETUP WITH WARMER LOWS. DROPPED LOWS A BIT MORE THAN PRIOR FORECAST
ESPECIALLY IN WESTERN CWA DUE TO THE VERY LOW DEWPOINTS AND IDEAL
RADIATIONAL SETUP WITH LIGHT WIND/CLEAR SKY REGIME FOR MUCH OF THE
NIGHT WITH THE PROXIMITY OF SURFACE HIGH. WAA CLOUDS INCREASE LATER
IN THE NIGHT...BUT THESE CLOUDS ARE STILL A LONG WAYS OFF IN SD/NEB.
EXPECT THE INITIAL SOUTHERLY RETURN 925 FLOW LATER TONIGHT TO NOT
MIX DOWN TO WARRANT WIND CHILL HEADLINE CONCERNS...ESP WITH ANY
MIXING LIKELY TO COINCIDE WITH THE CLOUD INCREASE AND SUBSEQUENT SFC
TEMP MODIFICATION. SO CONFIDENCE IN WIND CHILL CRITERIA BEING MET
FOR ANY LENGTH OF TIME IN THE WESTERN CWA IS QUITE LOW AT THIS TIME.
.FRIDAY - CONFIDENCE...MEDIUM
HIGH SHIFTS EAST AND 850/925 WAA WILL BE WELL UNDERWAY AHEAD OF NEXT
SYSTEM. FORCING MECHANISMS ARE QUESTIONABLE. VERY LITTLE IN THE WAY
OF VORTICITY TO LATCH ONTO...FLOW BECOMES MORE WESTERLY. UPPER JET
DYNAMICS ARE FAIRLY WEAK. THERE IS A HINT OF LOWER LEVEL
FRONTOGENESIS AND WEAK TO MODERATE ISENTROPIC ASCENT WITH INCREASING
SATURATION IN THE NORTHWEST CWA AS THE AFTERNOON WEARS ON. SO WILL
KEY HIGHEST POPS THERE.
.FRIDAY NIGHT...FORECAST CONFIDENCE - MEDIUM.
WEAKENING MID-LEVEL SHORT WAVE AND LOW LEVEL WARM AIR ADVECTION
SHOULD RESULT IN A PERIOD OF -SN OVER MOST OF THE AREA FRIDAY NIGHT.
SYSTEM WILL BE WEAKENING AS IT MOVES THROUGH BUT ENOUGH COLUMN
MOISTURE AND SYNOPTIC SCALE LIFT TO SQUEEZE OUT THE LIGHT PRECIP.
EXPECT -SN TO SPREAD INTO WESTERN CWA DURING THE EARLY
EVENING...EVENTUALLY CLEARING THE EASTERN AREAS BY LATE IN THE
NIGHT. SNOW LIQUID RATIOS AROUND 14 TO 1 BUT DENDRITES SHOULD REMAIN
SMALL. HENCE LOOKING AT ONE HALF INCH TO 2 INCH AMOUNTS WITH THE
HIGHEST TOTALS IN THE NORTH AND WEST.
.SATURDAY AND SATURDAY NIGHT...FORECAST CONFIDENCE - MEDIUM.
BRIEF LULL IN PRECIPITATION EXPECTED LATER FRIDAY NIGHT INTO
SATURDAY MORNING BEFORE NEXT PERIOD OF -SN DEVELOPS. ALL SHORT TERM
GUIDANCE SHOWS SOUTHERN WISCONSIN AFFECTED BY RIGHT ENTRANCE REGION
OF PASSING UPPER JET SATURDAY AFTN AND EVENING. WITH LOW LEVEL
BAROCLINIC ZONE REMAINING NEARBY...WEAK WARM AIR ADVECTION LOWERS
CONDENSATION PRESSURE DEFICITS RAPIDLY TO LESS THAN 10MB WITH WEAK
ISENTROPIC OMEGA. MORE OF THE CLOUD BEARING LAYER WILL BE IN A
FAVORABLE DENDRITIC SNOW GROWTH REGION FOR A TIME. WITH SLIGHTLY
HIGHER SNOW LIQUID RATIOS EXPECTED AND BETTER ENHANCED
FORCING...THINKING POTENTIAL FOR 2 TO 4 INCH SNOWFALL OVER MOST OF
THE AREA SATURDAY AFTN AND EVENING.
.SUNDAY...FORECAST CONFIDENCE - LOW.
SYNOPTIC SCALE FORCING SLIDES OFF TO THE EAST LATE SATURDAY NIGHT
HOWEVER LATEST NAM TRYING TO SHOW A PERIOD OF ONSHORE WINDS AS
MESOSCALE LOW PRESSURE TROUGH MOVES WWD ACROSS LAKE MI INTO FAR
EASTERN WI ON SUNDAY. GFS DOES NOT SHOW THIS FEATURE WITH WEAKER
ONSHORE WINDS AND POTENTIAL LAKE EFFECT REMAINING FARTHER SOUTH OVER
NORTHEAST IL. TOO MUCH UNCERTAINTY TO LEAN ONE WAY OR THE OTHER.
FOR NOW WILL KEEP SMALL POPS FOR -SHSN IN FOR SUNDAY. EXPANDING LAKE
ICE OVER NEARSHORE AND WESTERN OPEN WATERS WILL ALSO HELP TO CUT
BACK ON LAKE EFFECT.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. FORECAST CONFIDENCE -
MEDIUM TRENDING TOWARD LOW.
MORE ZONAL FLOW AT THE MID-LEVELS CONTINUES INTO EARLY NEXT WEEK
WITH SLIGHT WARMING IN SURFACE TEMPERATURES. ZONAL FLOW AND DRIER
AIR ASSOCIATED WITH SPRAWLING HIGH PRESSURE OVER THE NORTHERN PLAINS
HELPS TO DIVERT DEVELOPING LOW PRESSURE SYSTEM TO THE SOUTHEAST OF
WISCONSIN SUNDAY NIGHT AND MONDAY. HOWEVER MAY BE A PERIOD OF
NORTHEAST WINDS ON BACKSIDE OF LOW MOVING ACROSS TN VALLEY REGION.
GFS FORECAST SOUNDINGS FOR MONDAY SHOW MINIMAL LOW LEVEL MOISTURE
AND WEAKER LOW TO MID LEVEL FLOW...SO FOR NOW WL AVOID ADDING
THREAT OF LAKE EFFECT TO EASTERN AREAS EXCEPT IN THE FAR SOUTHEAST.
LOW PRESSURE SYSTEM AFFECTING EAST COAST REGION EARLY NEXT WEEK WILL
RESULT IN MID-LEVEL STEERING FLOW BECOMING MORE NORTHWEST FOR A
TIME. THIS CARRIES SPRAWLING HIGH PRESSURE SYSTEM FROM THE NORTHERN
PLAINS GRADUALLY EWD ACROSS WESTERN GREAT LAKES REGION ON TUESDAY.
HOWEVER AGREEMENT IN MEDIUM RANGE GUIDANCE IN WEAK TROUGH MOVING
SOUTHEAST ACROSS WI IN THE MONDAY NIGHT/TUE TIME FRAME...SO WL NEED
TO CONTINUE SMALL POPS FOR -SN. CLOUDS FROM THIS SYSTEM WILL ALSO
PREVENT RADIATIONAL COOLING AND BITTER COLD TEMPS MON NGT.
HIGH EVENTUALLY MOVES OFF TO THE EAST BY WEDNESDAY. MEDIUM RANGE
GUIDANCE DIVERGES AT THIS POINT AS ECMWF TURNS A BIT MORE WEST TO
SOUTHWEST AT THE MID-LEVELS AHEAD OF NEXT APPROACHING DISTURBANCE.
DGEX ALSO IN THIS CAMP WHILE GFS STEERING FLOW REMAINS MORE
NORTHWEST AND COLDER. BOTH DGEX AND ECMWF AGRESSIVE ON BRINGING
SURGE OF WARM AIR ADVECTION QPF INTO THE AREA LATER WED/WED
NGT...WHILE GFS SLOWER. NO MATTER...ALL MEDIUM RANGE GUIDANCE IN
AGREEMENT ON STRONGER MID-LEVEL TROUGH MOVING THROUGH THE REGION IN
THE THU/THU NGT TIME FRAME...SO MOST LATER PERIODS WL LIKELY HAVE
LOW POPS FOR -SN.
GFS 5-DAY 500H HEIGHTS RUNNING AROUND 100METERS BELOW NORMAL NEXT
SEVERAL DAYS BUT BEGIN TO SLOWLY MODERATE SO THAT BY THE SECOND WEEK
OF MARCH 500H HEIGHTS ACTUALLY AROUND NORMAL. HENCE WILL REMAIN
COLD AND BELOW NORMAL THROUGH THE EXTENDED FORECAST PERIOD BUT
RECORD COLD NOT EXPECTED.
&&
.AVIATION/00Z TAFS/...VFR MOSTLY SKC EXPECTED INTO THIS EVENING.
WILL START TO SEE SOME WAA MID CLOUDS RETURN LATER TONIGHT THROUGH
FRIDAY MORNING. ANY SNOW WITH NEXT SYSTEM EXPECTED TO HOLD OFF UNTIL
FRIDAY EVENING FOR THE TAF SITES. EXPECT MVFR CIGS/VSBYS TO INCREASE
ACROSS SRN WI DURING FRIDAY EVENING PER NAM MOS CIG FCST AND BUFKIT
LOW LEVEL SATURATION TRENDS.
&&
.MARINE...GRADIENT WILL TIGHTEN BACK UP AS HIGH SHIFTS EAST AND SSE
FLOW DEVELOPS BETWEEN THE DEPARTED HIGH AND APPROACHING LOW. HOISTED
SMALL CRAFT FOR GUSTY SSE WINDS FROM MID MORNING THROUGH LATE
AFTERNOON.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 9 AM TO 6 PM CST FRIDAY
FOR LMZ643>646.
&&
$$
TONIGHT/FRIDAY AND AVIATION/MARINE...PC
FRIDAY NIGHT THROUGH THURSDAY...MBK
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
235 AM MST SAT MAR 1 2014
.UPDATE
UPDATED AVIATION SECTION.
&&
.SYNOPSIS...
A WELL DEFINED PACIFIC STORM SYSTEM WILL SLOWLY MOVE THROUGH THE
AREA TODAY...EVENTUALLY BRINGING SHOWERS AND ISOLATED THUNDERSTORMS
TO THE PHOENIX AREA. CONDITIONS WILL DRY OUT FROM WEST TO EAST THIS
EVENING WITH NEARLY EVERYONE DRYING OUT COMPLETELY BY SUNDAY
AFTERNOON. FOLLOWING THE LOW...DRY WEATHER IS EXPECTED ALONG WITH A
RETURN TO ABOVE NORMAL TEMPERATURES BY LATE WEEK.
&&
.DISCUSSION...
FOR THOSE OF US IN THE PHOENIX AREA...THIS UPPER LOW HAS BEEN AN
ABYSMAL UNDER-PERFORMER THUS FAR. UNLESS YOU WERE ONE OF THE LUCKY
ONES CAUGHT UNDER A BRIEF SHOWER IN CAVE CREEK/CAREFREE FRIDAY
EVENING...YOU HAVENT SEEN A DROP THUS FAR. WHILE SOUTHEAST
CALIFORNIA AND WESTERN ARIZONA HAS FARED SOMEWHAT BETTER...RAINFALL
STILL HASNT FILLED IN TO THE EXTENT THAT IT SHOULD HAVE.
THAT BEING SAID...ALL HOPE IS NOT LOST...NOT BY A LONG-SHOT. THE 1+
INCH PWAT AXIS IS NOW SQUARELY POSITIONED OVERHEAD ALONG WITH
850-700MB WINDS AROUND 60-65KTS. NOT SURPRISINGLY...THOSE LOCATIONS
DIRECTLY WITHIN THE UPSLOPE FLOW /FOOTHILLS AND HIGHER TERRAIN NORTH
AND EAST OF PHOENIX/ ARE IN PRETTY GOOD SHAPE WITH THE REGIONAL
RADAR MOSAIC FILLING IN QUITE A BIT SINCE MIDNIGHT. THERES EVEN A
HINT AT NEW SHOWER DEVELOPMENT OVER THE FAR NORTH PART OF THE METRO
/CEILINGS HAVE BEEN GRADUALLY LOWERING SINCE MIDNIGHT/ AND KYUX IS
SHOWING SOME NEW ACTIVITY ACROSS FAR EASTERN YUMA/LA PAZ COUNTIES.
WITH A SOLID 10-12HRS WORTH OF ANOMALOUSLY STRONG UPSLOPE WINDS
FORECAST TO REMAIN IN PLACE OVER THE FORECAST AREA THROUGH 18Z
COINCIDENT WITH AT LEAST 1.1 INCH PWATS...EVEN THE DRIEST MODELS ARE
ADVERTISING CONVECTION TO DEVELOP AND FILL IN BY LATE
MORNING...ALBEIT AT A GLACIAL PACE. ONCE THE COLD CORE ALOFT MOVES
OVERHEAD BETWEEN 18Z AND 00Z...EXPECT ADDITIONAL DEVELOPMENT TO
BLOSSOM ACROSS THE LOWER DESERTS AS MID LEVEL LAPSE RATES STEEPEN
DRAMATICALLY. SOUTHEAST CALIFORNIA ISNT QUITE THROUGH WITH THE
PRECIP BUT AS THEY WILL LOSE THEIR DEEPEST MOISTURE LATER THIS
MORNING...THEIR POPS WILL BE A BIT LOWER THAN THOSE AROUND THE
PHOENIX AREA.
THUS...IM MAKING SOME ADJUSTMENTS TO POPS/QPF FOR THE ENTIRE
FORECAST AREA. POPS/QPF WILL BE LOWERED A BIT ACROSS THE BOARD
THROUGH LATE MORNING TO BETTER REFLECT WHAT HAS HAPPENED THUS FAR
AND WHAT LITTLE IS DEVELOPING ON RADAR TO OUR SOUTH...BUT WILL BE
RETAINED AROUND 100 PERCENT FOR LATE MORNING/AFTERNOON. GIVEN THEIR
PERFORMANCE THUS FAR...THE HI-RES WRFS AND NAM 4KM NEST APPEAR TO
HAVE THE BEST HANDLE ON THE SITUATION. HRRR AND RAP ARE SLOWLY
CATCHING ONTO REALITY BUT NOT FAST ENOUGH TO BE USED FOR THIS
MORNINGS FORECAST UNFORTUNATELY. COMPLETELY AVOIDING THE GFS EC AND
GEM GIVEN THEIR LACKLUSTER PERFORMANCE THUS FAR.
THE TROUGH AXIS PASSES OVERHEAD AROUND 06Z TONIGHT AND CONDITIONS
SHOULD BEGIN DRYING OUT AS EARLY AS SUNDAY MORNING. FOR THE VAST
MAJORITY OF THE LOWER DESERTS...SUNDAY MAY END UP TURNING OUT TO BE
A PRETTY NICE DAY WITH GRADUALLY CLEARING SKIES BY EARLY AFTERNOON.
SOUTHERN GILA COUNTY WILL LIKELY SEE SHOWERS HANG ON THE
LONGEST...BUT EVEN THEY MAY END UP CLEARING OUT SOONER THAN LATER.
POPS WERE ADJUSTED SLIGHTLY DOWNWARD ACROSS THE BOARD SUNDAY MORNING
THROUGH SUNDAY AFTERNOON.
AFTER THAT...ZONAL FLOW WILL ESTABLISH ITSELF ON MONDAY FOLLOWED BY
WEAK MID-WEEK RIDGING. LOOK FOR TEMPERATURES TO SLOWLY RESPOND BACK
TO NORMAL BY MID WEEK AND ABOVE NORMAL BY THE END OF THE WEEK. THERE
IS SOME SUGGESTION OF A TROUGH MOVING THROUGH THE FOUR CORNERS LATE
IN THE WEEK /FRIDAY OR SATURDAY/ BUT PRECIP POTENTIAL LOOKS MINIMAL
GIVEN THE SOURCE REGION OF THE TROUGH. COULD BRING SOME BREEZINESS
AND SLIGHTLY COOLER TEMPS BUT THAT LOOKS TO BE ABOUT IT.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
BAND OF LOW LEVEL MOISTURE MOVING ACROSS ARIZONA...ASSOCIATED WITH
WEAKENING FRONT...HAS CAUSED CIGS TO LOWER TO 4-6 KFT MSL AS OF
09Z...INCLUDING METRO PHOENIX AREA. EXPECT THIS TO CONTINUE FOR REST
OF THE DAY TODAY THOUGH SOME OCCASIONALLY HIGHER CIGS ARE QUITE
LIKELY. SHOWERS HOWEVER HAVE BEEN MUCH LESS WIDESPREAD THAN
PREVIOUSLY THOUGHT. HRRR MODEL HAS BEEN HANDLING THINGS WELL THE
PAST SEVERAL HOURS AND LATEST RUN DEPICTS ONLY SOME SPOTTY SHOWER
ACTIVITY OVER THE LOWER DESERTS UNTIL AT LEAST 16Z WHEN SHOWERS
BECOME MORE NUMEROUS AS UPPER LOW APPROACHES. LATEST TAF AMENDMENTS
REFLECT THAT THINKING. SOME LOCAL GUSTINESS OF 25-30 KTS IS POSSIBLE
EVEN WITH GARDEN VARIETY SHOWERS. COULD SEE SOME STRAY T-STORMS
MIDDAY ONWARD WHICH WOULD CREATE LOCALLY BRIEF HEAVY RAIN/SMALL
HAIL...STRONG GUSTS...LOWERED VIS...AND EVEN LOWER CIGS BUT
CONFIDENCE TOO LOW TO MENTION FOR ANY ONE TAF SITE AT THIS TIME.
OTHERWISE...ANTICIPATE WINDS FROM 200-230 DEGREES TO PREVAIL WITH
SOME OCCASIONAL GUSTS TO 20 KTS POSSIBLE.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SHOWER ACTIVITY HAS TAPERED OFF AS SHOWERS ARE STRUGGLING TO MAKE IT
OVER THE COASTAL MOUNTAINS. HRRR MODEL HAS CAPTURED TRENDS WELL OVER
THE LAST SEVERAL HOURS AND IT DEPICTS ONLY VERY ISOLATED SHOWERS
BEFORE 18Z FOLLOWED BY SCATTERED DEVELOPMENT FOR THE AFTERNOON. WEST
AND SOUTHWEST WINDS WILL PREVAIL WITH SOME GUSTS OF 25-30 KTS
POSSIBLE...MAINLY WEST OF LOWER COLORADO RIVER VALLEY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
A LOW PRESSURE SYSTEM WILL EXIT THE FORECAST AREA SUNDAY. THERE WILL
BE A LINGERING CHANCE OF SHOWERS SUNDAY...MAINLY OVER THE HIGHER
TERRAIN OF SOUTH-CENTRAL ARIZONA. TEMPERATURES WILL STILL BE BELOW
NORMAL SUNDAY AND HUMIDITIES WILL BE ELEVATED. HIGH PRESSURE BUILDS
BACK INTO THE REGION MONDAY THROUGH THURSDAY FOR A WARMING TREND
ALONG WITH LESS WIND. HUMIDITIES WILL DECREASE THOUGH OVERNIGHT
RECOVERY WILL REMAIN GOOD.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...AJ
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
123 AM MST SAT MAR 1 2014
.SYNOPSIS...
A WELL DEFINED PACIFIC STORM SYSTEM WILL SLOWLY MOVE THROUGH THE
AREA TODAY...EVENTUALLY BRINGING SHOWERS AND ISOLATED THUNDERSTORMS
TO THE PHOENIX AREA. CONDITIONS WILL DRY OUT FROM WEST TO EAST THIS
EVENING WITH NEARLY EVERYONE DRYING OUT COMPLETELY BY SUNDAY
AFTERNOON. FOLLOWING THE LOW...DRY WEATHER IS EXPECTED ALONG WITH A
RETURN TO ABOVE NORMAL TEMPERATURES BY LATE WEEK.
&&
.DISCUSSION...
FOR THOSE OF US IN THE PHOENIX AREA...THIS UPPER LOW HAS BEEN AN
ABYSMAL UNDER-PERFORMER THUS FAR. UNLESS YOU WERE ONE OF THE LUCKY
ONES CAUGHT UNDER A BRIEF SHOWER IN CAVE CREEK/CAREFREE FRIDAY
EVENING...YOU HAVENT SEEN A DROP THUS FAR. WHILE SOUTHEAST
CALIFORNIA AND WESTERN ARIZONA HAS FARED SOMEWHAT BETTER...RAINFALL
STILL HASNT FILLED IN TO THE EXTENT THAT IT SHOULD HAVE.
THAT BEING SAID...ALL HOPE IS NOT LOST...NOT BY A LONG-SHOT. THE 1+
INCH PWAT AXIS IS NOW SQUARELY POSITIONED OVERHEAD ALONG WITH
850-700MB WINDS AROUND 60-65KTS. NOT SURPRISINGLY...THOSE LOCATIONS
DIRECTLY WITHIN THE UPSLOPE FLOW /FOOTHILLS AND HIGHER TERRAIN NORTH
AND EAST OF PHOENIX/ ARE IN PRETTY GOOD SHAPE WITH THE REGIONAL
RADAR MOSAIC FILLING IN QUITE A BIT SINCE MIDNIGHT. THERES EVEN A
HINT AT NEW SHOWER DEVELOPMENT OVER THE FAR NORTH PART OF THE METRO
/CEILINGS HAVE BEEN GRADUALLY LOWERING SINCE MIDNIGHT/ AND KYUX IS
SHOWING SOME NEW ACTIVITY ACROSS FAR EASTERN YUMA/LA PAZ COUNTIES.
WITH A SOLID 10-12HRS WORTH OF ANOMALOUSLY STRONG UPSLOPE WINDS
FORECAST TO REMAIN IN PLACE OVER THE FORECAST AREA THROUGH 18Z
COINCIDENT WITH AT LEAST 1.1 INCH PWATS...EVEN THE DRIEST MODELS ARE
ADVERTISING CONVECTION TO DEVELOP AND FILL IN BY LATE
MORNING...ALBEIT AT A GLACIAL PACE. ONCE THE COLD CORE ALOFT MOVES
OVERHEAD BETWEEN 18Z AND 00Z...EXPECT ADDITIONAL DEVELOPMENT TO
BLOSSOM ACROSS THE LOWER DESERTS AS MID LEVEL LAPSE RATES STEEPEN
DRAMATICALLY. SOUTHEAST CALIFORNIA ISNT QUITE THROUGH WITH THE
PRECIP BUT AS THEY WILL LOSE THEIR DEEPEST MOISTURE LATER THIS
MORNING...THEIR POPS WILL BE A BIT LOWER THAN THOSE AROUND THE
PHOENIX AREA.
THUS...IM MAKING SOME ADJUSTMENTS TO POPS/QPF FOR THE ENTIRE
FORECAST AREA. POPS/QPF WILL BE LOWERED A BIT ACROSS THE BOARD
THROUGH LATE MORNING TO BETTER REFLECT WHAT HAS HAPPENED THUS FAR
AND WHAT LITTLE IS DEVELOPING ON RADAR TO OUR SOUTH...BUT WILL BE
RETAINED AROUND 100 PERCENT FOR LATE MORNING/AFTERNOON. GIVEN THEIR
PERFORMANCE THUS FAR...THE HI-RES WRFS AND NAM 4KM NEST APPEAR TO
HAVE THE BEST HANDLE ON THE SITUATION. HRRR AND RAP ARE SLOWLY
CATCHING ONTO REALITY BUT NOT FAST ENOUGH TO BE USED FOR THIS
MORNINGS FORECAST UNFORTUNATELY. COMPLETELY AVOIDING THE GFS EC AND
GEM GIVEN THEIR LACKLUSTER PERFORMANCE THUS FAR.
THE TROUGH AXIS PASSES OVERHEAD AROUND 06Z TONIGHT AND CONDITIONS
SHOULD BEGIN DRYING OUT AS EARLY AS SUNDAY MORNING. FOR THE VAST
MAJORITY OF THE LOWER DESERTS...SUNDAY MAY END UP TURNING OUT TO BE
A PRETTY NICE DAY WITH GRADUALLY CLEARING SKIES BY EARLY AFTERNOON.
SOUTHERN GILA COUNTY WILL LIKELY SEE SHOWERS HANG ON THE
LONGEST...BUT EVEN THEY MAY END UP CLEARING OUT SOONER THAN LATER.
POPS WERE ADJUSTED SLIGHTLY DOWNWARD ACROSS THE BOARD SUNDAY MORNING
THROUGH SUNDAY AFTERNOON.
AFTER THAT...ZONAL FLOW WILL ESTABLISH ITSELF ON MONDAY FOLLOWED BY
WEAK MID-WEEK RIDGING. LOOK FOR TEMPERATURES TO SLOWLY RESPOND BACK
TO NORMAL BY MID WEEK AND ABOVE NORMAL BY THE END OF THE WEEK. THERE
IS SOME SUGGESTION OF A TROUGH MOVING THROUGH THE FOUR CORNERS LATE
IN THE WEEK /FRIDAY OR SATURDAY/ BUT PRECIP POTENTIAL LOOKS MINIMAL
GIVEN THE SOURCE REGION OF THE TROUGH. COULD BRING SOME BREEZINESS
AND SLIGHTLY COOLER TEMPS BUT THAT LOOKS TO BE ABOUT IT.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SOUTHERLY CROSS WINDS AT KPHX AND KIWA...OCCASIONALLY GUSTING AOA
20KT WILL BE ONE AVIATION CONCERN THROUGH THE ENTIRE NIGHT WITH THE
STRONG PRESSURE GRADIENT NOT ALLOWING WINDS TO RELINQUISH THEIR
GUSTY CHARACTER. INITIAL BANDS OF SHOWERS WILL REMAIN NORTH AND WEST
OF CNTRL ARIZONA TERMINALS THROUGH THE EVENING...WITH BETTER CHANCES
FOR MORE ORGANIZED SHOWERS AFTER 06Z. WHILE CHANCES FOR TS OVERNIGHT
EXIST...PROBABILITIES ARE VERY LOW. THERE IS SOME MODEL INDICATIONS
OF PERSISTENT CIGS FALLING INTO A 4K-5K FT LEVEL SAT MORNING AS SCT
SHOWERS MAY LINGER IN THE VICINITY AFTER SUNRISE. THE BEST CHANCES
FOR MDT/HVY SHOWERS WILL EXIST SAT AFTERNOON...THOUGH CIGS SHOULD
RISE AOA 6K FT.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE AHEAD OF
AN APPROACHING FRONTAL BOUNDARY THIS EVENING...WITH ACTIVITY
EXPECTED TO MOVE EAST AFTER 03Z-06Z. WIND GUSTS TO AOA 25 KT WILL BE
PREVALENT...THOUGH GUSTS APPROACHING 40KT WITH SHIFTING DIRECTION
WILL BE POSSIBLE IN STRONGER SHOWERS. EMBEDDED ISOLD TS WILL ALSO BE
POSSIBLE THIS EVENING. REDEVELOPMENT OF ISOLD/SCT SHOWERS MAY BE
POSSIBLE SAT AFTERNOON...THOUGH CIGS THROUGH THE PERIOD SHOULD
REMAIN AOA 6K FT.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
A LOW PRESSURE SYSTEM WILL EXIT THE FORECAST AREA SUNDAY. THERE WILL
BE A LINGERING CHANCE OF SHOWERS SUNDAY...MAINLY OVER THE HIGHER
TERRAIN OF SOUTH-CENTRAL ARIZONA. TEMPERATURES WILL STILL BE BELOW
NORMAL SUNDAY AND HUMIDITIES WILL BE ELEVATED. HIGH PRESSURE BUILDS
BACK INTO THE REGION MONDAY THROUGH THURSDAY FOR A WARMING TREND
ALONG WITH LESS WIND. HUMIDITIES WILL DECREASE THOUGH OVERNIGHT
RECOVERY WILL REMAIN GOOD.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...MO
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS RENO NV
850 PM PST FRI FEB 28 2014
.UPDATE...
ONGOING FORECAST IS LARGELY ON TRACK FOR SNOWFALL AND TRENDS IN
THE SIERRA, WHERE SNOW IS GRADUALLY TAPERING TO SHOWERS. WILL
ALLOW WARNING AND ADVISORY FOR MONO CO AND TAHOE RESPECTIVELY, TO
EXPIRE AT 10 PM. PERIODS OF LIGHT TO MODERATE SNOW SHOWERS ARE
EXPECTED OVERNIGHT BUT ACCUMULATIONS SHOULD BE LIMITED TO AN INCH
OR TWO MAINLY ALONG THE CREST. IN FACT, SNOW HAS REALLY STRUGGLED
TO SPILL OVER INTO TRUCKEE/TAHOE LAST FEW HOURS.
NOW, FURTHER NORTH GUIDANCE HAS BEEN INDICATING THE DEVELOPMENT
OF A DEFORMATION BAND OF RAIN/SNOW NORTH OF SUSANVILLE-GERLACH
FROM NOW UNTIL ABOUT 12Z/SAT. THE HRRR REALLY PICKS UP ON THIS AS
DOES THE NAM, AND TO A LESSER EXTENT THE GFS. RADAR IS ALSO
SHOWING A BAND IN THIS AREA, MOVING SLOWLY NORTH. FORECAST
SOUNDINGS SHOW SNOW LEVELS DROPPING TO BELOW 5000 FEET. THIS
PATTERN SEEMS FAVORABLE FOR SEVERAL INCHES OF SNOW ACCUMULATION
FOR CEDARVILLE AND ADJACENT AREAS - SO WILL BE ISSUING AN
OVERNIGHT ADVISORY FOR THOSE ZONES.
REST OF FORECAST UNCHANGED. UPDATED PRODUCTS OUT SHORTLY.
CS
&&
.PREVIOUS DISCUSSION... /ISSUED 255 PM PST FRI FEB 28 2014/
SYNOPSIS...
A WINTER STORM WILL CONTINUE TO PROVIDE PERIODS OF HEAVY SIERRA
SNOWFALL THIS EVENING, PARTICULARLY IN MONO COUNTY. A MIX OF LIGHT
RAIN AND SNOW SHOWERS THIS EVENING FOR WESTERN NEVADA. SHOWERS
WILL DIMINISH BY SATURDAY AFTERNOON WITH ADDITIONAL WEAKER STORMS
MOVING INTO THE WEST COAST NEXT WEEK. EACH WILL BRING THE POTENTIAL
FOR SNOW IN THE SIERRA WITH RAIN SHOWERS FOR WESTERN NEVADA.
SHORT TERM...
AN OCCLUDED LOW OFF THE COAST CONTINUES TO STREAM MOISTURE ACROSS
CENTRAL CALIFORNIA AND INTO THE SIERRA. THIS PROVIDED PERIODS OF
HEAVY SNOWFALL ACROSS THE SIERRA PARTICULARLY IN MONO COUNTY. A
TEMPORARY LULL IN SNOWFALL WILL PERSIST EARLY THIS AFTERNOON WITH
ANOTHER PUSH OF HEAVIER SNOWFALL BEGINNING TO MOVE ACROSS THE
SIERRA IN MONO COUNTY.
TEMPERATURES IN THE SIERRA VALLEYS HAVE WARMED INTO THE LOW 40S BUT
COULD SEE SNOW LEVELS EASILY FALL BACK TO LAKE LEVEL DUE TO THE
CONVECTIVE NATURE OF THE INCOMING BANDS OF PRECIPITATION. COULD SEE
AN ADDITIONAL 3-6" OF SNOW THROUGH THIS EVENING IN THE SIERRA ABOVE
7000 FEET WITH 6-9" IN MONO COUNTY. UP TO 3 INCHES OF ADDITIONAL
SNOWFALL IS POSSIBLE FOR AREAS BELOW 7000 FEET. AREAS WITHIN
CONVECTIVE BANDS COULD SEE RATES OF 3-4"/HR BUT PREDICTABILITY OF
WHERE THEY DEVELOP IS LOW. AS SUCH, WILL ALLOW WINTER WARNING AND
ADVISORIES TO CONTINUE INTO THIS EVENING. ACROSS WESTERN NEVADA
MAINLY LIGHT SHOWERS WILL PERSIST THROUGH THIS EVENING WILL ONLY
LIGHT RAIN AND SNOW ACCUMULATIONS EXPECTED WITH SNOW LEVELS
GENERALLY AROUND 5500-6000 FEET THIS EVENING. SHOWERS WILL DIMINISH
OVERNIGHT WITH SOME BANDED RAIN SHOWERS POSSIBLE ACROSS NORTHERN
WASHOE AND CHURCHILL COUNTIES.
ON SATURDAY THE UPPER LOW DROPS TO OUR SOUTH LEAVING US WITH MAINLY
CLOUDY CONDITIONS. LINGERING SHOWERS POSSIBLE WITH ONLY ABOUT AN
INCH OR TWO OF ADDITIONAL SNOWFALL POSSIBLE ALONG THE CREST AND
FEW HUNDREDTHS OF AN INCH OF RAINFALL ACROSS WESTERN NEVADA. ON
SUNDAY, FLOW TURNS ZONAL WITH MOSTLY CLOUDY CONDITIONS REMAINING
WITH CHANCES FOR RAIN/SNOW SHOWERS MAINLY NORTH OF I-80 THROUGH
WESTERN PORTIONS OF LASSEN COUNTY. FUENTES
WARM BUT CLOUDY CONDITIONS SUNDAY NIGHT AND MONDAY AS THE MOIST
ONSHORE FLOW CONTINUES. MODELS ARE VARYING ON THE TRACK OF WAVES
MOVING INTO THE WEST COAST, BUT AT THIS TIME BEST CHANCE OF RAIN
AND SNOW REMAINS NORTH OF INTERSTATE 80. THE WARM NATURE OF THE
FLOW WILL KEEP SNOW LEVELS AT 6500-7500 FEET, WITH ONLY LIGHT
SNOW ACCUMULATIONS POSSIBLE NEAR THE SIERRA CREST. BRONG
LONG TERM...TUESDAY THROUGH FRIDAY...
CHANCES FOR PRECIPITATION WERE CUT BACK TUESDAY AND WEDNESDAY,
ESPECIALLY ALONG/SOUTH OF INTERSTATE 80, OTHERWISE NO SIGNIFICANT
CHANGES TO THE LONG TERM FORECAST.
TUESDAY AND WEDNESDAY, SHORTWAVE RIDGING IS PROJECTED BY MOST MODELS
TO BUILD OVER THE SIERRA AND WESTERN NEVADA. THEREFORE, I TRENDED
THE SHOWER COVERAGE FOR THOSE DAYS DOWN SLIGHTLY AND THEY COULD BE
CUT BACK FURTHER IF THE MODELS/ENSEMBLES HOLD TRUE TO THE RIDGE
CONCEPT. TEMPERATURES WILL BE MILD AT AROUND 10 DEGREES ABOVE
AVERAGE.
WEDNESDAY NIGHT AND THURSDAY, AN UPPER LOW MOVES INTO THE PACIFIC
NORTHWEST AND SUPPRESSES THE UPPER RIDGE OVER THE REGION. WEDNESDAY
NIGHT AND THURSDAY LOOKS TO BE BREEZY TO WINDY AS THE UPPER LOW
MOVES INTO THE PACIFIC NORTHWEST AND PUSHES A COLD FRONT INTO
NORTHERN CALIFORNIA AND NEVADA. PRECIPITATION-WISE, THE BEST UPPER
FORCING IN THE 12Z GFS/ECMWF APPEARS TO REMAIN NORTH OF THE REGION.
WITH THE UPPER FORCING REMAINING MOSTLY NORTH, A MODERATE MID LEVEL
MOISTURE FEED MOVING IN AHEAD OF THE UPPER LOW COULD WEAKEN AND
BECOME DISJOINTED WITH LOWER LEVEL MOISTURE AS IT MOVES INTO THE
SIERRA/WESTERN NEVADA. STILL, THERE SHOULD BE AMPLE MOISTURE AND
MID LEVEL FLOW TO PUSH PRECIPITATION OVER THE CREST INTO NORTHEAST
CALIFORNIA (TAHOE NORTH). IT IS JUST FURTHER SOUTH AND EAST INTO
MONO COUNTY AND WESTERN NEVADA THAT PRECIPITATION MAY BE SHADOWED
SIGNIFICANTLY, SETTING UP MORE OF A WIND EVENT THAN ANYTHING ELSE.
THURSDAY NIGHT AND FRIDAY, AN UPPER RIDGE IS EXPECTED TO BUILD BACK
OVERHEAD FOR DRIER CONDITIONS. TEMPERATURES WILL BE KNOCKED DOWN
BEHIND THURSDAY`S FRONT TO MORE SEASONAL NUMBERS IN THE 40S (SIERRA)
AND 50S (LOWER VALLEYS). SNYDER
&&
AVIATION...
LOW PRESSURE OFF THE CENTRAL CALIFORNIA COAST WILL MOVE INLAND ON
SATURDAY. FOR TONIGHT, SOUTHERLY FLOW IS PUSHING WIDESPREAD LIGHT TO
MODERATE LOWER VALLEY RAIN AND MOUNTAIN SNOW INTO THE SIERRA AND FAR
WESTERN NEVADA. PRECIPITATION WILL TAPER TO LIGHT SHOWERS, MAINLY IN
THE SIERRA, BY LATE TONIGHT AND EARLY SATURDAY MORNING.
FOR TONIGHT, THE MAIN CIG/VIS/PRECIPITATION CONCERN REMAINS IN THE
SIERRA AND PERHAPS OUT INTO EXTREME WESTERN NEVADA SOUTH OF CARSON
CITY/KCXP. WIDESPREAD TERRAIN OBSCURATION AND IFR/VIFR CIGS WILL
PERSIST FOR MUCH OF THE NIGHT AS PRECIPITATION CONTINUES, ESPECIALLY
SOUTH OF HIGHWAY 50 WHERE THE HEAVIEST PRECIPITATION IS LIKELY.
AS FAR AS SNOWFALL AT TERMINALS, THE BEST SHOT FOR ACCUMULATING
SNOWS ON UNTREATED SURFACES WILL BE AT KMMH AND KTVL THIS EVENING
(AFTER 5 PM/01Z) WHEN THE HEAVIEST SNOW COMBINES WITH COOLING
SURFACES NEAR SUNSET. BELOW ABOUT 5500 FEET TONIGHT, PRECIPITATION
WILL REMAIN MOSTLY RAIN FOR LITTLE THREAT OF SNOW ACCUMULATIONS. OUT
IN WESTERN NEVADA, THIS WILL MEAN THE BIGGEST IMPACT WILL BE HIGHER
TERRAIN OBSCURATION. SNYDER
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER WEATHER ADVISORY UNTIL 4 AM PST SATURDAY NVZ005.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING NVZ002.
CA...WINTER WEATHER ADVISORY UNTIL 4 AM PST SATURDAY CAZ070.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING CAZ073.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING CAZ072.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1102 PM CST Fri Feb 28 2014
...AVIATION UPDATE...
.UPDATE...
Issued at 950 PM CST FRI FEB 28 2014
Have updated the forecast to hold off on the patchy freezing
drizzle until after 12Z Saturday. The RAP/NAM/GFS isentropic progs
show the upglide developing between 12 and 15Z. Think this is when
any patchy freezing drizzle is most likely to occur, and it still
looks like some flurries could fly through the day as the lower
portion of the forecast soundings cool down enough for dendrites
to form.
The 00Z NAM has not cleared things up much. It is now more
aggressive in advecting dry air in from the north and ends the
precip by Sunday morning. Do not have much confidence in making
adjustments based solely off the NAM so will maintain the watch
for now. In general it looks like we could see some isentropic
upglide through the day Saturday, then a band of frontogenesis
moving across central and eastern KS overnight. Forecast soundings
from the 00Z NAM continue to suggest sleet may be the more
predominate precip type with its warm nose remaining over much of
the area until midnight. With no cyclogenesis or strong synoptic
scale forcing progged by any of the models (upper closed low
progged to weaken quite a bit as it moves across the Rockies and
become an open wave moving across OK) am wondering if a shorter
duration event is becoming more likely. Will wait to digest the
GFS and other models before making substantial changes to the
forecast.
&&
.SHORT TERM...(This Evening through Saturday)
Issued at 404 PM CST FRI FEB 28 2014
Current sfc analysis places the cold front or trough across central
KS and into SE NE. The arctic front associated with the cold air is
plowing southward through central NE at the moment, and should reach
the northwest forecast area in about an hour or two, and exit the
southeast forecast area by around midnight. Ahead of the front low
level moisture has been slow to spread northward, but has finally
made it into most of northern KS in the form of a stratus deck.
With the moisture in place isolated to scattered rain showers are
possible along and behind the front mainly north of interstate 70
for the rest of this evening as it progresses eastward along the NE
KS border. Any precip that falls should remain light. Winds shift
behind the front the to NNE and increase to around 15 mph with gusts
up to 20 mph. Some of the latest guidance is suggesting the low
level lift and saturation remains over eastern KS through the
overnight hours. With temperatures rapidly falling behind the front
there could be a period of light freezing drizzle. As the deep cold
air continues to filter southward temperatures within the layer of
lift may be cold enough for ice growth therefore flurries could mix
in as well. The NAM keeps the lift through tomorrow afternoon,
although there could be a lull early tomorrow morning before picking
up again ahead of the approaching system. Do not expect much impact
from the freezing drizzle since the warm temperatures today and
flurries could mix in as well. Also not confident how long the low
level lift persists behind the front. Temperatures will bottom out
overnight and should reach the low 10s in north central KS to the
mid 20s in far east central KS by sunrise tomorrow. Temperatures
will basically remain steady through the day tomorrow with the highs
only a few degrees warmer than the morning lows as of now. As the
lift and saturation increases in the mid levels tomorrow afternoon
snow could develop especially areas north of interstate 70. Models
do agree that the warm nose could still be present tomorrow
afternoon as far north as the NE KS border so could not rule out
periods of sleet as well.
.LONG TERM...(Saturday Night through Friday)
Issued at 404 PM CST FRI FEB 28 2014
The bulk of the attention today was placed on the period from
Saturday evening through Monday morning, when a potentially
significant winter storm combined with dangerously cold wind chills
will impact the area. From a forecast perspective, uncertainty is
higher than normal and the potential spread of forecast solutions is
quite large. So, while the entire area will experience hazardous
winter weather, the magnitude of the winter storm remains very much
in question.
In this rather complex weather scenario, the first player will be an
upper trough and jet max that moves well to our north and into the
Great Lakes region. This system will send increasingly cold air into
Kansas, air which will also be a bit drier in nature. The associated
frontogenesis and favorable jet dynamics will also provide enhanced
vertical motion across the area and associated precipitation. At the
same time...a well developed storm system will move out of the
southern Rockies. Ahead of this trough, a broad area of warm moist
advection will overtake the Southern Plains and nose into the
Central Plains...overriding the cold air incoming from the north.
This will create a very dynamic situation by Saturday evening
through Sunday morning during which a battle between dry cold
advection from the north and moist warm advection from the south
will result in bands of probably intense vertical motion. In more
detail, these bands will be comprised mainly of intense
frontogenesis in the mid levels, isentropic ascent within and above
the nose of warm advection aloft, favorable jet dynamics, and the
coincidence of this lift with weakly stable to convectively unstable
thermal profiles. The expected result is a WSW to ENE oriented band
of heavy precipitation gradually moving south across the area from
Saturday evening into Sunday. As the southwest trough approaches,
the progression of the heavy precipitation band will slow and nearly
stop...with some model guidance suggesting additional precipitation
developing north of the heaviest band and spreading back across the
area. Some of the latest mid day guidance however is more aggressive
with the intrusion of the northerly dry air and maintains a track
of the upper trough a bit farther south...which would limit precip
in northern parts of the forecast area on Sunday.
There are currently two primary questions with this forecast. The
first is the magnitude of the dry air incoming from the north. If
this airmass marches well into the forecast area on Sunday...which
would also be tied to the storm track of the incoming upper
trough...then precip amounts on Sunday would be substantially lower
especially north of I-70. If this precip falls, it would be entirely
snow so any reduction in precip on Sunday would be a stark reduction
in snow totals on top of any sleet/snow combo that falls with the
heaviest band. The other primary forecast question revolves around
whether we get more sleet or snow as the heaviest band drifts
overhead. Sleet is definitely favored early in the event near and
south of I-70, and it could pile up quickly before turning over to
snow. This would cause snow amounts to be much lower however. The
current forecast reflects this in lower snow amounts along the I-35
corridor despite higher expected liquid content. A quicker change
over to snow would obviously result in less sleet and a lot more
snow. As it stands, expect some locations especially near and south
of I-35 to be in the 0.5 to 1 inch of sleet range. Snow amounts near
the Nebraska border should be lightest...probably in the 1-5 inch
range with more uncertainty farther south. Would not be surprised to
have several observations of 6 to 8 inches in addition to some
sleet. With all of this in mind, have maintained the winter storm
watch for most of the area, but did issue a winter weather advisory
for the far northern counties as the probability of a non-warning
winter weather event is likely in this area.
Wind chills will be very cold from Saturday night through Monday
morning, and will not rise above -10 during the day on Sunday before
approaching -25 on Monday morning. Beyond Monday, a gradual warming
trend is expected with no high impact weather expected through the
remainder of the forecast.
&&
.AVIATION...(For the 06Z TAFs through 06Z Saturday Night)
Issued at 1102 PM CST FRI FEB 28 2014
Models are in reasonable agreement that MVFR CIGS will persist
through the period. The RAP and NAM isentropic surfaces continue
to show relatively deep upglide developing by mid morning, and think
there is a good chance for patchy freezing drizzle and flurries in
the late morning and through the afternoon. Confidence in the
start of the heavier banded sleet and snow with possible IFR CIGS
and VSBY is a little more marginal, and may begin closer to 06Z
Sunday. Therefore will not include any IFR conditions at this time
and let later shifts refine the timing.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH from Saturday evening through late Sunday
night FOR KSZ021>024-026-034>040-054>056-058-059.
WINTER WEATHER ADVISORY from 6 PM Saturday to 6 AM CST Monday
FOR KSZ008>012-020.
&&
$$
UPDATE...Wolters
SHORT TERM...Sanders
LONG TERM...Barjenbruch
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1228 AM EST SAT MAR 1 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 341 PM EST FRI FEB 28 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW ARCTIC BRANCH WNW
FLOW ALF OVER THE UPR LKS TO THE S OF CORE OF ARCTIC AIRMASS/CLOSED
LO CENTERED OVER SRN HUDSON BAY. 12Z H5 TEMP WAS AS LO AS AN
IMPRESSIVE -50C OVER NRN QUEBEC...AND -30C OR LOWER H85 TEMPS WERE
PRESENT WITHIN THE CORE OF COLDEST AIR. A FAIRLY STRONG SHRTWV
EMBEDDED IN THE ARCTIC BRANCH IS CURRENTLY JUST W OF LK WINNIPEG...
WITH SUPPORTING AXIS OF STRONGER H3 WINDS AOA 100KT STRETCHING FM
JUST S OF THE SHRTWV ACRS THE UPR LKS INTO NEW ENGLAND. SOME
ENHANCED CLDS ARE PRESENT OVER THE NRN PLAINS INTO MN IN WHAT
APPEARS TO BE THE RRQ OF SPEED MAX SUPPORTING THE LK WINNIPEG
SHRTWV. THIS AREA IS ALSO EXPERIENCING GENERAL WAD/ISENTROPIC ASCENT
IN THE SW FLOW AHEAD OF ACCOMPANYING H85 LO CENTER JUST S OF LK
WINNIPEG. DESPITE QUITE A BIT OF VERY DRY LLVL AIR SHOWN ON LOCAL
12Z RAOBS...H925 DEWPT DEPRESSION WAS AS HI AS 26C AT MPX AT 12Z...
SOME PATCHY LGT SN HAS BROKEN OUT OVER NE MN WHERE LATEST RUC
ANALYSIS INDICATES SHARPER ISENTROPIC ASCENT/MOISTENING ON THE
270-280K SFCS /ABOUT H85-7/. DESPITE WHAT APPEARS TO BE FAIRLY
EXTENSIVE ICE COVER ON VSBL STLT IMAGE OVER THE N PORTION OF LK
MI...A BAND OF -SHSN IN THE LLVL SSW WIND UP THE LENGTH OF LK MOVED
AS FAR N AS INTO MANISTIQUE BY LATE IN THE MRNG. ANOTHER BAND OF SN
UNDER AXIS OF SHARPER MID LVL FGEN IS STREAKING ENEWD THRU WI TOWARD
SCENTRAL UPR MI. OTRW...SFC TEMPS OVER UPR MI HAVE RECOVERED ABV
ZERO FM THE RECORD COLD OBSVD THIS MRNG DESPITE THE THICKENING WAD
CLDS. THE LOWEST TEMP REPORTED WAS -41F AT NEWBERRY CITY.
MAIN FCST CONCERNS IN THE SHORT TERM WL BE SN TRENDS/POPS/GOING
HEADLINES ASSOCIATED WITH SHRTWV/SFC LO NOW NEAR LK WINNIPEG. FOCUS
FOR LATER TNGT INTO SAT TURNS TO TEMPS ONCE DRIER AIR RETURNS ALF
AND ENDS THE PCPN. PER NCEP GUIDANCE AND ITS CONSISTENT HANDLING OF
APRCHG DISTURBANCE...GENERALLY FOLLOWED THE 12Z GFS FOR FCST PREP.
LATE THIS AFTN/TNGT...AREA OF DEEP LYR QVECTOR CNVGC/ISENTROPIC
ASCENT ASSOCIATED WITH UPSTREAM SHRWTV IS FCST TO OVERSPREAD THE UPR
LKS BY THIS EVNG BEFORE PUSHING OFF TO THE EAST AFT MIDNGT WITH
VIGOROUS MID LVL DRYING/DEEP LYR QVECTOR DVGC FOLLOWING. EXPECT THE
PATCHY LGT SN IN NRN MN EARLY THIS AFTN TO OVERSPREAD MOST OF UPR MI
BY LATE AFTN. MODELS CONTINUE TO INDICATE THE WAD PCPN WL BE
ENHANCED A BIT BY SOME UPR DVGC IN RRQ OF 120KT H3 JET MAX THAT IS
SUPPORTING THE ENHANCED CLDS NOW OVER MN AND WHICH WL BE STREAKING
EWD ACRS LK SUP AND INTO SE ONTARIO AFTER 00Z. LOOKS LIKE THE
HEAVIEST PCPN WL FALL OVER THE SE HALF OF THE CWA CLOSER TO AXIS OF
SHARPEST MID LVL FGEN AND WHERE THERE WL BE SOME ENHANCEMENT WITH
LLVL SSW FLOW UP THE LENGTH OF LK MI...INCLUDING THE OPEN WATERS S
OF THE LATITUDE OF MENOMINEE WHERE LES BAND WAS QUITE APRNT ON VSBL
STLT IMAGERY BEFORE THE ARRIVAL OF HIER CLDS OBSCURED THIS FEATURE.
THE ARRIVAL OF THE MID LVL DRYING/DEEP LYR QVECTOR DVGC WL END
OVERALL LIGHTER PCPN OVER THE W EARLY THIS EVNG AND OVER THE E SOON
AFT 06Z. AS FOR SN TOTALS...H7 SPECIFIC HUMIDITY IS FCST TO INCRS TO
1.5-2.0 G/KG OVER THE SE CWA AT 00Z. WITH A 6HR PERIOD OF SYNOPTIC
SN AT MOST LOCATIONS...THAT WOULD EQUATE TO UP TO 2 INCHES OF ACCUM.
BUT FCST SDNGS CONT TO EXHIBIT A DEEP DGZ THAT IS 10K FT OR EVEN
DEEPER. WITH FVRBL SN/WATER RATIOS THAT MAY BE AS HI AS 25-30:1...
EXPECT UP TO 4 INCHES SN TOTAL OVER MUCH OF THE SE CWA WHERE DYNAMIC
SUPPORT WL BE GREATEST. WITH SOME ENHANCEMENT OFF LK MI THAT MIGHT
ADD AN ADDITIONAL INCH OR 2 TO THE SN TOTALS...GOING ADVYS FOR
DELTA/SRN SCHOOLCRAFT COUNTIES STILL SEEM ON TARGET. AFTER THE PCPN
ENDS...A DVLPG NW FLOW IN THE WAKE OF THE SFC LO CENTER TRACKING
ACRS LK SUP WL ADVECT COLDER AIR BACK INTO THE UPR LKS...DROPPING
H85 TEMPS TO ARND -25C OVER THE NW BY 12Z SAT. WITH EXTENSIVE ICE
COVER ON LK SUP...ANY LK EFFECT SHSN IN THE NW WIND SN BELTS SHOULD
BE NO MORE THAN ISOLD. SO MAINTAINED ONLY SCHC POPS IN THESE
LOCATIONS. THE REST OF THE CWA WL BE DRY AFT THE EVNG PCPN EXITS.
ONE CONCERN IS THE POTENTIAL FOR ADVY LVL WIND CHILLS OVER THE W
LATER ON. PREFER THE SOMEWHAT STRONGER WINDS SHOWN BY THE FAVORED
GFS...WHICH HAS CONSISTENTLY SHOWN A DEEPER SFC LO TRACKING ACRS LK
SUP. BUT EVEN THE HIER GFS NW WINDS AND FCST MIN TEMPS CLOSE TO -10F
OVER THE W RESULT IN ONLY MARGINAL WIND CHILLS NEAR -25F LATE TNGT
INTO SAT MRNG. SO OPTED TO HOLD OFF ON ADVY FOR NOW.
SAT...THE CWA WL BE DOMINATED BY COLD...ACYC NW FLOW E OF ARCTIC HI
PRES BLDG INTO THE NRN PLAINS. H85 TEMPS ON SAT ARE FCST TO FALL TO
-29C OVER THE NW TO -25C OVER THE SE CWA BY 00Z SUN. OVERALL ACYC
FLOW AND NEAR ABSENCE OF OPEN WATER OVER LK SUP SHOULD RESTRICT LES
POPS TO NO HIER THAN LO CHC. GUSTY NW WINDS WITH UNSTABLE LLVL LAPSE
RATES UP TO INVRN BASE NEAR H85 WL ALLOW FOR SOME BLSN MAINLY IN
OPEN AREAS NEAR LK SUP DOWNWIND OF SNOW COVERED ICE THAT HAVE BEEN
PLAGUED BY THESE EVENTS THRU THIS COLD WINTER. BUT SINCE LTL IF ANY
SN WL BE FALLING...SUSPECT THERE WL BE NO SGNFT ISSUES. GIVEN THE
ANOMALOUSLY COLD H85 TEMPS...TENDED TOWARD THE LOWER END OF GUIDANCE
FOR MAX TEMPS...WHICH ARE SUPPORTED BY MIXING TO H85 ON THE GFS FCST
SDNGS. WITH DISTURBANCE STREAKING E TOWARD THE LOWER LKS...NOT OUT
OF THE QUESTION THE NRN FRINGE OF -SN SHIELD COULD BRUSH THE FAR
SCNTRL LATE IN THE DAY. RETAINED SCHC POPS THERE.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 436 PM EST FRI FEB 28 2014
BY EARLY NEXT WEEK...MODELS POINT TOWARD A BREAK IN THE HIGHLY
AMPLIFIED WEST COAST/ERN PACIFIC RIDGE AND BROAD DOWNSTREAM TROUGH
PATTERN WHICH HAS CHARACTERIZED MUCH OF OUR RECORD COLD WINTER.
MODELS INDICATE THAT THE NRN END OF THE WRN RIDGE IS FCST TO CLOSE
OFF AND RETROGRADE TO SIBERIA...ALLOWING PACIFIC FLOW TO STRENGTHEN
INTO THE CONUS. THIS WILL BRING ABOUT A SLOW MODERATION IN TEMPS FOR
NEXT WEEK. HOWEVER...MEDIUM RANGE GUIDANCE CONTINUES TO SHOW A
TENDENCY FOR SOME DEGREE OF WRN RIDGING WHICH SHOULD ENSURE
GENERALLY BELOW NORMAL TEMPS PERSIST ACROSS UPPER MI FOR THE FIRST
COUPLE OF WEEKS OF MARCH. SYNOPTIC PCPN APPEARS TO BE MININAL IN
THIS PATTERN WITH THE BEST CHANCE FOR PCPN MID TO LATE WEEK AS A
SERIES OF SHORTWAVES MOVE ONSHORE FROM THE PACIFIC AND TRACK E
ACROSS THE NRN CONUS IN A MORE LOWER AMPLITUDE MORE PROGRESSIVE
FLOW. LINGERING COLD AIRMASS FOR LATE THIS WEEKEND INTO EARLY NEXT
WEEK WOULD NORMALLY RESULT IN LES OFF LAKE SUPERIOR IN NW FLOW...
BUT GIVEN NEAR 100PCT ICE COVER...LES MAY BE SHUTDOWN THRU THIS FCST
PERIOD.
SAT NIGHT INTO MONDAY...A HIGH PRES RIDGE STRETCHING FROM THE SFC
HIGH CENTER OVER THE NRN PLAINS INTO THE UPPER LAKES WILL ENSURE A
PERIOD OF DRY...BUT STILL VERY COLD WEATHER SAT NIGHT INTO SUNDAY
NIGHT. FORECASTING TEMPS WILL BE A CHALLENGE FOR SAT NIGHT INTO
EARLY NEXT WEEK AS MIN TEMPS COULD BE VERY COLD EACH NIGHT (WELL BLO
LOWEST GUIDANCE) UNDER LINGERING BUT GRADUALLY MODERATING ARCTIC AIR
MASS. HIGH CLOUDS ON THE NRN FRINGE OF DISTURBANCE PASSING TO THE S
OF THE AREA MAY LIMIT COOLING SOME SAT NIGHT. OTHERWISE...CLOUD
COVER MAY NOT BE THAT MUCH OF AN ISSUE THRU EARLY NEXT WEEK AS
BUILDING HIGH PRESSURE SHOULD ENSURE MOSTLY CLEAR SKIES AND THERE
SHOULD BE LITTLE IF ANY STRATOCU OFF WHAT SHOULD BE A TOTALLY ICE
COVERED LAKE SUPERIOR. EXPECT WINDS TO BE MOSTLY LIGHT EACH NIGHT AS
SFC HIGH PRES DOMINATES SO WILL CONTINUE TO FAVOR MIN TEMPS
GENERALLY AT OR BLO THE LOWEST GUIDANCE SAT NIGHT AND SUN
NIGHT...ESPECIALLY FOR TRADITIONAL COLD SPOTS. WITH MODELS TRENDING
FARTHER SOUTH WITH SHORTWAVE NOW FCST TO MOVE THROUGH THE NORTHERN
PLAINS AND LOWER MIDWEST...CLOUDS MAY NOT BE AS MUCH OF A FACTOR AS
PREV THOUGHT SO HAVE TRENDED COLDER WITH MIN TEMPS FOR MON
NIGHT...CLOSER TO GEM-NH BIAS CORRECTED VALUES. INCREASINGLY
HIGHER SUN ANGLE AT THIS TIME OF YEAR WORKING ON LOWER ALBEDO
FORESTED TERRAIN WILL HELP TEMPS REBOUND INTO THE SINGLE DIGITS AND
LOWER TEENS ABOVE ZERO FROM FRIGID OVERNIGHT LOWS EACH DAY...THOUGH
MAX TEMPS WILL STILL BE WELL BLO NORMAL.
12Z MODELS NOW SHOWING BIGGER DISCREPANCIES FOR MID TO LATE NEXT
WEEK. BOTH THE GEM-NH AND ECMWF AND TO A LESSER EXTENT THE UKMET
SHOW A SHORTWAVE ROTATING DOWN FM HUDSON BAY BRINGING ANOTHER PUSH
OF ARCTIC AIR INTO THE REGION. THE GEM-NH IS DEEPER AND SLOWER WITH
THIS FEATURE THAN THE ECMWF AND EVENTUALLY FORMS A CLOSED LOW BY 12Z
THU OVER THE WRN GREAT LAKES. MEANWHILE THE GFS SHOWS THIS SHORTWAVE
STAYING WELL NE AND NOT IMPACTING THE GREAT LAKES. GIVEN
UNCERTAINTY...FEEL INCLINED TO FOLLOW ALONG WITH THE ECMWF WHICH IS
MORE OF A COMPROMISE BETWEEN THE GFS AND MORE EXTREME GEM-NH SOLN.
THIS WILL KEEP MORE OF AN ARCTIC AIRMASS OVER THE AREA FOR ONE MORE
DAY WITH DOUBLE DIGIT BELOW ZERO TEMPS POSSIBLE AGAIN ON TUE NIGHT
BEFORE AIRMASS BEGINS TO MODERATE ON WEDNESDAY. MODELS STILL SHOW A
PACIFIC SHORTWAVE COMING INTO THE AREA TOWARD THE END OF THE WEEK
WITH SIGNIFICANT TIMING ISSUES. THE GFS IS MUCH MORE PROGRESSIVE
BRINGING THE SHORTWAVE AND ASSOC FRONT THROUGH THU AFTERNOON AND
EVENING WHILE THE ECMWF DOES NOT BRING IT THROUGH UNTIL LATE THU
NIGHT AND FRI. FOR NOW WILL FOLLOW CONSENSUS MODEL GUIDANCE RESULTING
IN 30 TO 40 PCT POPS FOR LIGHT SNOW MAINLY THU NIGHT INTO FRI. TEMPS
BY THE END OF THE WEEK WILL MODERATE INTO THE 20S AND MAY EVEN
APPROACH 30F AT A FEW SITES ALONG THE WI BORDER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1228 AM EST SAT MAR 1 2014
MVFR/VFR CONDITIONS EXPECTED EARLY THIS AM AS LINGERING SNOW
SHOWERS WANE WITH INCREASING SUBSIDENCE AND DRIER AIR MOVING IN.
MVFR CIGS TO LINGER THROUGH SAT MRNG AT IWD/CMX WITH STEADY...
UPSLOPE NW FLOW OF COLDER AIR. EXTENSIVE ICE COVER OVER LAKE
SUPERIOR WILL LIMIT THE POTENTIAL FOR HEAVIER LES THAT WOULD
NORMALLY BE A PROBLEM AT THESE LOCATIONS. DOWNSLOPE NW FLOW SHOULD
RESULT IN PREDOMINANTLY VFR CONDITIONS AT SAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 436 PM EST FRI FEB 28 2014
EXPECT S WINDS UP TO 20-25 KTS AHEAD OF LO PRES CROSSING LAKE
SUPERIOR THIS EVENING TO SHIFT TO THE NW LATE TONIGHT ONCE THE LO
SHIFTS INTO SE ONTARIO AND THEN INCREASE UP TO 25-30 KTS INTO SAT
UNDER SHARPENING PRES GRADIENT BETWEEN THE DEPARTING LO AND HI PRES
BUILDING INTO THE NORTHERN PLAINS. A RIDGE BUILDING ACROSS THE GREAT
LAKES FROM THE N PLAINS AND S CENTRAL CANADA SATURDAY THROUGH MONDAY
WILL ENSURE LIGHT WINDS. HIGH PRESSURE AND GENERALLY LIGHT WINDS WILL
CONTINUE TO DOMINATE THE UPPER GREAT LAKES INTO THE MIDDLE OF NEXT
WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 1 AM EST EARLY THIS MORNING FOR
MIZ014.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...VOSS
AVIATION...JLB/RJT
MARINE...KC/VOSS
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1041 PM CST Fri Feb 28 2014
.UPDATE:
Issued at 817 PM CST Fri Feb 28 2014
Going forecast looks on track. Radar continues to show weak
returns over central and southeast Missouri with high dewpoint
depressions and no precipitation reports on the surface
observations. Will maintain slight chances for rain and snow for
these returns which are being forced by weak moisture convergence
that shows up well in the RAP. RAP also shows that precipitation
now over northwestern MO will continue to move east and reach the
northern CWA after midnight.
Britt
&&
.SHORT TERM: (Through Late Tonight)
Issued at 351 PM CST Fri Feb 28 2014
(Tonight)
System currently over the south-central United States and its attendant
precipitation shield is forecast to continue to weaken as it slowly
travels to the north and east. Main impact across our CWFA will be
increasing mid/high level cloudiness. Did keep slow low chc PoPs in case
some light rain showers do hold together over portions of south-central
and southeastern Missouri early this evening. Also kept chc PoPs over
portions of northeastern Missouri and west-central Illinois roughly along
arctic baroclinic zone. For temperatures...leaned warmer ahead of boundary
overnight tonight due to expected cloud cover and southerly component to
winds.
Gosselin
.LONG TERM: (Saturday through Next Friday)
Issued at 351 PM CST Fri Feb 28 2014
Saturday through Monday: Upper shortwave ridging moves across the
area tomorrow, ensuring quiet conditions through at least the
morning hours and probably for most of the afternoon as well.
Attention then turns to a potentially high-impact late winter
storm which is expected to bring a veritable cornucopia of
precipitation types to the LSX CWA this weekend, especially from
Saturday night through Sunday night.
The overall thinking remains similar to previous forecast packages:
snow in the north (including KUIN/KHAE), freezing rain in the south
(including KFAM), a band of mixed precip in the middle (including
KCOU, KSTL, KSLO), and a gradual changeover with time from mixed
ptypes to pure snow after colder air moves into the region. The
primary forecast issues are precipitation types and amounts,
although forecasting these details is difficult since neither the
main system nor its leading shortwaves have been sampled by the
upper air network. Regardless, all guidance suggests that the
specific amounts of each precipitation type are far less important
than the cumulative effects of a widespread and prolonged wintry
mix over the region. No changes were made to the ongoing Winter
Storm Watch at this time due to continued uncertainty regarding
precipitation types and amounts.
Atmospheric features that will affect ptypes and amounts during
this event include 1) a sharpening baroclinic zone to the south of
the CWA, 2) an Arctic air mass spreading across the area from the
north, 3) a warm nose aloft associated with a LLJ, 4) several
hours where the maximum lift occurs just below or within the DGZ
in an environment which is saturated WRT ice, and 5) a secondary
DGZ which develops below 5000 ft on Sunday and may re-introduce
ice crystals at low levels. This forecast package reflects a blend
of several models excluding the SREF, which was discounted because
it was much warmer and farther north than any other guidance.
Precipitation will probably begin as snow in the north and rain or
freezing rain farther south, depending on surface temperatures. A
prolonged period of sleet (occasionally mixing with rain, freezing
rain, and/or snow depending on the location) is expected across a
broad part of the CWA. One of the factors contributing to the
prolonged period of sleet is that as the depth of the surface cold
layer gradually increases to 3000-4000 ft, the strength of the
warm nose aloft will become less important since partially or
fully melted snowflakes will have plenty of time and distance to
refreeze into ice pellets. In general, precipitation types should
change from ZR -> ZR/IP -> IP -> IP/SN -> SN. Isolated thunder is
possible on Sunday, which would tend to increase precipitation
rates.
The greatest snow accumulations are expected across northeast
MO/west central IL and the greatest ice accumulations are expected
across southern and southeastern MO into southern IL.
1020-1030 hPa surface high builds into the region on Monday
behind the departing system with unseasonably cold air returning
to the area.
Kanofsky
Tuesday through Friday: Very cold ams in the wake of the weekend
storm will mean more unusually cold early March weather lingering
into Tuesday. All of the latest raw model output and MOS-based
guidance are indicating single digits lows in the offing for the
entire CWA on Tuesday morning, with highs rebounding into the
lower 20s to lower 30s during the afternoon hours.
Heading into the latter half of the week, mean UA flow over the
CONUS takes on a much more zonal look, which should translate into
moderating temperatures. Operational GFS is forecasting a very big
warmup by Thursday, however the ECMWF, GEM, and to a lesser extent
the GFS ensemble keep heights much lower over the northeast U.S.,
which in turn keeps surface ridge entrenched from the Great Lakes
into the mid Mississippi Valley and slows the ewd erosion of the
cold air. Given the snow cover that should be blanketing much of the
region, as well as the cold track record of this winter, have used
with model consensus and gone with a slower warming trend, with
temps finally rebounding to near normal levels by Friday.
Precipitation threat looks fairly low for much of the extended
period. All medium range models to forecast shortwave to pass over
the area Wed-Wed night, but with surface ridge nosing into area
moisture should be modest so have kept PoPs in the slight chance
range for now.
Truett
&&
.AVIATION: (For the 06z TAFs through 06z Saturday Night)
Issued at 1014 PM CST Fri Feb 28 2014
Low level cloud cover around 3000-6000 ft which has advected into
COU should continue spreading ewd into the rest of the taf sites
around or shortly after 06z Saturday. A cold front extending from
just north of UIN to just southeast of MCI will drop sewd through
UIN and COU just after 06z Saturday, and through the St Louis
metro area around 12z Saturday with the wind veering around to a
n-nwly direction and strengthening after fropa. The cloud ceiling
will lower into the MVFR catagory after fropa as well. A narrow
band of precipitation along this front across nwrn MO will move
through UIN late tgt. This precipitation band may weaken some as
it gets further east, but should lead to a brief period of light
rain/snow in UIN, possibly mixed with sleet. Heavier and more
widespread precipitation should move into the area Saturday evng
as a s-swly low level jet brings strong low-mid level warm air
advection and increasing low level moisture to the region.
Precipitation type is uncertain but should be mainly snow in UIN,
and freezing rain and sleet at the other taf sites. The cloud
ceiling may also lower into the IFR catagory as well.
Specifics for KSTL: S-sely surface winds will veer around to a
swly direction late tgt. The surface wind will continue to veer
around to a n-nwly direction early Saturday mrng after fropa and
strengthen through the day and into Saturday evng. VFR, low level
clouds will advect into STL just after 06z Saturday, and lower
into the MVFR catagory Saturday mrng after fropa. Precipitation
should move into the STL area by late Saturday evng. Precipitation
type is uncertain but will likely be freezing rain and sleet. The
cloud ceiling will lower into the IFR catagory Saturday evng as
well.
GKS
&&
.CLIMATE:
Issued at 351 PM CST Fri Feb 28 2014
Potentially historically cold arctic air is forecast to move into
the region beginning on Sunday and lasting into Tuesday. Several
records are in jeopardy of being broken at our three official
climate sites which can be seen below:
St. Louis, MO (1874-present):
Date Record low Record low maximum
3/2 2 (1980) 19 (1943)
3/3 1 (1943) 19 (2002)
3/4 -1 (1978) 15 (1960)
Columbia, MO (1890-present):
Date Record low Record low maximum
3/2 -5 (1890) 17 (1943)
3/3 1 (1900) 16 (2002)
3/4 -5 (1978) 12 (1960)
Quincy, IL (1901-present):
Date Record low Record low maximum
3/2 -2 (1980) 21 (1960)
3/3 -1 (1913) 14 (2002)
3/4 -8 (1978) 11 (1960)
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...WINTER STORM WATCH from Saturday evening through late Sunday
night FOR Audrain MO-Boone MO-Callaway MO-Cole MO-Crawford
MO-Franklin MO-Gasconade MO-Iron MO-Jefferson MO-Knox MO-
Lewis MO-Lincoln MO-Madison MO-Marion MO-Moniteau MO-Monroe
MO-Montgomery MO-Osage MO-Pike MO-Ralls MO-Reynolds MO-
Shelby MO-St. Charles MO-St. Francois MO-St. Louis City MO-
St. Louis MO-Ste. Genevieve MO-Warren MO-Washington MO.
IL...WINTER STORM WATCH from Saturday evening through late Sunday
night FOR Adams IL-Bond IL-Brown IL-Calhoun IL-Clinton IL-
Fayette IL-Greene IL-Jersey IL-Macoupin IL-Madison IL-
Marion IL-Monroe IL-Montgomery IL-Pike IL-Randolph IL-St.
Clair IL-Washington IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1115 PM CST FRI FEB 28 2014
.UPDATE...
ISSUED AT 748 PM CST FRI FEB 28 2014
FIRST BATCH OF PRECIPITATION WAS MOVING OUT OF THE FA WITH A
LINGERING FREEZING RAIN/SNOW MIX THROUGH ABOUT 03Z FAR SERN
COUNTIES...WITH A FEW TRAILING FLURRIES/SNOW SHOWERS AN HR OR SO
LONGER. THIS WAS HANDLED WITH UPDATE A BIT AGO. OTHERWISE 18Z AND
LATEST SHORT-TERM HRRR MODELS SUGGESTED THE ONSET OF THE NEXT
ROUND OF SNOW WILL BE A BIT SLOWER. THUS PUSHED BACK START TIME OF
WINTER WEATHER ADVISORY 3 TO 6 HRS. NO OTHER SIGNIFICANT CHANGES
AT THIS TIME.
&&
.SHORT TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 305 PM CST FRI FEB 28 2014
WHAT A WAY TO START THE MONTH OF MARCH...SOME OF THE COLDEST AIR
OF THE SEASON IS EXPECTED TO SETTLE OVER THE AREA THIS WEEKEND
WITH THE POTENTIAL TO SMASH LOW TEMPERATURE RECORDS FOR THE DATES.
THE COLD FRONT THAT WILL USHER IN THE ARCTIC AIR WAS MOVING INTO
SOUTHEAST NEBRASKA AND SOUTHWEST IOWA AT 20Z WITH RADAR SHOWING A
FRONTOGENETIC BAND OF LIGHT PRECIP OVER EAST CENTRAL NEBRASKA.
EXPECT THE MAJORITY OF THIS PRECIP TO BE EAST OF THE MISSOURI
RIVER AT THE START OF THE PERIOD AND SHOULD SEE A PERIOD OF
LIGHT SNOW EARLY THIS EVENING IN PARTS OF SOUTHWEST IOWA AS THE
COLD AIR DEEPENS IN THE LOW LEVELS BEFORE MOVING OFF TO THE EAST.
A SECOND ROUND OF LIGHT SNOW IS EXPECTED TO DEVELOP TONIGHT NEAR
THE NEBRASKA SOUTH DAKOTA BORDER AND SPREAD EAST INTO NORTHWEST
PARTS OF THE FORECAST AREA AFTER MIDNIGHT. THE FRONTOGENETIC
FORCING ASSOCIATED WITH THIS BAND OF SNOW PUSHES SOUTH ACROSS
THE REST OF THE AREA DURING THE DAY ON SATURDAY AND INTO KANSAS
AND NORTHERN MISSOURI SATURDAY NIGHT WHERE STRONGER FORCING IS
INDICATED ALONG THE 850MB FRONT. EXPECT SNOW RATIOS TO BE RATHER
HIGH WITH THIS EVENT DUE TO THE EXTREMELY COLD AIR SO SNOWFALL IN
THE 4 TO 6 INCH RANGE IS POSSIBLE ACROSS EASTERN NEBRASKA AND
SOUTHWEST IOWA WITH ISOLATED 6+ IN FAR SOUTHEAST NEBRASKA. THE
MAJORITY OF SNOWFALL FOR THE FORECAST AREA IS EXPECTED DURING THE
DAY ON SATURDAY WITH ADDITIONAL AMOUNTS IN THE SOUTH SATURDAY
NIGHT. SNOW MAY LINGER OVER THE FAR SOUTH INTO SUNDAY WITH SOME
LIGHT ACCUMULATION BEFORE ENDING SUNDAY AFTERNOON.
WITH THE ADDITION OF FRESH SNOW COVER...RECORD COLD TEMPERATURES
LOOK LIKELY WITH FORECAST HIGHS WELL BELOW CURRENT RECORD LOW
MAXIMUMS AT ALL THREE CLIMATE STATIONS ON SATURDAY AND SUNDAY.
RECORD LOW MINIMUMS ARE ALSO POSSIBLE AT SEVERAL SITES.
WIND CHILL HEADLINES ARE LIKELY TO REPLACE WINTER WEATHER
HEADLINES AFTER THEIR EXPIRATION SATURDAY NIGHT AND SUNDAY AS THE
ARCTIC HIGH PRESSURE WORKS SOUTH INTO THE LOWER MISSOURI VALLEY
SUNDAY NIGHT AND MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 305 PM CST FRI FEB 28 2014
MONDAY NIGHT THROUGH NEXT FRIDAY...THIS FORECAST PERIOD IS
CHARACTERIZED BY A WARMING TREND THROUGH THE WORK WEEK AND MEAGER
PRECIPITATION CHANCES THROUGHOUT.
MONDAY NIGHT WILL BE COLD...BUT NOT NEARLY AS COLD AS THE PREVIOUS
NIGHT. TEMPERATURES REBOUND A BIT WITH LOWS STAYING ABOVE
ZERO...NOWHERE NEAR RECORD TERRITORY. BY TUESDAY AFTERNOON WE BEGIN
A GRADUAL WARM-UP AS 850MB TEMPERATURES FINALLY RISE ABOVE ZERO
CELSIUS. THIS WARMING TREND CONTINUES THROUGH THE WORK WEEK WITH
850MB TEMPERATURES PUSHING 10 CELSIUS BY THURSDAY AND THURSDAY
NIGHT. GIVEN THIS AMOUNT OF WARMTH...DAYTIME HIGHS WILL LIKELY
EXCEED 50 DEGREES THURSDAY AND MAYBE EVEN FRIDAY DEPENDING ON THE
TIMING OF THE WEEKEND SYSTEM.
PRECIPITATION-WISE THE FORECAST IS GENERALLY DRY. A COUPLE DIFFERENT
SHORTWAVES EMBEDDED IN THE MID-LEVEL NORTHWEST FLOW WILL TRANSLATE
THROUGH THE FORECAST AREA. HOWEVER MEAGER MOISTURE PROFILES ONLY
POINT TO A SLIGHT CHANCE OF PRECIPITATION ON WEDNESDAY...OTHERWISE
WE ANTICIPATE DRY WEATHER THROUGH THURSDAY NIGHT AS UPPER LEVEL
RIDGING DOMINATES. BY FRIDAY THE UPPER LEVEL RIDGE BREAKS DOWN AND
THE NEXT WEATHER MAKER ENTERS THE PICTURE. AT THIS TIME MODEL
GUIDANCES POINTS TO AN INCREASED POTENTIAL FOR
PRECIPITATION...LIKELY A RAIN/SNOW MIX...BY FRIDAY NIGHT AND
CONTINUING INTO THE WEEKEND.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1115 PM CST FRI FEB 28 2014
SNOW IS EXPECTED TO MOVE BACK INTO NERN NEBRASKA LATE TONIGHT AND
THEN ACROSS KLNK/KOMA SITES BY LATE MORNING/EARLY AFTERNOON. A
TEMPO GROUP WITH VSBYS BELOW 1SM WAS CARRIED AT EACH SITE DURING
THE WINDOW WHEN BEST FORCING WAS EXPECTED TO PROVIDE LOWEST
CONDITIONS. MAIN QUESTION WILL BE PREVAILING CIGS/VSBYS DURING
MUCH OF THE EVENT. THERE IS SOME CHANCE PREVAILING CONDITIONS
COULD BE A BIT BETTER THAN 06Z FORECAST INDICATED...BUT ALSO
NEARLY EQUAL CHANCES THAT THE POOREST CONDITIONS COULD LAST
LONGER AS WELL.
&&
.CLIMATE...
ISSUED AT 305 PM FRI FEB 28 2014
COLD MAX TEMP AND RECORD MIN TEMP RECORDS FOR THE FIRST FEW DAYS
IN MARCH. ASTERISK VALUES INDICATE POTENTIAL BROKEN RECORDS BASED
ON CURRENT FORECAST.
3/1 3/2 3/3
OMAHA 12*/-9 13*/-4* 10*/-5*
LINCOLN 16*/-6 14*/-7 10/-10
NORFOLK 11*/-11 10*/-15* 6/-10*
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY FROM 9 AM SATURDAY TO 6 AM CST SUNDAY
FOR NEZ034-043>045-050>053-065>067-078.
WINTER WEATHER ADVISORY FROM NOON SATURDAY TO NOON CST SUNDAY
FOR NEZ068-088>093.
WINTER WEATHER ADVISORY FROM 3 AM SATURDAY TO MIDNIGHT CST
SATURDAY NIGHT FOR NEZ011-012-015>018-030>033-042.
IA...WINTER WEATHER ADVISORY FROM 9 AM SATURDAY TO 6 AM CST SUNDAY
FOR IAZ043-055-056-069-079-080.
WINTER WEATHER ADVISORY FROM NOON SATURDAY TO NOON CST SUNDAY
FOR IAZ090-091.
&&
$$
UPDATE...CHERMOK
SHORT TERM...FOBERT
LONG TERM...PEARSON
AVIATION...CHERMOK
CLIMATE...FOBERT
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
345 AM CST SAT MAR 1 2014
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 345 AM CST SAT MAR 1 2014
WIND CHILLS WILL BE THE MAIN CONCERN THIS PERIOD. 00Z MODELS ARE
IN GOOD AGREEMENT AND WILL USE A BLEND FOR DETAILS.
TODAY...A VERY COLD AIRMASS WITH 925MB TEMPS -30C TO -32C WILL
SETTLE OVER THE REGION AS SFC HIGH PRESSURE BUILDS. MAX TEMPS
TODAY WILL STRUGGLE TO REACH -10F TO -15F MOST AREAS. WINDS WILL
BE LIGHTER...BUT STILL 5-10 KNOTS. ALTHOUGH WE LIKELY WILL NEED TO
EXTEND THE WIND CHILL HEADLINES INTO THIS AFTERNOON AND
TONIGHT...WILL PASS THIS DUTY TO THE DAY SHIFT. THERE IS AN AREA
OF CLOUDS AND FLURRIES ACROSS SOUTHWEST MANITOBA ASSOCIATED WITH
AN UPPER JET STREAK. RAP GUIDANCE INDICATES THESE CONDITIONS WILL
PROPAGATE SOUTHEAST THROUGH THE DAY...ADJUSTED SKY GRIDS
ACCORDINGLY (AND ADDED FLURRIES).
TONIGHT-SUNDAY...HIGH PRESSURE CONTINUES TO ESTABLISH ITSELF. THIS
SHOULD END WIND CHILL HEADLINES BY LATER SUNDAY AFTERNOON AS WINDS
BECOME CALM. TEMPERATURES MAY BE SLIGHTLY WARMER ON SUNDAY...BUT
STILL BELOW ZERO MOST AREAS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 345 AM CST SAT MAR 1 2014
SUNDAY NIGHT-MONDAY NIGHT...HIGH PRESSURE MOVES EAST AS A WEAK
SHORTWAVE FROM THE PAC NW APPROACHES AND MOVES THROUGH THE REGION.
TIMING AND QPF AMOUNTS STILL A BIT UNCERTAIN...BUT MOST GUIDANCE
DOES INDICATE SOMETHING LATER MONDAY AFTERNOON INTO THE EVENING.
SNOW AMTS APPEAR TOWARD THE LIGHTER SIDE. TEMPERATURES SHOULD
CONTINUE THE GRADUAL WARMING TREND (BUT STILL WELL BELOW NORMAL
VALUES).
TUESDAY-FRIDAY...LONG WAVE PATTERN IS SPLIT WITH ZONAL FLOW
ACROSS THE STATES. LONG WAVE UPPER LOW OVER THE CANADIAN
ARCHIPELAGO MOVES TO THE NORTHWEST BY THE END OF THE PERIOD. LONG
WAVE PATTERN AMPLIFIES BY THE END OF THE PERIOD WITH AN UPPER
LEVEL RIDGE OVER THE WEST COAST AND LONG WAVE TROUGH OVER EASTERN
NORTH AMERICA.
THE GFS WAS FASTER THAN THE ECMWF THROUGH WED. THEN THE GFS WAS
SLOWER WITH THE NEXT SHORT WAVE ACROSS SOUTHERN CANADA FOR THU AND
FRI. THE ECMWF HAS BEEN TRENDING FASTER WHILE THE GFS HAS TRENDED
SLOWER. WILL BLEND THE TWO MODELS.
WILL KEEP YESTERDAY POPS FOR TUE. WILL KEEP YESTERDAYS POPS IN THE
WEST FOR TUE NIGHT. WILL EXPAND POPS FARTHER WEST ON WED NIGHT. WILL
TRIM BACK POPS IN THE SOUTH FOR THU NIGHT.
HIGH TEMPS WERE INCREASED 3 TO 4 DEGREES FOR THU...A DEGREE OR SO
FOR WED AND FRI AND NO CHANGE TO THU FROM YESTERDAYS RUN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1115 PM CST FRI FEB 28 2014
VFR CONDITIONS EXPECTED WITH WINDS SLOWLY SHIFTING MORE WESTERLY
BY SATURDAY AFTERNOON. THERE IS A BAND OF VFR CIGS IN CANADA THAT
COULD MOVE THROUGH TOMORROW...BUT MODELS DISSIPATE THESE CLOUDS
AND HAVE NOT MENTIONED THEM BUT SOMETHING TO KEEP IN MIND.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR NDZ038-039-
049-052-053.
WIND CHILL WARNING UNTIL 1 PM CST THIS AFTERNOON FOR NDZ006>008-
014>016-024-026>030-054.
MN...WIND CHILL ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR MNZ003-024-
027>032-040.
WIND CHILL WARNING UNTIL 1 PM CST THIS AFTERNOON FOR MNZ001-002-
004>009-013>017-022-023.
&&
$$
SHORT TERM...TG
LONG TERM...TG/HOPPES
AVIATION...DK
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1134 PM CST FRI FEB 28 2014
.UPDATE...FOR 06Z AVIATION
&&
.AVIATION...
A MIX OF VERY LIGHT RAIN/SLEET WILL CONTINUE TO MOVE ACROSS MIDDLE
TN WITH VFR CIGS FOR THE NEXT FEW HOURS. MVFR CIGS TRAIL THE
UPPER DISTURBANCE MOVING OVERHEAD...SO WILL KEEP THAT IN THE AREA
TERMINALS FOR EARLY SATURDAY. AN APPROACHING WARM FRONT WILL PUSH
ACROSS THE STATE SAT AFTN...VEERING WINDS AROUND TO THE SSW AND
SCATTERING OUT THE CLOUDS. WINDS MAY BECOME GUSTY TOWARDS THE END
OF THIS TAF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 747 PM CST FRI FEB 28 2014/
UPDATE...RECENTLY RECEIVED SOME REPORTS OF SLEET FROM OUR
SOUTHERN COUNTIES AND RUC SOUNDINGS INDICATE THAT SLEET WILL
REMAIN A POSSIBILITY ALONG THE LEADING EDGE OF THE PRECIP BAND AS
IT TRAVERSES OUR AREA TONIGHT. LOOKS LIKE TEMPS AND DEW POINTS
WARM SUFFICIENTLY ALONG THE LAGGING PART OF THE BAND, SO THAT
PRECIP WILL LIKELY CHANGE BACK TO ALL RAIN BEFORE ENDING. THUS,
HAVE ADDED A BRIEF PERIOD FOR THE POSSIBILITY OF SLEET INTO THE
OVERNIGHT FORECAST. OTHERWISE, NO CHANGE.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AL
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1156 PM CST FRI FEB 28 2014
.AVIATION...
06Z TAFS...A COLD FRONT WILL CONTINUE TO BACK SOUTHWEST ACROSS THE
PANHANDLES TONIGHT...WITH LOW CLOUDS AND FOG DEVELOPING BEHIND IT.
LOW CLOUDS ARE ALREADY NEARING KGUY...AND IFR CIGS ARE EXPECTED TO
FILL IN AT KGUY OVERNIGHT AND LAST INTO LATE SATURDAY MORNING.
CONDITIONS ARE EXPECTED TO IMPROVE TO MVFR AND VFR FOR A TIME AT KGUY
LATE SATURDAY MORNING AND SATURDAY AFTERNOON...BEFORE QUICKLY
DETERIORATING AGAIN EARLY SATURDAY EVENING AS CIGS FALL AND
PRECIPITATION DEVELOPS...LIKELY IN THE FORM OF -FZRA.
FOR KAMA AND KDHT...CONFIDENCE IS LOWER REGARDING HOW FAR SOUTH AND
WEST THE LOW CLOUDS AND FOG WILL MAKE IT OVERNIGHT. DO THINK THE LOW
CLOUDS WILL MAKE IT INTO KDHT AND HAVE INTRODUCED SOME IFR CONDITIONS
ACCORDINGLY. KAMA LOOKS TO BE RIGHT ON THE EDGE WITH SOME VERY
SHALLOW MOISTENING DEPICTED IN FORECAST SOUNDINGS. THUS HAVE
INTRODUCED SOME MVFR VSBYS WITH FOG...BUT CONDITIONS COULD CERTAINLY
GO LOWER THAN THIS IN THE 11-15Z TIMEFRAME. INCREASING
SOUTH/SOUTHWEST WINDS SHOULD SCOUR OUT ANY LOW CLOUDS/FOG AT KAMA AND
KDHT BY LATE SATURDAY MORNING WITH VFR CONDITIONS THEN EXPECTED
THROUGH THE AFTERNOON. MID-LEVEL CLOUDS WILL THICKEN SUNDAY
EVENING...WITH SOME -RA POSSIBLE.
KB
&&
.PREV DISCUSSION... /ISSUED 939 PM CST FRI FEB 28 2014/
UPDATE...
ADDED FOG TO THE FORECAST FOR LATE TONIGHT INTO SATURDAY MORNING
ACROSS ALL BUT THE FAR SOUTHWEST TX PANHANDLE. LOW-LEVEL EASTERLY UPSLOPE
FLOW APPEARS CONDUCIVE TO FOG DEVELOPMENT...AND MODEL LOW-LEVEL RH
PROGS...SREF VSBY PROBS...AND HRRR VSBY PROGS ALL SUPPORT THIS. MAY
SEE A FETCH OF LOWER SFC DEWPOINTS WORK INTO THE CENTRAL AND EASTERN
OK PANHANDLE...LIMITING THE FOG THREAT AND SUPPORTING MORE OF A LOW
CLOUD SCENARIO IN THESE AREAS /AND STILL CANNOT RULE OUT SOME PATCHY
DZ OR FZDZ TOWARD DAYBREAK IF THE LOW-LEVEL MOIST LAYER DEEPENS
ENOUGH IN THIS FAR NORTHEAST PORTION OF THE CWA/. FARTHER SOUTH
HOWEVER...FOG LOOKS LIKE A BETTER BET ACROSS ALL BUT THE FAR
SOUTHWEST TX PANHANDLE. TEMPS ARE EXPECTED TO FALL A LITTLE BELOW
FREEZING ACROSS THE NORTHERN PANHANDLES...BUT WARM GROUND TEMPS FROM
THE RECENT WARM STRETCH SHOULD PREVENT ANY REAL ICING PROBLEMS ON
ROADWAYS. NOT TO MENTION...THE GREATER PROBABILITIES OF DENSER FOG
APPEAR TO BE FARTHER SOUTH WHERE TEMPS WILL BE MAINLY ABOVE FREEZING.
KB
PREV DISCUSSION... /ISSUED 401 PM CST FRI FEB 28 2014/
SHORT TERM...
THROUGH TONIGHT: AN ARCTIC FRONT WILL OOZE ITS WAY INTO THE
PANHANDLES LATE TONIGHT BEFORE STALLING. BEHIND THE FRONT, LOW
CLOUDS WILL RAPIDLY DEVELOP, ESPECIALLY ACROSS THE NORTHERN AND
EASTERN PANHANDLES. ISENTROPIC ASCENT MAY DEEPEN LOW-LEVEL MOISTURE
JUST ENOUGH TO WARRANT A MENTION OF PATCHY DRIZZLE/FREEZING DRIZZLE
DEPENDING ON SURFACE TEMPERATURES. IF THE DRIZZLE IS IN THE FROZEN
FORM, IT SHOULDN`T CAUSE ANY TRAVEL PROBLEMS AS GROUND TEMPERATURES
HAVE BEEN RATHER WARM LATELY. NONETHELESS, IT COULD STICK TO
ELEVATED AND METAL SURFACES.
SATURDAY-SUNDAY NIGHT: THE ARCTIC FRONT WILL PLAY HAVOC WITH
TEMPERATURES TOMORROW, AND WE`RE A LITTLE CONCERNED THE FRONT COULD
SEEP FARTHER SOUTH AND WEST THAN WE`RE CURRENTLY FORECASTING. LIKE
THE PREVIOUS SHIFT MENTIONED, IF THIS SCENARIO OCCURS, HIGH
TEMPERATURES WILL BE FAR TOO WARM OVER THE SOUTHWEST HALF OF THE
FORECAST AREA. THE THERMAL GRADIENT WILL BE VERY IMPRESSIVE ALONG
THE FRONT SUCH THAT TEMPERATURES MAY VARY BY NEARLY 40 DEGREES
WITHIN A 50-MILE DISTANCE. LARGE SCALE FORCING FOR ASCENT WILL
GRADUALLY BEGIN INCREASING TOMORROW AFTERNOON FROM WEST TO EAST.
EXPECT TO SEE SOME HIGH-BASED SHOWERS, POSSIBLY EVEN A THUNDERSTORM,
MOVE OUT OF NORTHEAST NEW MEXICO INTO OUR NORTHWEST AREAS AFTER 2
PM. THESE HIGH-BASED SHOWERS COULD PRODUCE LOCALLY GUSTY WINDS UP TO
45 MPH BENEATH THEM, BUT NO SEVERE WEATHER IS EXPECTED. BY SATURDAY
NIGHT AND SUNDAY MORNING, FORCING FOR ASCENT STRENGTHENS WITH THE
APPROACH OF THE MAIN UPPER TROUGH. AS THE COLD FRONT SETTLES
SOUTHWARD, ARCTIC AIR WILL GRADUALLY DEEPEN WITH TIME FROM NORTHEAST
TO SOUTHWEST. AS THIS OCCURS IN CONJUNCTION WITH THE UPPER FORCING,
PRECIPITATION WILL INCREASE IN COVERAGE, ESPECIALLY FOR LOCATIONS
NORTH AND WEST OF THE HIGHWAY 60 CORRIDOR. PRECIPITATION TYPE IS
VERY DIFFICULT AS THE NAM REMAINS THE FASTEST AND DEEPEST WITH THE
ARCTIC AIR. IN FACT, IF THE NAM IS CORRECT, SNOW WILL BE THE
PREDOMINANT TYPE OF PRECIPITATION AS THE BOUNDARY LAYER ESSENTIALLY
BECOMES THE DENDRITIC GROWTH ZONE, ESPECIALLY LATE SATURDAY NIGHT
AND SUNDAY. HOWEVER, ALL OTHER MODELS ARE NOT AS DEEP AND FAST WITH
THE COLD AIR, MAKING FOR A MESSY PRECIPITATION TYPE FORECAST. AS A
RESULT, WE THINK WE`LL INITIALLY SEE RAIN CHANGE TO FREEZING RAIN
AND THEN FINE SNOW GRAINS AS THE COLD AIR DEEPENS. ACROSS THE
SOUTHWESTERN TEXAS PANHANDLE, FREEZING RAIN AND RAIN WILL BE THE
PREDOMINANT PRECIPITATION TYPES. THE PRECIPITATION TYPE WILL BECOME
PREDOMINANTLY SNOW FOR THE SOUTHWEST TEXAS PANHANDLE AS THE ARCTIC
AIR MASS BECOMES FULLY ENTRENCHED, BUT A BRIEF PERIOD OF SLEET CAN`T
BE RULED OUT SUNDAY MORNING. THE PRECIPITATION IS EXPECTED TO BEGIN
TAPERING OFF FROM WEST TO EAST LATE SUNDAY AFTERNOON. VERY COLD
TEMPERATURES ARE EXPECTED ON SUNDAY WITH HIGHS RANGING FROM NEAR 40
IN THE SOUTHWEST (NEAR SUNRISE) TO THE MID TEENS IN THE NORTHEAST.
THE HIGHEST SNOWFALL AMOUNTS ARE EXPECTED TO OCCUR ACROSS THE
NORTHERN HALF OF THE PANHANDLES WHERE 1 TO 3 INCHES OF SNOW MAY
OCCUR. ICE ACCUMULATIONS FROM FREEZING RAIN WILL MAINLY IMPACT THE
TEXAS PANHANDLE WITH AMOUNTS EXPECTED TO REMAIN LESS THAN 0.10 OF AN
INCH. HOWEVER, A WINTER WEATHER ADVISORY WILL LIKELY BE REQUIRED FOR
PART OR ALL OF THE AREA SATURDAY NIGHT AND SUNDAY. BLOWING SNOW
COULD ALSO LEAD TO REDUCED VISIBILITIES AND SOME DRIFTING.
LONG TERM...
THE GFS IS DEPICTING SOME POSSIBILITY OF LOCALIZED FREEZING
FOG/FREEZING DRIZZLE ACROSS THE EASTERN OKLAHOMA AND NORTHEASTERN
TEXAS PANHANDLES EARLY MONDAY MORNING, BUT CONFIDENCE REMAINS A
LITTLE LOW TO INSERT INTO THE FORECAST CURRENTLY.
MONDAY NIGHT A WEAK SHORTWAVE IS DEPICTED TO MOVE ACROSS THE
PANHANDLES. MODELS AGREE THAT THIS SHORTWAVE SHOULD MOVE THROUGH DRY
AS LOW LEVEL MOISTURE WILL BE LIMITED. HOWEVER SOME PRECIP MAY BE
POSSIBLE A BIT NORTH OF THE OKLAHOMA PANHANDLE WHERE THE FORCING
FROM THE SHORTWAVE AND THE ENTRANCE REGION OF THE SPLIT FLOW JET
OVERLAP.
ZONAL FLOW ALOFT WILL IS EXPECTED TO PREVAIL TUESDAY AND MOST OF
WEDNESDAY. WEDNESDAY NIGHT A BROAD TROUGH WILL DROP ACROSS THE
PANHANDLES. MEDIUM RANGE MODELS DISAGREE ON WHERE THERE WILL BE
SUFFICIENT DYNAMICS AND MOISTURE FOR PRECIP TO OCCUR. THE ECMWF IS
MORE FAVORABLE FOR PRECIP WHILE THE GFS IS A LITTLE LESS FAVORABLE.
THE FORECAST LEANS CLOSER TO THE DRY GFS.
NORTHERLY TO NORTHWESTERLY FLOW ALOFT IS EXPECTED FOR THURSDAY WHICH
WILL ALLOW TEMPERATURES TO WARM NICELY BACK INTO THE MID TO UPPER
60S. PREVIOUS MODEL RUNS HINTED AT SOME PRECIP CHANCES FOR FRIDAY BUT
THESE CHANCES HAVE BEEN PUSHED BACK TO FRIDAY NIGHT FOR THE GFS AND
INTO SATURDAY FOR THE ECMWF.
FIRE WEATHER...
ELEVATED FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS THE
SOUTHWESTERN TEXAS PANHANDLE SATURDAY AFTERNOON AS RELATIVE
HUMIDITIES DROP TO 18 TO 20 PERCENT. TWENTY FOOT WINDS ARE EXPECTED
TO INCREASE INTO THE 17 TO 25 MPH RANGE BY THE EARLY AFTERNOON FROM
A SOUTHERLY TO SOUTH-SOUTHWESTERLY DIRECTION. FROM SATURDAY NIGHT
THROUGH WEDNESDAY OF THIS COMING WEEK...NEITHER ELEVATED NOR
CRITICAL FIRE WEATHER CONDITIONS ARE ANTICIPATED AT THIS TIME.
ELEVATED FIRE WEATHER WILL BE POSSIBLE THURSDAY AFTERNOON ACROSS THE
WESTERN AND CENTRAL PORTIONS OF THE TEXAS AND OKLAHOMA PANHANDLES.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1148 PM CST FRI FEB 28 2014
.AVIATION...
A FRONT HAS SAGGED THROUGH KCDS WITH LIGHT EASTERLY WINDS IN ITS
WAKE. THIS FRONT MAY MAKE IT ALL THE WAY TO KLBB TOWARD 11-12Z.
CONDITIONS SHOULD STAY VFR AT KLBB...BUT KCDS IS LIKELY TO SEE LOW
CLOUDS AND FOG DEVELOP AROUND THIS SAME TIME...WITH IFR TO LIFR
CONDITIONS POSSIBLE. THESE SUB-VFR CONDITIONS WILL LIKELY PERSIST
AT KCDS THROUGH MUCH OF THE MORNING BEFORE THE CLOUDS/FOG
LIFT/SCATTER AND VFR CONDITIONS RETURN DURING THE AFTERNOON HOURS.
HOWEVER...CIGS WILL LIKELY REDEVELOP SATURDAY EVENING BEHIND
A STRONGER FRONTAL SURGE. KLBB WILL LIKELY REMAIN VFR THROUGH THE
TAF CYCLE...BUT WILL SEE GUSTY SOUTHWESTERLY WINDS MATERIALIZE
DURING THE AFTERNOON HOURS BEFORE DECREASING IN THE EVENING.
&&
.PREV DISCUSSION... /ISSUED 1009 PM CST FRI FEB 28 2014/
UPDATE...
A WEAK FRONT IS IN THE PROCESS OF BACK-DOORING INTO THE AREA FROM
THE NORTHEAST...WITH CHILDRESS AND NORTHFIELD ALREADY EXPERIENCING
LIGHT EASTERLY BREEZES. THIS FRONT WILL CONTINUE ON ITS
SOUTHWESTWARD PUSH THROUGH THE OVERNIGHT HOURS UNTIL STALLING OVER
THE CENTRAL SOUTH PLAINS SATURDAY MORNING...THEN RETREATING
SATURDAY AFTERNOON. BEHIND THE FRONT...LIGHT EASTERLY WINDS WILL
CONTINUE TO TAP INCREASING AMOUNTS OF MOISTURE ALONG THE RED RIVER
VALLEY. AS TEMPERATURES CONTINUE TO FALL AND LOW-LEVEL MOISTURE
INCREASES...THE PROSPECTS FOR FOG AND LOW CLOUDS WILL INCREASE
ACROSS THE EASTERN ZONES...LIKELY AFTER 09Z. THIS LOW CLOUD AND
FOG DECK COULD ADVANCE AS FAR WESTWARD AS ROUGHLY A DIMMITT TO
PLAINVIEW TO ASPERMONT LINE BY MID-MORNING BEFORE
THINNING...LIFTING AND SCATTERING OUT. GIVEN THIS...WE HAVE
UPDATED THE FORECAST TO INCLUDE AREAS OF FOG ACROSS ROUGHLY THE
NORTHEAST HALF OF THE CWA IN THE 09-16Z TIME-FRAME. EARLY
ON...SKY GRIDS WERE DECREASED GIVEN THE MOSTLY CLEAR SKIES
CURRENTLY IN PLACE...BUT WERE BOOSTED ACROSS THE NORTHEAST ZONES
AFTER 09Z AS THE LOW CLOUDS AND FOG ARE EXPECTED TO FILL IN. ASIDE
FROM THE WEATHER AND SKY GRIDS...MINOR ADJUSTMENTS WERE ALSO MADE
TO THE TEMPERATURE...DEWPOINT AND RH GRIDS. THE UPGRADED PRODUCTS
HAVE BEEN SENT.
PREV DISCUSSION... /ISSUED 556 PM CST FRI FEB 28 2014/
UPDATE...
WINDS CONTINUE TO GRADUALLY DECREASE EARLY THIS EVENING BRINGING
AN END TO THE CRITICAL FIRE WEATHER CONDITIONS FOR THE SOUTH
PLAINS REGION. THUS...THE RED FLAG WARNING WILL BE ALLOWED TO
EXPIRE AS SCHEDULED AT 00Z.
PREV DISCUSSION... /ISSUED 348 PM CST FRI FEB 28 2014/
SHORT TERM...
FOLLOWING A COMPACT S/W TROUGH THAT GENERATED TSTORMS IN PARTS OF
THE TX PANHANDLE LAST NIGHT...THE AXIS OF STRONG WESTERLY WINDS HAVE
SINCE EXITED THE FORECAST AREA ON SCHEDULE. THESE WINDS DID RESULT
IN A BIT MORE DRAMA THAN EXPECTED THANKS TO A 59 MPH GUST AS
MEASURED BY THE GRAHAM WEST TX MESONET...BUT AS A WHOLE THE BLOWING
DUST THIS MORNING WAS NOTHING UNUSUAL FOR THE HARDY RESIDENTS THAT
FREQUENT THESE PARTS.
ALREADY BY SUNSET...A WEAK COLD FRONT WILL BE EDGING SOUTHWEST
ACROSS THE EASTERN PANHANDLE WELL AHEAD OF A BROODING ARCTIC HIGH
STILL POISED IN THE WESTERN CANADIAN PRAIRIES. DO BELIEVE THE
NON-RUC GUIDANCE IS TOO CONSERVATIVE WITH THIS FRONT/S PROGRESS
TONIGHT...SO HAVE EDGED LOW TEMPS DOWN A BIT ESPECIALLY NORTHEAST
OF THE HIGHWAY 84 CORRIDOR WHERE THE RUC HAS THIS BOUNDARY ROUGHLY
STALLING BY DAYBREAK. THIS BOUNDARY HOWEVER WILL RETREAT BY LATE
MORNING AS WINDS ALOFT BACK SWLY AND AMPLIFY MODESTLY AHEAD OF
SUNDAY/S UPPER TROUGH. AS WE SAW TODAY...EARLIER MODELS WERE MUCH
TOO MOIST WITH 2M DEWPOINTS...BUT THIS WAS EXPECTED IN PRIOR
FORECASTS AND WE CONTINUE TO EMPLOY THIS RATIONALE WITH TOMORROW/S
SETUP BEHIND THE RETREATING FRONT. NUDGED HIGHS UP A FEW DEGREES ON
THE CAPROCK WHERE THE DRIEST AIR WILL BE FOUND AND THIS WILL ALSO
RESULT IN SOME FIRE WX CONCERNS...ALTHOUGH NOT TO THE DEGREE THAT WE
SAW TODAY.
LONG TERM...
BROAD SOUTHWESTERLY FLOW WILL BE IN PLACE BY LATE SATURDAY. WHAT IS
CURRENTLY A WOUND-UP SPIRAL OFF THE COAST WILL BECOME AN OPEN TROUGH
FROM THE GREAT BASIN TO BAJA. NORTH OF THE BORDER...A COMPLEX
ELONGATED LOW SPANNING MUCH OF CANADA IS LATITUDINALLY ORIENTED
AROUND 55N. MODEL GUIDANCE IS FAIRLY CONSISTENT WITH THE SYNOPTIC
SCALE FEATURES OVER THE NEXT 7 DAYS. THE WEST COAST TROUGH IS
EXPECTED TO APPROACH ON SUNDAY FOLLOWED BY A MORE SUBTLE EMBEDDED
TROUGH INTO MONDAY. ON WEDNESDAY...YET ANOTHER TROUGH AXIS
APPROACHES AND STARTS TO DEEPEN BEFORE DIVING INTO THE GULF COAST
SATES LATE WEEK. OUR FINAL TROUGH OF THE EXTENDED APPROACHES ON
FRIDAY.
YET ANOTHER BACK DOOR COLD FRONT SNEAKS INTO THE AREA ON SUNDAY
MAKING FCST HIGHS QUITE TRICKY AS THE BOUNDARY HANGS UP FOR SEVERAL
HOURS ACROSS THE CWFA. THEN...WITH THE FALL OF NIGHT...THE COLDER
AIR SHOULD FILTER INTO THE REGION. OVERNIGHT BUT NOT BEFORE THERE
IS SOME OPPORTUNITY FOR PRECIPITATION.
MONDAY SHOULD REMAIN DRY AND QUITE COOL BEFORE RETURN FLOW SETS UP
ON TUESDAY QUICKLY REBOUNDING TEMPERATURES THOUGH PERHAPS REMAINING
A FEW DEGREES SHY OF CLIMATOLOGICAL AVERAGES. ANOTHER COLD FRONT
ENTERS THE REGION WEDNESDAY MORNING HELPING TO HOLD TEMPS DOWN ONE
MORE DAY BEFORE SOUTHWESTERLY SURFACE FLOW PICKS UP FOR THURSDAY
WITH THE POTENTIAL FOR ANOTHER BOUT OF FIRE WEATHER LATE NEXT WEEK.
YET ANOTHER PUSH OF COLD AIR ENTERS FOR SEVERE WEATHER AWARENESS DAY.
FIRE WEATHER...
WIDESPREAD RED FLAG CONDITIONS CONTINUE THIS AFTERNOON ACROSS THE
SOUTH PLAINS AND MUCH OF THE ROLLING PLAINS. THE STRONGEST WINDS
HAVE SINCE DEPARTED THE REGION...BUT 20-FOOT SPEEDS OF 20-25 MPH
WILL CONTINUE UNTIL 6 PM AT WHICH POINT THE RED FLAG WARNING SHOULD
BE ALLOWED TO EXPIRE.
BY THIS EVENING AND OVERNIGHT...A LIGHT NORTHEAST WIND SHIFT WILL
PUSH SOUTHWEST ACROSS THE ROLLING PLAINS AND EASTERN SOUTH PLAINS
BEFORE RETREATING NORTHEAST BY LATE SATURDAY MORNING. ELEVATED TO
MARGINALLY CRITICAL FIRE WEATHER IS POSSIBLE BY SATURDAY AFTERNOON
ON THE CAPROCK AS SOUTHWEST WINDS RISE TO 15 TO 25 MPH WITH MIN RH
VALUES FALLING INTO THE LOWER-TO-MID TEENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 36 75 32 34 12 / 0 0 20 30 10
TULIA 37 75 25 29 10 / 0 0 20 20 10
PLAINVIEW 39 77 27 32 11 / 0 0 10 20 10
LEVELLAND 39 80 33 45 15 / 0 0 10 20 10
LUBBOCK 38 80 29 40 14 / 0 0 10 20 10
DENVER CITY 44 79 36 54 20 / 0 0 10 20 10
BROWNFIELD 42 80 34 46 18 / 0 0 10 20 10
CHILDRESS 37 68 24 25 10 / 0 0 10 20 10
SPUR 39 80 25 34 13 / 0 0 10 20 10
ASPERMONT 39 83 25 31 12 / 0 0 20 20 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
23/33/23
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
1009 PM CST FRI FEB 28 2014
.UPDATE...
A WEAK FRONT IS IN THE PROCESS OF BACK-DOORING INTO THE AREA FROM
THE NORTHEAST...WITH CHILDRESS AND NORTHFIELD ALREADY EXPERIENCING
LIGHT EASTERLY BREEZES. THIS FRONT WILL CONTINUE ON ITS
SOUTHWESTWARD PUSH THROUGH THE OVERNIGHT HOURS UNTIL STALLING OVER
THE CENTRAL SOUTH PLAINS SATURDAY MORNING...THEN RETREATING
SATURDAY AFTERNOON. BEHIND THE FRONT...LIGHT EASTERLY WINDS WILL
CONTINUE TO TAP INCREASING AMOUNTS OF MOISTURE ALONG THE RED RIVER
VALLEY. AS TEMPERATURES CONTINUE TO FALL AND LOW-LEVEL MOISTURE
INCREASES...THE PROSPECTS FOR FOG AND LOW CLOUDS WILL INCREASE
ACROSS THE EASTERN ZONES...LIKELY AFTER 09Z. THIS LOW CLOUD AND
FOG DECK COULD ADVANCE AS FAR WESTWARD AS ROUGHLY A DIMMITT TO
PLAINVIEW TO ASPERMONT LINE BY MID-MORNING BEFORE
THINNING...LIFTING AND SCATTERING OUT. GIVEN THIS...WE HAVE
UPDATED THE FORECAST TO INCLUDE AREAS OF FOG ACROSS ROUGHLY THE
NORTHEAST HALF OF THE CWA IN THE 09-16Z TIME-FRAME. EARLY
ON...SKY GRIDS WERE DECREASED GIVEN THE MOSTLY CLEAR SKIES
CURRENTLY IN PLACE...BUT WERE BOOSTED ACROSS THE NORTHEAST ZONES
AFTER 09Z AS THE LOW CLOUDS AND FOG ARE EXPECTED TO FILL IN. ASIDE
FROM THE WEATHER AND SKY GRIDS...MINOR ADJUSTMENTS WERE ALSO MADE
TO THE TEMPERATURE...DEWPOINT AND RH GRIDS. THE UPGRADED PRODUCTS
HAVE BEEN SENT.
&&
.PREV DISCUSSION... /ISSUED 556 PM CST FRI FEB 28 2014/
UPDATE...
WINDS CONTINUE TO GRADUALLY DECREASE EARLY THIS EVENING BRINGING
AN END TO THE CRITICAL FIRE WEATHER CONDITIONS FOR THE SOUTH
PLAINS REGION. THUS...THE RED FLAG WARNING WILL BE ALLOWED TO
EXPIRE AS SCHEDULED AT 00Z.
AVIATION...
GUSTY WINDS AT KLBB WILL QUICKLY DIMINISH OVER THE NEXT HOUR OR
SO...WITH LIGHT WINDS EXPECTED THROUGH THE REMAINDER OF THE NIGHT.
A FRONT WILL MOVE THROUGH KCDS EARLY THIS EVENING WITH LIGHT
NORTHEAST TO EASTERLY WINDS IN ITS WAKE. THIS FRONT MAY BRIEFLY
EDGE THROUGH KLBB BY 10-12Z WITH AN EASTERLY WIND SHIFT...BUT
GUSTY SOUTHWESTERLY WINDS SHOULD RETURN TO THE TERMINAL BY AROUND
MIDDAY ON SATURDAY. AT KCDS...EASTERLY WINDS WILL WILL LIKELY
PERSIST THROUGH THE PERIOD. IN ADDITION...THERE WILL BE A CHANCE
OF LOW CLOUDS DEVELOPING AT KCDS BY AROUND 12Z. IF CLOUDS DO
FORM...THEY COULD PERSIST THROUGH MUCH OF THE MORNING BEFORE
LIFTING AND SCATTERING OUT. CURRENTLY HAVE INDICATED A MVFR DECK
AT KCDS...BUT THERE IS A CHANCE THE CLOUDS COULD BE LOWER...IN THE
IFR TO LIFR CATEGORY. AT KLBB...VFR CONDITIONS SHOULD PREVAIL
THROUGH THE TAF CYCLE.
PREV DISCUSSION... /ISSUED 348 PM CST FRI FEB 28 2014/
SHORT TERM...
FOLLOWING A COMPACT S/W TROUGH THAT GENERATED TSTORMS IN PARTS OF
THE TX PANHANDLE LAST NIGHT...THE AXIS OF STRONG WESTERLY WINDS HAVE
SINCE EXITED THE FORECAST AREA ON SCHEDULE. THESE WINDS DID RESULT
IN A BIT MORE DRAMA THAN EXPECTED THANKS TO A 59 MPH GUST AS
MEASURED BY THE GRAHAM WEST TX MESONET...BUT AS A WHOLE THE BLOWING
DUST THIS MORNING WAS NOTHING UNUSUAL FOR THE HARDY RESIDENTS THAT
FREQUENT THESE PARTS.
ALREADY BY SUNSET...A WEAK COLD FRONT WILL BE EDGING SOUTHWEST
ACROSS THE EASTERN PANHANDLE WELL AHEAD OF A BROODING ARCTIC HIGH
STILL POISED IN THE WESTERN CANADIAN PRAIRIES. DO BELIEVE THE
NON-RUC GUIDANCE IS TOO CONSERVATIVE WITH THIS FRONT/S PROGRESS
TONIGHT...SO HAVE EDGED LOW TEMPS DOWN A BIT ESPECIALLY NORTHEAST
OF THE HIGHWAY 84 CORRIDOR WHERE THE RUC HAS THIS BOUNDARY ROUGHLY
STALLING BY DAYBREAK. THIS BOUNDARY HOWEVER WILL RETREAT BY LATE
MORNING AS WINDS ALOFT BACK SWLY AND AMPLIFY MODESTLY AHEAD OF
SUNDAY/S UPPER TROUGH. AS WE SAW TODAY...EARLIER MODELS WERE MUCH
TOO MOIST WITH 2M DEWPOINTS...BUT THIS WAS EXPECTED IN PRIOR
FORECASTS AND WE CONTINUE TO EMPLOY THIS RATIONALE WITH TOMORROW/S
SETUP BEHIND THE RETREATING FRONT. NUDGED HIGHS UP A FEW DEGREES ON
THE CAPROCK WHERE THE DRIEST AIR WILL BE FOUND AND THIS WILL ALSO
RESULT IN SOME FIRE WX CONCERNS...ALTHOUGH NOT TO THE DEGREE THAT WE
SAW TODAY.
LONG TERM...
BROAD SOUTHWESTERLY FLOW WILL BE IN PLACE BY LATE SATURDAY. WHAT IS
CURRENTLY A WOUND-UP SPIRAL OFF THE COAST WILL BECOME AN OPEN TROUGH
FROM THE GREAT BASIN TO BAJA. NORTH OF THE BORDER...A COMPLEX
ELONGATED LOW SPANNING MUCH OF CANADA IS LATITUDINALLY ORIENTED
AROUND 55N. MODEL GUIDANCE IS FAIRLY CONSISTENT WITH THE SYNOPTIC
SCALE FEATURES OVER THE NEXT 7 DAYS. THE WEST COAST TROUGH IS
EXPECTED TO APPROACH ON SUNDAY FOLLOWED BY A MORE SUBTLE EMBEDDED
TROUGH INTO MONDAY. ON WEDNESDAY...YET ANOTHER TROUGH AXIS
APPROACHES AND STARTS TO DEEPEN BEFORE DIVING INTO THE GULF COAST
SATES LATE WEEK. OUR FINAL TROUGH OF THE EXTENDED APPROACHES ON
FRIDAY.
YET ANOTHER BACK DOOR COLD FRONT SNEAKS INTO THE AREA ON SUNDAY
MAKING FCST HIGHS QUITE TRICKY AS THE BOUNDARY HANGS UP FOR SEVERAL
HOURS ACROSS THE CWFA. THEN...WITH THE FALL OF NIGHT...THE COLDER
AIR SHOULD FILTER INTO THE REGION. OVERNIGHT BUT NOT BEFORE THERE
IS SOME OPPORTUNITY FOR PRECIPITATION.
MONDAY SHOULD REMAIN DRY AND QUITE COOL BEFORE RETURN FLOW SETS UP
ON TUESDAY QUICKLY REBOUNDING TEMPERATURES THOUGH PERHAPS REMAINING
A FEW DEGREES SHY OF CLIMATOLOGICAL AVERAGES. ANOTHER COLD FRONT
ENTERS THE REGION WEDNESDAY MORNING HELPING TO HOLD TEMPS DOWN ONE
MORE DAY BEFORE SOUTHWESTERLY SURFACE FLOW PICKS UP FOR THURSDAY
WITH THE POTENTIAL FOR ANOTHER BOUT OF FIRE WEATHER LATE NEXT WEEK.
YET ANOTHER PUSH OF COLD AIR ENTERS FOR SEVERE WEATHER AWARENESS DAY.
FIRE WEATHER...
WIDESPREAD RED FLAG CONDITIONS CONTINUE THIS AFTERNOON ACROSS THE
SOUTH PLAINS AND MUCH OF THE ROLLING PLAINS. THE STRONGEST WINDS
HAVE SINCE DEPARTED THE REGION...BUT 20-FOOT SPEEDS OF 20-25 MPH
WILL CONTINUE UNTIL 6 PM AT WHICH POINT THE RED FLAG WARNING SHOULD
BE ALLOWED TO EXPIRE.
BY THIS EVENING AND OVERNIGHT...A LIGHT NORTHEAST WIND SHIFT WILL
PUSH SOUTHWEST ACROSS THE ROLLING PLAINS AND EASTERN SOUTH PLAINS
BEFORE RETREATING NORTHEAST BY LATE SATURDAY MORNING. ELEVATED TO
MARGINALLY CRITICAL FIRE WEATHER IS POSSIBLE BY SATURDAY AFTERNOON
ON THE CAPROCK AS SOUTHWEST WINDS RISE TO 15 TO 25 MPH WITH MIN RH
VALUES FALLING INTO THE LOWER-TO-MID TEENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 36 75 32 34 12 / 0 0 20 30 10
TULIA 37 75 25 29 10 / 0 0 20 20 10
PLAINVIEW 39 77 27 32 11 / 0 0 10 20 10
LEVELLAND 39 80 33 45 15 / 0 0 10 20 10
LUBBOCK 38 80 29 40 14 / 0 0 10 20 10
DENVER CITY 44 79 36 54 20 / 0 0 10 20 10
BROWNFIELD 42 80 34 46 18 / 0 0 10 20 10
CHILDRESS 37 68 24 25 10 / 0 0 10 20 10
SPUR 39 80 25 34 13 / 0 0 10 20 10
ASPERMONT 39 83 25 31 12 / 0 0 20 20 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
23/33
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
615 AM MST SAT MAR 1 2014
.UPDATE...
UPDATED AVIATION AND FIRE WEATHER SECTIONS.
&&
.SYNOPSIS...
A WELL DEFINED PACIFIC STORM SYSTEM WILL SLOWLY MOVE THROUGH THE
AREA TODAY...EVENTUALLY BRINGING SHOWERS AND ISOLATED THUNDERSTORMS
TO THE PHOENIX AREA. CONDITIONS WILL DRY OUT FROM WEST TO EAST THIS
EVENING WITH NEARLY EVERYONE DRYING OUT COMPLETELY BY SUNDAY
AFTERNOON. FOLLOWING THE LOW...DRY WEATHER IS EXPECTED ALONG WITH A
RETURN TO ABOVE NORMAL TEMPERATURES BY LATE WEEK.
&&
.DISCUSSION...
FOR THOSE OF US IN THE PHOENIX AREA...THIS UPPER LOW HAS BEEN AN
ABYSMAL UNDER-PERFORMER THUS FAR. UNLESS YOU WERE ONE OF THE LUCKY
ONES CAUGHT UNDER A BRIEF SHOWER IN CAVE CREEK/CAREFREE FRIDAY
EVENING...YOU HAVENT SEEN A DROP THUS FAR. WHILE SOUTHEAST
CALIFORNIA AND WESTERN ARIZONA HAS FARED SOMEWHAT BETTER...RAINFALL
STILL HASNT FILLED IN TO THE EXTENT THAT IT SHOULD HAVE.
THAT BEING SAID...ALL HOPE IS NOT LOST...NOT BY A LONG-SHOT. THE 1+
INCH PWAT AXIS IS NOW SQUARELY POSITIONED OVERHEAD ALONG WITH
850-700MB WINDS AROUND 60-65KTS. NOT SURPRISINGLY...THOSE LOCATIONS
DIRECTLY WITHIN THE UPSLOPE FLOW /FOOTHILLS AND HIGHER TERRAIN NORTH
AND EAST OF PHOENIX/ ARE IN PRETTY GOOD SHAPE WITH THE REGIONAL
RADAR MOSAIC FILLING IN QUITE A BIT SINCE MIDNIGHT. THERES EVEN A
HINT AT NEW SHOWER DEVELOPMENT OVER THE FAR NORTH PART OF THE METRO
/CEILINGS HAVE BEEN GRADUALLY LOWERING SINCE MIDNIGHT/ AND KYUX IS
SHOWING SOME NEW ACTIVITY ACROSS FAR EASTERN YUMA/LA PAZ COUNTIES.
WITH A SOLID 10-12HRS WORTH OF ANOMALOUSLY STRONG UPSLOPE WINDS
FORECAST TO REMAIN IN PLACE OVER THE FORECAST AREA THROUGH 18Z
COINCIDENT WITH AT LEAST 1.1 INCH PWATS...EVEN THE DRIEST MODELS ARE
ADVERTISING CONVECTION TO DEVELOP AND FILL IN BY LATE
MORNING...ALBEIT AT A GLACIAL PACE. ONCE THE COLD CORE ALOFT MOVES
OVERHEAD BETWEEN 18Z AND 00Z...EXPECT ADDITIONAL DEVELOPMENT TO
BLOSSOM ACROSS THE LOWER DESERTS AS MID LEVEL LAPSE RATES STEEPEN
DRAMATICALLY. SOUTHEAST CALIFORNIA ISNT QUITE THROUGH WITH THE
PRECIP BUT AS THEY WILL LOSE THEIR DEEPEST MOISTURE LATER THIS
MORNING...THEIR POPS WILL BE A BIT LOWER THAN THOSE AROUND THE
PHOENIX AREA.
THUS...IM MAKING SOME ADJUSTMENTS TO POPS/QPF FOR THE ENTIRE
FORECAST AREA. POPS/QPF WILL BE LOWERED A BIT ACROSS THE BOARD
THROUGH LATE MORNING TO BETTER REFLECT WHAT HAS HAPPENED THUS FAR
AND WHAT LITTLE IS DEVELOPING ON RADAR TO OUR SOUTH...BUT WILL BE
RETAINED AROUND 100 PERCENT FOR LATE MORNING/AFTERNOON. GIVEN THEIR
PERFORMANCE THUS FAR...THE HI-RES WRFS AND NAM 4KM NEST APPEAR TO
HAVE THE BEST HANDLE ON THE SITUATION. HRRR AND RAP ARE SLOWLY
CATCHING ONTO REALITY BUT NOT FAST ENOUGH TO BE USED FOR THIS
MORNINGS FORECAST UNFORTUNATELY. COMPLETELY AVOIDING THE GFS EC AND
GEM GIVEN THEIR LACKLUSTER PERFORMANCE THUS FAR.
THE TROUGH AXIS PASSES OVERHEAD AROUND 06Z TONIGHT AND CONDITIONS
SHOULD BEGIN DRYING OUT AS EARLY AS SUNDAY MORNING. FOR THE VAST
MAJORITY OF THE LOWER DESERTS...SUNDAY MAY END UP TURNING OUT TO BE
A PRETTY NICE DAY WITH GRADUALLY CLEARING SKIES BY EARLY AFTERNOON.
SOUTHERN GILA COUNTY WILL LIKELY SEE SHOWERS HANG ON THE
LONGEST...BUT EVEN THEY MAY END UP CLEARING OUT SOONER THAN LATER.
POPS WERE ADJUSTED SLIGHTLY DOWNWARD ACROSS THE BOARD SUNDAY MORNING
THROUGH SUNDAY AFTERNOON.
AFTER THAT...ZONAL FLOW WILL ESTABLISH ITSELF ON MONDAY FOLLOWED BY
WEAK MID-WEEK RIDGING. LOOK FOR TEMPERATURES TO SLOWLY RESPOND BACK
TO NORMAL BY MID WEEK AND ABOVE NORMAL BY THE END OF THE WEEK. THERE
IS SOME SUGGESTION OF A TROUGH MOVING THROUGH THE FOUR CORNERS LATE
IN THE WEEK /FRIDAY OR SATURDAY/ BUT PRECIP POTENTIAL LOOKS MINIMAL
GIVEN THE SOURCE REGION OF THE TROUGH. COULD BRING SOME BREEZINESS
AND SLIGHTLY COOLER TEMPS BUT THAT LOOKS TO BE ABOUT IT.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
LOWER LEVEL MOISTURE AND SCATTERED SHOWERS ASSOCIATED WITH A PASSING
FRONTAL ZONE HAS CAUSED CIGS TO LOWER TO 4-6 KFT MSL IN THE VICINITY
OF THE SHOWERS...BRIEFLY LOWER IN SOME SPOTS. HOWEVER...CLOUD BASES
ARE HIGHLY VARIABLE BETWEEN SHOWERS...ABOVE 6 KFT MSL OVER SOUTHEAST
METRO PHOENIX AS OF 13Z. FLUCTUATING CIGS WITH PASSING SHOWERS IS
ANTICIPATED TO CONTINUE THROUGH 16Z BEFORE SHOWERS TEMPORARILY
DECREASE. ANTICIPATE RENEWED DEVELOPMENT THIS AFTERNOON AS THE UPPER
LOW GETS CLOSER. ISOLATED T-STORMS POSSIBLE BUT CONFIDENCE TOO LOW
AT ANY GIVEN SPOT TO REFLECT IN THE TAFS. ANTICIPATE SCATTERED
SHOWERS TO CONTINUE INTO THE EVENING BEFORE TRAILING OFF OVERNIGHT.
SOUTHWEST WINDS WILL PREVAIL WITH OCCASIONAL GUSTS TO 20 KTS.
STRONGER SHOWERS COULD PRODUCE 25+ KTS.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SHOWERS ARE STRUGGLING TO MAKE IT OVER THE COASTAL MOUNTAINS TO THE
WEST. HRRR MODEL INDICATES ISOLATED SHOWER DEVELOPMENT AFTER 14Z
INCREASING TO SCATTERED COVERAGE AFTER 20Z AND THIS IS REFLECTED IN
THE TAFS. ISOLATED T-STORMS POSSIBLE BUT CONFIDENCE TOO LOW AT ANY
GIVEN SPOT TO REFLECT IN THE TAFS. ANTICIPATE SCATTERED SHOWERS TO
CONTINUE INTO THE EVENING BEFORE TRAILING OFF OVERNIGHT. LIGHT AND
VARIABLE SURFACE WINDS WILL BECOME SOUTHWEST BY MIDDAY WITH
OCCASIONAL GUSTS TO 20 KTS. STRONGER SHOWERS COULD PRODUCE 25+ KTS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
HIGH PRESSURE BUILDS BACK INTO THE REGION MONDAY THROUGH WEDNESDAY
FOR A WARMING TREND ALONG WITH LESS WIND. HUMIDITIES WILL DECREASE
THOUGH OVERNIGHT RECOVERY WILL REMAIN GOOD. MODELS INDICATE HIGH
PRESSURE WEAKENING THURSDAY AND FRIDAY BUT HIGH TEMPERATURES WILL
STILL BE WELL ABOVE NORMAL. NORTHERLY BREEZINESS IS ANTICIPATED
FRIDAY...MAINLY OVER SOUTHEAST CALIFORNIA AND SOUTHWEST
ARIZONA...BUT NO STRONG WIND EVENTS ARE ANTICIPATED THROUGH THE
PERIOD.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...AJ
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS PUEBLO CO
704 AM MST SAT MAR 1 2014
.UPDATE...
ISSUED AT 703 AM MST SAT MAR 1 2014
EXTENDED DENSE FOG ADVISORY UNTIL 9 AM.
ALSO BROUGHT IN LATEST HRRR WINDS/TEMPS INTO NDFD.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 AM MST SAT MAR 1 2014
...SIGNIFICANT SNOWS ALONG THE CONTDVD...WIDE RANGING TEMPS ON THE
PLAINS TODAY...
CURRENTLY...AS OF 4 AM...COLD AIR HAS WORKED BACK TOWARDS THE
MOUNTAINS. GENERALLY AREAS AOA 6000 FEET WERE IN THE COLD AIR (20S)
WHILE ELEVATIONS ABOVE WERE IN THE WARM AIR (40S TO AROUND 50F). THE
EXCEPTION TO THIS WAS N EL PASO COUNTY WHERE UPSLOPE FLOW WAS
DRIVING THE LOW CLOUDS/FOG UP THE PALMER DVD.
MTN VALLEYS WERE WARM AS BUENA VISTA...SALIDA AND A GOOD PART OF
THE SAN LUIS VALLEY WERE ABOVE FREEZING (35-40F). HEAVY SNOW WAS
LIKELY POUNDING THE MTNS (KGJT RADAR IS OUT OF COMMISSION AND WONT
RETURN TO SERVICE UNTIL AT LEAST SUNDAY). WOLF CREEK OB HAS BEEN
REPORTING HEAVY SNOW THROUGHOUT THE EARLY MORNING HOURS.
IN ADDITION...WEB CAMS WERE SHOWING DENSE FOG ACROSS N EL PASO
COUNTY. KCOS WAS ALSO REPORTING DENSE FOG. SOME FREEZING DRIZZLE WAS
BEING OBSERVED AT SCHRIEVER AFB.
TODAY...
HEAVY SNOW WILL CONTINUE ACROSS THE CONTDVD TODAY. AN ADDITIONAL
FOOT OF SNOW IS LIKELY ACROSS THE SAN JUANS WITH 6-12" ACROSS THE
CENTRAL MTNS. HEAVY SNOW...5-10"...WILL OCCUR ACROSS THE TOP OF THE
SANGRES.
DENSE FOG WILL CONTINUE THIS EARLY MORNING ACROSS NORTHERN EL PASO
COUNTY GIVEN THE STRONG UPSLOPE FLOW.
TEMPS TODAY WILL VARY DRAMATICALLY ACROSS THE PLAINS. HI RES
GUIDANCE INDICATES COLD AIR WILL BE PUSHED TO THE EAST...BUT I DO
NOT THINK IT WILL GO AS FAR EAST AS GUIDANCE INDICATES. THE WARMEST
AIR WILL LIKELY AFFECT THE PALMER DIVIDE AND AREAS ABOVE 5500 FEET
ON THE PLAINS. MONUMENT HILL WILL LIKELY BE WARMER THAN DOWNTOWN
COLORADO SPRINGS. PUEBLO WEST WILL BE WARMER THAN PUEBLO.
WALSENBURG...TRINIDAD AND PINON CANYON WILL BE IN THE 60S WHILE EADS
AND LAMAR WILL LIKELY REMAIN IN THE 20S. SPRINGFIELD WILL BE
TRICKY...MAX TEMPS THERE I HAVE IN THE 40S...BUT IT IS NOT OUT OF
THE QUESTION THAT THEY MAY NOT GET OUT OF THE 20S. BY LATE IN THE
AFTERNOON WHEREVER THE BOUNDARY IS...IT WILL START TO WORK ITS WAY
BACK TO THE WEST.
AS FOR PRECIP ON THE PLAINS...THE OVERALL BEST CHANCE OF SOME PRECIP
WILL BE ALONG THE CO/NM BORDER...BUT ALL AREAS MAY SEE PASSING
SHOWERS LATER TODAY. PRECIP TYPE WILL BE DEPENDENT ON WHERE THE
BOUNDARY LIES. FREEZING DRIZZLE WILL BE POSSIBLE TODAY WITH A BETTER
CHANCE OF RAIN/SNOW LATER TODAY AS THE MOISTURE DEEPENS ACROSS THE
PLAINS.
THE BEST CHANCE FOR THE SAN LUIS VALLEY TO SEE PRECIP WILL BE
TODAY...WITH THE BEST CHANCE OF PRECIP OVER THE SOUTHERN AND WESTERN
PART OF THE VALLEY.
TONIGHT...
TROUGH ALOFT WILL MOVE ACROSS THE REGION. SNOWS WILL CONTINUE OVER
THE MOUNTAINS. THE HEAVIEST SNOWS IN THE SAN JUANS WILL AFFECT AREAS
JUST SOUTH OF WOLF CREEK PASS DOWN TO THE CO/NM BORDER. WITH FLOW
TRANSITIONING TO MORE WEST NORTHWESTERLY...SNOWS WILL CONTINUE OVER
THE CENTRAL MOUNTAINS. 4-8" WILL FALL IN THE SAN JUANS S OF WOLF
CREEK...AND 3-7" WILL FALL IN THE C MTNS. A FEW MORE INCHES WILL
FALL ON TOP OF THE SANGRES.
THE PLAINS WILL SEE SNOW BUT OVERALL ACCUMS WILL GENERALLY BE LESS
THAN AN INCH. THE HEAVIEST AMOUNTS WILL OCCUR OVER FAR SE CO. THE
ENTIRE PLAINS WILL BE IN THE COLD UPSLOPE AND EXPECT CLOUDY SKIES
WITH SINGLE DIGIT TEMPS OVER THE FAR E PLAINS AND TEENS ELSEWHERE.
THE MTNS/VALLEYS WILL BE IN THE MID TEENS/20S FOR LOWS TONIGHT.
/HODANISH
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 405 AM MST SAT MAR 1 2014
...COLD SUNDAY...
THE UPPER TROUGH AXIS WILL BE THROUGH CENTRAL CO AT 12Z SUN...AND NR THE
KS BORDER BY 18Z. EXPECT RAPID DECREASE IN PRECIP ACROSS THE MT AREAS
SUN MORNING...MAYBE EVEN SOME BREAKS IN THE CLOUDS...BUT SOME LIGHT
ONGOING SNOW SHOWERS WILL BE LIKELY GIVEN INCREASED INSTABILITY. IF
THERE ARE ANY BREAKS...THERE WILL BE RAPID REDEVELOPMENT OF CONVECTION
OVER THE PEAKS SO CONTINUED HIGH POPS LOOK REASONABLE. ADDITIONAL
ACCUMS WILL BE LIGHT FOR THE MTS...MAYBE AN INCH OR TWO.
MAIN QUESTION SUNDAY WILL BE PRECIP FOR THE PLAINS. GIVEN THE TREND FOR
A FASTER TROUGH PASSAGE...IT LOOKS LIKE THE MODELS ARE SHIFTING THE
POTENTIAL FOR SNOW OVER THE PLAINS EWD...MAINLY INTO KS AND THE
PANHANDLES SUN MORNING. THE NAM CONTINUES TO SHOW A MOSTLY DRY
FORECAST EXCEPT NR THE KS BORDER. STILL SEE SOME POTENTIAL FOR
BANDED SNOW OVR THE PLAINS...ESPECIALLY GIVEN THE CONVECTIVE NATURE
OF THIS SYSTEM...SO WILL MAINTAIN CHANCE POPS MAINLY FOR THE MORNING
HOURS AND AREAS E OF I-25. NOT READY TO THROW IN THE TOWEL QUITE YET
FOR SN OVER THE I-25 ZONES. IT WILL DEFINITELY BE COLD ENOUGH...WITH
SHALLOW COLD AIR FIRMLY IN PLACE AND TEMPS NOT LIKELY TO MAKE IT
ABOVE FREEZING ANYWHERE OVER THE ERN PLAINS. WARMEST WX WILL BE IN
THE HIGH VALLEYS WHICH COULD SEE SOME MID 40S.
WE DRY OUT MON-TUE AS QUASI-ZONAL FLOW RESUMES OVER OUR AREA. A
COUPLE WEAK DISTURBANCES MOVE THROUGH THE FLOW...THE FIRST MON
AFTERNOON AND A SECOND TUE NIGHT. THESE COULD BRING SOME RENEWED
SHSN TO THE MTS...ESPECIALLY THE CENTRAL MTS. THE GFS EVEN HINTS AT
THE POSSIBILITY OF SOME LIGHT PRECIP OVER THE PLAINS LATE TUE OR
EARLY WED...BUT WILL KEEP POPS SILENT FOR NOW.
AFTER A DRY AND WARM THU...WITH TEMPS IN THE MID 60S OVER THE
PLAINS...NEXT STORM SYSTEM ARRIVES FRI FROM THE NW. LOOKS LIKE
ANOTHER FRONTAL PUSH IS POSSIBLE ACROSS THE PLAINS. IT IS STILL
QUITE A WAYS OUT...SO WILL MAINTAIN POPS IN THE 20-30 PERCENT RANGE
FOR THIS TIME PERIOD. THEN A HIGH AMPLITUDE RIDGE BUILDS...GIVING
US A WARMER AND DRY NEXT WEEKEND. ROSE
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 405 AM MST SAT MAR 1 2014
VFR CONDITIONS WILL OCCUR ACROSS THE 3 TAF SITES...KPUB...KCOS
AND KALS NEXT 24H. MAIN CONCERN TODAY AT KCOS AND ESPECIALLY KPUB
WILL BE GUSTY WEST TO NORTHWEST WINDS AT 15 TO 30 KNOTS. KALS MAY
HAVE -SN VCNTY TOWARDS SUNRISE TOMORROW. THERE IS A VERY LOW
CHANCE THAT SOME FOG COULD DEVELOP AT KCOS AND KPUB AROUND SUNRISE
TOMORROW.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM MST THIS MORNING FOR COZ084.
WINTER WEATHER ADVISORY UNTIL 5 AM MST SUNDAY FOR COZ059-061-064-
067-073-075.
WINTER STORM WARNING UNTIL 5 AM MST SUNDAY FOR COZ058-060-066-
068.
&&
$$
UPDATE...HODANISH
SHORT TERM...HODANISH
LONG TERM...ROSE
AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
553 AM CST SAT MAR 1 2014
.DISCUSSION...
400 AM CST
MAIN CONCERN FOR THE FORECAST PERIOD WILL BE THE POTENTIAL FOR HEAVY
SNOW THROUGH THE WEEKEND.
FOR THE REMAINDER OF THE OVERNIGHT HOURS...A WEAK SHORTWAVE INVOF
THE LEFT EXIT REGION OF A STRONG UPPER LEVEL JET IS PROVIDING THE
DYNAMICS TO GENERATE A QUICK ROUND OF SNOW EARLY THIS MORNING. WITH
ONLY WEAK SFC TROUGHING AND VERY MODEST LOW LEVEL FORCING...THE SNOW
IS ALMOST ENTIRELY RELYING ON UPPER LEVEL DYNAMICS TO SUPPORT THE
SNOW GENERATION. LATEST RADAR TRENDS INDICATE THAT THE BAND OF SNOW
EXTENDS FROM WAUKEGAN TO PERU AND IS MOVING VERY QUICKLY TO THE
EAST. THE SNOW WILL END SHORTLY IN THE ROCKFORD AREA AND WILL
QUICKLY PUSH PAST THE CHICAGO METRO AREA SHORTLY AFTER
DAYBREAK...AND EVEN ENDING OVER THE FAR EASTERN PORTIONS OF THE CWA
BY LATE THIS MORNING. SINCE THE SYSTEM IS MOVING SO QUICKLY...ONLY
AROUND AN INCH OF ACCUMULATION IS EXPECTED.
THE MAIN SNOW CONCERN IS SETTING UP FOR LATE THIS AFTERNOON...AND
PERSISTING ACROSS PORTIONS OF THE REGION UNTIL LATE SUNDAY NIGHT.
GIVEN THE LONG DURATION OF THE EVENT...HAVE OPTED TO ISSUE A WINTER
WEATHER ADVISORY FOR THE ENTIRE CWA. THE ADVISORY WILL BE IN 2
SEGMENTS...BEGINNING EARLIER FOR LOCATIONS NORTH OF THE ILLINOIS AND
KANKAKEE RIVERS...AND THEN SPREADING SOUTH OVERNIGHT TONIGHT.
THE MAIN FEATURE OF CONCERN IS A STRONG CLOSED UPPER LOW OFF THE
CENTRAL CALIFORNIA COAST. THE GUIDANCE HAS CONVERGED INTO
RELATIVELY GOOD AGREEMENT IN THE LARGER SCALE DETAILS WITH THE
SYSTEM EVOLVING INTO AN OPEN WAVE AS THE SYSTEM MOVES ON SHORE LATE
THIS AFTERNOON. THIS WILL SET UP A STREAM OF SWLY FLOW ALOFT AS
WEAK UPPER RIDGING BUILDS OVER THE CENTRAL CONUS AND THE UPPER
TROUGH DIGS OVER THE WEST. A BROAD UPPER LOW CENTERED OVER HUDSON
BAY...WITH TROUGHING THROUGH THE UPPER GREAT LAKES WILL SQUEEZE THE
UPPER LEVEL FLOW...SETTING UP VERY FAST FLOW ALOFT RIPPLES OF SHORT
WAVE ENERGY EJECTING OUT OF THE SOUTHERN ROCKIES WITH A DIRECT
TRAJECTORY ACROSS THE MIDDLE MISSISSIPPI VALLEY TO THE GREAT LAKES.
AT THE SURFACE...POLAR HIGH PRESSURE WILL BUILD OUT OF CANADA AND
SPREAD ACROSS THE NORTHERN PLAINS AND INTO THE MIDDLE AND UPPER
MISSISSIPPI VALLEY TODAY. AFTER A RELATIVELY MILD FRIDAY...THIS
AREA OF HIGH PRESSURE WILL BRING AN ARCTIC AIRMASS BACK TO THE REGION
AT THE SFC. THE SNOW WILL AGAIN LARGELY BE DRIVEN BY UPPER LEVEL
DYNAMICS...WITH THE BAND OF STRONGEST FORCING SAGGING SOUTHWARD
THROUGH THE CWA. CURRENTLY...ANTICIPATE THAT THE SNOW WILL BEGIN
OVER THE NWRN PORTIONS OF THE CWA...INCLUDING THE ROCKFORD METRO
AREA BY AROUND 3PM THIS AFTERNOON AND GRADUALLY SPREAD SOUTH AND
EAST...WITH HEAVIER SNOW REACHING THE CHICAGO METRO AREA DURG THE
EARLY EVENING HOURS. AS THE UPPER LEVEL TROUGHING EXTENDING FROM
HUDSON BAY BACK TOWARD SOUTH CENTRAL CANADA BEGINS TO DIG SOUTHWARD
ACROSS THE UPPER GREAT LAKES LATE TONIGHT AND EARLY SUNDAY...THE
AREA OF SNOW WILL BE QUICKLY FORCED SOUTH...WITH SNOW ENDING OVER
THE NORTHERN TIER COUNTIES BY EARLY SUNDAY MORNING. HOWEVER...THE
MAIN SHORTWAVE TROUGH ASSOCIATED WITH THE PACIFIC SYSTEM WILL EJECT
OUT OF THE SOUTHERN ROCKIES BY SUNDAY MORNING AND TRACK ACROSS THE
PLAINS TO THE MIDDLE MISSISSIPPI VALLEY BY SUNDAY NIGHT...AND THEN
PUSH QUICKLY EAST OF THE AREA BY EARLY MONDAY MORNING. WHILE THE
CANADIAN TROUGH WILL FORCE AN END TO THE SYNOPTIC SNOW OVER THE NRN
PORTIONS OF THE BY EARLY SUNDAY MORNING...THE PACIFIC SHORTWAVE
ENERGY WILL KEEP THE SNOW POTENTIAL GOING OVER THE SRN PORTIONS OF
THE CWA THROUGH LATE SUNDAY NIGHT. ALL TOTAL...EXPECT AROUND 3 TO 5
INCHES ACCUMULATION OF RELATIVELY DRIER SNOW OVER THE NORTHERN
PORTIONS OF THE CWA...AND 5 TO 7 INCHES OVER THE SOUTHERN PORTIONS
OF THE CWA...THOUGH THE SNOW OVER THE SOUTHERN LOCATIONS MAY LIKELY
CONTAIN SLIGHTLY HIGHER LIQUID WATER CONTENT DUE TO THE LONGER
DURATION OF THE PACIFIC SYSTEM IMPACTING THE REGION.
AS THE SYNOPTIC SNOW TAPERS OFF OVER THE NORTHERN PORTIONS OF THE
CWA EARLY SUNDAY MORNING...THE SFC HIGH PRESSURE WILL SPREAD EAST
ACROSS THE UPPER MISSISSIPPI VALLEY AND THE GREAT LAKES REGION. THE
LARGER SCALE MODELS...IN PARTICULAR...THE GFS...HAVE BEEN
ADVERTISING THE POTENTIAL FOR A LAKE EFFECT BAND OF SNOW TO DEVELOP
OVER LAKE MICHIGAN BY SUNDAY MORNING. THE SHORTER RANGE HIGH RES
GUIDANCE IS NOW SHOWING A SIMILAR SETUP WITH SFC CONVERGENCE SETTING
UP OVER WESTERN LAKE MICHIGAN. THIS COULD BRING PERIODS OF LAKE
EFFECT SNOW SHOWERS TO FAR NERN IL...AND EVENTUALLY FAR NWRN INDIANA
AS THE LAKE PLUME MIGRATES EWD INTO EARLY MONDAY MORNING. GIVEN THE
EXTENSIVE ICE COVER ON LAKE MICHIGAN AND RELATIVELY COLD SFC WATER
TEMPERATURES...INVERSION HEIGHTS WILL BE RELATIVELY SHALLOW AND
EQUILIBRIUM LEVELS ONLY AROUND 5-6KFT AND CAPE VALUES OF 300-400
J/KG. THE MODEST CONVECTIVE DEPTH AND INSTABILITY WOULD SUGGEST
THAT SIGNIFICANT LAKE EFFECT SNOW IS NOT LIKELY...BUT PERIODS OF
LAKE EFFECT SNOW SHOWERS PRODUCING ADDITIONAL LIGHT ACCUMULATIONS
OVER THE CHICAGO METRO AREA ARE CERTAINLY POSSIBLE SUNDAY AND SUNDAY
NIGHT.
AS THE COLD HIGH PRESSURE SETTLES OVER THE REGION EARLY NEXT
WEEK...THE REGION CAN EXPECT A FEW MORE DAYS WITH LOW TEMPERATURES
RANGING FROM THE SINGLE DIGITS ABOVE ZERO TO THE SINGLE DIGITS BELOW
ZERO. BRISK NORTH WINDS SHOULD DRIVE WIND CHILL READING TO AROUND 5
TO 15 BELOW ZERO FOR SUNDAY MORNING. AS THE CENTER OF THE HIGH
SETTLES OVER IOWA BY MONDAY MORNING...COLD ADVECTION WILL DRIVE
TEMPERATURES BELOW ZERO FOR PORTIONS OF THE AREA GENERALLY WEST OF
THE I-57 CORRIDOR AND THE FOX VALLEY...WHERE TEMPERATURES COULD DIP
TO AROUND 5 BELOW ZERO...WITH WIND CHILLS TO 20 BELOW ZERO. THE
CENTER OF THE HIGH WILL MOVE OVER THE AREA FOR TUESDAY MORNING...SO
CLEAR SKIES...LIGHT WINDS AND FRESH SNOW COVER WILL ALLOW FOR MORE
WIDESPREAD LOWS BELOW ZERO DUE TO RADIATIVE COOLING.
FOR THE EXTENDED FORECAST PERIOD...FOR TUESDAY THROUGH FRIDAY...THE
LONGER RANGE GUIDANCE CONTINUES TO ADVERTISE A GRADUAL WARMING TREND
BY THE END OF THE PERIOD. WEDNESDAY SHOULD REMAIN RELATIVELY COOL
WITH HIGHS STILL ONLY IN THE MIDDLE 20S...BUT AS THE ARCTIC HIGH MOST
WELL TO THE EAST BY THURSDAY...SETTING UP A WARM ADVECTIVE
PATTERN...TEMPERATURES SHOULD REBOUND INTO THE LOWER 30S BY THURSDAY
AND COULD EVEN PEG 40F BY FRIDAY. A SERIES OF MID LEVEL SHORTWAVES
COULD BRING PERIODIC CHANCES FOR SOME LIGHT SNOW ON WEDNESDAY AND
THURSDAY...BUT NOTHING SIGNIFICANT IS LIKELY.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* IFR CIGS IMPROVING TO VARIABLE MVFR/VFR NEXT 1-2 HOURS.
* MORE SNOW ARRIVES LATE THIS AFTERNOON WITH PERIODIC
MODERATE/HEAVY SNOW POSSIBLE AT TIMES DURING THE EVENING. SUB
1SM VSBY LIKELY AT TIMES WITH 1/4-1/2SM VSBY POSSIBLE.
* LAKE EFFECT SNOW SHOWERS POSSIBLE SUNDAY.
* NORTH-NORTHWEST TO NORTH-NORTHEAST WINDS THROUGH THE PERIOD.
MDB
//DISCUSSION...UPDATED 12Z...
LAST OF THE LIGHT SNOW CONTINUES TO EXIT THE TERMINALS EARLY THIS
MORNING. A BAND OF IFR CIGS HAS DEVELOPED IN THE WAKE OF THE BAND
BUT SHOULD BE PROGRESSING EAST AWAY FROM THE TERMINALS IN THE NEXT
FEW HOURS. VARIABLE MVFR/VFR CIGS EXTEND BACK TO THE MISSISSIPPI
RIVER OR SO WITH STEADIER VFR TO THE WEST. WINDS HAVE OR WILL BE
TURNING NORTHERLY SHORTLY AND EXPECT THAT THERE WILL BE
FLUCTUATIONS BETWEEN NW AND NNE THROUGH THE DAY.
ATTENTION TURNS TO THE NEXT ROUND OF MORE SIGNIFICANT SNOW WHICH
WILL ARRIVE LATER THIS AFTERNOON FROM WEST TO EAST. SNOW SHOULD
QUICKLY INCREASE IN INTENSITY LATE THIS AFTERNOON AT RFD AND RIGHT
AROUND 00Z IN THE CHICAGO AREA...THOUGH LIGHT SNOW MAY DEVELOP
JUST PRIOR TO THAT. TIMING MAY STILL NEED SOME TWEAKING BUT HAVE
GOOD CONFIDENCE OVERALL. PERIOD OF MODERATE TO EVEN BRIEFLY HEAVY
SNOW ARE EXPECTED FROM LATE THIS AFTERNOON INTO MID EVENING AT RFD
AND PRIMARILY DURING THE EVENING IN THE CHICAGO AREA. PREVAILING
VSBY OF 1 TO 1.5SM IS LIKELY WITH PERIODS OF 1/2 TO 3/4SM VSBY
POSSIBLE AS WELL. CANNOT RULE OUT SOME BRIEF PERIODS OF 1/4SM AS
WELL. ACCUMULATION RATES OF 0.5 TO 1 INCH PER HOUR ARE ALSO LIKELY
AT TIMES. THE MAIN FORCING FOR THE SNOW WILL PUSH SOUTHWARD FROM
LATE EVENING INTO THE OVERNIGHT ALLOWING SNOW INTENSITY TO TAPER
OFF AT THE TERMINALS...THOUGH SOME LIGHT SNOW MAY CONTINUE THROUGH
DAYBREAK. LAKE EFFECT PROCESSES WILL THEN TRY TO TAKE OVER WHICH
SHOULD LEAD TO LAKE EFFECT SNOW SHOWERS. THE CHALLENGE WILL BE
DETERMINING THE LOCATION AND INTENSITY DETAILS. WITH A SLIGHT
NORTHEAST WIND COMPONENT TO THE WINDS SOME OF THIS ACTIVITY MAY
DRIFT TOWARD OR OVER ORD/MDW DURING THE DAY SUNDAY. SHOULD THIS
OCCUR THEN PERIODIC BURSTS OF MORE INTENSE SNOW WILL BE POSSIBLE
WITH GREATLY REDUCED VSBY. GYY IS PROBABLY THE MOST FAVORED FOR
LAKE EFFECT ACTIVITY GIVEN THE PRIMARILY NORTH WIND BU OVERALL
CONFIDENCE IS LIMITED SO CONTINUE TO MONITOR FOR THE LATEST
THINKING.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN IFR CIGS IMPROVING TO VARIABLE
MVFR/VFR...MEDIUM CONFIDENCE IN TIMING. MEDIUM CONFIDENCE IN CIG
TRENDS FROM MID MORNING THROUGH AFTERNOON.
* HIGH CONFIDENCE IN SNOW ARRIVING LATER TODAY...WITH MEDIUM-HIGH
CONFIDENCE IN TIMING. LOW-MEDIUM CONFIDENCE IN WHETHER 1/2SM OR
LESS VSBY OCCURS...BUT MEDIUM-HIGH CONFIDENCE THAT IT WOULD BE
DURING THE EVENING IF IT DID.
* LOW CONFIDENCE IN LAKE EFFECT SNOW SHOWER DETAILS SUNDAY.
* HIGH CONFIDENCE IN WIND TRENDS.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE FOR SNOW SHOWERS WITH IFR/MVFR POSSIBLE.
MONDAY THROUGH FRIDAY...MAINLY VFR WITH PERIODIC LOW CHANCES FOR
LIGHT SNOW.
MDB
&&
.MARINE...
302 AM CST
LOW PRESSURE JUST EAST OF NORTHERN LAKE SUPERIOR WILL MOVE EASTWARD
INTO WESTERN QUEBEC INTO THE EARLY AFTERNOON HOURS. A COLD FRONT IS
TRAILING THIS LOW AND IS PUSHING ACROSS LAKE MICHIGAN EARLY THIS
MORNING BRINGING A SHIFT TO NORTH AND NORTHWEST WINDS. SPEEDS WILL
INCREASE INTO THE 15 TO 25 KT RANGE BEHIND THE FRONT THIS MORNING
THEN EASE UP A BIT THIS EVENING. NORTHERLY WINDS WILL CONTINUE
THROUGH SUNDAY WITH SOME CONVERGENCE LIKELY SETTING UP ACROSS
CENTRAL AND SOUTHERN SECTIONS OF THE LAKE AS LAKE EFFECT PROCESSES
TAKE OVER. AS THIS OCCURS AN INVERTED TROUGH WILL DEVELOP FROM
SOUTHWEST TO NORTHEAST ACROSS THE OHIO VALLEY THEN SHIFT SOUTHWARD
SUNDAY AND MONDAY. STRONG HIGH PRESSURE CENTERED OVER ALBERTA AND
ITS ASSOCIATED RIDGE EXTENDING SOUTHEASTWARD INTO THE CENTRAL PLAINS
WILL DRIFT SOUTHEAST OVER THE NEXT SEVERAL DAYS. THE RIDGE AXIS WILL
RE-ORIENT SOMEWHAT AND POSITION ITSELF ACROSS THE WESTERN GREAT
LAKES LATER TONIGHT...BEFORE THE HIGH BECOMES CENTERED OVER THE
PLAINS AND MID AND UPPER MISSISSIPPI RIVER VALLEY LATER SUNDAY. THE
PRESSURE GRADIENT LOOKS TO TIGHTEN ACROSS LAKE MICHIGAN SUNDAY NIGHT
ALLOWING NORTHERLY WINDS TO INCREASE ONCE AGAIN. THE HIGH WILL MOVE
EASTWARD MONDAY ALLOWING WINDS TO DROP OFF AND BECOME VARIABLE. AS
THE HIGH PASSES WINDS SHIFT TO THE EAST AND SOUTHEAST FOR MID WEEK
BEFORE TURNING SOUTHERLY LATE IN THE WEEK.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-
ILZ022...3 PM SATURDAY TO 9 AM SUNDAY.
WINTER WEATHER ADVISORY...ILZ023-ILZ032-ILZ033-ILZ039...9 PM
SATURDAY TO MIDNIGHT MONDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...9
PM SATURDAY TO MIDNIGHT MONDAY.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
510 AM CST Sat Mar 1 2014
.DISCUSSION...
ISSUED 328 AM CST Sat Mar 1 2014
SHORT TERM...Today through Sunday
At 08Z/2AM Arctic cold front was just entering the NW CWA
accompanied by a narrow band of light snow, which has briefly
dropped vsbys to 3-5 miles. Latest trends and short range models
indicate what snow there is will dissipate as the front continues
to shift southeast this morning. Did include low chance pops this
afternoon across the northern third where models show weak omega
behind front off weak dpva.
As the Arctic front shifts south towards the Ohio Valley this
evening, a strong 140+ kt 300mb jet sets up over the Great Lakes.
This in conjunction with a tightening mid-level baroclinic zone to
our south sets up good moisture transport into a region of strong
frontogenesis over Iowa and northern IL. As this zone gradually
shifts south this evening, expect snow to increase in coverage and
intensity. Given the strength of projected frontogenesis and a
hint of negative EPV above this zone would expect some banding and
enhance snowfall rates overnight. 00Z guidance has trended more
progressive the the band of stronger forcing, shifting this south
of I-72 Sunday morning. This seems reasonable given the fact this is an
open wave at 850/700 mb. Snow will likely continue over the
southern half Sunday afternoon, and into Sunday night far SE, as additional
shortwave energy ejects from southern plains trough.
Thermal profiles off consistent GFS/ECMWF show snow for much of
the CWA, except south of I-70 where a sleet/freezing rain mix is
possible for several hours after onset. Have discounted aggressive
warmer NAM thermal structure (which would bring mixed precip north
of I-72) due to open wave feature. This does lead to lower overall
confidence in p-type than would be desired at 24 hrs. Given
precipitable water values 0.6-0.9 and projected forcing, model qpf
raning from 0.3 NW to 0.75 SE looks reasonable. Used 12:1
snow:liquid ratio, except 10:1 south of I-70 due to thermal
profiles. For the northwest half of the CWA projected totals of 4-6"
in 18+ hours fall short of warning criteria (6"+ in 12 hours or
8"+ in 24 hours) and have issued winter wx advisory for 6 PM
tonight through 6 PM Sunday. For areas southeast of a Shebyville
to Monticello to Rantoul line, 5-8" forecast over a 24+ hour period
also falls short of warning criteria. The potential for mixed
precip does complicate things, as warning sleet/ice accums would
be possible under NAM solution. With uncertaininty remaning in
this area will keep winter storm watch going (midnight tonight
through 6 AM Monday morning), and let day shift make the call
after looking over 12Z data.
LONG TERM...Monday through Friday
Bitterly cold air moves into the region behind the departing
storm. Late season Arctic high pressure will produce temps 20-25
degrees below normal, with lows likely dropping below zero across
the north Monday and Tuesday mornings. A weak shortwave dropping
through in northwest flow behind the high, will bring a chance of
light snow to the northern half of the CWA Tuesday. With low
moisture availablity have kept pops to slight chance. While temps
will remain below normal through the week, readings will gradually
moderate as mid level flow flattens. Dry weather is expected as
split flow keeps major systems well to our north and south.
25
&&
.AVIATION...
ISSUED 510 AM CST Sat Mar 1 2014
IFR CIGs behind cold front beginning to work into central Illinois
from the northwest. KGBG has dropped to OVC007 and large area of
CIGs between 007 and 012 extends approximately 100 nm behind the
cold front. Although diurnal influence may raise the CIGs slightly
as they work southeast, latest HRRR suggest the band will hold
together much of the day. Have translated the IFR/MVFR clouds into
the terminals this morning as front pushes through. So far only
minor reductions in VSBYs and will leave as P6SM for now.
Jet streak induced broad area of snow is expected to develop
across the upper Mississippi Valley this afternoon and advect
southward into the terminals this evening. Will likely be
occasional VSBYs lower, will currently broadbrush with 2 nm. As
the area develops later packages can hone the details on exactly
when LIFR VSBYs might occur.
Barker
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH from late tonight through late Sunday night
FOR ILZ044>046-054>057-061>063-066>068-071>073.
WINTER WEATHER ADVISORY from 6 PM this evening to 6 PM CST
Sunday FOR ILZ027>031-036>038-040>043-047>053.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
518 AM MST SAT MAR 1 2014
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 419 AM MST SAT MAR 1 2014
MAIN FORECAST CONCERNS...AMONG VERY MANY...WILL BE PHASE OF
PRECIPITATION AND AMOUNT OF ICE AND SNOW ACCUMULATION INTO TOMORROW
SATELLITE CONTINUING TO SHOW AN AMPLIFIED/COMPLEX AND EVEN
RETROGRESSIVE PATTERN FROM THE PACIFIC INTO CANADA. HIGH AMPLITUDE
RIDGE RESIDES ALONG THE WEST COAST OF NORTH AMERICA WITH BROAD AND
COLD UPPER TROUGH OVER CANADA. WEAKENING/FILLING SYSTEM IS MOVING
TOWARD THE CALIFORNIA COAST WITH A LARGE AMOUNT OF MID AND UPPER
LEVEL MOISTURE STREAMING OUT AHEAD OF IT. A SIGNIFICANT LOBE ROTATING
AROUND THE CANADIAN TROUGH IS PUSHING SOUTH.
AT JET LEVEL...MODELS INITIALIZED POORLY WITH JET SEGMENT IN
ADVANCE OF SYSTEM OFF THE CALIFORNIA COAST. THE UKMET AND NAM WERE
DOING THE BEST BUT WERE STILL OFF. AT MID LEVELS...THE GFS...ECMWF
...CANADIAN AND SREF WERE DOING ABOUT THE SAME AND THE BEST OF THE
AVAILABLE OUTPUT. THE ECMWF WAS DOING A LITTLE BETTER THAN THE
SREF ON THE SURFACE WIND AND PRESSURE FIELD. THE UKMET...GFS...NAM
AND CANADIAN WERE DOING WELL ON THE LOW LEVEL THERMAL FIELD.
EVEN THOUGH THEY ARE NOT PRODUCING A LOT OF QPF...THEY ARE TENDING
TO OVERDO IT WITH THE GFS...NAM...AND SREF THE WORST.
THIS WILL CONTINUE TO BE A VERY LOW CONFIDENCE FORECAST DUE TO POOR
INITIAL ANALYSIS ON MID AND UPPER LEVEL FEATURES...MODEL
DIFFERENCES IN THERMAL AND MOISTURE PROFILES...AND MODELS CHANGING
FROM THEIR SOLUTIONS...SOMETIMES DRAMATICALLY...FROM 24 HOURS AGO.
SAYING ALL THAT...THE WINTER WEATHER ADVISORY DOES STILL LOOK ON
TRACK DUE TO THE VARIABLE PHASES...VARIABLE ICE AND SNOW AMOUNTS.
IN GENERAL DID INCREASE ICE AMOUNTS...STILL BELOW A TENTH OF AN
INCH...DUE TO A LONGER TIME FOR ICE ACCUMULATION...AND LOWERED
SNOW AMOUNTS SLIGHTLY DUE TO NOT VERY MUCH SNOW ACCUMULATION UNTIL
TONIGHT.
TODAY/TONIGHT...JET SETUP BY THE END OF THE DAY IS DIFFERENT THAN
WHAT WAS DEPICTED YESTERDAY. BY LATE IN THE DAY THE MAIN JET
SEGMENT IS STILL TO THE WEST OF MY AREA WITH THE RIGHT FRONT
QUADRANT OVER THE AREA. SO AT FIRST GLANCE THERE DOES NOT APPEAR TO
BE A LOT TO DRIVE PRECIPITATION DEVELOPMENT DUE TO ANY STRONG
FEATURES. HOWEVER...MODELS DO CONTINUE TO PRODUCE LIGHT AMOUNTS OF
QPF. THE LIFT IS BEING GENERATED BY LOW LEVEL UPSLOPE AND
ISENTROPIC LIFT ABOVE THIS DOME OF COLD AIR.
PRECIPITATION HAS BEEN SLOWER TO START THAN WHAT WAS PREVIOUSLY
EXPECTED. SURFACE OBSERVATIONS ARE STARTING TO SHOW SOME
PRECIPITATION. SO BELIEVE WILL HAVE LIGHT PRECIPITATION AROUND FOR
MOST OF THE DAY. SO QUESTION BECOMES PHASE. 00Z SOUNDINGS SHOW
EITHER A DRY AIR MASS OR ONLY A SATURATED SHALLOW AIR MASS AND
THAT WAS EVIDENT IN SOME FOG DEVELOPMENT WHICH I WILL ADD. GFS HAS
CHANGED ITS TUNE FROM YESTERDAY. IT IS NOT AS AGGRESSIVE IN
SATURATING THE COLUMN TO A DEEPER DEPTH. THE NAM ALSO CHANGED ITS
TUNE AND SATURATED TO GREATER DEPTH...AT LEAST IN THE BEGINNING...IN
A SIMILAR FASHION AS THE GFS WHICH IS SLIGHTLY DRIER ALOFT THAN
THE NAM.
WARM LAYER APPEARS IN ALL AREAS OR ALMOST ALL AREAS AT THE BEGINNING
WITH THE GFS SHOWING WARMER TEMPERATURES ALOFT. NORTHERN AREAS
SHOULD SEE ALL SNOW ONLY BECAUSE THE DENDRITIC ZONE IS AT THE
SURFACE. FOR A FEW COUNTIES SOUTH AND WEST OF THAT A MIXTURE OF
FREEZING DRIZZLE...SNOW AND SLEET IS INDICATED WITH THE FAR SOUTH
AND WEST INDICATING SLEET AND FREEZING DRIZZLE. THIS AREA WORKS ITS
WAY SOUTH GRADUALLY THROUGH THE DAY. ALL IN ALL THE PREVIOUS
FORECAST HAD THE POP AND PHASE LAYOUT IN GOOD SHAPE AND ONLY MADE
MINOR ADJUSTMENTS. WITH NOT VERY STRONG LIFT...DID REDUCE THE
ALREADY LIGHT SNOW AMOUNTS A LITTLE.
RIGHT REAR QUADRANT OF THE JET MOVES ACROSS THE AREA DURING THE
NIGHT. AT THE SAME A SHORTWAVE TROUGH MOVES ACROSS THE AREA WITH
ISENTROPIC LIFT STILL IN PLACE. GFS CONTINUES TO NOT HAVE A DEEP OF
A SATURATED LAYER AS YESTERDAY. HOWEVER...THE DENDRITIC ZONE REMAINS
NEAR OR AT THE SURFACE. WHAT IS ALSO DIFFERENT FROM YESTERDAY IS
THAT THE GFS IS DOING WHAT THE NAM WAS DOING YESTERDAY WHICH IS
KEEPING A MIXTURE IN PLACE FOR MUCH LONGER. IF SOUNDINGS ARE
CORRECT THE FAR SOUTH AND WEST MAY NOT DO A COMPLETE CHANGE OVER TO
SNOW UNTIL AFTER MIDNIGHT.
AM CONCERNED THAT THE MODELS MAY BE UNDERDOING PRECIPITATION/SNOW
AMOUNTS DUE TO THE STRONG LIFT FROM THE JET/UPPER DEFORMATION MOVING
ACROSS. BY MIDNIGHT THE MAIN AREA OF SNOW WILL HAVE MOVED INTO THE
SOUTHEAST HALF AND THAT IS WHERE WE WILL HAVE TO WATCH AMOUNTS
CAREFULLY.
FOR MAXES...MODEL GUIDANCE IS WARMER AND THAT LOOKS TO BE MAINLY
DUE TO THE MODELS NOT COOLING OFF TEMPERATURES AS MUCH FOR THIS
MORNING. MAXES MAY BE EARLY. USED A COMBINATION OF HRRR AND MAV TO
ADJUST THE MAXES. KEPT MINS WARMER AND ABOVE THE COLDEST GUIDANCE
DUE TO THE CLOUDS AND UPSLOPE WINDS. CONSEQUENTLY THE WIND CHILL
READINGS ARE NOT AS LOW AS PREVIOUS FEW DAYS WITH MARGINAL WIND
CHILL ADVISORY CRITERIA ALONG AND EAST OF THE COLORADO BORDER.
SUNDAY/SUNDAY NIGHT...MODELS DIFFERING ON THE SPEED/POSITION A
LITTLE BUT IN GENERAL THEY SHOW THE RIGHT REAR QUADRANT AFFECTING
THE SOUTHEAST HALF OF THE AREA AT THE BEGINNING OF THE DAY. THIS IS
TO THE EAST OF THE AREA BY 18Z. IT IS ALSO BY THIS TIME THAT
DOWNGLIDE IS OCCURRING ON 290 SURFACE. PRECIPITATION BE HIGHEST IN
THE SOUTHEAST HALF OF THE FORECAST AREA DUE TO THE JET AND SHORTWAVE
TROUGH. SO KEPT HIGHER POPS THERE AND LOWERED THEM OVER THE REST OF
THE AREA. SNOW WILL GRADUALLY DECREASE DURING THE DAY WITH FLURRIES
EXPECTED DURING THE EVENING. BASED ON SATURATED LOW LEVELS DID TOSS
IN SOME PATCHY FREEZING FOG DURING THE OVERNIGHT HOURS.
CLOUDS...UPSLOPE WINDS AND COLD AIR ADVECTION WILL BE PLACE FOR THE
ENTIRE DAY. NOT SURE WHY MODEL GUIDANCE IS WARMING UP MAXES SO
MUCH. KEPT THE MAXES NEAR THE COLDER SIDE AND NEAR THE BETTER
PERFORMING GUIDANCE. MINS WILL BE WARMER THAN THE PREVIOUS NIGHT
WHICH AGAIN MEANS WIND CHILL READINGS NOT GETTING AS COLD. AGAIN
REACHING MARGINAL ADVISORY VALUES.
MONDAY/MONDAY NIGHT...WEAK RIGHT REAR QUADRANT OF THE JET DEVELOPS
OVER THE AREA BY THE MIDDLE OF THE DAY AND AFFECTS THE AREA AT
LEAST THROUGH THE EVENING. THERE WILL BE A DEEP DRY LAYER SO ONLY
CLOUDS WILL RESULT. SO THIS PERIOD WILL JUST END UP BEING A
TEMPERATURE FORECAST. DEPENDING ON HOW MUCH SNOW FALLS AND WHERE...
THAT COULD CAUSE IN THE TEMPERATURE LAYOUT I HAVE IN THERE. MODELS
ARE BRINGING IN WARMER AIR FURTHER EAST AND FOR THE MOST PART I
BELIEVE THEY ARE TOO AGGRESSIVE. SINCE THE ECMWF HAS A BETTER
DEPICTION OF THE SURFACE...DO LIKE ITS TEMPERATURES A LITTLE
BETTER. HOWEVER...MODELS HAVE HAD A TENDENCY TO HOLD TO COLD
TEMPERATURES TOO LONG IN THIS PATTERN WHICH BECOMES STRONG ZONAL.
WARM AIR ADVECTION PATTERN DEVELOPS IN ERNEST DURING THE NIGHT AND
MAY END UP HAVING WARMING TEMPERATURES DURING THE OVERNIGHT HOURS.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 419 AM MST SAT MAR 1 2014
NEAR TO ABOVE NORMAL TEMPERATURES WILL START OUT THIS PERIOD AS THE
COLD FRONT FROM THE WEEKEND CONTINUES TO MOVE EAST OUT OF THE AREA.
THE NEXT CHANCE FOR PRECIPITATION WILL BE WEDNESDAY AS AN UPPER
LEVEL SHORT WAVE TROUGH MOVES ACROSS THE AREA BRINGING A BRIEF SHOT
FOR SOME RAIN/SNOW. TEMPERATURES CONTINUE TO WARM THURSDAY AS A
SHORT WAVE RIDGE BUILDS OVER THE AREA. HIGHS WILL BE IN THE 60S AND
LOWS WILL BE IN THE 30S. FRIDAY ANOTHER STRONGER UPPER LEVEL SHORT
WAVE TROUGH MOVES OVER THE AREA...REMAINING OVER THE AREA UNTIL
SATURDAY. LATE FRIDAY AFTERNOON AND FRIDAY EVENING A COLD FRONT
WILL MOVE THROUGH THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 446 AM MST SAT MAR 1 2014
COMPLICATED/MESSY SET OF TAFS...ESPECIALLY AT KGLD. IFR CEILINGS
CAN BE EXPECTED AT KGLD THROUGH 06Z TONIGHT. THIS MORNING
PRECIPITATION COULD RANGE AND CHANGE BACK AND FORTH FROM
SNOW...SLEET AND FREEZING DRIZZLE. THIS IS CURRENTLY HAPPENING.
THIS AFTERNOON THE PHASE TRANSITION WILL BE FROM A SLEET/SNOW MIX
TO ALL SNOW BY LATE THIS AFTERNOON/EARLY THIS EVENING. VISIBILITIES
DURING THIS TIME SHOULD STAY IN THE 3 TO 5 MILE RANGE. AT 06Z...MVFR
CONDITIONS ARE EXPECTED. EASTERLY WINDS SHOULD BECOME GUSTY BY LATE
THIS MORNING AND CONTINUE THROUGH THE AFTERNOON.
FOR KMCK...SOME FOG CAN BE EXPECTED THIS MORNING WITH THE PHASE
BEING SNOW. CONDITIONS AT KMCK WILL START AS MVFR AND THEN DROP TO
IFR BY 18Z. IFR CONDITIONS WILL REMAIN UNTIL 06Z WHEN CEILINGS
COME UP TO MVFR. VISIBILITIES WILL ALSO REMAIN IN THE 3 TO 5 MILE
RANGE. EASTERLY WINDS SHOULD BECOME GUSTY BY LATE THIS MORNING AND
CONTINUE THROUGH THE AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY UNTIL 5 PM MST /6 PM CST/ SUNDAY FOR
KSZ001>004-013>016-027>029-041-042.
CO...WINTER WEATHER ADVISORY UNTIL 5 PM MST SUNDAY FOR COZ090>092.
NE...WINTER WEATHER ADVISORY UNTIL 5 PM MST /6 PM CST/ SUNDAY FOR
NEZ079>081.
&&
$$
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
419 AM MST SAT MAR 1 2014
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 419 AM MST SAT MAR 1 2014
MAIN FORECAST CONCERNS...AMONG VERY MANY...WILL BE PHASE OF
PRECIPITATION AND AMOUNT OF ICE AND SNOW ACCUMULATION INTO TOMORROW
SATELLITE CONTINUING TO SHOW AN AMPLIFIED/COMPLEX AND EVEN
RETROGRESSIVE PATTERN FROM THE PACIFIC INTO CANADA. HIGH AMPLITUDE
RIDGE RESIDES ALONG THE WEST COAST OF NORTH AMERICA WITH BROAD AND
COLD UPPER TROUGH OVER CANADA. WEAKENING/FILLING SYSTEM IS MOVING
TOWARD THE CALIFORNIA COAST WITH A LARGE AMOUNT OF MID AND UPPER
LEVEL MOISTURE STREAMING OUT AHEAD OF IT. A SIGNIFICANT LOBE ROTATING
AROUND THE CANADIAN TROUGH IS PUSHING SOUTH.
AT JET LEVEL...MODELS INITIALIZED POORLY WITH JET SEGMENT IN
ADVANCE OF SYSTEM OFF THE CALIFORNIA COAST. THE UKMET AND NAM WERE
DOING THE BEST BUT WERE STILL OFF. AT MID LEVELS...THE GFS...ECMWF
...CANADIAN AND SREF WERE DOING ABOUT THE SAME AND THE BEST OF THE
AVAILABLE OUTPUT. THE ECMWF WAS DOING A LITTLE BETTER THAN THE
SREF ON THE SURFACE WIND AND PRESSURE FIELD. THE UKMET...GFS...NAM
AND CANADIAN WERE DOING WELL ON THE LOW LEVEL THERMAL FIELD.
EVEN THOUGH THEY ARE NOT PRODUCING A LOT OF QPF...THEY ARE TENDING
TO OVERDO IT WITH THE GFS...NAM...AND SREF THE WORST.
THIS WILL CONTINUE TO BE A VERY LOW CONFIDENCE FORECAST DUE TO POOR
INITIAL ON MID AND UPPER LEVEL FEATURES...MODEL DIFFERENCES IN
THERMAL AND MOISTURE PROFILES...AND MODELS CHANGING FROM THEIR
SOLUTIONS...SOMETIMES DRAMATICALLY...FROM 24 HOURS AGO.
SAYING ALL THAT...THE WINTER WEATHER ADVISORY DOES STILL LOOK ON
TRACK DUE TO THE VARIABLE PHASES AND SNOW AMOUNTS.
TODAY/TONIGHT...JET SETUP BY THE END OF THE DAY IS DIFFERENT THAN
WHAT WAS DEPICTED YESTERDAY. BY LATE IN THE DAY THE MAIN JET
SEGMENT IS STILL TO THE WEST OF MY AREA WITH THE RIGHT FRONT
QUADRANT OVER THE AREA. SO AT FIRST GLANCE THERE DOES NOT APPEAR TO
BE A LOT TO DRIVE PRECIPITATION DEVELOPMENT DUE TO ANY STRONG
FEATURES. HOWEVER...MODELS DO CONTINUE TO PRODUCE LIGHT AMOUNTS OF
QPF. THE LIFT IS BEING GENERATED BY LOW LEVEL UPSLOPE AND
ISENTROPIC LIFT ABOVE THIS DOME OF COLD AIR.
PRECIPITATION HAS BEEN SLOWER TO START THAN WHAT WAS PREVIOUSLY
EXPECTED SURFACE OBSERVATIONS ARE STARTING TO SHOW IT. SO BELIEVE
WILL LIGHT PRECIPITATION AROUND FOR MOST OF THE DAY. SO QUESTION
BECOMES PHASE. 00Z SOUNDINGS SHOW EITHER A DRY AIR MASS OR ONLY A
SATURATED SHALLOW AIR MASS AND THAT WAS EVIDENT IN SOME FOG
DEVELOPMENT. GFS HAS CHANGED ITS TUNE FROM YESTERDAY. IT IS NOT AS
AGGRESSIVE IN SATURATING THE COLUMN TO A DEEPER DEPTH. THE NAM ALSO
CHANGED ITS TUNE AND SATURATED TO GREATER DEPTH...AT LEAST IN THE
BEGINNING...IN A SIMILAR AS THE GFS WHICH IS SLIGHTLY DRIER ALOFT
THAN THE NAM.
WARM LAYER APPEARS IN ALL AREAS OR ALMOST ALL AREAS AT THE BEGINNING
WITH THE GFS SHOWING WARMER TEMPERATURES ALOFT. NORTHERN AREAS
SHOULD SEE ALL SNOW ONLY BECAUSE THE DENDRITIC ZONE IS AT THE
SURFACE. FOR A FEW COUNTIES SOUTH AND WEST OF THAT A MIXTURE OF
FREEZING DRIZZLE...SNOW AND SLEET IS INDICATED WITH THE FAR SOUTH
AND WEST INDICATING SLEET AND FREEZING DRIZZLE. THIS AREA WORKS ITS
WAY SOUTH GRADUALLY THROUGH THE DAY. ALL IN ALL THE PREVIOUS
FORECAST HAD THE POP AND PHASE LAYOUT IN GOOD SHAPE AND ONLY MADE
MINOR ADJUSTMENTS. WITH NOT VERY STRONG LIFT...DID REDUCE THE
ALREADY LIGHT SNOW AMOUNTS A LITTLE.
RIGHT REAR QUADRANT OF THE JET MOVES ACROSS THE AREA DURING THE
NIGHT. AT THE SAME A SHORTWAVE TROUGH MOVES ACROSS THE AREA WITH
ISENTROPIC LIFT STILL IN PLACE. GFS CONTINUES TO NOT HAVE A DEEP OF
A SATURATED LAYER AS YESTERDAY. HOWEVER...THE DENDRITIC ZONE REMAINS
NEAR OR AT THE SURFACE. WHAT IS ALSO DIFFERENT FROM YESTERDAY IS
THAT THE GFS IS DOING WHAT THE NAM WAS DOING YESTERDAY WHICH IS
KEEPING A MIXTURE IN PLACE FOR MUCH LONGER. IF SOUNDINGS ARE
CORRECT THE FAR SOUTH AND WEST MAY NOT DO A COMPLETE CHANGE OVER TO
SNOW UNTIL AFTER MIDNIGHT. BY THE EARLY MORNING HOURS SHOULD CHANGE
OVER TO SNOW.
AM CONCERNED THAT THE MODELS MAY BE UNDERDOING PRECIPITATION/SNOW
AMOUNTS DUE TO THE STRONG LIFT FROM THE JET/UPPER DEFORMATION MOVING
ACROSS. BY MIDNIGHT THE MAIN AREA OF SNOW WILL HAVE MOVED INTO THE
SOUTHEAST HALF AND THAT IS WHERE WE WILL HAVE TO WATCH AMOUNTS
CAREFULLY.
FOR MAXES...MODEL GUIDANCE IS WARMER AND THAT LOOKS TO BE MAINLY
DUE TO THE MODELS NOT COOLING OFF TEMPERATURES AS MUCH FOR THIS
MORNING. MAXES MAY BE EARLY. USED A COMBINATION OF HRRR AND MAV TO
ADJUST THE MAXES. KEPT MINS WARMER AND ABOVE THE COLDEST GUIDANCE
DUE TO THE CLOUDS AND UPSLOPE WINDS. CONSEQUENTLY THE WIND CHILL
READINGS ARE NOT AS LOW AS PREVIOUS FEW DAYS WITH MARGINAL WIND
CHILL ADVISORY CRITERIA ALONG AND EAST OF THE COLORADO BORDER.
SUNDAY/SUNDAY NIGHT...MODELS DIFFERING ON THE SPEED/POSITION A
LITTLE BUT IN GENERAL THEY SHOW THE RIGHT REAR QUADRANT AFFECTING
THE SOUTHEAST HALF OF THE AREA AT THE BEGINNING OF THE DAY. THIS IS
TO THE EAST OF THE AREA BY 18Z. IT IS ALSO BY THIS TIME THAT
DOWNGLIDE IS OCCURRING ON 290 SURFACE. PRECIPITATION BE HIGHEST IN
THE SOUTHEAST HALF OF THE FORECAST AREA DUE TO THE JET AND SHORTWAVE
TROUGH. SO KEPT HIGHER POPS THERE AND LOWERED THEM OVER THE REST OF
THE AREA. SNOW WILL GRADUALLY DECREASE DURING THE DAY WITH FLURRIES
EXPECTED DURING THE EVENING. BASED ON SATURATED LOW LEVELS DID TOSS
IN SOME PATCHY FREEZING FOG DURING THE OVERNIGHT HOURS.
CLOUDS...UPSLOPE WINDS AND COLD AIR ADVECTION WILL BE PLACE FOR THE
ENTIRE DAY. NOT SURE WHY MODEL GUIDANCE IS WARMING UP MAXES SO
MUCH. KEPT THE MAXES NEAR THE COLDER SIDE AND NEAR THE BETTER
PERFORMING GUIDANCE. MINS WILL BE WARMER THAN THE PREVIOUS NIGHT
WHICH AGAIN MEANS WIND CHILL READINGS NOT GETTING AS COLD. AGAIN
REACHING MARGINAL ADVISORY VALUES.
MONDAY/MONDAY NIGHT...WEAK RIGHT REAR QUADRANT OF THE JET DEVELOPS
OVER THE AREA BY THE MIDDLE OF THE DAY AND AFFECTS THE AREA AT
LEAST THROUGH THE EVENING. THERE WILL BE A DEEP DRY LAYER SO ONLY
CLOUDS WILL RESULT. SO THIS PERIOD WILL JUST END UP BEING A
TEMPERATURE FORECAST. DEPENDING ON HOW MUCH SNOW FALLS AND WHERE...
THAT COULD CAUSE IN THE TEMPERATURE LAYOUT I HAVE IN THERE. MODELS
ARE BRINGING IN WARMER AIR FURTHER EAST AND FOR THE MOST PART I
BELIEVE THEY ARE TOO AGGRESSIVE. SINCE THE ECMWF HAS A BETTER
DEPICTION OF THE SURFACE...DO LIKE ITS TEMPERATURES A LITTLE
BETTER. HOWEVER...MODELS HAVE HAD A TENDENCY TO HOLD TO COLD
TEMPERATURES TOO LONG IN THIS PATTERN WHICH BECOMES STRONG ZONAL.
WARM AIR ADVECTION PATTERN DEVELOPS IN ERNEST DURING THE NIGHT AND
MAY END UP HAVING WARMING TEMPERATURES DURING THE OVERNIGHT HOURS.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 419 AM MST SAT MAR 1 2014
NEAR TO ABOVE NORMAL TEMPERATURES WILL START OUT THIS PERIOD AS THE
COLD FRONT FROM THE WEEKEND CONTINUES TO MOVE EAST OUT OF THE AREA.
THE NEXT CHANCE FOR PRECIPITATION WILL BE WEDNESDAY AS AN UPPER
LEVEL SHORT WAVE TROUGH MOVES ACROSS THE AREA BRINGING A BRIEF SHOT
FOR SOME RAIN/SNOW. TEMPERATURES CONTINUE TO WARM THURSDAY AS A
SHORT WAVE RIDGE BUILDS OVER THE AREA. HIGHS WILL BE IN THE 60S AND
LOWS WILL BE IN THE 30S. FRIDAY ANOTHER STRONGER UPPER LEVEL SHORT
WAVE TROUGH MOVES OVER THE AREA...REMAINING OVER THE AREA UNTIL
SATURDAY. LATE FRIDAY AFTERNOON AND FRIDAY EVENING A COLD FRONT
WILL MOVE THROUGH THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1025 PM MST FRI FEB 28 2014
VERY DIFFICULT FORECAST FOR BOTH KGLD AND KMCK. WHAT WE CAN SAY
WITH SOME CONFIDENCE IS CIGS WILL BE MVFR-IFR THROUGH THE PERIOD.
KGLD...EAST WINDS 10-15KTS TO VEER SLIGHTLY TO THE EAST/SOUTHEAST
BY 12Z THEN SLOWLY BACK TO THE NORTHEAST AND INCREASE 15G25KTS OR
SO THROUGH THE DAY. GUSTS SHOULD DISSIPATE SHORTLY AFTER 00Z OR SO
WITH PRIMARY WIND FROM THE NORTHEAST AROUND 10KTS. PRECIP
TYPE/INTENSITY WILL BE CHALLENGING. NOT EXPECTING PRECIP TIL THE
09Z-12Z TIMEFRAME WHEN LOW LEVEL CONVERGENCE INCREASES A BIT AND
REMAINS SO THROUGH MUCH OF THE DAY. SHOULD SEE A MIX OF -FZDZSN
INITIALLY WITH POSSIBLY A TRANSITION TO -PLSN AFTER 15Z OR SO WITH
LIGHT SNOW EXPECTED BY LATE MORNING THROUGH THE REST OF THE TAF
PERIOD. SOME FOG/MIST ALSO EXPECTED. CONFIDENCE IS LOW.
KMCK...NORTHEAST WINDS AROUND 15KTS EXPECTED TO VEER SLIGHTLY TO
THE EAST BY 09Z AND REMAIN SO WHILE ALSO BECOMING GUSTY FROM 15Z
THROUGH THE DAY THEN DECREASE TOWARD 10KTS AFTER SUNSET. PRECIP
TYPE SHOULD BE ALL SNOW. CONFIDENCE IN TIMING IS LOW.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY FROM 8 PM MST /9 PM CST/ THIS EVENING
TO 5 PM MST /6 PM CST/ SUNDAY FOR KSZ001>004-013>016-027>029-
041-042.
CO...WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 5 PM MST
SUNDAY FOR COZ090>092.
NE...WINTER WEATHER ADVISORY FROM 8 PM MST /9 PM CST/ THIS EVENING
TO 5 PM MST /6 PM CST/ SUNDAY FOR NEZ079>081.
&&
$$
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...DDT
AREA FORECAST DISCUSSION
NWS TOPEKA KS
430 AM CST Sat Mar 1 2014
.SHORT TERM...(Today)
Issued at 430 AM CST SAT MAR 1 2014
High pressure continues to nose south into the Plains early this
morning with local values ranging from the teens in the north to
near freezing in the south. Low level winds via upstream profiles
show north to northeast winds over the lower few thousand feet,
though sensors in Kansas indicate veering winds over the cold dome.
First hints and higher near-surface saturation occurring here with
EMP visibility at 7 SM and somewhat enhanced reflectivities from
KTWX. 0Z upper air obs from KAMA, KDDC, and KLBF showing drier mid
levels behinds yesterday`s weak wave.
Latest guidance quite similar and not different from earlier
forecasts. Mid level isentropic lift increases through the day, but
still much dry air to overcome to get precipitation generated aloft
to reach the ground. Deeper saturation takes place from northwest to
southeast and have modest precipitation chances following this
afternoon. Much of the day will see some concern for very light
precip formed via 900-800 mb frontogenesis. Lower clouds already in
place so not much lift should be needed to get something to fall,
especially later in the day. Lift seems to be high enough into the
frontal zone for this to occur temps warmer than ice crystal
formation values, but fall into colder, ice-generating temps. Along
with inherent uncertainty in the models handling of the near-surface
layers, have mentioned both freezing drizzle and flurries, but if
the former can dominate, become persistent and heavy, initial travel
problems could occur before main precip starts and this will need to
be watched today. Continued near-surface cold air advection should
bring slowly falling temps.
(Tonight through Monday)...
Complex weather scenario tonight through Sunday. The upper low was
still over the eastern Pacific off the California coast this morning
will move onshore today then out into the Rockies tonight before
moving out into the Southern and Central Plains on Sunday.
Main concern with this system is the amount of warm air above the
cold dome. 00Z NAM was the most aggressive with the warm
nose...while the 06Z run backed off a little with the regards to the
northern extent of the warm air. Good isentropic lift will be
ongoing this evening and strengthening overnight. Forecast time
sections show prolonged frontogenetic forcing along with periods of
CI or CSI trending toward banded precipitation and locally higher
amounts. As mentioned above with regards to the warm nose, forecast
soundings suggest that much of east central and northeast Kansas
will see a prolonged period of sleet this evening and into the early
morning hours on Sunday before becoming all snow. The sleet could
accumulate up to an inch. There still is some uncertainty with
snowfall amounts as the placement of the heavy band could change.
Have decided to issue a Winter Storm Warning for the snow and sleet
combination and amounts may need to be further refined with time.
Current thinking is that anywhere from 3 to 7 inches is possible.
The NAM is the faster of the model solutions with bringing in the
dry air and ending precipitation. Trended toward the GFS and ECMWF
with timing. However the new 06Z GFS is even a little slower than
the 00Z run.
The upper trough is forecast to move off to the east Sunday night
with precipitation coming to an end during the evening hours. In
addition to the snow and sleet very cold temperatures and winds of
15 to 20 mph will produce wind chills of 15 to 21 below tonight and
from 18 to 23 below zero Sunday night. High pressure will move into
the eastern Kansas on Monday. Lows tonight will fall into the single
digits with areas along the Nebraska border ranging from zero to 2
below. Highs on Sunday will rise little with temperatures remaining
in the 4 to 7 degree range.
.LONG TERM...(Monday night through Friday)
Issued at 430 AM CST SAT MAR 1 2014
Monday night through Friday...
A few longer-wavelength waves remain on track to pass mainly west to
east through the region. ECMWF stronger with the first on Monday
night into early Tuesday but hard to see anything but trace amounts
falling in even the stronger scenario. Next wave around Wednesday
deepens as it passes for a somewhat better precip opportunity, with
the final around the end of the forecast, again looking to deep as
it comes east, but much uncertainty in just how this wave pans out.
Temperatures still should generally moderate with time however.
&&
.AVIATION...(For the 06Z TAFs through 06Z Saturday Night)
Issued at 1102 PM CST FRI FEB 28 2014
Models are in reasonable agreement that MVFR CIGS will persist
through the period. The RAP and NAM isentropic surfaces continue
to show relatively deep upglide developing by mid morning, and think
there is a good chance for patchy freezing drizzle and flurries in
the late morning and through the afternoon. Confidence in the
start of the heavier banded sleet and snow with possible IFR CIGS
and VSBY is a little more marginal, and may begin closer to 06Z
Sunday. Therefore will not include any IFR conditions at this time
and let later shifts refine the timing.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING from 6 PM this evening to Midnight CST
Sunday Night FOR KSZ022>024-026-035>040.
WINTER WEATHER ADVISORY from 6 PM this evening to Midnight CST
Sunday Night FOR KSZ008>012-020-021-034.
WINTER STORM WARNING from 6 PM this evening to 6 AM CST Monday
FOR KSZ054>056-058-059.
&&
$$
SHORT TERM...65/53
LONG TERM...65
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1000 AM CST SAT MAR 1 2014
.UPDATE...
ISSUED AT 959 AM CST SAT MAR 1 2014
RADAR AND SURFACE OBS SHOW BLOSSOMING LIGHT SNOW /-SN/ PRIMARILY
WITHIN THE LOW-LEVEL DECK OF STRATUS THAT RESIDES WITHIN THE
DENDRITIC GROWTH ZONE /DGZ/. EVEN THOUGH I AM NOT CONFIDENT ALL
AREAS WILL MELT .01" LIQUID EQUIVALENT...POPS WERE INCREASED TO
80% THRU 20Z FOR THE ENTIRE FCST AREA. THIS WAS DONE TO TO FORCE
THE FCST TO BEST DEPICT WHAT WILL PROBABLY CONT THRU THE
AFTERNOON. THERE IS NO WAY WE CAN PINPOINT WHERE AND WHEN IT WILL
SNOW. SO FCST WILL NOW READ AS PERIODS OF -SN. AM NOT EXPECTING
MUCH MORE THAN A GOOD DUSTING HERE AND THERE TO THE S OF I-80.
N OF I-80 THE SAME APPLIES BUT WITH A SOMEWHAT BETTER CHANCE FOR
MODEST ACCUM.
IT WILL BE INTERESTING TO SEE WHAT UNFOLDS THIS AFTERNOON. MODEL
GUIDANCE IS ALL OVER THE PLACE...RESULTING IN ABOVE NORMAL
UNCERTAINTY. SOME GUIDANCE INDICATES WE COULD SEE A REDEVELOPMENT
OF MORE ROBUST SNOWFALL FOR A TIME...MAINLY OVER PARTS OF S-CNTRL
NEB.
UPDATE ISSUED AT 742 AM CST SAT MAR 1 2014
SENT AN EARLY ENHANCED SHORT-TERM FCST /ESTF/ UPDATE AS OUR
HOURLY FCST TEMPS WERE RUNNING A LITTLE COLDER THAN REALITY. WE
WILL STILL SEE A SLOW DOWNWARD SLIDE TODAY...BUT CURRENT TEMPS
WERE MERGED WITH THE 11Z HRRR THRU MIDDAY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 336 AM CST SAT MAR 1 2014
THE FOCUS DURING THE SHORT TERM PERIODS IS ON DEVELOPING SNOW...SNOW
AMOUNTS...BITTER COLD TEMPS/WIND CHILLS AND ASSOCIATED WINTER
HEADLINES.
AN ARCTIC AIRMASS HAD SETTLED ACROSS THE PLAINS STATES WITH EARLY
MORNING TEMPS AVERAGING IN THE SINGLE DIGITS AND TEENS. SNOW HAS
BEEN DEVELOPING/FALLING ACROSS NW/NORTHERN NEB THROUGH MUCH OF THE
PRE DAWN HOURS WITH VSBYS AS LOW AS 3/4SM AT TIMES. THE SNOW IS IN
ASSOCIATION WITH ISENTROPIC LIFT AHEAD OF AN APPROACHING WAVE MOVING
OUT OF THE CENTRAL ROCKIES...AND IN FAVORABLE UPPER JET DYNAMICS.
THE SNOW WILL DEVELOP IN BANDS WITH THE GREATEST ACCUMULATIONS TODAY
OCCURRING ACROSS NORTHERN NEBRASKA WITH OUR NORTHERN CWA ON THE
PERIPHERY OF THE HIGHEST ACCUMULATIONS. SHORT TERM MODELS INDICATE
THAT A DECENT SNOW BAND SHOULD ESTABLISH ACROSS VALLEY AND GREELEY
COUNTIES AND SNOW AMOUNTS WILL BE DEPENDENT UPON WHERE THE BANDS
SET UP. HAVE WENT WITH SNOWFALL ACCUMULATIONS OF 2 TO 4 INCHES
WHERE OUR CURRENT WINTER WEATHER ADVISORY IS IN EFFECT...GENERALLY
ALONG AND NORTH OF A LINE FROM LOUP CITY TO OSCEOLA NEB. FARTHER
SOUTH...AREAS OF LIGHTER SNOW SHOULD DEVELOP/SPREAD EASTWARD BY
MID DAY. HEADING INTO THE EVENING...THE SNOW SHOULD BEGIN TO TAPER
OFF IN OUR NW ZONES FIRST AS A 1042MB SFC RIDGE BUILDS SOUTH FM
THE DAKOTAS. NEXT ISSUE IS WHERE A SECOND ROUND/BAND OF SNOW WILL
SET UP ACROSS KANSAS SATURDAY NIGHT INTO SUNDAY AS NEXT SYSTEM
CROSSES THE SOUTHERN/CENTRAL PLAINS. THE 00Z MODELS KEPT THE BRUNT
OF THIS NEXT SYSTEM TO OUR SOUTH WHERE THE POTENTIAL EXISTS FOR A
SWATH OF HEAVY SNOWFALL IN GOOD DYNAMICS/ISENTROPIC
LIFT/JET/FRONTOGENESIS WITH THIS STRONGER WAVE. OF CONCERN IS THAT
THE 06Z NAM IS TRENDING FARTHER NORTH WITH THE BAND AND CLIPS OUR
SE KS COUNTIES IN A BAND OF POTENTIAL HEAVY SNOW. DO NOT WANT TO
JUMP ON ONE MODEL RUN AS TRENDS HAVE BEEN FARTHER SOUTH WITH THE
BAND...AND SREF SNOW PLUMES DO NOT SUPPORT SNOWFALL AS HIGH AS
LATEST NAM INDICATES IN THIS AREA. FOR SOME LOCATIONS IT COULD BE
AN ALL OR NOTHING TYPE OF EVENT BUT DID INCLUDED THE POTENTIAL FOR
A COUPLE TO SEVERAL INCHES ACROSS PORTIONS OF NC KANSAS AND WILL
NEED TO CLOSELY MONITOR HOW THIS SYSTEM EVOLVES AS IT MOVES INLAND
TODAY.
FOR HEADLINES...AGAIN THE CURRENT WINTER WX ADVISORY WILL COVER THE
SNOWFALL ACROSS OUR NORTHERN COUNTIES TODAY. CURRENT SNOWFALL
FORECAST ACROSS THE REMAINDER OF OUR CWA DOES NOT SUPPORT A WINTER
WX ADVISORY YET...AND ENOUGH UNCERTAINTY REMAINS IN KS TONIGHT TO
HOLD OFF ON SNOW HEADLINE IN THIS AREA. NEXT CONCERN IS THE FRIGID
WIND CHILLS EXPECTED THE COUPLE OF NIGHTS...AND WIND CHILLS FOR
TONIGHT/SATURDAY NIGHT ARE EXPECTED TO DROP TO 25 TO 35 BELOW ZERO IN
OUR NORTHERN ZONES. RATHER THAN ISSUE A WIND CHILL WARNING FOR
TONIGHT IN THE SAME AREA THAT HAS THE WINTER WEATHER ADVISORY FOR
TODAY...WILL GO WITH A WIND CHILL WATCH FOR TONIGHT AND LOCATIONS
FARTHER SOUTH CAN BE INCLUDED IN A WIND CHILL ADVISORY IF THE
GREATER SNOW REMAINS SOUTH...OR A WINTER WEATHER ADVISORY IF SNOW
AMOUNTS LOOK HIGHER THAN CURRENT FORECAST.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 336 AM CST SAT MAR 1 2014
ON THE LARGE SCALE...ZONAL TO NORTHWEST FLOW REGIME WILL BE THE RULE
THROUGH THE PERIOD. THERE WILL BE A FEW SHORT WAVES MOVING THROUGH
THE FLOW...WITH THE MOST ORGANIZED WAVE FORECAST OVER THE AREA ON
WEDNESDAY.
SPECIFICALLY...EXPECT DRY WEATHER SUNDAY NIGHT THROUGH TUESDAY NIGHT
WITH A GRADUAL WARMING TREND. WEDNESDAY LEFT A LOW CHANCE OF
PRECIP...SNOW NORTHEAST AND RAIN SOUTHWEST. LOOKS LIKE THERE WILL BE
ENOUGH LIFT BUT MOISTURE WILL BE LIMITED AS THE SYSTEM DEVELOPS OVER
THE AREA. THE SYSTEM IS FORECAST TO DEEPEN AS IT MOVES EAST OF THE
AREA AND THIS CYCLOGENESIS WILL FORCE INCREASED MOISTURE ADVECTION.
SO RIGHT NOW IT APPEARS PRECIP AMOUNTS WILL BE ON THE LOW END. WE
WILL HAVE TO CONTINUE TO MONITOR... THURSDAY AND FRIDAY APPEAR TO BE
DRY...AS THE NEXT SHORT WAVE AND APPROACHES FROM THE NORTHWEST.
AS MENTIONED...WE EXPECT A GRADUAL WARMING TREND MONDAY THROUGH
FRIDAY AS THE ARCTIC AIR MASS CURRENTLY ON TOP OF US IS GRADUALLY
MODIFIED AND PUSHED EAST. A SOUTHERLY FLOW WILL MIX IN WARMER TEMPS
MONDAY AND TUESDAY. THE POTENTIAL DEVELOPING LOW PRESSURE AREA WILL
NOT BRING A SIGNIFICANT TEMPERATURE CHANGE BEHIND IT...AS A MATTER
OF FACT...IT IS FORECAST TO MOVE OFF FAST ENOUGH THAT WINDS WILL
QUICKLY REBOUND TO THE SOUTH ON THURSDAY AND FRIDAY AND BRING NEAR
NORMAL TEMPS TO THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 519 AM CST SAT MAR 1 2014
TIMING OF SNOW AND LOWERING CIGS/VSBYS REMAINS THE MAIN CHALLENGE
FOR KGRI. SNOW HAS BEEN FALLING ACROSS NORTHERN/NORTHWEST NEBRASKA
ALL NIGHT AND SHORT TERM FORECAST MODELS SUGGEST THE SNOW WILL
REACH KGRI AROUND MID DAY. KGRI WILL BE ON THE PERIPHERY OF
HEAVIER SNOWFALL TO THE NORTH AND SNOW SHOULD BE INTERMITTENT
DEPENDING ON WHERE SNOW BANDS SET UP. AT THE ONSET OF THE PCPN
HAVE LOWERED CIGS/VSBYS TO MVFR...WITH IMPROVING CONDITIONS/DRYING
OUT TONIGHT AS SNOW BAND SHIFTS FARTHER SOUTH.
&&
.CLIMATE...
ISSUED AT 359 PM CST FRI FEB 28 2014
FOLLOWING BELOW IS A RECAP OF THE DAILY RECORD COLDEST HIGH
TEMPERATURES FOR GRAND ISLAND AND HASTINGS THAT WILL BE IN
JEOPARDY SUNDAY. ITS NOT OUT OF THE REALM OF POSSIBILITY THAT
SUNDAY COULD COME VERY CLOSE TO THE COLDEST MAXIMUM (HIGH)
TEMPERATURE ON RECORD FOR ANY DAY IN MARCH:
THE DAILY RECORDS FOR COLDEST MAX TEMP STAND AS FOLLOWS:
- MARCH 2: GRAND ISLAND...10 IN 2002
HASTINGS...11 IN 2002
- MARCH 3: GRAND ISLAND...8 IN 1916
HASTINGS...10 IN 2002
THE COLDEST MAX TEMP ON RECORD FOR ANY DAY IN MARCH:
- GRAND ISLAND: 4 DEGREES ON 3-10-1948
- HASTINGS: 3 DEGREES ON 3-11-1948
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
NEZ039>041-046>049.
WIND CHILL WATCH FROM THIS EVENING THROUGH SUNDAY MORNING FOR
NEZ039>041-046>049.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...FAY
LONG TERM...EDDY
AVIATION...FAY
CLIMATE...PFANNKUCH/HALBLAUB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
742 AM CST SAT MAR 1 2014
.UPDATE...
ISSUED AT 742 AM CST SAT MAR 1 2014
SENT AN EARLY ENHANCED SHORT-TERM FCST /ESTF/ UPDATE AS OUR
HOURLY FCST TEMPS WERE RUNNING A LITTLE COLDER THAN REALITY. WE
WILL STILL SEE A SLOW DOWNWARD SLIDE TODAY...BUT CURRENT TEMPS
WERE MERGED WITH THE 11Z HRRR THRU MIDDAY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 336 AM CST SAT MAR 1 2014
THE FOCUS DURING THE SHORT TERM PERIODS IS ON DEVELOPING SNOW...SNOW
AMOUNTS...BITTER COLD TEMPS/WIND CHILLS AND ASSOCIATED WINTER
HEADLINES.
AN ARCTIC AIRMASS HAD SETTLED ACROSS THE PLAINS STATES WITH EARLY
MORNING TEMPS AVERAGING IN THE SINGLE DIGITS AND TEENS. SNOW HAS
BEEN DEVELOPING/FALLING ACROSS NW/NORTHERN NEB THROUGH MUCH OF THE
PRE DAWN HOURS WITH VSBYS AS LOW AS 3/4SM AT TIMES. THE SNOW IS IN
ASSOCIATION WITH ISENTROPIC LIFT AHEAD OF AN APPROACHING WAVE MOVING
OUT OF THE CENTRAL ROCKIES...AND IN FAVORABLE UPPER JET DYNAMICS.
THE SNOW WILL DEVELOP IN BANDS WITH THE GREATEST ACCUMULATIONS TODAY
OCCURRING ACROSS NORTHERN NEBRASKA WITH OUR NORTHERN CWA ON THE
PERIPHERY OF THE HIGHEST ACCUMULATIONS. SHORT TERM MODELS INDICATE
THAT A DECENT SNOW BAND SHOULD ESTABLISH ACROSS VALLEY AND GREELEY
COUNTIES AND SNOW AMOUNTS WILL BE DEPENDENT UPON WHERE THE BANDS
SET UP. HAVE WENT WITH SNOWFALL ACCUMULATIONS OF 2 TO 4 INCHES
WHERE OUR CURRENT WINTER WEATHER ADVISORY IS IN EFFECT...GENERALLY
ALONG AND NORTH OF A LINE FROM LOUP CITY TO OSCEOLA NEB. FARTHER
SOUTH...AREAS OF LIGHTER SNOW SHOULD DEVELOP/SPREAD EASTWARD BY
MID DAY. HEADING INTO THE EVENING...THE SNOW SHOULD BEGIN TO TAPER
OFF IN OUR NW ZONES FIRST AS A 1042MB SFC RIDGE BUILDS SOUTH FM
THE DAKOTAS. NEXT ISSUE IS WHERE A SECOND ROUND/BAND OF SNOW WILL
SET UP ACROSS KANSAS SATURDAY NIGHT INTO SUNDAY AS NEXT SYSTEM
CROSSES THE SOUTHERN/CENTRAL PLAINS. THE 00Z MODELS KEPT THE BRUNT
OF THIS NEXT SYSTEM TO OUR SOUTH WHERE THE POTENTIAL EXISTS FOR A
SWATH OF HEAVY SNOWFALL IN GOOD DYNAMICS/ISENTROPIC
LIFT/JET/FRONTOGENESIS WITH THIS STRONGER WAVE. OF CONCERN IS THAT
THE 06Z NAM IS TRENDING FARTHER NORTH WITH THE BAND AND CLIPS OUR
SE KS COUNTIES IN A BAND OF POTENTIAL HEAVY SNOW. DO NOT WANT TO
JUMP ON ONE MODEL RUN AS TRENDS HAVE BEEN FARTHER SOUTH WITH THE
BAND...AND SREF SNOW PLUMES DO NOT SUPPORT SNOWFALL AS HIGH AS
LATEST NAM INDICATES IN THIS AREA. FOR SOME LOCATIONS IT COULD BE
AN ALL OR NOTHING TYPE OF EVENT BUT DID INCLUDED THE POTENTIAL FOR
A COUPLE TO SEVERAL INCHES ACROSS PORTIONS OF NC KANSAS AND WILL
NEED TO CLOSELY MONITOR HOW THIS SYSTEM EVOLVES AS IT MOVES INLAND
TODAY.
FOR HEADLINES...AGAIN THE CURRENT WINTER WX ADVISORY WILL COVER THE
SNOWFALL ACROSS OUR NORTHERN COUNTIES TODAY. CURRENT SNOWFALL
FORECAST ACROSS THE REMAINDER OF OUR CWA DOES NOT SUPPORT A WINTER
WX ADVISORY YET...AND ENOUGH UNCERTAINTY REMAINS IN KS TONIGHT TO
HOLD OFF ON SNOW HEADLINE IN THIS AREA. NEXT CONCERN IS THE FRIGID
WIND CHILLS EXPECTED THE COUPLE OF NIGHTS...AND WIND CHILLS FOR
TONIGHT/SATURDAY NGIHT ARE EXPECTED TO DROP TO 25 TO 35 BELOW ZERO IN
OUR NORTHERN ZONES. RATHER THAN ISSUE A WIND CHILL WARNING FOR
TONIGHT IN THE SAME AREA THAT HAS THE WINTER WEATHER ADVISORY FOR
TODAY...WILL GO WITH A WIND CHILL WATCH FOR TONIGHT AND LOCATIONS
FARTHER SOUTH CAN BE INCLUDED IN A WIND CHILL ADVISORY IF THE
GREATER SNOW REMAINS SOUTH...OR A WINTER WEATHER ADVISORY IF SNOW
AMOUNTS LOOK HIGHER THAN CURRENT FORECAST.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 336 AM CST SAT MAR 1 2014
ON THE LARGE SCALE...ZONAL TO NORTHWEST FLOW REGIME WILL BE THE RULE
THROUGH THE PERIOD. THERE WILL BE A FEW SHORT WAVES MOVING THROUGH
THE FLOW...WITH THE MOST ORGANIZED WAV FORECAST OVER THE AREA ON
WEDNESDAY.
SPECIFICALLY...EXPECT DRY WEATHER SUNDAY NIGHT THROUGH TUESDAY NIGHT
WITH A GRADUAL WARMING TREND. WEDNESDAY LEFT A LOW CHANCE OF
PRECIP...SNOW NORTHEAST AND RAIN SOUTHWEST. LOOKS LIKE THERE WILL BE
ENOUGH LIFT BUT MOISTURE WILL BE LIMTED AS THE SYSTEM DEVELOPS OVER
THE AREA. THE SYSTEM IS FORECAST TO DEEPEN AS IT MOVES EAST OF THE
AREA AND THIS CYCLOGENISIS WILL FORCE INCREASED MOISTURE ADVECTION.
SO RIGHT NOW IT APPEARS PRECIP AMOUNTS WILL BE ON THE LOW END. WE
WILL HAVE TO CONTINUE TO MONITOR... THURSDAY AND FRIDAY APPEAR TO BE
DRY...AS THE NEXT SHORT WAVE AND APPROCHES FROM THE NORTHWEST.
AS MENTIONED...WE EXPECT A GRADUAL WARMING TREND MONDAY THROUGH
FRIDAY AS THE ARCTIC AIR MASS CURRENTLY ON TOP OF US IS GRADUALLY
MODIFIED AND PUSHED EAST. A SOUTHERLY FLOW WILL MIX IN WARMER TEMPS
MONDAY AND TUESDAY. THE POTENTIAL DEVELOPING LOW PRESSURE AREA WILL
NOT BRING A SIGNIFICANT TEMPERATURE CHANGE BEHIND IT...AS A MATTER
OF FACT...IT IS FORECASTTOMOVE OFF FAST ENOUGH THAT WINDS WILL
QUICKLY REBOUND TO THE SOUTH ON THURSDAY AND FRIDAY AND BRING NEAR
NORMAL TEMPS TO THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 519 AM CST SAT MAR 1 2014
TIMING OF SNOW AND LOWERING CIGS/VSBYS REMAINS THE MAIN CHALLENGE
FOR KGRI. SNOW HAS BEEN FALLING ACROSS NORTHERN/NORTHWEST NEBRASKA
ALL NIGHT AND SHORT TERM FORECAST MODELS SUGGEST THE SNOW WILL
REACH KGRI AROUND MID DAY. KGRI WILL BE ON THE PERIPHERY OF
HEAVIER SNOWFALL TO THE NORTH AND SNOW SHOULD BE INTERMITTENT
DEPENDING ON WHERE SNOW BANDS SET UP. AT THE ONSET OF THE PCPN
HAVE LOWERED CIGS/VSBYS TO MVFR...WITH IMPROVING CONDITIONS/DRYING
OUT TONIGHT AS SNOW BAND SHIFTS FARTHER SOUTH.
&&
.CLIMATE...
ISSUED AT 359 PM CST FRI FEB 28 2014
FOLLOWING BELOW IS A RECAP OF THE DAILY RECORD COLDEST HIGH
TEMPERATURES FOR GRAND ISLAND AND HASTINGS THAT WILL BE IN
JEOPARDY SUNDAY. ITS NOT OUT OF THE REALM OF POSSIBILITY THAT
SUNDAY COULD COME VERY CLOSE TO THE COLDEST MAXIMUM (HIGH)
TEMPERATURE ON RECORD FOR ANY DAY IN MARCH:
THE DAILY RECORDS FOR COLDEST MAX TEMP STAND AS FOLLOWS:
- MARCH 2: GRAND ISLAND...10 IN 2002
HASTINGS...11 IN 2002
- MARCH 3: GRAND ISLAND...8 IN 1916
HASTINGS...10 IN 2002
THE COLDEST MAX TEMP ON RECORD FOR ANY DAY IN MARCH:
- GRAND ISLAND: 4 DEGREES ON 3-10-1948
- HASTINGS: 3 DEGREES ON 3-11-1948
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
NEZ039>041-046>049.
WIND CHILL WATCH FROM THIS EVENING THROUGH SUNDAY MORNING FOR
NEZ039>041-046>049.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...FAY
LONG TERM...EDDY
AVIATION...FAY
CLIMATE...PFANNKUCH/HALBLAUB
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
944 AM CST SAT MAR 1 2014
.UPDATE...
ISSUED AT 944 AM CST SAT MAR 1 2014
LOTS OF SUN TODAY WITH THE EXCEPTION OF THE FAR SOUTHERN FA. MAIN
QUESTION TODAY IS HOW MUCH TEMP RECOVERY CAN OCCUR WITH EARLY
MARCH SUN UNDER AN AIRMASS THAT STAYS BELOW -30C AT 925MB THRU THE
DAY. TEMPS HAVE SHOWN VERY LITTLE SIGN OF RISING YET BUT WILL HAVE
TO WATCH A WHILE LONGER TO SEE WHAT HAPPENS. FOR NOW WILL EXTEND
THE WIND CHILL HEADLINES PAST 18Z TODAY INTO 18Z SUNDAY. WIND
CHILLS MAY RISE BRIEFLY OUT OF WARNING CRITERIA ACROSS THE NORTH
BUT WILL QUICKLY DROP BACK INTO THEM BY LATE AFTERNOON INTO THE
EVENING.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 345 AM CST SAT MAR 1 2014
WIND CHILLS WILL BE THE MAIN CONCERN THIS PERIOD. 00Z MODELS ARE
IN GOOD AGREEMENT AND WILL USE A BLEND FOR DETAILS.
TODAY...A VERY COLD AIRMASS WITH 925MB TEMPS -30C TO -32C WILL
SETTLE OVER THE REGION AS SFC HIGH PRESSURE BUILDS. MAX TEMPS
TODAY WILL STRUGGLE TO REACH -10F TO -15F MOST AREAS. WINDS WILL
BE LIGHTER...BUT STILL 5-10 KNOTS. ALTHOUGH WE LIKELY WILL NEED TO
EXTEND THE WIND CHILL HEADLINES INTO THIS AFTERNOON AND
TONIGHT...WILL PASS THIS DUTY TO THE DAY SHIFT. THERE IS AN AREA
OF CLOUDS AND FLURRIES ACROSS SOUTHWEST MANITOBA ASSOCIATED WITH
AN UPPER JET STREAK. RAP GUIDANCE INDICATES THESE CONDITIONS WILL
PROPAGATE SOUTHEAST THROUGH THE DAY...ADJUSTED SKY GRIDS
ACCORDINGLY (AND ADDED FLURRIES).
TONIGHT-SUNDAY...HIGH PRESSURE CONTINUES TO ESTABLISH ITSELF. THIS
SHOULD END WIND CHILL HEADLINES BY LATER SUNDAY AFTERNOON AS WINDS
BECOME CALM. TEMPERATURES MAY BE SLIGHTLY WARMER ON SUNDAY...BUT
STILL BELOW ZERO MOST AREAS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 345 AM CST SAT MAR 1 2014
SUNDAY NIGHT-MONDAY NIGHT...HIGH PRESSURE MOVES EAST AS A WEAK
SHORTWAVE FROM THE PAC NW APPROACHES AND MOVES THROUGH THE REGION.
TIMING AND QPF AMOUNTS STILL A BIT UNCERTAIN...BUT MOST GUIDANCE
DOES INDICATE SOMETHING LATER MONDAY AFTERNOON INTO THE EVENING.
SNOW AMTS APPEAR TOWARD THE LIGHTER SIDE. TEMPERATURES SHOULD
CONTINUE THE GRADUAL WARMING TREND (BUT STILL WELL BELOW NORMAL
VALUES).
TUESDAY-FRIDAY...LONG WAVE PATTERN IS SPLIT WITH ZONAL FLOW
ACROSS THE STATES. LONG WAVE UPPER LOW OVER THE CANADIAN
ARCHIPELAGO MOVES TO THE NORTHWEST BY THE END OF THE PERIOD. LONG
WAVE PATTERN AMPLIFIES BY THE END OF THE PERIOD WITH AN UPPER
LEVEL RIDGE OVER THE WEST COAST AND LONG WAVE TROUGH OVER EASTERN
NORTH AMERICA.
THE GFS WAS FASTER THAN THE ECMWF THROUGH WED. THEN THE GFS WAS
SLOWER WITH THE NEXT SHORT WAVE ACROSS SOUTHERN CANADA FOR THU AND
FRI. THE ECMWF HAS BEEN TRENDING FASTER WHILE THE GFS HAS TRENDED
SLOWER. WILL BLEND THE TWO MODELS.
WILL KEEP YESTERDAY POPS FOR TUE. WILL KEEP YESTERDAYS POPS IN THE
WEST FOR TUE NIGHT. WILL EXPAND POPS FARTHER WEST ON WED NIGHT. WILL
TRIM BACK POPS IN THE SOUTH FOR THU NIGHT.
HIGH TEMPS WERE INCREASED 3 TO 4 DEGREES FOR THU...A DEGREE OR SO
FOR WED AND FRI AND NO CHANGE TO THU FROM YESTERDAYS RUN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 625 AM CST SAT MAR 1 2014
VFR CONDITIONS SHOULD CONTINUE THROUGH THIS TAF PERIOD. COULD BE
SCATTERED VFR CIGS THIS AFTERNOON...AND POSSIBLY FLURRIES.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR NDZ038-039-
049-052-053.
WIND CHILL WARNING UNTIL 1 PM CST THIS AFTERNOON FOR NDZ006>008-
014>016-024-026>030-054.
MN...WIND CHILL ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR MNZ003-024-
027>032-040.
WIND CHILL WARNING UNTIL 1 PM CST THIS AFTERNOON FOR MNZ001-002-
004>009-013>017-022-023.
&&
$$
UPDATE...GODON
SHORT TERM...TG
LONG TERM...TG/HOPPES
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
625 AM CST SAT MAR 1 2014
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 345 AM CST SAT MAR 1 2014
WIND CHILLS WILL BE THE MAIN CONCERN THIS PERIOD. 00Z MODELS ARE
IN GOOD AGREEMENT AND WILL USE A BLEND FOR DETAILS.
TODAY...A VERY COLD AIRMASS WITH 925MB TEMPS -30C TO -32C WILL
SETTLE OVER THE REGION AS SFC HIGH PRESSURE BUILDS. MAX TEMPS
TODAY WILL STRUGGLE TO REACH -10F TO -15F MOST AREAS. WINDS WILL
BE LIGHTER...BUT STILL 5-10 KNOTS. ALTHOUGH WE LIKELY WILL NEED TO
EXTEND THE WIND CHILL HEADLINES INTO THIS AFTERNOON AND
TONIGHT...WILL PASS THIS DUTY TO THE DAY SHIFT. THERE IS AN AREA
OF CLOUDS AND FLURRIES ACROSS SOUTHWEST MANITOBA ASSOCIATED WITH
AN UPPER JET STREAK. RAP GUIDANCE INDICATES THESE CONDITIONS WILL
PROPAGATE SOUTHEAST THROUGH THE DAY...ADJUSTED SKY GRIDS
ACCORDINGLY (AND ADDED FLURRIES).
TONIGHT-SUNDAY...HIGH PRESSURE CONTINUES TO ESTABLISH ITSELF. THIS
SHOULD END WIND CHILL HEADLINES BY LATER SUNDAY AFTERNOON AS WINDS
BECOME CALM. TEMPERATURES MAY BE SLIGHTLY WARMER ON SUNDAY...BUT
STILL BELOW ZERO MOST AREAS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 345 AM CST SAT MAR 1 2014
SUNDAY NIGHT-MONDAY NIGHT...HIGH PRESSURE MOVES EAST AS A WEAK
SHORTWAVE FROM THE PAC NW APPROACHES AND MOVES THROUGH THE REGION.
TIMING AND QPF AMOUNTS STILL A BIT UNCERTAIN...BUT MOST GUIDANCE
DOES INDICATE SOMETHING LATER MONDAY AFTERNOON INTO THE EVENING.
SNOW AMTS APPEAR TOWARD THE LIGHTER SIDE. TEMPERATURES SHOULD
CONTINUE THE GRADUAL WARMING TREND (BUT STILL WELL BELOW NORMAL
VALUES).
TUESDAY-FRIDAY...LONG WAVE PATTERN IS SPLIT WITH ZONAL FLOW
ACROSS THE STATES. LONG WAVE UPPER LOW OVER THE CANADIAN
ARCHIPELAGO MOVES TO THE NORTHWEST BY THE END OF THE PERIOD. LONG
WAVE PATTERN AMPLIFIES BY THE END OF THE PERIOD WITH AN UPPER
LEVEL RIDGE OVER THE WEST COAST AND LONG WAVE TROUGH OVER EASTERN
NORTH AMERICA.
THE GFS WAS FASTER THAN THE ECMWF THROUGH WED. THEN THE GFS WAS
SLOWER WITH THE NEXT SHORT WAVE ACROSS SOUTHERN CANADA FOR THU AND
FRI. THE ECMWF HAS BEEN TRENDING FASTER WHILE THE GFS HAS TRENDED
SLOWER. WILL BLEND THE TWO MODELS.
WILL KEEP YESTERDAY POPS FOR TUE. WILL KEEP YESTERDAYS POPS IN THE
WEST FOR TUE NIGHT. WILL EXPAND POPS FARTHER WEST ON WED NIGHT. WILL
TRIM BACK POPS IN THE SOUTH FOR THU NIGHT.
HIGH TEMPS WERE INCREASED 3 TO 4 DEGREES FOR THU...A DEGREE OR SO
FOR WED AND FRI AND NO CHANGE TO THU FROM YESTERDAYS RUN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 625 AM CST SAT MAR 1 2014
VFR CONDITIONS SHOULD CONTINUE THROUGH THIS TAF PERIOD. COULD BE
SCATTERED VFR CIGS THIS AFTERNOON...AND POSSIBLY FLURRIES.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR NDZ038-039-
049-052-053.
WIND CHILL WARNING UNTIL 1 PM CST THIS AFTERNOON FOR NDZ006>008-
014>016-024-026>030-054.
MN...WIND CHILL ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR MNZ003-024-
027>032-040.
WIND CHILL WARNING UNTIL 1 PM CST THIS AFTERNOON FOR MNZ001-002-
004>009-013>017-022-023.
&&
$$
SHORT TERM...TG
LONG TERM...TG/HOPPES
AVIATION...TG
AREA FORECAST DISCUSSION
NWS PORTLAND OR
435 AM PST SAT MAR 1 2014
...CORRECTION TO AVIATION SECTION.
.SYNOPSIS...STRONG LOW PRESSURE IS DRIFTING INTO SOUTHERN CALIFORNIA
THIS MORNING. LEFTOVER MOISTURE FROM AN ASSOCIATED FRONT CONTINUES TO
BRING RAIN AND HIGH ELEVATION SNOW TO PORTIONS OF LANE AND LINN
COUNTIES. OTHERWISE THE BIG STORY TODAY WILL BE A STRONG PUSH OF COLD
AIR COMING DOWN FROM THE CANADIAN ROCKIES. A BACKDOOR COLD FRONT HAS
PUSHED SOUTHWEST ACROSS THE COLUMBIA BASIN...AND HAS ARRIVED ALONG
THE EAST SLOPES OF THE CASCADES. THIS FRONT WILL PUSH WESTWARD
THROUGH THE GORGE AND ACROSS THE PORTLAND METRO AREA TODAY WITH COLD
EAST WINDS TO FOLLOW LATER TODAY THROUGH SUNDAY. WHILE IT DOES NOT
APPEAR IT WILL BE COLD ENOUGH FOR WINTRY PRECIP IN THE PORTLAND METRO
AREA...THERE IS A THREAT FOR SIGNIFICANT SNOW AND ICE IN THE GORGE
AND HOOD RIVER VALLEY TONIGHT UNTIL THE COLD AIR SCOURS OUT SUNDAY
NIGHT OR MONDAY. OTHERWISE...A SERIES OF PACIFIC STORM SYSTEMS WILL
BRING PERIODS OF RAIN...MOUNTAIN SNOW...AND COASTAL WIND FOR MUCH OF
THE UPCOMING WEEK.
&&
.SHORT TERM...TODAY THROUGH MONDAY...LET ME START OFF BY SAYING THIS
IS ONE OF THE MOST CHALLENGING FORECASTS THUS FAR IN MY CAREER...AS
IT IS A VERY ODD PATTERN WHERE A MAJOR SURGE OF COLD AIR MAY OR MAY
NOT BE SUCCESSFUL PUSHING ALL THE WAY SOUTHWEST FROM THE CANADIAN
PRAIRIE PROVINCES ACROSS BOTH THE ROCKIES AND CASCADES. THIS IS VERY
TOUGH FOR COLD AIR TO DO SUCCESSFULLY...BUT IT IS POSSIBLE AND MOST
MODELS HAVE BEEN FAIRLY CONSISTENT IN SUGGESTING IT WILL. SOME MODELS
SUCH AS THE NAM STILL SUGGEST THERE COULD BE WINTRY PRECIPITATION IN
THE PORTLAND METRO AREA LATER TODAY INTO EARLY SUNDAY...WHILE OTHERS
SUCH AS THE RAP ARE NOT EVEN BRINGING ENOUGH COLD AIR TO CREATE A
SIGNIFICANT SNOW/ICE EVENT IN THE GORGE OR HOOD RIVER VALLEY. TO GIVE
AN EXAMPLE OF THE UNCERTAINTY HERE...THE 06Z NAM BUFR SOUNDING
SUGGESTED TEMPS WILL BE IN THE LOW 20S IN HOOD RIVER AT 3 PM THIS
AFTERNOON. MEANWHILE THE 06Z RAP SUGGESTS TEMPS WILL BE IN THE UPPER
40S AT THE SAME PLACE AT THE SAME TIME. I BELIEVE BOTH ARE
WRONG...STICKING TO THE TYPICAL BIASES OF THE NAM BEING TOO COLD AND
THE RAP BEING TOO WARM. THE REALITY WILL MOST LIKELY SOMEWHERE IN
BETWEEN THESE EXTREMES. NEEDLESS TO SAY CONFIDENCE IN ANY
DETERMINISTIC FORECAST IS UNUSUALLY LOW IN THIS SITUATION...BUT WE
WILL DO OUR BEST.
LETS START WITH THE TWO MODELS I MENTIONED EARLIER...THE NAM AND THE
RAP. THE COLD AIR IS ALREADY WELL BEHIND THE 00Z NAM FORECAST AND
EVEN THE 06Z INITIALIZATION. CHECKING SFC PRESSURES...THE 09Z NAM
FORECAST FOR CENTRAL WA ARE ALREADY 4-6 MB TOO HIGH. TEMPS REMAIN
ABOVE FREEZING FOR ALL BUT THE EASTERN THIRD OF WASHINGTON...EXCEPT
MOSES LAKE AND EPHRATA. THE 06Z NAM BUFR SOUNDING FOR KDLS SAID IT
WOULD BE 28 DEG F BY NOW...THE 11Z OB FOR KDLS SAYS IT IS STILL 42.
THIS MARKS LITTLE CHANGE FROM WHERE THE TEMP HAS BEEN SITTING AT KDLS
MUCH OF THE NIGHT. HOWEVER THE COLD ADVECTION HAS JUST STARTED...
EAST WINDS AT 10 KT HAVE PICKED UP AND THE DEWPOINT FELL 7 DEG F IN
ONE HOUR. SO IT IS SAFE TO SAY OUR BACKDOOR COLD FRONT HAS PUSHED
W-SW INTO THE COLUMBIA GORGE...BUT IS DOING SO MUCH SLOWER AND WITH
MUCH LESS BLUSTER THAN THE NAM SUGGESTED. MEANWHILE THE RAP HAS BEEN
DOING MUCH BETTER WITH THE HANDLING OF THE COLD AIR...BEING MUCH
SLOWER AS IT HAS THE BENEFIT OF BEING REINITIALIZED EACH HOUR. WHERE
THE RAP LIKELY GOES WRONG IS WHAT IT DOES WITH THE COLD AIR LATER
TODAY. STRANGELY...THE RAP HAS THE EASTSIDE COLD POOL ESSENTIALLY
SURRENDERING LATER TODAY DUE TO INCREASING WESTERLY FLOW ALOFT AND
SUPPOSED WARM ADVECTION IN BRITISH COLUMBIA ASSOCIATED WITH A
DISTURBANCE SLIDING DOWN THE COAST. THIS DISTURBANCE APPEARS FAR TOO
WEAK TO DEFEAT A FULL-ON PUSH OF ARCTIC AIR...AND THE RAP IS OUT ON
ITS OWN WITH THIS IDEA. SUSPECT THE EASTSIDE COLD POOL WILL CONTINUE
TO STRENGTHEN OVER THE NEXT 12-24 HRS AS THE NAM/GFS/UKMET/ ECMWF/GEM
ALL INDICATE TO SOME DEGREE.
THE 00Z/06Z GFS ALSO HAS DONE MUCH BETTER WITH ITS INITIALIZATION...
BOTH WITH SFC PRESSURES AND THE MAGNITUDE/PROGRESS OF THE COLD AIR.
IT ALSO SEEMS TO BE HANDLING THE STRONG LOW OFF CALIFORNIA AND
ACTIVITY FURTHER OUT INTO THE PACIFIC FAIRLY WELL. THEREFORE THE
LATEST RUNS OF THE GFS ARE PREFERRED...AND ESSENTIALLY OUR FORECAST
IS A BLEND BETWEEN THE PREVIOUS FORECAST AND THE GFS/WRFGFS.
WE DECIDED TO PUSH BACK THE START OF THE WINTER WX ADVISORY IN THE
GORGE TO 6 PM FOR SEVERAL REASONS. FIRST...THE DELAY IN ARRIVAL OF
COLD AIR. SECOND...THE UNCERTAINTY IN THE AMOUNT OF QPF EXPECTED
TODAY. AND THIRD...THE EARLY MARCH SUN AND ITS IMPACT ON SURFACE
TEMPS. TEMPS HAVE GENERALLY BEEN IN THE 40S ALL NIGHT...SO SURFACES
TAKE SOME TIME TO COOL OFF ENOUGH TO ALLOW ICE ACCRETION. THE
STRONGER EARLY MARCH SUN WILL BE FIGHTING THE COLD AIR...EVEN THOUGH
IT WILL LIKELY BE CLOUDY THROUGHOUT THE DAY THERE WILL LIKELY BE
ENOUGH SOLAR ENERGY TO KEEP MOST SURFACES ABOVE FREEZING THROUGHOUT
THE DAY. OUTSIDE OF THE GORGE...TODAY WILL SEE RAIN GRADUALLY
INCREASING ACROSS THE AREA DUE TO LOW AND MID-LEVEL FRONTOGENESIS
ASSOCIATED WITH THE BACKDOOR COLD FRONT MEETING THE MILD AND MOIST
AIR MASS IN PLACE.
AS COLD HIGH PRESSURE BUILDS EAST OF THE CASCADES...EASTERLY PRES
GRADIENTS AND THUS EAST WINDS WILL INCREASE THROUGH THE GORGE. THIS
SHOULD CAUSE TEMPS TO STAY STEADY OR SLOWLY FALL THROUGH THE DAY IN
THE PDX METRO AREA...WHILE AREAS OUTSIDE OF THE GORGE OUTFLOW ONCE
AGAIN AIM FOR THE 50S. IT APPEARS VERY QUESTIONABLE WINDS WILL BE
STRONG ENOUGH FOR AN ADVISORY...BUT THERE IS ENOUGH UNCERTAINTY IN
THIS SITUATION TO KEEP THE EXISTING WIND ADVISORY IN PLACE FOR THE
EAST PORTLAND METRO. NORTHEAST WINDS ASSOCIATED WITH THE COLD
ADVECTION ARE RATHER STRONG IN THE COLUMBIA BASIN...IT WILL BE
INTERESTING TO SEE WHAT THEY DO THIS MORNING WHEN THEY REACH THE
CASCADES. THE COLD POOL WILL LIKELY BE DEEP ENOUGH TO SUPPORT A WINDY
DAY FOR MUCH OF THE METRO...RATHER THAN CONFINE STRONGER WINDS TO THE
GORGE. EXPECT MANY SPOTS IN AND AROUND PORTLAND/VANCOUVER WILL SEE
GUSTS IN THE 30-40 MPH RANGE...WITH PERHAPS AN ISOLATED 45 MPH GUST
OR TWO.
THE RESULTING DOWNSLOPING OF THE BROADER EAST WIND MAY ALSO TAKE A
BIT OF THE EDGE OFF THE MAGNITUDE OF THE COLD AIR TRYING TO SPILL
WEST OF THE CASCADES. AS A RESULT WE BUMPED TEMPS UP SLIGHTLY
TODAY...AND LEFT ONLY A SLIGHT CHANCE OF FZRA AROUND TROUTDALE
TONIGHT. KEEP IN MIND THE NAM BUFR SOUNDINGS CONTINUE TO SUGGEST A
HIGH IMPACT ICE EVENT THROUGHOUT THE METRO THIS AFTERNOON THROUGH
SUNDAY MORNING...BUT AGAIN THE NAM HAS BEEN DISCOUNTED DUE TO THE
FACT IT IS FAR TOO FAST AND STRONG WITH THE EASTSIDE COLD AIR.
A PACIFIC DISTURBANCE WILL BEGIN TO SPREAD MORE RAIN ACROSS THE
DISTRICT SUNDAY. AS THE LOW PRESSURE SYSTEM APPROACHES...THERE MAY BE
A BIT OF A COASTAL JET WHICH WOULD ALLOW BRIEF WINDS GUSTING 40-50
MPH ALONG THE BEACHES AND HEADLANDS. ANOTHER SIMILAR SYSTEM IS
EXPECTED FOR MONDAY...AND THESE SYSTEMS WILL HAVE AN INCREASING TAP
OF SUBTROPICAL MOISTURE. THIS MOISTURE WILL BE OVERRUNNING THE COLD
AIR IN THE GORGE AND HOOD RIVER VALLEY... POSSIBLY RESULTING IN
SUBSTANTIAL SNOW AND ICE ACCUMULATIONS BEFORE THE COLD AIR FINALLY
SCOURS OUT MONDAY. AT THIS MOMENT OUR HUNCH IS THAT TEMPS WILL
MODERATE JUST ENOUGH SUNDAY TO ALLOW THE SECOND SURGE OF MOISTURE TO
FALL AS PLAIN RAIN IN THE GORGE AND NEAR HOOD RIVER. AGAIN...LEFT THE
EXISTING WINTER STORM WATCH IN PLACE DUE TO THE UNCERTAINTY... BUT IT
APPEARS THE BEST CHANCE FOR WINTRY PRECIP SUN NIGHT/MON WILL BE IN
UPPER PORTIONS OF THE HOOD RIVER VALLEY AND POSSIBLY EASTERN SKAMANIA
COUNTY.
TEMPS WARM WELL INTO THE 50S ON GUSTY SOUTH WINDS THROUGH THE
WILLAMETTE VALLEY MONDAY...POSSIBLY INTO THE 40S AND LOWER 50S IN THE
GORGE BY MONDAY AFTERNOON OR EVENING. AN ACTIVE PACIFIC STORM TRACK
WILL KEEP THINGS WET WELL INTO THE UPCOMING WEEK...BUT TEMPS WILL
WARM UP JUST ENOUGH TO GIVE MANY OF US A HINT OF SPRING TO THE AIR BY
MIDWEEK. WEAGLE
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
MONDAY NIGHT THROUGH FRIDAY...MILD BUT WET CONDITIONS ARE EXPECTED
NEXT WEEK AS STRONG WESTERLY FLOW PREVAILS. A MOIST PACIFIC FRONTAL
SYSTEM WILL MOVE ONSHORE LATE MONDAY...LIFTING SNOW LEVELS ABOVE PASS
LEVEL. STRONG OROGRAPHIC LIFT WILL ALLOW ABUNDANT PRECIPITATION OVER
THE CASCADES AND COAST RANGE MONDAY NIGHT INTO TUESDAY. BOTH THE 12Z
GFS AND ECMWF ARE STILL IN GOOD AGREEMENT SHOWING BACK TO BACK
SYSTEMS MOVING THROUGH WEDNESDAY AND THURSDAY. THEY BOTH SETUP AN
UPPER LOW IN THE GULF OF ALASKA AND ANOTHER JUST OFF THE
OREGON/CALIFORNIA BORDER. THE 12Z ECMWF HAS A 985 MB SURFACE LOW
DEVELOPING LATE WEDNESDAY NIGHT AND HAS IT SETUP A LITTLE FURTHER
SOUTH OF THE GFS SOLUTION. MAY SEE SOME DECENT COASTAL WINDS WITH
THIS SETUP AS THE LOW LIFTS NORTH ALONG THE COAST THROUGH THURSDAY
MORNING. POST FRONTAL SHOWERS CONTINUE INTO LATE NEXT WEEK AS MODELS
SUGGEST AN AMPLIFYING TROUGH OVER THE PACIFIC NORTHWEST. /27
&&
.AVIATION...VFR ACROSS REGION THIS AM. HOWEVER...OCCASIONAL LIGHT
RAIN WITH CIGS MVFR AND LOCALLY IFR S BETWEEN KS12 AND
K61S...MOSTLY AFFECTING KEUG. NOT MUCH CHANGE TODAY WITH MOSTLY
VFR ALONG THE COAST AND INLAND N OF KSLE. THAT SAID...CIGS WILL
GRADUALLY LOWER ACROSS INLAND NW OREGON TODAY AS MORE MOISTURE
ALOFT ARRIVES FROM THE S. OFFSHORE FLOW WILL GRADUALLY INCREASE
TODAY OVER W WASHINGTON AND NW OREGON TODAY...WITH BREEZY WINDS
FOR AREAS N OF A KTMK TO KUAO LINE.
KPDX AND APPROACHES...VFR TODAY BUT CIGS LOWER TO 5000 FT 14Z TO
16Z. CIGS LOWER FURTHER LATE TODAY...WITH MVFR BECOMING MORE
DOMINANT BETWEEN 02Z AND 06Z. MAIN IMPACT WILL BE GUSTY E WINDS
AFTER 18Z...WITH PEAK GUSTS 30 TO 35 KT.ROCKEY.
&&
.MARINE...CONDITIONS WILL REMAIN FAIRLY BENIGN ACROSS THE
COASTAL WATERS TODAY INTO EARLY SUN. LIGHT TO MODERATE OFFSHORE
FLOW MAY BECOME GUSTY AT TIMES BY LATE AM...WITH A FEW GUSTS UP
TO 25 KT POSSIBLE...MAINLY BELOW THE COASTAL GAPS AND THROUGH THE
COLUMBIA RIVER.
A MORE ACTIVE WEATHER PATTERN LOOKS TO BEGIN LATER SUN/MON. A WARM
FRONT WILL LIFT N ACROSS THE COASTAL WATERS SUN NIGHT INTO MON AM.
A STRONG FRONT WILL ARRIVE TUE NIGHT...WITH INCREASING POTENTIAL
OF SOUTHERLY GALES AT THAT TIME. REST OF WEEK WILL REMAIN BREEZY
AND UNSETTLED AS MORE FRONTS ARRIVE. ROCKEY.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY FROM 6 AM THIS MORNING TO 6 AM PST SUNDAY FOR
GREATER PORTLAND METRO AREA.
WINTER WEATHER ADVISORY FROM 6 PM TONIGHT TO 6 AM PST SUNDAY
FOR CENTRAL COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-
WESTERN COLUMBIA RIVER GORGE.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR CENTRAL COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-
WESTERN COLUMBIA RIVER GORGE.
WA...WIND ADVISORY FROM 6 AM THIS MORNING TO 6 AM PST SUNDAY FOR
GREATER VANCOUVER AREA.
WINTER WEATHER ADVISORY FROM 6 PM TONIGHT TO 6 AM PST SUNDAY
FOR CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE-
SOUTH WASHINGTON CASCADES.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER
GORGE-SOUTH WASHINGTON CASCADES.
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
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 PORTLAND OR
337 AM PST SAT MAR 1 2014
.SYNOPSIS...STRONG LOW PRESSURE IS DRIFTING INTO SOUTHERN CALIFORNIA
THIS MORNING. LEFTOVER MOISTURE FROM AN ASSOCIATED FRONT CONTINUES TO
BRING RAIN AND HIGH ELEVATION SNOW TO PORTIONS OF LANE AND LINN
COUNTIES. OTHERWISE THE BIG STORY TODAY WILL BE A STRONG PUSH OF COLD
AIR COMING DOWN FROM THE CANADIAN ROCKIES. A BACKDOOR COLD FRONT HAS
PUSHED SOUTHWEST ACROSS THE COLUMBIA BASIN...AND HAS ARRIVED ALONG
THE EAST SLOPES OF THE CASCADES. THIS FRONT WILL PUSH WESTWARD
THROUGH THE GORGE AND ACROSS THE PORTLAND METRO AREA TODAY WITH COLD
EAST WINDS TO FOLLOW LATER TODAY THROUGH SUNDAY. WHILE IT DOES NOT
APPEAR IT WILL BE COLD ENOUGH FOR WINTRY PRECIP IN THE PORTLAND METRO
AREA...THERE IS A THREAT FOR SIGNIFICANT SNOW AND ICE IN THE GORGE
AND HOOD RIVER VALLEY TONIGHT UNTIL THE COLD AIR SCOURS OUT SUNDAY
NIGHT OR MONDAY. OTHERWISE...A SERIES OF PACIFIC STORM SYSTEMS WILL
BRING PERIODS OF RAIN...MOUNTAIN SNOW...AND COASTAL WIND FOR MUCH OF
THE UPCOMING WEEK.
&&
.SHORT TERM...TODAY THROUGH MONDAY...LET ME START OFF BY SAYING THIS
IS ONE OF THE MOST CHALLENGING FORECASTS THUS FAR IN MY CAREER...AS
IT IS A VERY ODD PATTERN WHERE A MAJOR SURGE OF COLD AIR MAY OR MAY
NOT BE SUCCESSFUL PUSHING ALL THE WAY SOUTHWEST FROM THE CANADIAN
PRAIRIE PROVINCES ACROSS BOTH THE ROCKIES AND CASCADES. THIS IS VERY
TOUGH FOR COLD AIR TO DO SUCCESSFULLY...BUT IT IS POSSIBLE AND MOST
MODELS HAVE BEEN FAIRLY CONSISTENT IN SUGGESTING IT WILL. SOME MODELS
SUCH AS THE NAM STILL SUGGEST THERE COULD BE WINTRY PRECIPITATION IN
THE PORTLAND METRO AREA LATER TODAY INTO EARLY SUNDAY...WHILE OTHERS
SUCH AS THE RAP ARE NOT EVEN BRINGING ENOUGH COLD AIR TO CREATE A
SIGNIFICANT SNOW/ICE EVENT IN THE GORGE OR HOOD RIVER VALLEY. TO GIVE
AN EXAMPLE OF THE UNCERTAINTY HERE...THE 06Z NAM BUFR SOUNDING
SUGGESTED TEMPS WILL BE IN THE LOW 20S IN HOOD RIVER AT 3 PM THIS
AFTERNOON. MEANWHILE THE 06Z RAP SUGGESTS TEMPS WILL BE IN THE UPPER
40S AT THE SAME PLACE AT THE SAME TIME. I BELIEVE BOTH ARE
WRONG...STICKING TO THE TYPICAL BIASES OF THE NAM BEING TOO COLD AND
THE RAP BEING TOO WARM. THE REALITY WILL MOST LIKELY SOMEWHERE IN
BETWEEN THESE EXTREMES. NEEDLESS TO SAY CONFIDENCE IN ANY
DETERMINISTIC FORECAST IS UNUSUALLY LOW IN THIS SITUATION...BUT WE
WILL DO OUR BEST.
LETS START WITH THE TWO MODELS I MENTIONED EARLIER...THE NAM AND THE
RAP. THE COLD AIR IS ALREADY WELL BEHIND THE 00Z NAM FORECAST AND
EVEN THE 06Z INITIALIZATION. CHECKING SFC PRESSURES...THE 09Z NAM
FORECAST FOR CENTRAL WA ARE ALREADY 4-6 MB TOO HIGH. TEMPS REMAIN
ABOVE FREEZING FOR ALL BUT THE EASTERN THIRD OF WASHINGTON...EXCEPT
MOSES LAKE AND EPHRATA. THE 06Z NAM BUFR SOUNDING FOR KDLS SAID IT
WOULD BE 28 DEG F BY NOW...THE 11Z OB FOR KDLS SAYS IT IS STILL 42.
THIS MARKS LITTLE CHANGE FROM WHERE THE TEMP HAS BEEN SITTING AT KDLS
MUCH OF THE NIGHT. HOWEVER THE COLD ADVECTION HAS JUST STARTED...
EAST WINDS AT 10 KT HAVE PICKED UP AND THE DEWPOINT FELL 7 DEG F IN
ONE HOUR. SO IT IS SAFE TO SAY OUR BACKDOOR COLD FRONT HAS PUSHED
W-SW INTO THE COLUMBIA GORGE...BUT IS DOING SO MUCH SLOWER AND WITH
MUCH LESS BLUSTER THAN THE NAM SUGGESTED. MEANWHILE THE RAP HAS BEEN
DOING MUCH BETTER WITH THE HANDLING OF THE COLD AIR...BEING MUCH
SLOWER AS IT HAS THE BENEFIT OF BEING REINITIALIZED EACH HOUR. WHERE
THE RAP LIKELY GOES WRONG IS WHAT IT DOES WITH THE COLD AIR LATER
TODAY. STRANGELY...THE RAP HAS THE EASTSIDE COLD POOL ESSENTIALLY
SURRENDERING LATER TODAY DUE TO INCREASING WESTERLY FLOW ALOFT AND
SUPPOSED WARM ADVECTION IN BRITISH COLUMBIA ASSOCIATED WITH A
DISTURBANCE SLIDING DOWN THE COAST. THIS DISTURBANCE APPEARS FAR TOO
WEAK TO DEFEAT A FULL-ON PUSH OF ARCTIC AIR...AND THE RAP IS OUT ON
ITS OWN WITH THIS IDEA. SUSPECT THE EASTSIDE COLD POOL WILL CONTINUE
TO STRENGTHEN OVER THE NEXT 12-24 HRS AS THE NAM/GFS/UKMET/ ECMWF/GEM
ALL INDICATE TO SOME DEGREE.
THE 00Z/06Z GFS ALSO HAS DONE MUCH BETTER WITH ITS INITIALIZATION...
BOTH WITH SFC PRESSURES AND THE MAGNITUDE/PROGRESS OF THE COLD AIR.
IT ALSO SEEMS TO BE HANDLING THE STRONG LOW OFF CALIFORNIA AND
ACTIVITY FURTHER OUT INTO THE PACIFIC FAIRLY WELL. THEREFORE THE
LATEST RUNS OF THE GFS ARE PREFERRED...AND ESSENTIALLY OUR FORECAST
IS A BLEND BETWEEN THE PREVIOUS FORECAST AND THE GFS/WRFGFS.
WE DECIDED TO PUSH BACK THE START OF THE WINTER WX ADVISORY IN THE
GORGE TO 6 PM FOR SEVERAL REASONS. FIRST...THE DELAY IN ARRIVAL OF
COLD AIR. SECOND...THE UNCERTAINTY IN THE AMOUNT OF QPF EXPECTED
TODAY. AND THIRD...THE EARLY MARCH SUN AND ITS IMPACT ON SURFACE
TEMPS. TEMPS HAVE GENERALLY BEEN IN THE 40S ALL NIGHT...SO SURFACES
TAKE SOME TIME TO COOL OFF ENOUGH TO ALLOW ICE ACCRETION. THE
STRONGER EARLY MARCH SUN WILL BE FIGHTING THE COLD AIR...EVEN THOUGH
IT WILL LIKELY BE CLOUDY THROUGHOUT THE DAY THERE WILL LIKELY BE
ENOUGH SOLAR ENERGY TO KEEP MOST SURFACES ABOVE FREEZING THROUGHOUT
THE DAY. OUTSIDE OF THE GORGE...TODAY WILL SEE RAIN GRADUALLY
INCREASING ACROSS THE AREA DUE TO LOW AND MID-LEVEL FRONTOGENESIS
ASSOCIATED WITH THE BACKDOOR COLD FRONT MEETING THE MILD AND MOIST
AIR MASS IN PLACE.
AS COLD HIGH PRESSURE BUILDS EAST OF THE CASCADES...EASTERLY PRES
GRADIENTS AND THUS EAST WINDS WILL INCREASE THROUGH THE GORGE. THIS
SHOULD CAUSE TEMPS TO STAY STEADY OR SLOWLY FALL THROUGH THE DAY IN
THE PDX METRO AREA...WHILE AREAS OUTSIDE OF THE GORGE OUTFLOW ONCE
AGAIN AIM FOR THE 50S. IT APPEARS VERY QUESTIONABLE WINDS WILL BE
STRONG ENOUGH FOR AN ADVISORY...BUT THERE IS ENOUGH UNCERTAINTY IN
THIS SITUATION TO KEEP THE EXISTING WIND ADVISORY IN PLACE FOR THE
EAST PORTLAND METRO. NORTHEAST WINDS ASSOCIATED WITH THE COLD
ADVECTION ARE RATHER STRONG IN THE COLUMBIA BASIN...IT WILL BE
INTERESTING TO SEE WHAT THEY DO THIS MORNING WHEN THEY REACH THE
CASCADES. THE COLD POOL WILL LIKELY BE DEEP ENOUGH TO SUPPORT A WINDY
DAY FOR MUCH OF THE METRO...RATHER THAN CONFINE STRONGER WINDS TO THE
GORGE. EXPECT MANY SPOTS IN AND AROUND PORTLAND/VANCOUVER WILL SEE
GUSTS IN THE 30-40 MPH RANGE...WITH PERHAPS AN ISOLATED 45 MPH GUST
OR TWO.
THE RESULTING DOWNSLOPING OF THE BROADER EAST WIND MAY ALSO TAKE A
BIT OF THE EDGE OFF THE MAGNITUDE OF THE COLD AIR TRYING TO SPILL
WEST OF THE CASCADES. AS A RESULT WE BUMPED TEMPS UP SLIGHTLY
TODAY...AND LEFT ONLY A SLIGHT CHANCE OF FZRA AROUND TROUTDALE
TONIGHT. KEEP IN MIND THE NAM BUFR SOUNDINGS CONTINUE TO SUGGEST A
HIGH IMPACT ICE EVENT THROUGHOUT THE METRO THIS AFTERNOON THROUGH
SUNDAY MORNING...BUT AGAIN THE NAM HAS BEEN DISCOUNTED DUE TO THE
FACT IT IS FAR TOO FAST AND STRONG WITH THE EASTSIDE COLD AIR.
A PACIFIC DISTURBANCE WILL BEGIN TO SPREAD MORE RAIN ACROSS THE
DISTRICT SUNDAY. AS THE LOW PRESSURE SYSTEM APPROACHES...THERE MAY BE
A BIT OF A COASTAL JET WHICH WOULD ALLOW BRIEF WINDS GUSTING 40-50
MPH ALONG THE BEACHES AND HEADLANDS. ANOTHER SIMILAR SYSTEM IS
EXPECTED FOR MONDAY...AND THESE SYSTEMS WILL HAVE AN INCREASING TAP
OF SUBTROPICAL MOISTURE. THIS MOISTURE WILL BE OVERRUNNING THE COLD
AIR IN THE GORGE AND HOOD RIVER VALLEY... POSSIBLY RESULTING IN
SUBSTANTIAL SNOW AND ICE ACCUMULATIONS BEFORE THE COLD AIR FINALLY
SCOURS OUT MONDAY. AT THIS MOMENT OUR HUNCH IS THAT TEMPS WILL
MODERATE JUST ENOUGH SUNDAY TO ALLOW THE SECOND SURGE OF MOISTURE TO
FALL AS PLAIN RAIN IN THE GORGE AND NEAR HOOD RIVER. AGAIN...LEFT THE
EXISTING WINTER STORM WATCH IN PLACE DUE TO THE UNCERTAINTY... BUT IT
APPEARS THE BEST CHANCE FOR WINTRY PRECIP SUN NIGHT/MON WILL BE IN
UPPER PORTIONS OF THE HOOD RIVER VALLEY AND POSSIBLY EASTERN SKAMANIA
COUNTY.
TEMPS WARM WELL INTO THE 50S ON GUSTY SOUTH WINDS THROUGH THE
WILLAMETTE VALLEY MONDAY...POSSIBLY INTO THE 40S AND LOWER 50S IN THE
GORGE BY MONDAY AFTERNOON OR EVENING. AN ACTIVE PACIFIC STORM TRACK
WILL KEEP THINGS WET WELL INTO THE UPCOMING WEEK...BUT TEMPS WILL
WARM UP JUST ENOUGH TO GIVE MANY OF US A HINT OF SPRING TO THE AIR BY
MIDWEEK. WEAGLE
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
MONDAY NIGHT THROUGH FRIDAY...MILD BUT WET CONDITIONS ARE EXPECTED
NEXT WEEK AS STRONG WESTERLY FLOW PREVAILS. A MOIST PACIFIC FRONTAL
SYSTEM WILL MOVE ONSHORE LATE MONDAY...LIFTING SNOW LEVELS ABOVE PASS
LEVEL. STRONG OROGRAPHIC LIFT WILL ALLOW ABUNDANT PRECIPITATION OVER
THE CASCADES AND COAST RANGE MONDAY NIGHT INTO TUESDAY. BOTH THE 12Z
GFS AND ECMWF ARE STILL IN GOOD AGREEMENT SHOWING BACK TO BACK
SYSTEMS MOVING THROUGH WEDNESDAY AND THURSDAY. THEY BOTH SETUP AN
UPPER LOW IN THE GULF OF ALASKA AND ANOTHER JUST OFF THE
OREGON/CALIFORNIA BORDER. THE 12Z ECMWF HAS A 985 MB SURFACE LOW
DEVELOPING LATE WEDNESDAY NIGHT AND HAS IT SETUP A LITTLE FURTHER
SOUTH OF THE GFS SOLUTION. MAY SEE SOME DECENT COASTAL WINDS WITH
THIS SETUP AS THE LOW LIFTS NORTH ALONG THE COAST THROUGH THURSDAY
MORNING. POST FRONTAL SHOWERS CONTINUE INTO LATE NEXT WEEK AS MODELS
SUGGEST AN AMPLIFYING TROUGH OVER THE PACIFIC NORTHWEST. /27
&&
.AVIATION...VFR ACROSS REGION THIS AM. HOWEVER...OCCASIONAL LIGHT
RAIN WITH CIGS MVFR AND LOCALLY IFR S BETWEEN KS12 AND
K61S...MOSTLY AFFECTING KEUG. NOT MUCH CHANGE TODAY WITH MOSTLY
VFR ALONG THE COAST AND INLAND N OF KSLE. THAT SAID...CIGS WILL
GRADUALLY LOWER ACROSS INLAND NW OREGON TODAY AS MORE MOISTURE
ALOFT ARRIVES FROM THE S. OFFSHORE FLOW WILL GRADUALLY INCREASE
TODAY OVER W WASHINGTON AND NW OREGON TODAY...WITH BREEZY WINDS
FOR AREAS N OF A KTMK TO KUAO LINE.
KPDX AND APPROACHES...VFR TODAY BUT CIGS LOWER TO 5000 FT 18Z TO
20Z. CIGS LOWER FURTHER LATE TODAY...WITH MVFR BECOMING MORE
DOMINANT BETWEEN 02Z AND 06Z. MAIN IMPACT WILL BE GUSTY E WINDS
AFTER 18Z...WITH PEAK GUSTS 30 TO 35 KT.ROCKEY.
&&
.MARINE...CONDITIONS WILL REMAIN FAIRLY BENIGN ACROSS THE
COASTAL WATERS TODAY INTO EARLY SUN. LIGHT TO MODERATE OFFSHORE
FLOW MAY BECOME GUSTY AT TIMES BY LATE AM...WITH A FEW GUSTS UP
TO 25 KT POSSIBLE...MAINLY BELOW THE COASTAL GAPS AND THROUGH THE
COLUMBIA RIVER.
A MORE ACTIVE WEATHER PATTERN LOOKS TO BEGIN LATER SUN/MON. A WARM
FRONT WILL LIFT N ACROSS THE COASTAL WATERS SUN NIGHT INTO MON AM.
A STRONG FRONT WILL ARRIVE TUE NIGHT...WITH INCREASING POTENTIAL
OF SOUTHERLY GALES AT THAT TIME. REST OF WEEK WILL REMAIN BREEZY
AND UNSETTLED AS MORE FRONTS ARRIVE. ROCKEY.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY FROM 6 AM THIS MORNING TO 6 AM PST SUNDAY FOR
GREATER PORTLAND METRO AREA.
WINTER WEATHER ADVISORY FROM 6 PM TONIGHT TO 6 AM PST SUNDAY
FOR CENTRAL COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-
WESTERN COLUMBIA RIVER GORGE.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR CENTRAL COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-
WESTERN COLUMBIA RIVER GORGE.
WA...WIND ADVISORY FROM 6 AM THIS MORNING TO 6 AM PST SUNDAY FOR
GREATER VANCOUVER AREA.
WINTER WEATHER ADVISORY FROM 6 PM TONIGHT TO 6 AM PST SUNDAY
FOR CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE-
SOUTH WASHINGTON CASCADES.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER
GORGE-SOUTH WASHINGTON CASCADES.
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
629 AM CST SAT MAR 1 2014
.UPDATE...TO CORRECT GRAMMAR IN FIRST LINE
&&
.AVIATION...12Z AVIATION FORECAST
&&
.PREV DISCUSSION... /ISSUED 618 AM CST SAT MAR 1 2014/
UPDATE...FOR 12Z AVIATION FORECAST
AVIATION...
..POOR FLYING WEATHER SUNDAY NIGHT INTO MONDAY IN MIDDLE TENNESSEE...
SHORT WAVE THAT BROUGHT RAIN OVERNIGHT HAS PUSHED OFF TO THE EAST
AND CAN BE SEEN IN THE LATEST WATER VAPOR LOOP OVER EASTERN
GEORGIA INTO THE CAROLINAS. SOUTHERN BRANCH OF THE POLAR JET WILL
PUSH NORTHWARD TODAY FROM GULF. THIS IS ALREADY TAKING PLACE AS
CAN BE SEEN BY HEIGHT FIELDS FROM GULF REGION LIFTING NORTHWARD IN
LATEST RUC LOOP. THINK STRATOCU WILL REMAIN ACROSS THE AREA NEXT
24 HOURS WITH A LOWERING IN THE CEILING AFTER 00Z THIS EVENING
POSSIBLY INTO THE IFR RANGE LATE TONIGHT. IN THE LATEST CONUS
WATER VAPOR LOOP ONE CAN SEE A STRONG TWIST IN THE IMAGERY NEARING
THE CALIFORNIA COAST. THIS WILL BE THE NEXT WEATHER MAKER THAT
PILOTS WILL HAVE TO CONTEND WITH. BY SUNDAY THIS SYSTEM WILL
DEVELOP A STRONG BAROCLINIC ZONE FROM TEXAS NORTHEASTWARD THROUGH
THE OHIO VALLEY AND EVENTUALLY INTO THE NORTHEAST. WINTRY PRECIP
IN THE FORM OF FREEZING RAIN AND SLEET BEGINNING TO LOOK LIKELY
ACROSS THE NORTHWEST HALF OF MIDDLE TENNESSEE SUNDAY NIGHT INTO
EARLY MONDAY.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
BOYD
01
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
534 AM CST SAT MAR 1 2014
.AVIATION...
AN AREA OF LOW CIGS AND VISBYS WERE RAPIDLY APPROACHING KCDS. LOW
VISIBILITIES ARE EXPECTED TO PERSIST FOR A FEW HOURS HOWEVER THE
LOW CIGS ARE MORE UNCERTAIN. IT IS LIKELY THAT LOW CIGS WILL LAST
AT LEAST THROUGH THE MORNING BUT THEIR RESIDENCE COULD BE EXTENDED
WELL INTO THE AFTERNOON HOURS. AS THE LOW CLOUDS MOVE IN TO THE
TERMINAL...THEY WILL LIKELY BE IFR OR EVEN LIFR. BY LATE IN THE
MORNING AND INTO THE AFTERNOON THE CEILING HEIGHT IS ANTICIPATED
TO RISE NEAR MVFR. SIMILAR TO YESTERDAY...STRONG WINDS WILL AFFECT
KLBB WITH SOME POSSIBLE LIGHT VISIBILITY RESTRICTIONS DUE TO
BLOWING DUST. A COLD FRONT WILL PUSH INTO THE REGION OVERNIGHT
BRINGING ADDITIONAL LOW CIGS TO BOTH TERMINALS BY SUNDAY MORNING.
&&
.PREV DISCUSSION... /ISSUED 453 AM CST SAT MAR 1 2014/
SHORT TERM...
THIS FORECAST WAS COMPLICATED WITH A TOUGH ROW TO HOE. THE FIRST
ISSUE TO DEAL WITH WAS THE FOG AND LOW STRATUS CLOSING IN ON THE
AREA BOTH FROM THE EAST AND NORTH. THE LOW LEVEL MOISTURE WILL
CONTINUE TO PROGRESS INTO THE ROLLING PLAINS ON THE EAST SIDE OF THE
FRONTAL BOUNDARY THIS MORNING. THE FRONT WILL LIKELY MAKE ADDITIONAL
PROGRESS WESTWARD EARLY THIS MORNING. THE FRONTAL POSITION WILL
LIKELY BE A GOOD DIVIDING POINT BETWEEN CLEAR SKIES AND THE LOW
STRATUS LAYER. THE CLOUDS THEN PRESENT A PROBLEM WITH THE
TEMPERATURE FORECAST OVER THE SOUTHEASTERN TEXAS PANHANDLE. MOST
GUIDANCE DEPICTS LOW STRATUS HANGING OUT FOR THE ENTIRE MORNING. IN
FACT...THE LATEST RAP GUIDANCE SHOWS THIS LOW STRATUS CAMPING OUT
NEAR CHILDRESS. THE LATER SITUATION WOULD CLEARLY KEEP TEMPERATURES
FROM CLIMBING VERY MUCH AT CHILDRESS THIS AFTERNOON. THIS FRONTS
WESTWARD PROGRESSION WILL BE HALTED BY A CLOSED LOW MOVING ONSHORE
IN SOUTHERN CALIFORNIA TODAY. THIS WILL INCREASE SOUTHWEST FLOW
ALOFT WITH THE FRONT RETREATING A BIT THIS AFTERNOON.
SURFACE LEE TROUGHING WILL DEVELOP BY THIS AFTERNOON BUMPING UP
WINDS INTO THE BREEZY CATEGORY AGAIN. WINDS ALOFT WILL BE MARKEDLY
LOWER THAN OBSERVED YESTERDAY ALTHOUGH STILL BETWEEN 30 AND 40KT AT
700MB. HIGH CLOUDS MOVING IN FROM THE WEST MAY KEEP ATMOSPHERIC
MIXING FROM REACHING ITS FULL POTENTIAL TODAY BUT IT WILL STILL
NONETHELESS BE BREEZY. DOWNSLOPING WINDS COMBINED WITH STRONG LARGE
SCALE SUBSIDENCE WILL LEAD TO SURFACE CONDITIONS LIKELY DRIER THAN
WHAT MODELS ADVERTISE AS WAS THE CASE YESTERDAY. THE LOW LEVEL
THERMAL RIDGE AXIS WILL INCREASE FROM THE TRANS PECOS EXTENDING INTO
THE SOUTHWESTERN PANHANDLE.
BY SUNDAY MORNING...THE SPRAWLING HIGH PRESSURE OVER THE PLAINS WILL
BEGIN TO EXERT INFLUENCE OVER WEST TEXAS AS THE COLD FRONT PUSHES
FARTHER WEST. LARGE SCALE LIFT WILL INCREASE OVER THE AREA BY SUNDAY
MORNING WITH A 110KT UPPER LEVEL JET MOVING OVERHEAD. NEAR SURFACE
CONDITIONS WILL SEE A MASHUP OF BOTH THE ARCTIC FRONT AND PACIFIC
FRONT MAKING ITS WAY THROUGH THE WEST. THIS WILL CREATE CLEARLY
DEFINED AREAS OF FRONTOGENETICAL FORCING. PRECIPITATION CHANCES WILL
INCREASE AFTER MIDNIGHT WITH STRONGER LOW LEVEL MOISTURE ADVECTING
INTO THE REGION BEHIND THE COLD FRONT. MID AND UPPER LEVELS WILL BE
FAIRLY SATURATED WITH PACIFIC MOISTURE AS THE UPPER LOW IN THE
SOUTHWEST EDGES CLOSER. AREAS TO THE WEST OF THE FRONT WILL LIKELY
STAY WARM ENOUGH FOR ALL LIQUID PRECIPITATION. ON THE EAST SIDE OF
THE FRONT...COOLER AIR ADVECTING INTO THE REGION AT THE LOWEST
LEVELS WILL CHANGE PRECIPITATION TYPE TO MOST LIKELY A MIX OF
FREEZING RAIN AND SLEET. THE LOWEST TEMPERATURE IN THE NEAR SURFACE
SUB FREEZING LAYER APPROACHES AND MAY EXCEED -10C. IN
CONTRAST...EAST OF THE AREA...STRONG ISENTROPIC LIFT ABOVE THE
FRONTAL BOUNDARY WILL CREATE CHANCES OF PRECIPITATION. ALTHOUGH THE
BEST CHANCES WILL REMAIN EAST...THERE WILL ALSO EXIST A POTENTIAL
FOR A RUMBLE OF THUNDER WITH IMPRESSIVE ELEVATED INSTABILITY.
LONG TERM...
QUITE AN IMPRESSIVE UPPER LEVEL STORM SYSTEM ALONG THE CALIFORNIA
CENTRAL COAST WILL EJECT EASTWARD ACROSS THE SOUTHERN ROCKIES LATE
TONIGHT THEN THE SOUTHERN HIGH PLAINS ON SUNDAY. A GLACIAL AIRMASS
MEANWHILE WILL PRESS SOUTHWARD OUT OF THE NORTHERN PLAINS AND
COULD BE POISED TO SWEEP OVER THE AREA SUNDAY. THE RATE OF DECAY
OF THE CALIFORNIA SYSTEM WILL BE KEY IN DE TERMING EVERY ASPECT OF
WEATHER FOR SUNDAY. AND EVEN THOUGH SOLUTIONS SEEM SIMILAR ALOFT
IN THIS ASPECT THEY TOY WITH US IN A VARIETY OF MANNERS REGARDING
FRONTAL MOVEMENT...THERMAL CONTOURING...PRECIPITATION AREAS...
AMOUNTS...AND TYPES. OUR AREA SEEMS TO BE GROUND ZERO FOR THE
MODEL DISSENT GIVING RISE TO ANY NUMBER OF OUTCOMES SUNDAY
RANGING FROM FIRE WEATHER CONDITIONS IN THE SOUTHWESTERN SOUTH
PLAINS...SNOW AND ICE ACCUMULATIONS IN THE NORTH-CENTRAL...FOG
AND FREEZING DRIZZLE FOR THE EAST-NORTHEAST...AND MAYBE EVEN A
RUMBLE OF THUNDER HERE AND THERE. AND OF COURSE PRECIPITATION COULD
TOTALLY DISAPPOINT SHOULD THE SYSTEM PASSING ALOFT REMAIN TOO WEAK
OR IF VERY DRY AIR DOMINATES THE LOWER ATMOSPHERE.
THIS COMPLEX AND LOW CONFIDENCE ENVIRONMENT LENDS ITSELF TO A
SOMEWHAT SIMPLIFIED FORECAST. IN PARTICULAR WE BLENDED THE
WRF/NAM AND GFS PRECIPITATION COVERAGE ON SUNDAY WHICH GAVE FAIRLY
UNIFORM CHANCE CATEGORY ACROSS THE AREA. THEN...WE SIDED WITH THE
MOST RECENT BLEND OF FRONTAL POSITIONS FAVORING THE FRONT
STRUGGLING TO MANEUVER THROUGH THE INCREASED WESTERLY COMPONENTS
EXPECTED EARLY SUNDAY ACROSS THE WESTERN SOUTH PLAINS. THIS FORCED
US TO ADJUST THE FRONT A BIT TO THE EAST WITH 35 DEGREE TEMPERATURE
GRADIENT SOUTHWEST TO NORTHEAST. ALSO...WE CONSIDERED POTENTIAL
LIFT FROM A SLOPED FRONTAL BOUNDARY FOR LOCAL SIGNIFICANT TOTALS
SHOULD SYSTEM REMAIN SLIGHTLY MORE VIGOROUS. BUT OUR CONFIDENCE IN
PINPOINTING THESE AREAS WAS LOW. SO WE ALSO SIMPLIFIED POTENTIAL
PRECIPITATION AMOUNTS AND TYPES FAVORING GENERALLY WARM PHASE
SOUTHWEST...FREEZING EAST...AND CHANGE TO FROZEN NORTH.
THIS SYSTEM WILL EJECT BY LATE SUNDAY WITH NO MAJOR CHANGES FOR
THE WEEK AHEAD. VERY COLD DUMP LASTING INTO EARLY TUESDAY WITH
SLOW MODERATION BEYOND. GENERAL FLAT PATTERN ALOFT ALTHOUGH A FEW
WAVES PASSING EARLY TO MID WEEK MAY NEED CONSIDERATION OF
PRECIPITATION CHANCES DEPENDING ON DEPTH OF THE LINGERING COLD AIR...
ALTHOUGH DRY AIR STILL LOOKS TO REMAIN DOMINANT. RMCQUEEN
FIRE WEATHER...
CRITICAL FIRE WEATHER CONDITIONS APPEAR TO BE LIKELY OVER THE
SOUTHWESTERN SOUTH PLAINS THIS AFTERNOON. STRONG SOUTHWESTERLY
SURFACE WINDS WILL DEVELOP IN RESPONSE TO AN UPPER LEVEL LOW MOVING
ONSHORE INTO THE DESERT SOUTHWEST. ADDITIONALLY...DEEP ATMOSPHERIC
MIXING WILL BRING STRONG WINDS ALOFT DOWN TO THE SURFACE. THESE
STRONG SOUTHWESTERLY WINDS WILL BUMP UP TEMPERATURES WELL ABOVE
SEASONAL AVERAGES WITH AFTERNOON TEMPERATURES AROUND 80F. VERY DRY
AIR WILL STAY IN PLACE WHICH WILL RESULT IN AFTERNOON RELATIVE
HUMIDITY VALUES AROUND 10 PERCENT.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 75 36 36 15 47 / 0 30 40 10 0
TULIA 73 26 30 13 40 / 0 20 30 10 0
PLAINVIEW 76 29 33 13 41 / 0 10 30 10 0
LEVELLAND 80 39 50 17 45 / 0 10 30 10 0
LUBBOCK 82 36 44 16 42 / 0 10 30 10 0
DENVER CITY 79 40 58 19 46 / 0 10 30 0 0
BROWNFIELD 81 39 53 17 44 / 0 10 30 10 0
CHILDRESS 61 24 26 11 32 / 0 20 30 0 0
SPUR 80 28 32 14 36 / 0 10 30 10 0
ASPERMONT 84 28 30 13 36 / 0 20 30 10 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 11 AM THIS MORNING TO 6 PM CST THIS
EVENING FOR THE FOLLOWING ZONES: TXZ027-033-034-039-040.
&&
$$
01
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
453 AM CST SAT MAR 1 2014
.SHORT TERM...
THIS FORECAST WAS COMPLICATED WITH A TOUGH ROW TO HOE. THE FIRST
ISSUE TO DEAL WITH WAS THE FOG AND LOW STRATUS CLOSING IN ON THE
AREA BOTH FROM THE EAST AND NORTH. THE LOW LEVEL MOISTURE WILL
CONTINUE TO PROGRESS INTO THE ROLLING PLAINS ON THE EAST SIDE OF THE
FRONTAL BOUNDARY THIS MORNING. THE FRONT WILL LIKELY MAKE ADDITIONAL
PROGRESS WESTWARD EARLY THIS MORNING. THE FRONTAL POSITION WILL
LIKELY BE A GOOD DIVIDING POINT BETWEEN CLEAR SKIES AND THE LOW
STRATUS LAYER. THE CLOUDS THEN PRESENT A PROBLEM WITH THE
TEMPERATURE FORECAST OVER THE SOUTHEASTERN TEXAS PANHANDLE. MOST
GUIDANCE DEPICTS LOW STRATUS HANGING OUT FOR THE ENTIRE MORNING. IN
FACT...THE LATEST RAP GUIDANCE SHOWS THIS LOW STRATUS CAMPING OUT
NEAR CHILDRESS. THE LATER SITUATION WOULD CLEARLY KEEP TEMPERATURES
FROM CLIMBING VERY MUCH AT CHILDRESS THIS AFTERNOON. THIS FRONTS
WESTWARD PROGRESSION WILL BE HALTED BY A CLOSED LOW MOVING ONSHORE
IN SOUTHERN CALIFORNIA TODAY. THIS WILL INCREASE SOUTHWEST FLOW
ALOFT WITH THE FRONT RETREATING A BIT THIS AFTERNOON.
SURFACE LEE TROUGHING WILL DEVELOP BY THIS AFTERNOON BUMPING UP
WINDS INTO THE BREEZY CATEGORY AGAIN. WINDS ALOFT WILL BE MARKEDLY
LOWER THAN OBSERVED YESTERDAY ALTHOUGH STILL BETWEEN 30 AND 40KT AT
700MB. HIGH CLOUDS MOVING IN FROM THE WEST MAY KEEP ATMOSPHERIC
MIXING FROM REACHING ITS FULL POTENTIAL TODAY BUT IT WILL STILL
NONETHELESS BE BREEZY. DOWNSLOPING WINDS COMBINED WITH STRONG LARGE
SCALE SUBSIDENCE WILL LEAD TO SURFACE CONDITIONS LIKELY DRIER THAN
WHAT MODELS ADVERTISE AS WAS THE CASE YESTERDAY. THE LOW LEVEL
THERMAL RIDGE AXIS WILL INCREASE FROM THE TRANS PECOS EXTENDING INTO
THE SOUTHWESTERN PANHANDLE.
BY SUNDAY MORNING...THE SPRAWLING HIGH PRESSURE OVER THE PLAINS WILL
BEGIN TO EXERT INFLUENCE OVER WEST TEXAS AS THE COLD FRONT PUSHES
FARTHER WEST. LARGE SCALE LIFT WILL INCREASE OVER THE AREA BY SUNDAY
MORNING WITH A 110KT UPPER LEVEL JET MOVING OVERHEAD. NEAR SURFACE
CONDITIONS WILL SEE A MASHUP OF BOTH THE ARCTIC FRONT AND PACIFIC
FRONT MAKING ITS WAY THROUGH THE WEST. THIS WILL CREATE CLEARLY
DEFINED AREAS OF FRONTOGENETICAL FORCING. PRECIPITATION CHANCES WILL
INCREASE AFTER MIDNIGHT WITH STRONGER LOW LEVEL MOISTURE ADVECTING
INTO THE REGION BEHIND THE COLD FRONT. MID AND UPPER LEVELS WILL BE
FAIRLY SATURATED WITH PACIFIC MOISTURE AS THE UPPER LOW IN THE
SOUTHWEST EDGES CLOSER. AREAS TO THE WEST OF THE FRONT WILL LIKELY
STAY WARM ENOUGH FOR ALL LIQUID PRECIPITATION. ON THE EAST SIDE OF
THE FRONT...COOLER AIR ADVECTING INTO THE REGION AT THE LOWEST
LEVELS WILL CHANGE PRECIPITATION TYPE TO MOST LIKELY A MIX OF
FREEZING RAIN AND SLEET. THE LOWEST TEMPERATURE IN THE NEAR SURFACE
SUB FREEZING LAYER APPROACHES AND MAY EXCEED -10C. IN
CONTRAST...EAST OF THE AREA...STRONG ISENTROPIC LIFT ABOVE THE
FRONTAL BOUNDARY WILL CREATE CHANCES OF PRECIPITATION. ALTHOUGH THE
BEST CHANCES WILL REMAIN EAST...THERE WILL ALSO EXIST A POTENTIAL
FOR A RUMBLE OF THUNDER WITH IMPRESSIVE ELEVATED INSTABILITY.
&&
.LONG TERM...
QUITE AN IMPRESSIVE UPPER LEVEL STORM SYSTEM ALONG THE CALIFORNIA
CENTRAL COAST WILL EJECT EASTWARD ACROSS THE SOUTHERN ROCKIES LATE
TONIGHT THEN THE SOUTHERN HIGH PLAINS ON SUNDAY. A GLACIAL AIRMASS
MEANWHILE WILL PRESS SOUTHWARD OUT OF THE NORTHERN PLAINS AND
COULD BE POISED TO SWEEP OVER THE AREA SUNDAY. THE RATE OF DECAY
OF THE CALIFORNIA SYSTEM WILL BE KEY IN DE TERMING EVERY ASPECT OF
WEATHER FOR SUNDAY. AND EVEN THOUGH SOLUTIONS SEEM SIMILAR ALOFT
IN THIS ASPECT THEY TOY WITH US IN A VARIETY OF MANNERS REGARDING
FRONTAL MOVEMENT...THERMAL CONTOURING...PRECIPITATION AREAS...
AMOUNTS...AND TYPES. OUR AREA SEEMS TO BE GROUND ZERO FOR THE
MODEL DISSENT GIVING RISE TO ANY NUMBER OF OUTCOMES SUNDAY
RANGING FROM FIRE WEATHER CONDITIONS IN THE SOUTHWESTERN SOUTH
PLAINS...SNOW AND ICE ACCUMULATIONS IN THE NORTH-CENTRAL...FOG
AND FREEZING DRIZZLE FOR THE EAST-NORTHEAST...AND MAYBE EVEN A
RUMBLE OF THUNDER HERE AND THERE. AND OF COURSE PRECIPITATION COULD
TOTALLY DISAPPOINT SHOULD THE SYSTEM PASSING ALOFT REMAIN TOO WEAK
OR IF VERY DRY AIR DOMINATES THE LOWER ATMOSPHERE.
THIS COMPLEX AND LOW CONFIDENCE ENVIRONMENT LENDS ITSELF TO A
SOMEWHAT SIMPLIFIED FORECAST. IN PARTICULAR WE BLENDED THE
WRF/NAM AND GFS PRECIPITATION COVERAGE ON SUNDAY WHICH GAVE FAIRLY
UNIFORM CHANCE CATEGORY ACROSS THE AREA. THEN...WE SIDED WITH THE
MOST RECENT BLEND OF FRONTAL POSITIONS FAVORING THE FRONT
STRUGGLING TO MANEUVER THROUGH THE INCREASED WESTERLY COMPONENTS
EXPECTED EARLY SUNDAY ACROSS THE WESTERN SOUTH PLAINS. THIS FORCED
US TO ADJUST THE FRONT A BIT TO THE EAST WITH 35 DEGREE TEMPERATURE
GRADIENT SOUTHWEST TO NORTHEAST. ALSO...WE CONSIDERED POTENTIAL
LIFT FROM A SLOPED FRONTAL BOUNDARY FOR LOCAL SIGNIFICANT TOTALS
SHOULD SYSTEM REMAIN SLIGHTLY MORE VIGOROUS. BUT OUR CONFIDENCE IN
PINPOINTING THESE AREAS WAS LOW. SO WE ALSO SIMPLIFIED POTENTIAL
PRECIPITATION AMOUNTS AND TYPES FAVORING GENERALLY WARM PHASE
SOUTHWEST...FREEZING EAST...AND CHANGE TO FROZEN NORTH.
THIS SYSTEM WILL EJECT BY LATE SUNDAY WITH NO MAJOR CHANGES FOR
THE WEEK AHEAD. VERY COLD DUMP LASTING INTO EARLY TUESDAY WITH
SLOW MODERATION BEYOND. GENERAL FLAT PATTERN ALOFT ALTHOUGH A FEW
WAVES PASSING EARLY TO MID WEEK MAY NEED CONSIDERATION OF
PRECIPITATION CHANCES DEPENDING ON DEPTH OF THE LINGERING COLD AIR...
ALTHOUGH DRY AIR STILL LOOKS TO REMAIN DOMINANT. RMCQUEEN
&&
.FIRE WEATHER...
CRITICAL FIRE WEATHER CONDITIONS APPEAR TO BE LIKELY OVER THE
SOUTHWESTERN SOUTH PLAINS THIS AFTERNOON. STRONG SOUTHWESTERLY
SURFACE WINDS WILL DEVELOP IN RESPONSE TO AN UPPER LEVEL LOW MOVING
ONSHORE INTO THE DESERT SOUTHWEST. ADDITIONALLY...DEEP ATMOSPHERIC
MIXING WILL BRING STRONG WINDS ALOFT DOWN TO THE SURFACE. THESE
STRONG SOUTHWESTERLY WINDS WILL BUMP UP TEMPERATURES WELL ABOVE
SEASONAL AVERAGES WITH AFTERNOON TEMPERATURES AROUND 80F. VERY DRY
AIR WILL STAY IN PLACE WHICH WILL RESULT IN AFTERNOON RELATIVE
HUMIDITY VALUES AROUND 10 PERCENT.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 75 36 36 15 47 / 0 30 40 10 0
TULIA 73 26 30 13 40 / 0 20 30 10 0
PLAINVIEW 76 29 33 13 41 / 0 10 30 10 0
LEVELLAND 80 39 50 17 45 / 0 10 30 10 0
LUBBOCK 82 36 46 16 42 / 0 10 30 10 0
DENVER CITY 79 40 58 19 46 / 0 10 30 0 0
BROWNFIELD 81 39 53 17 44 / 0 10 30 10 0
CHILDRESS 63 24 26 11 32 / 0 20 30 0 0
SPUR 80 28 32 14 36 / 0 10 30 10 0
ASPERMONT 84 28 30 13 36 / 0 20 30 10 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 11 AM THIS MORNING TO 6 PM CST THIS
EVENING FOR THE FOLLOWING ZONES: TXZ027-033-034-039-040.
&&
$$
01/05
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
1008 AM MST SAT MAR 1 2014
.SYNOPSIS...
A WELL DEFINED PACIFIC STORM SYSTEM WILL SLOWLY MOVE THROUGH THE
AREA TODAY...BRINGING SHOWERS AND ISOLATED THUNDERSTORMS TO THE
PHOENIX AREA. CONDITIONS WILL DRY OUT FROM WEST TO EAST THIS EVENING
WITH NEARLY EVERYONE DRYING OUT COMPLETELY BY SUNDAY AFTERNOON. DRY
WEATHER IS EXPECTED NEXT WEEK ALONG WITH A RETURN TO ABOVE NORMAL
TEMPERATURES.
&&
.DISCUSSION...
NOT MUCH CHANGE IN FORECAST THINKING AT THIS POINT...AS WE REMAIN
UNDER THE WETTER INFLUENCE OF A STRONG UPPER LEVEL LOW THAT
CONTINUES TO SPIN OFF THE CALIFORNIA COAST THIS MORNING. MANY
LOCATIONS ACROSS SOUTHEAST CALIFORNIA...SOUTHWEST AND SOUTH-CENTRAL
ARIZONA HAVE SEEN PERIODS OF RAINFALL OVER THE PAST 24 HOURS OR
SO...AN AVERAGE OF 0.25IN TO 0.75IN FOR MANY LOWER DESERT ELEVATION
SITES ACROSS OUR CWA...AND JUST OVER 1.0IN FOR OUR HIGHER MOUNTAIN
SITES IN JTNP IN CALIFORNIA...AND ALSO GLOBE IN ARIZONA.
THE PATTERN WILL CONTINUE TODAY...BUT MORE SO OVER OUR ARIZONA
ZONES/LOCATIONS EAST OF THE LOWER COLORADO RIVER VALLEY...AS A
PRECIPITABLE WATER AXIS IN EXCESS OF 1.0IN REMAINS POSITIONED OVER
SOUTH-CENTRAL ARIZONA ALONG WITH 850-700MB WINDS AROUND 60-65KTS.
MANY LOCATION ACROSS MARICOPA COUNTY...INCLUDING THE GREAT PHOENIX
METROPOLITAN HAVE EXCELLENT CHANCES TO PICK UP AN ADDITIONAL QUARTER
TO ONE HALF INCH MORE RAIN BEFORE THE DAY IS THROUGH....AND HIGHER
TERRAIN AREAS TO THE EAST NEAR GLOBE AND ROOSEVELT...MAYBE UP TO ONE
MORE INCH.
REGIONAL RADAR MOSAIC CONTINUES TO SHOW STORMS FORMING OVER PORTIONS
OF MARICOPA COUNTY AND SOUTHERN GILA COUNTY...SOME OF THE MORE
INTENSE CELLS HAVE PRODUCED CLOSE TO 0.30IN IN A 15 MINUTE PERIOD
BEFORE QUICKLY MOVING OFF TO THE NORTHEAST. THIS RATE IS NOT A BIG
CONCERN UNLESS THE STORMS SLOW DOWN AND/OR BEGIN TRAINING OVER THE
SAME AREA...SO WE WILL BE MONITORING FOR ANY LOCALIZED PONDING OR
FLOODING OF ROADWAYS.
THE HI-RES WRFS/NAM 4KM NEST CONTINUE TO HAVE THE BEST HANDLE ON HOW
CONVECTION AND SHOWERS WILL EVOLVE IN THE SHORT TERM. ANTICIPATING
THAT ONCE THE 500MB COLD CORE MOVES OVERHEAD BETWEEN 18Z AND 00Z...
STORMS WILL BLOSSOM AGAIN ACROSS THE LOWER DESERTS AS MID LEVEL
LAPSE RATES STEEPEN DRAMATICALLY. SOUTHEAST CALIFORNIA WILL LOSE
THEIR DEEPEST MOISTURE LATER THIS MORNING...SO POPS ACROSS THAT AREA
WILL BE LESS THAN THAT OVER THE GREATER PHOENIX AREA AND POINT EAST.
THE TROUGH AXIS PASSES OVERHEAD AROUND 06Z TONIGHT AND CONDITIONS
SHOULD BEGIN DRYING OUT AS EARLY AS SUNDAY MORNING. FOR THE VAST
MAJORITY OF THE LOWER DESERTS...SUNDAY MAY END UP TURNING OUT TO BE
A PRETTY NICE DAY WITH GRADUALLY CLEARING SKIES BY EARLY AFTERNOON.
SOUTHERN GILA COUNTY WILL LIKELY SEE SHOWERS HANG ON THE
LONGEST...BUT EVEN THEY MAY END UP CLEARING OUT SOONER THAN LATER.
POPS WERE ADJUSTED SLIGHTLY DOWNWARD ACROSS THE BOARD SUNDAY MORNING
THROUGH SUNDAY AFTERNOON.
AFTER THAT...ZONAL FLOW WILL ESTABLISH ITSELF ON MONDAY FOLLOWED BY
WEAK MID-WEEK RIDGING. LOOK FOR TEMPERATURES TO SLOWLY RESPOND BACK
TO NORMAL BY MID WEEK AND ABOVE NORMAL BY THE END OF THE WEEK. THERE
IS SOME SUGGESTION OF A TROUGH MOVING THROUGH THE FOUR CORNERS LATE
IN THE WEEK /FRIDAY OR SATURDAY/ BUT PRECIP POTENTIAL LOOKS MINIMAL
GIVEN THE SOURCE REGION OF THE TROUGH. COULD BRING SOME BREEZINESS
AND SLIGHTLY COOLER TEMPS BUT THAT LOOKS TO BE ABOUT IT.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
LOWER LEVEL MOISTURE AND SCATTERED SHOWERS ASSOCIATED WITH A PASSING
FRONTAL ZONE HAS CAUSED CIGS TO LOWER TO 4-6 KFT MSL IN THE VICINITY
OF THE SHOWERS...BRIEFLY LOWER IN SOME SPOTS. HOWEVER...CLOUD BASES
ARE HIGHLY VARIABLE BETWEEN SHOWERS...ABOVE 6 KFT MSL OVER SOUTHEAST
METRO PHOENIX AS OF 13Z. FLUCTUATING CIGS WITH PASSING SHOWERS IS
ANTICIPATED TO CONTINUE THROUGH 16Z BEFORE SHOWERS TEMPORARILY
DECREASE. ANTICIPATE RENEWED DEVELOPMENT THIS AFTERNOON AS THE UPPER
LOW GETS CLOSER. ISOLATED T-STORMS POSSIBLE BUT CONFIDENCE TOO LOW
AT ANY GIVEN SPOT TO REFLECT IN THE TAFS. ANTICIPATE SCATTERED
SHOWERS TO CONTINUE INTO THE EVENING BEFORE TRAILING OFF OVERNIGHT.
SOUTHWEST WINDS WILL PREVAIL WITH OCCASIONAL GUSTS TO 20 KTS.
STRONGER SHOWERS COULD PRODUCE 25+ KTS.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SHOWERS ARE STRUGGLING TO MAKE IT OVER THE COASTAL MOUNTAINS TO THE
WEST. HRRR MODEL INDICATES ISOLATED SHOWER DEVELOPMENT AFTER 14Z
INCREASING TO SCATTERED COVERAGE AFTER 20Z AND THIS IS REFLECTED IN
THE TAFS. ISOLATED T-STORMS POSSIBLE BUT CONFIDENCE TOO LOW AT ANY
GIVEN SPOT TO REFLECT IN THE TAFS. ANTICIPATE SCATTERED SHOWERS TO
CONTINUE INTO THE EVENING BEFORE TRAILING OFF OVERNIGHT. LIGHT AND
VARIABLE SURFACE WINDS WILL BECOME SOUTHWEST BY MIDDAY WITH
OCCASIONAL GUSTS TO 20 KTS. STRONGER SHOWERS COULD PRODUCE 25+ KTS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
HIGH PRESSURE BUILDS BACK INTO THE REGION MONDAY THROUGH WEDNESDAY
FOR A WARMING TREND ALONG WITH LESS WIND. HUMIDITIES WILL DECREASE
THOUGH OVERNIGHT RECOVERY WILL REMAIN GOOD. MODELS INDICATE HIGH
PRESSURE WEAKENING THURSDAY AND FRIDAY BUT HIGH TEMPERATURES WILL
STILL BE WELL ABOVE NORMAL. NORTHERLY BREEZINESS IS ANTICIPATED
FRIDAY...MAINLY OVER SOUTHEAST CALIFORNIA AND SOUTHWEST
ARIZONA...BUT NO STRONG WIND EVENTS ARE ANTICIPATED THROUGH THE
PERIOD.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...MEYERS/LEINS
AVIATION...AJ
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS TUCSON AZ
925 AM MST SAT MAR 1 2014
.SYNOPSIS...EXPECT VALLEY RAIN AND MOUNTAIN SNOW THROUGH TONIGHT...
THEN PRECIPITATION WILL END FROM WEST TO EAST SUNDAY. STRONG AND
GUSTY WINDS WILL OCCUR TODAY...ESPECIALLY SOUTHEAST OF TUCSON. MUCH
COOLER TEMPERATURES WILL ALSO OCCUR THIS WEEKEND. THEREAFTER...DRY
CONDITIONS WITH A WARMING TREND WILL PREVAIL DURING THE UPCOMING
WEEK.
&&
.DISCUSSION...KEMX WSR-88D DETECTED SCATTERED TO NUMEROUS 30-50 DBZ
ECHOES GENERALLY NORTHWEST OF A KITT PEAK-TUCSON-SAN CARLOS
RESERVOIR LINE AT 1620Z. MUCH OF THE REST OF SE AZ WAS VOID OF
PRECIP ECHOES AT THIS TIME. ISOLATED THUNDERSTORMS HAVE ALSO
OCCURRED DURING ABOUT THE PAST 30 MINS. AREAL COVERAGE OF PRECIP HAS
GREATLY INCREASED DURING THE PAST 1-2 HOURS. DEWPOINTS VALID 16Z
RANGED FROM THE MID 20S NEAR KDUG TO AROUND 50 F ACROSS WRN PIMA
COUNTY. 01/12Z KTWC SOUNDING TOTAL PRECIP WATER VALUE WAS NEAR 0.90
INCH...AN INCREASE OF NEARLY 0.30 INCH DURING THE PAST 12 HOURS.
01/12Z UPPER AIR PLOTS INDICATED 538 DM LOW PRESSURE WAS CENTERED
JUST OFF THE CENTRAL CALIFORNIA COAST. A VERY TIGHT MID-LEVEL
GRADIENT WAS ACROSS SE AZ...WITH 700 MB 50 KT OBSERVED WIND SPEED AT
KTWC.
AREAL COVERAGE OF PRECIP IS EXPECTED TO INCREASE MARKEDLY DURING THE
NEXT SEVERAL HOURS AS PER THE 01/14Z RUC HRRR. THE BULK OF THE
PRECIP IS PROGGED TO EXPAND FROM GENERALLY FROM THE TUCSON METRO
EWD/SWD...QUITE SIMILAR TO THE OFFICIAL FORECAST DEPICTION OF
PRECIP. ISOLATED THUNDERSTORMS WILL ALSO OCCUR GIVEN THE MODEST CAPE
ACROSS THE AREA. SNOW LEVELS AS PER RAWS OBSERVATIONS AND DUAL POL
RADAR YIELDED ABOUT 8500-9000 FEET. THESE LEVELS ARE EXPECTED TO
VERY GRADUALLY FALL TO NEAR 7500-8000 FEET FROM THE CATALINA
MOUNTAINS NEWD TO THE WHITE MOUNTAINS BY THIS EVENING. GIVEN THE
ONGOING PRECIP...BELIEVE HIGH TEMPS FROM TUCSON WWD ARE REASONABLE.
THE UPSHOT...THERE ARE NO CHANGES FORTHCOMING TO THE OFFICIAL
FORECAST AT THIS TIME. PLEASE REFER TO THE ADDITIONAL SECTIONS FOR
FURTHER DETAIL.
&&
.PREV DISCUSSION...THE CURRENT FORECAST STILL LOOKED IN GOOD SHAPE
AS DEEPER MOISTURE CONTINUED TO ADVECT INTO ARIZONA AHEAD OF A STORM
SYSTEM APPROACHING THE CENTRAL CALIFORNIA COAST EARLY THIS MORNING.
RECENT MOSAIC RADAR IMAGERY WAS SHOWING SHOWERS AND A FEW
THUNDERSTORMS IN WESTERN PIMA COUNTY. STILL EXPECTING SHOWERS AND
THUNDERSTORMS TO DEVELOP AND SPREAD EASTWARD ACROSS SOUTHERN ARIZONA
TODAY AS THE SYSTEM ENTERS SOUTHEASTERN CALIFORNIA.
A WINTER STORM WARNING FOR HEAVY SNOW AND BLOWING SNOW WILL REMAIN
IN EFFECT FROM 1 PM TODAY TO 10 AM MST SUNDAY ABOVE 7000 FEET FOR
THE WHITE MOUNTAINS OF GRAHAM AND GREENLEE COUNTIES...AND THE
GALIURO/PINALENO MOUNTAINS. A WINTER WEATHER ADVISORY FOR SNOW ALSO
REMAINS IN EFFECT FROM 1 PM TODAY TO 10 AM MST SUNDAY ABOVE 7000
FEET FOR THE CATALINA/RINCON MOUNTAINS. TOTAL SNOW ACCUMULATIONS
WITHIN THESE ZONES ARE FORECAST TO RANGE FROM 7 INCHES IN THE
SOUTHERN MOST MOUNTAINS TO 22 INCHES ACROSS THE WHITE MOUNTAINS.
SNOW LEVELS WILL BE NEAR 8000-8500 FEET BY MIDDAY TODAY THEN LOWER
TO AROUND 6500 FEET BY SUNDAY MORNING. IN ADDITION TO THE
PRECIPITATION...STRONG AND GUSTY WINDS WILL ACCOMPANY THE STORM
TODAY ESPECIALLY EAST OF TUCSON. THAT SAID...A WIND ADVISORY ALSO IS
IN EFFECT THROUGH 4 PM MST TODAY FOR SOUTHERN COCHISE COUNTY WHERE
SOUTHWEST WINDS OF 25-35 MPH WITH GUSTS TO 45 MPH CAN BE EXPECTED.
THE BULK OF PRECIPITATION WILL END BY SUNDAY EVENING...WITH DRY
CONDITIONS PREVAILING THE REST OF THE WEEK.
HIGH TEMPERATURES TODAY WILL BE ABOUT 10-15 DEGREES COOLER VERSUS
TEMPERATURES OBSERVED YESTERDAY AFTERNOON...THEN ANOTHER 2-6 DEGREES
OF COOLING SUNDAY. A WARMING TREND WILL FOLLOW THE REST OF THE WEEK.
&&
.AVIATION...VALID THRU 02/18Z.
VALLEY RAIN AND MOUNTAIN SNOW WILL OCCUR ACROSS SOUTHEAST ARIZONA
THROUGH TONIGHT...THEN PRECIPITATION IS EXPECTED TO DIMINISH FROM
WEST TO EAST SUNDAY MORNING. MVFR CONDITIONS WILL PREVAIL ESPECIALLY
NEAR HIGHER TERRAIN DUE TO CLOUDS/PRECIP. ISOLATED -TSRA WILL ALSO
OCCUR TODAY. SURFACE WIND THRU THIS EVENING GENERALLY SWLY/WLY AT
12-25 KTS WITH GUSTS TO NEAR 35 KTS. HOWEVER...EVEN STRONGER WIND
SPEEDS WILL OCCUR ACROSS SOUTHERN COCHISE COUNTY THROUGH THIS
AFTERNOON. THE KDUG TERMINAL MAY EXPERIENCE SUSTAINED WINDS OF 25-35
KTS WITH GUSTS TO AROUND 45 KTS. WINDS ARE EXPECTED TO DIMINISH TO
MOSTLY LESS THAN 12 KTS LATE TONIGHT AND CONTINUE INTO SUNDAY
MORNING. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...VALLEY RAIN AND MOUNTAIN SNOW WILL OCCUR THROUGH
ABOUT MIDDAY SUNDAY...THEN SNOW SHOWERS WILL BE CONFINED MAINLY TO
THE WHITE MOUNTAINS SUNDAY AFTERNOON AND SUNDAY NIGHT. STRONG AND
GUSTY SOUTH TO SOUTHWEST WINDS WILL OCCUR TODAY...WITH THE STRONGEST
WINDS ACROSS COCHISE COUNTY SOUTHEAST OF TUCSON. CRITICAL FIRE
WEATHER CONDITIONS ARE NOT EXPECTED TO OCCUR DUE TO THE AMPLE
MOISTURE. DRY CONDITIONS WILL PREVAIL ALONG WITH A WARMING TREND
MONDAY THROUGH FRIDAY.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 1 PM THIS AFTERNOON TO 10 AM MST
SUNDAY FOR AZZ510-511 ABOVE 7000 FEET.
WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 10 AM MST
SUNDAY FOR AZZ514 ABOVE 7000 FEET.
WIND ADVISORY UNTIL 4 PM MST THIS AFTERNOON FOR AZZ507-508-
512-513.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
FRANCIS
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1144 AM MST SAT MAR 1 2014
.UPDATE...
ISSUED AT 1135 AM MST SAT MAR 1 2014
UPDATED FORECAST TO ADD WINTER WEATHER ADVISORY FOR THE FAR
SOUTHEAST PLAINS WHERE A MIXTURE OF FREEZING
DRIZZLE...SLEET...SNOW...AND FOG WILL CONTINUE WITH CONDITIONS
WORSENING LATE THIS AFTERNOON THROUGH TONIGHT. SOME AREAS COULD
PICK UP AN INCH OR TWO OF SNOW/SLEET ACCUMULATION...THOUGH ANY ICE
ACCRETION SHOULD REMAIN LIGHT AND GENERALLY LESS THAN A TENTH OF
AN INCH. STILL SOME UNCERTAINTIES FOR TOMORROW MORNING...WITH 12Z
GFS SUGGESTING UP TO 4 INCHES OF SNOW WILL BE POSSIBLE OVER BACA
COUNTY...WHILE NAM12 HAS CONSIDERABLY LESS. WILL CARRY THE WINTER
WEATHER ADVISORY THROUGH 18Z FOR THOSE AREAS AND SEE HOW SHORT
RES/HIGH RES MODELS EVOLVE ON THIS. FOR NOW...THINKING IS MORE IN
THE REALM OF 1 TO 2 INCHES. MEANWHILE...SNOW WILL CONTINUE OUT
WEST TODAY...WITH SIGNIFICANT ADDITIONAL ACCUMULATIONS ACROSS THE
HIGHER ELEVATIONS. ALSO SEEING AREAS OF BLOWING DUST BEING
REPORTED ALONG THE SOUTHERN I-25 CORRIDOR...SOUTH OF COLORADO CITY
WHERE WINDS GUSTING TO AROUND 50 MPH FROM THE SOUTHWEST...AND
TEMPERATURES HAVE ALREADY HIT THE LOWER 60S. HAVE PUT UP A BLOWING
DUST ADVISORY FOR MAINLY HUERFANO AND WESTERN LAS ANIMAS
COUNTIES...THOUGH AS WINDS SHIFT OUT OF THE EAST LATER THIS
AFTERNOON THIS MAY END THE BLOWING DUST THREAT. -KT
UPDATE ISSUED AT 930 AM MST SAT MAR 1 2014
UPDATED FORECAST SHORTLY BEFORE 9 AM TO EXTEND DENSE FOG ADVISORY
FOR NORTHERN EL PASO COUNTY THROUGH 11 AM. ALSO ADDED SOUTHERN EL
PASO COUNTY TO THE ADVISORY AS WEB CAMS SHOW VISIBILITIES...PARTICULARLY
NEAR THE BROADMOOR AREA...AND ACROSS EASTERN PARTS OF THE COUNTY...
LOOK FAIRLY LOW. ANTICIPATE THE WESTERLY WINDS WILL EAT AWAY AT
THE STRATUS DECK ACROSS NORTHERN EL PASO COUNTY THROUGH THE LATE
MORNING...BUT DENSE FREEZING FOG MAY CONTINUE ACROSS EASTERN
PORTIONS OF EL PASO COUNTY WHERE SOUTHEAST UPSLOPE FLOW CONTINUES UNTIL
11 AM. FARTHER EAST...GETTING INCREASINGLY CONCERNED FOR THE
POTENTIAL FOR A SLEET/SNOW MIX LATE THIS AFTERNOON AND EVENING.
QUICK CALLS TO LAW ENFORCEMENT INDICATING THAT PCPN OUT THAT WAY
IS VERY LIGHT AND NOT POSING PROBLEMS FOR THE ROADS JUST YET. FOG
IS REDUCING VISIBILITIES TO AROUND A MILE OR LESS WITH ACCRETION OF
ICE ON COLD SURFACES SUCH AS WIND SHIELDS. WILL BE INTERROGATING
REMAINING 12Z RUNS THIS MORNING AND MAKING A DECISION ON A POSSIBLE
WINTER WEATHER ADVISORY FOR FAR EASTERN PORTIONS OF THE DISTRICT.
-KT
UPDATE ISSUED AT 703 AM MST SAT MAR 1 2014
EXTENDED DENSE FOG ADVISORY UNTIL 9 AM.
ALSO BROUGHT IN LATEST HRRR WINDS/TEMPS INTO NDFD.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 AM MST SAT MAR 1 2014
...SIGNIFICANT SNOWS ALONG THE CONTDVD...WIDE RANGING TEMPS ON THE
PLAINS TODAY...
CURRENTLY...AS OF 4 AM...COLD AIR HAS WORKED BACK TOWARDS THE
MOUNTAINS. GENERALLY AREAS AOA 6000 FEET WERE IN THE COLD AIR (20S)
WHILE ELEVATIONS ABOVE WERE IN THE WARM AIR (40S TO AROUND 50F). THE
EXCEPTION TO THIS WAS N EL PASO COUNTY WHERE UPSLOPE FLOW WAS
DRIVING THE LOW CLOUDS/FOG UP THE PALMER DVD.
MTN VALLEYS WERE WARM AS BUENA VISTA...SALIDA AND A GOOD PART OF
THE SAN LUIS VALLEY WERE ABOVE FREEZING (35-40F). HEAVY SNOW WAS
LIKELY POUNDING THE MTNS (KGJT RADAR IS OUT OF COMMISSION AND WONT
RETURN TO SERVICE UNTIL AT LEAST SUNDAY). WOLF CREEK OB HAS BEEN
REPORTING HEAVY SNOW THROUGHOUT THE EARLY MORNING HOURS.
IN ADDITION...WEB CAMS WERE SHOWING DENSE FOG ACROSS N EL PASO
COUNTY. KCOS WAS ALSO REPORTING DENSE FOG. SOME FREEZING DRIZZLE WAS
BEING OBSERVED AT SCHRIEVER AFB.
TODAY...
HEAVY SNOW WILL CONTINUE ACROSS THE CONTDVD TODAY. AN ADDITIONAL
FOOT OF SNOW IS LIKELY ACROSS THE SAN JUANS WITH 6-12" ACROSS THE
CENTRAL MTNS. HEAVY SNOW...5-10"...WILL OCCUR ACROSS THE TOP OF THE
SANGRES.
DENSE FOG WILL CONTINUE THIS EARLY MORNING ACROSS NORTHERN EL PASO
COUNTY GIVEN THE STRONG UPSLOPE FLOW.
TEMPS TODAY WILL VARY DRAMATICALLY ACROSS THE PLAINS. HI RES
GUIDANCE INDICATES COLD AIR WILL BE PUSHED TO THE EAST...BUT I DO
NOT THINK IT WILL GO AS FAR EAST AS GUIDANCE INDICATES. THE WARMEST
AIR WILL LIKELY AFFECT THE PALMER DIVIDE AND AREAS ABOVE 5500 FEET
ON THE PLAINS. MONUMENT HILL WILL LIKELY BE WARMER THAN DOWNTOWN
COLORADO SPRINGS. PUEBLO WEST WILL BE WARMER THAN PUEBLO.
WALSENBURG...TRINIDAD AND PINON CANYON WILL BE IN THE 60S WHILE EADS
AND LAMAR WILL LIKELY REMAIN IN THE 20S. SPRINGFIELD WILL BE
TRICKY...MAX TEMPS THERE I HAVE IN THE 40S...BUT IT IS NOT OUT OF
THE QUESTION THAT THEY MAY NOT GET OUT OF THE 20S. BY LATE IN THE
AFTERNOON WHEREVER THE BOUNDARY IS...IT WILL START TO WORK ITS WAY
BACK TO THE WEST.
AS FOR PRECIP ON THE PLAINS...THE OVERALL BEST CHANCE OF SOME PRECIP
WILL BE ALONG THE CO/NM BORDER...BUT ALL AREAS MAY SEE PASSING
SHOWERS LATER TODAY. PRECIP TYPE WILL BE DEPENDENT ON WHERE THE
BOUNDARY LIES. FREEZING DRIZZLE WILL BE POSSIBLE TODAY WITH A BETTER
CHANCE OF RAIN/SNOW LATER TODAY AS THE MOISTURE DEEPENS ACROSS THE
PLAINS.
THE BEST CHANCE FOR THE SAN LUIS VALLEY TO SEE PRECIP WILL BE
TODAY...WITH THE BEST CHANCE OF PRECIP OVER THE SOUTHERN AND WESTERN
PART OF THE VALLEY.
TONIGHT...
TROUGH ALOFT WILL MOVE ACROSS THE REGION. SNOWS WILL CONTINUE OVER
THE MOUNTAINS. THE HEAVIEST SNOWS IN THE SAN JUANS WILL AFFECT AREAS
JUST SOUTH OF WOLF CREEK PASS DOWN TO THE CO/NM BORDER. WITH FLOW
TRANSITIONING TO MORE WEST NORTHWESTERLY...SNOWS WILL CONTINUE OVER
THE CENTRAL MOUNTAINS. 4-8" WILL FALL IN THE SAN JUANS S OF WOLF
CREEK...AND 3-7" WILL FALL IN THE C MTNS. A FEW MORE INCHES WILL
FALL ON TOP OF THE SANGRES.
THE PLAINS WILL SEE SNOW BUT OVERALL ACCUMS WILL GENERALLY BE LESS
THAN AN INCH. THE HEAVIEST AMOUNTS WILL OCCUR OVER FAR SE CO. THE
ENTIRE PLAINS WILL BE IN THE COLD UPSLOPE AND EXPECT CLOUDY SKIES
WITH SINGLE DIGIT TEMPS OVER THE FAR E PLAINS AND TEENS ELSEWHERE.
THE MTNS/VALLEYS WILL BE IN THE MID TEENS/20S FOR LOWS TONIGHT.
/HODANISH
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 405 AM MST SAT MAR 1 2014
...COLD SUNDAY...
THE UPPER TROUGH AXIS WILL BE THROUGH CENTRAL CO AT 12Z SUN...AND NR THE
KS BORDER BY 18Z. EXPECT RAPID DECREASE IN PRECIP ACROSS THE MT AREAS
SUN MORNING...MAYBE EVEN SOME BREAKS IN THE CLOUDS...BUT SOME LIGHT
ONGOING SNOW SHOWERS WILL BE LIKELY GIVEN INCREASED INSTABILITY. IF
THERE ARE ANY BREAKS...THERE WILL BE RAPID REDEVELOPMENT OF CONVECTION
OVER THE PEAKS SO CONTINUED HIGH POPS LOOK REASONABLE. ADDITIONAL
ACCUMS WILL BE LIGHT FOR THE MTS...MAYBE AN INCH OR TWO.
MAIN QUESTION SUNDAY WILL BE PRECIP FOR THE PLAINS. GIVEN THE TREND FOR
A FASTER TROUGH PASSAGE...IT LOOKS LIKE THE MODELS ARE SHIFTING THE
POTENTIAL FOR SNOW OVER THE PLAINS EWD...MAINLY INTO KS AND THE
PANHANDLES SUN MORNING. THE NAM CONTINUES TO SHOW A MOSTLY DRY
FORECAST EXCEPT NR THE KS BORDER. STILL SEE SOME POTENTIAL FOR
BANDED SNOW OVR THE PLAINS...ESPECIALLY GIVEN THE CONVECTIVE NATURE
OF THIS SYSTEM...SO WILL MAINTAIN CHANCE POPS MAINLY FOR THE MORNING
HOURS AND AREAS E OF I-25. NOT READY TO THROW IN THE TOWEL QUITE YET
FOR SN OVER THE I-25 ZONES. IT WILL DEFINITELY BE COLD ENOUGH...WITH
SHALLOW COLD AIR FIRMLY IN PLACE AND TEMPS NOT LIKELY TO MAKE IT
ABOVE FREEZING ANYWHERE OVER THE ERN PLAINS. WARMEST WX WILL BE IN
THE HIGH VALLEYS WHICH COULD SEE SOME MID 40S.
WE DRY OUT MON-TUE AS QUASI-ZONAL FLOW RESUMES OVER OUR AREA. A
COUPLE WEAK DISTURBANCES MOVE THROUGH THE FLOW...THE FIRST MON
AFTERNOON AND A SECOND TUE NIGHT. THESE COULD BRING SOME RENEWED
SHSN TO THE MTS...ESPECIALLY THE CENTRAL MTS. THE GFS EVEN HINTS AT
THE POSSIBILITY OF SOME LIGHT PRECIP OVER THE PLAINS LATE TUE OR
EARLY WED...BUT WILL KEEP POPS SILENT FOR NOW.
AFTER A DRY AND WARM THU...WITH TEMPS IN THE MID 60S OVER THE
PLAINS...NEXT STORM SYSTEM ARRIVES FRI FROM THE NW. LOOKS LIKE
ANOTHER FRONTAL PUSH IS POSSIBLE ACROSS THE PLAINS. IT IS STILL
QUITE A WAYS OUT...SO WILL MAINTAIN POPS IN THE 20-30 PERCENT RANGE
FOR THIS TIME PERIOD. THEN A HIGH AMPLITUDE RIDGE BUILDS...GIVING
US A WARMER AND DRY NEXT WEEKEND. ROSE
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1038 AM MST SAT MAR 1 2014
IFR TO LIFR CONDITIONS WILL CONTINUE UNTIL AROUND 20Z FOR KCOS AND
KPUB BEFORE FOG LIFTS AND CIGS RISE INTO THE MVFR CATEGORY.
MEANWHILE LIFR CONDITIONS WILL CONTINUE ACROSS MUCH OF THE FAR
SOUTHEAST PLAINS IN FZFG...FZDZ. SNOW...HEAVY AT TIMES WILL
CONTINUE ACROSS THE MOUNTAIN AREAS WITH WIDESPREAD MTN
OBSCURATIONS. KALS AND THE SOUTHERN I-25 CORRIDOR WILL SEE GUSTY
SOUTHWEST WINDS (UP TO 40-45 KTS) AND CIGS MAINLY IN THE VFR
CATEGORY...THOUGH SOME SCATTERED SHOWERS WILL MOVE OFF THE
MOUNTAINS THIS AFTERNOON THROUGH THIS EVENING AND COULD BRING SOME
BRIEF MVFR CIGS AT TIMES. STRATUS WILL SPREAD BACK WESTWARD ACROSS
THE SOUTHEAST PLAINS WITH CIGS AND VIS DROPPING BACK INTO THE IFR
TO LIFR CATEGORY DURING THE EVENING. AREAS OF FZDZ...SLEET...AND
SNOW WILL BE POSSIBLE ACROSS THE FAR EASTERN PLAINS THIS EVENING
WHERE CIGS AND VIS WILL REMAIN LIFR. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
BLOWING DUST ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR COZ087-
088.
WINTER WEATHER ADVISORY UNTIL 11 AM MST SUNDAY FOR COZ095>099.
WINTER WEATHER ADVISORY UNTIL 5 AM MST SUNDAY FOR COZ059-061-064-
067-073-075.
WINTER STORM WARNING UNTIL 5 AM MST SUNDAY FOR COZ058-060-066-
068.
&&
$$
UPDATE...KT
SHORT TERM...HODANISH
LONG TERM...ROSE
AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1043 AM MST SAT MAR 1 2014
.UPDATE...
ISSUED AT 930 AM MST SAT MAR 1 2014
UPDATED FORECAST SHORTLY BEFORE 9 AM TO EXTEND DENSE FOG ADVISORY
FOR NORTHERN EL PASO COUNTY THROUGH 11 AM. ALSO ADDED SOUTHERN EL
PASO COUNTY TO THE ADVISORY AS WEB CAMS SHOW VISIBILITIES...PARTICULARLY
NEAR THE BROADMOOR AREA...AND ACROSS EASTERN PARTS OF THE COUNTY...
LOOK FAIRLY LOW. ANTICIPATE THE WESTERLY WINDS WILL EAT AWAY AT
THE STRATUS DECK ACROSS NORTHERN EL PASO COUNTY THROUGH THE LATE
MORNING...BUT DENSE FREEZING FOG MAY CONTINUE ACROSS EASTERN
PORTIONS OF EL PASO COUNTY WHERE SOUTHEAST UPSLOPE FLOW CONTINUES UNTIL
11 AM. FARTHER EAST...GETTING INCREASINGLY CONCERNED FOR THE
POTENTIAL FOR A SLEET/SNOW MIX LATE THIS AFTERNOON AND EVENING.
QUICK CALLS TO LAW ENFORCEMENT INDICATING THAT PCPN OUT THAT WAY
IS VERY LIGHT AND NOT POSING PROBLEMS FOR THE ROADS JUST YET. FOG
IS REDUCING VISIBILITIES TO AROUND A MILE OR LESS WITH ACCRETION OF
ICE ON COLD SURFACES SUCH AS WIND SHIELDS. WILL BE INTERROGATING
REMAINING 12Z RUNS THIS MORNING AND MAKING A DECISION ON A POSSIBLE
WINTER WEATHER ADVISORY FOR FAR EASTERN PORTIONS OF THE DISTRICT.
-KT
UPDATE ISSUED AT 703 AM MST SAT MAR 1 2014
EXTENDED DENSE FOG ADVISORY UNTIL 9 AM.
ALSO BROUGHT IN LATEST HRRR WINDS/TEMPS INTO NDFD.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 AM MST SAT MAR 1 2014
...SIGNIFICANT SNOWS ALONG THE CONTDVD...WIDE RANGING TEMPS ON THE
PLAINS TODAY...
CURRENTLY...AS OF 4 AM...COLD AIR HAS WORKED BACK TOWARDS THE
MOUNTAINS. GENERALLY AREAS AOA 6000 FEET WERE IN THE COLD AIR (20S)
WHILE ELEVATIONS ABOVE WERE IN THE WARM AIR (40S TO AROUND 50F). THE
EXCEPTION TO THIS WAS N EL PASO COUNTY WHERE UPSLOPE FLOW WAS
DRIVING THE LOW CLOUDS/FOG UP THE PALMER DVD.
MTN VALLEYS WERE WARM AS BUENA VISTA...SALIDA AND A GOOD PART OF
THE SAN LUIS VALLEY WERE ABOVE FREEZING (35-40F). HEAVY SNOW WAS
LIKELY POUNDING THE MTNS (KGJT RADAR IS OUT OF COMMISSION AND WONT
RETURN TO SERVICE UNTIL AT LEAST SUNDAY). WOLF CREEK OB HAS BEEN
REPORTING HEAVY SNOW THROUGHOUT THE EARLY MORNING HOURS.
IN ADDITION...WEB CAMS WERE SHOWING DENSE FOG ACROSS N EL PASO
COUNTY. KCOS WAS ALSO REPORTING DENSE FOG. SOME FREEZING DRIZZLE WAS
BEING OBSERVED AT SCHRIEVER AFB.
TODAY...
HEAVY SNOW WILL CONTINUE ACROSS THE CONTDVD TODAY. AN ADDITIONAL
FOOT OF SNOW IS LIKELY ACROSS THE SAN JUANS WITH 6-12" ACROSS THE
CENTRAL MTNS. HEAVY SNOW...5-10"...WILL OCCUR ACROSS THE TOP OF THE
SANGRES.
DENSE FOG WILL CONTINUE THIS EARLY MORNING ACROSS NORTHERN EL PASO
COUNTY GIVEN THE STRONG UPSLOPE FLOW.
TEMPS TODAY WILL VARY DRAMATICALLY ACROSS THE PLAINS. HI RES
GUIDANCE INDICATES COLD AIR WILL BE PUSHED TO THE EAST...BUT I DO
NOT THINK IT WILL GO AS FAR EAST AS GUIDANCE INDICATES. THE WARMEST
AIR WILL LIKELY AFFECT THE PALMER DIVIDE AND AREAS ABOVE 5500 FEET
ON THE PLAINS. MONUMENT HILL WILL LIKELY BE WARMER THAN DOWNTOWN
COLORADO SPRINGS. PUEBLO WEST WILL BE WARMER THAN PUEBLO.
WALSENBURG...TRINIDAD AND PINON CANYON WILL BE IN THE 60S WHILE EADS
AND LAMAR WILL LIKELY REMAIN IN THE 20S. SPRINGFIELD WILL BE
TRICKY...MAX TEMPS THERE I HAVE IN THE 40S...BUT IT IS NOT OUT OF
THE QUESTION THAT THEY MAY NOT GET OUT OF THE 20S. BY LATE IN THE
AFTERNOON WHEREVER THE BOUNDARY IS...IT WILL START TO WORK ITS WAY
BACK TO THE WEST.
AS FOR PRECIP ON THE PLAINS...THE OVERALL BEST CHANCE OF SOME PRECIP
WILL BE ALONG THE CO/NM BORDER...BUT ALL AREAS MAY SEE PASSING
SHOWERS LATER TODAY. PRECIP TYPE WILL BE DEPENDENT ON WHERE THE
BOUNDARY LIES. FREEZING DRIZZLE WILL BE POSSIBLE TODAY WITH A BETTER
CHANCE OF RAIN/SNOW LATER TODAY AS THE MOISTURE DEEPENS ACROSS THE
PLAINS.
THE BEST CHANCE FOR THE SAN LUIS VALLEY TO SEE PRECIP WILL BE
TODAY...WITH THE BEST CHANCE OF PRECIP OVER THE SOUTHERN AND WESTERN
PART OF THE VALLEY.
TONIGHT...
TROUGH ALOFT WILL MOVE ACROSS THE REGION. SNOWS WILL CONTINUE OVER
THE MOUNTAINS. THE HEAVIEST SNOWS IN THE SAN JUANS WILL AFFECT AREAS
JUST SOUTH OF WOLF CREEK PASS DOWN TO THE CO/NM BORDER. WITH FLOW
TRANSITIONING TO MORE WEST NORTHWESTERLY...SNOWS WILL CONTINUE OVER
THE CENTRAL MOUNTAINS. 4-8" WILL FALL IN THE SAN JUANS S OF WOLF
CREEK...AND 3-7" WILL FALL IN THE C MTNS. A FEW MORE INCHES WILL
FALL ON TOP OF THE SANGRES.
THE PLAINS WILL SEE SNOW BUT OVERALL ACCUMS WILL GENERALLY BE LESS
THAN AN INCH. THE HEAVIEST AMOUNTS WILL OCCUR OVER FAR SE CO. THE
ENTIRE PLAINS WILL BE IN THE COLD UPSLOPE AND EXPECT CLOUDY SKIES
WITH SINGLE DIGIT TEMPS OVER THE FAR E PLAINS AND TEENS ELSEWHERE.
THE MTNS/VALLEYS WILL BE IN THE MID TEENS/20S FOR LOWS TONIGHT.
/HODANISH
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 405 AM MST SAT MAR 1 2014
...COLD SUNDAY...
THE UPPER TROUGH AXIS WILL BE THROUGH CENTRAL CO AT 12Z SUN...AND NR THE
KS BORDER BY 18Z. EXPECT RAPID DECREASE IN PRECIP ACROSS THE MT AREAS
SUN MORNING...MAYBE EVEN SOME BREAKS IN THE CLOUDS...BUT SOME LIGHT
ONGOING SNOW SHOWERS WILL BE LIKELY GIVEN INCREASED INSTABILITY. IF
THERE ARE ANY BREAKS...THERE WILL BE RAPID REDEVELOPMENT OF CONVECTION
OVER THE PEAKS SO CONTINUED HIGH POPS LOOK REASONABLE. ADDITIONAL
ACCUMS WILL BE LIGHT FOR THE MTS...MAYBE AN INCH OR TWO.
MAIN QUESTION SUNDAY WILL BE PRECIP FOR THE PLAINS. GIVEN THE TREND FOR
A FASTER TROUGH PASSAGE...IT LOOKS LIKE THE MODELS ARE SHIFTING THE
POTENTIAL FOR SNOW OVER THE PLAINS EWD...MAINLY INTO KS AND THE
PANHANDLES SUN MORNING. THE NAM CONTINUES TO SHOW A MOSTLY DRY
FORECAST EXCEPT NR THE KS BORDER. STILL SEE SOME POTENTIAL FOR
BANDED SNOW OVR THE PLAINS...ESPECIALLY GIVEN THE CONVECTIVE NATURE
OF THIS SYSTEM...SO WILL MAINTAIN CHANCE POPS MAINLY FOR THE MORNING
HOURS AND AREAS E OF I-25. NOT READY TO THROW IN THE TOWEL QUITE YET
FOR SN OVER THE I-25 ZONES. IT WILL DEFINITELY BE COLD ENOUGH...WITH
SHALLOW COLD AIR FIRMLY IN PLACE AND TEMPS NOT LIKELY TO MAKE IT
ABOVE FREEZING ANYWHERE OVER THE ERN PLAINS. WARMEST WX WILL BE IN
THE HIGH VALLEYS WHICH COULD SEE SOME MID 40S.
WE DRY OUT MON-TUE AS QUASI-ZONAL FLOW RESUMES OVER OUR AREA. A
COUPLE WEAK DISTURBANCES MOVE THROUGH THE FLOW...THE FIRST MON
AFTERNOON AND A SECOND TUE NIGHT. THESE COULD BRING SOME RENEWED
SHSN TO THE MTS...ESPECIALLY THE CENTRAL MTS. THE GFS EVEN HINTS AT
THE POSSIBILITY OF SOME LIGHT PRECIP OVER THE PLAINS LATE TUE OR
EARLY WED...BUT WILL KEEP POPS SILENT FOR NOW.
AFTER A DRY AND WARM THU...WITH TEMPS IN THE MID 60S OVER THE
PLAINS...NEXT STORM SYSTEM ARRIVES FRI FROM THE NW. LOOKS LIKE
ANOTHER FRONTAL PUSH IS POSSIBLE ACROSS THE PLAINS. IT IS STILL
QUITE A WAYS OUT...SO WILL MAINTAIN POPS IN THE 20-30 PERCENT RANGE
FOR THIS TIME PERIOD. THEN A HIGH AMPLITUDE RIDGE BUILDS...GIVING
US A WARMER AND DRY NEXT WEEKEND. ROSE
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1038 AM MST SAT MAR 1 2014
IFR TO LIFR CONDITIONS WILL CONTINUE UNTIL AROUND 20Z FOR KCOS AND
KPUB BEFORE FOG LIFTS AND CIGS RISE INTO THE MVFR CATEGORY.
MEANWHILE LIFR CONDITIONS WILL CONTINUE ACROSS MUCH OF THE FAR
SOUTHEAST PLAINS IN FZFG...FZDZ. SNOW...HEAVY AT TIMES WILL
CONTINUE ACROSS THE MOUNTAIN AREAS WITH WIDESPREAD MTN
OBSCURATIONS. KALS AND THE SOUTHERN I-25 CORRIDOR WILL SEE GUSTY
SOUTHWEST WINDS (UP TO 40-45 KTS) AND CIGS MAINLY IN THE VFR
CATEGORY...THOUGH SOME SCATTERED SHOWERS WILL MOVE OFF THE
MOUNTAINS THIS AFTERNOON THROUGH THIS EVENING AND COULD BRING SOME
BRIEF MVFR CIGS AT TIMES. STRATUS WILL SPREAD BACK WESTWARD ACROSS
THE SOUTHEAST PLAINS WITH CIGS AND VIS DROPPING BACK INTO THE IFR
TO LIFR CATEGORY DURING THE EVENING. AREAS OF FZDZ...SLEET...AND
SNOW WILL BE POSSIBLE ACROSS THE FAR EASTERN PLAINS THIS EVENING
WHERE CIGS AND VIS WILL REMAIN LIFR. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 11 AM MST THIS MORNING FOR COZ084-085.
WINTER WEATHER ADVISORY UNTIL 5 AM MST SUNDAY FOR COZ059-061-064-
067-073-075.
BLOWING DUST ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR COZ087-
088.
WINTER STORM WARNING UNTIL 5 AM MST SUNDAY FOR COZ058-060-066-
068.
&&
$$
UPDATE...KT
SHORT TERM...HODANISH
LONG TERM...ROSE
AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
940 AM MST SAT MAR 1 2014
.UPDATE...
ISSUED AT 930 AM MST SAT MAR 1 2014
UPDATED FORECAST SHORTLY BEFORE 9 AM TO EXTEND DENSE FOG ADVISORY
FOR NORTHERN EL PASO COUNTY THROUGH 11 AM. ALSO ADDED SOUTHERN EL
PASO COUNTY TO THE ADVISORY AS WEB CAMS SHOW VISIBILITIES...PARTICULARLY
NEAR THE BROADMOOR AREA...AND ACROSS EASTERN PARTS OF THE COUNTY...
LOOK FAIRLY LOW. ANTICIPATE THE WESTERLY WINDS WILL EAT AWAY AT
THE STRATUS DECK ACROSS NORTHERN EL PASO COUNTY THROUGH THE LATE
MORNING...BUT DENSE FREEZING FOG MAY CONTINUE ACROSS EASTERN
PORTIONS OF EL PASO COUNTY WHERE SOUTHEAST UPSLOPE FLOW CONTINUES UNTIL
11 AM. FARTHER EAST...GETTING INCREASINGLY CONCERNED FOR THE
POTENTIAL FOR A SLEET/SNOW MIX LATE THIS AFTERNOON AND EVENING.
QUICK CALLS TO LAW ENFORCEMENT INDICATING THAT PCPN OUT THAT WAY
IS VERY LIGHT AND NOT POSING PROBLEMS FOR THE ROADS JUST YET. FOG
IS REDUCING VISIBILITIES TO AROUND A MILE OR LESS WITH ACCRETION OF
ICE ON COLD SURFACES SUCH AS WIND SHIELDS. WILL BE INTERROGATING
REMAINING 12Z RUNS THIS MORNING AND MAKING A DECISION ON A POSSIBLE
WINTER WEATHER ADVISORY FOR FAR EASTERN PORTIONS OF THE DISTRICT.
-KT
UPDATE ISSUED AT 703 AM MST SAT MAR 1 2014
EXTENDED DENSE FOG ADVISORY UNTIL 9 AM.
ALSO BROUGHT IN LATEST HRRR WINDS/TEMPS INTO NDFD.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 AM MST SAT MAR 1 2014
...SIGNIFICANT SNOWS ALONG THE CONTDVD...WIDE RANGING TEMPS ON THE
PLAINS TODAY...
CURRENTLY...AS OF 4 AM...COLD AIR HAS WORKED BACK TOWARDS THE
MOUNTAINS. GENERALLY AREAS AOA 6000 FEET WERE IN THE COLD AIR (20S)
WHILE ELEVATIONS ABOVE WERE IN THE WARM AIR (40S TO AROUND 50F). THE
EXCEPTION TO THIS WAS N EL PASO COUNTY WHERE UPSLOPE FLOW WAS
DRIVING THE LOW CLOUDS/FOG UP THE PALMER DVD.
MTN VALLEYS WERE WARM AS BUENA VISTA...SALIDA AND A GOOD PART OF
THE SAN LUIS VALLEY WERE ABOVE FREEZING (35-40F). HEAVY SNOW WAS
LIKELY POUNDING THE MTNS (KGJT RADAR IS OUT OF COMMISSION AND WONT
RETURN TO SERVICE UNTIL AT LEAST SUNDAY). WOLF CREEK OB HAS BEEN
REPORTING HEAVY SNOW THROUGHOUT THE EARLY MORNING HOURS.
IN ADDITION...WEB CAMS WERE SHOWING DENSE FOG ACROSS N EL PASO
COUNTY. KCOS WAS ALSO REPORTING DENSE FOG. SOME FREEZING DRIZZLE WAS
BEING OBSERVED AT SCHRIEVER AFB.
TODAY...
HEAVY SNOW WILL CONTINUE ACROSS THE CONTDVD TODAY. AN ADDITIONAL
FOOT OF SNOW IS LIKELY ACROSS THE SAN JUANS WITH 6-12" ACROSS THE
CENTRAL MTNS. HEAVY SNOW...5-10"...WILL OCCUR ACROSS THE TOP OF THE
SANGRES.
DENSE FOG WILL CONTINUE THIS EARLY MORNING ACROSS NORTHERN EL PASO
COUNTY GIVEN THE STRONG UPSLOPE FLOW.
TEMPS TODAY WILL VARY DRAMATICALLY ACROSS THE PLAINS. HI RES
GUIDANCE INDICATES COLD AIR WILL BE PUSHED TO THE EAST...BUT I DO
NOT THINK IT WILL GO AS FAR EAST AS GUIDANCE INDICATES. THE WARMEST
AIR WILL LIKELY AFFECT THE PALMER DIVIDE AND AREAS ABOVE 5500 FEET
ON THE PLAINS. MONUMENT HILL WILL LIKELY BE WARMER THAN DOWNTOWN
COLORADO SPRINGS. PUEBLO WEST WILL BE WARMER THAN PUEBLO.
WALSENBURG...TRINIDAD AND PINON CANYON WILL BE IN THE 60S WHILE EADS
AND LAMAR WILL LIKELY REMAIN IN THE 20S. SPRINGFIELD WILL BE
TRICKY...MAX TEMPS THERE I HAVE IN THE 40S...BUT IT IS NOT OUT OF
THE QUESTION THAT THEY MAY NOT GET OUT OF THE 20S. BY LATE IN THE
AFTERNOON WHEREVER THE BOUNDARY IS...IT WILL START TO WORK ITS WAY
BACK TO THE WEST.
AS FOR PRECIP ON THE PLAINS...THE OVERALL BEST CHANCE OF SOME PRECIP
WILL BE ALONG THE CO/NM BORDER...BUT ALL AREAS MAY SEE PASSING
SHOWERS LATER TODAY. PRECIP TYPE WILL BE DEPENDENT ON WHERE THE
BOUNDARY LIES. FREEZING DRIZZLE WILL BE POSSIBLE TODAY WITH A BETTER
CHANCE OF RAIN/SNOW LATER TODAY AS THE MOISTURE DEEPENS ACROSS THE
PLAINS.
THE BEST CHANCE FOR THE SAN LUIS VALLEY TO SEE PRECIP WILL BE
TODAY...WITH THE BEST CHANCE OF PRECIP OVER THE SOUTHERN AND WESTERN
PART OF THE VALLEY.
TONIGHT...
TROUGH ALOFT WILL MOVE ACROSS THE REGION. SNOWS WILL CONTINUE OVER
THE MOUNTAINS. THE HEAVIEST SNOWS IN THE SAN JUANS WILL AFFECT AREAS
JUST SOUTH OF WOLF CREEK PASS DOWN TO THE CO/NM BORDER. WITH FLOW
TRANSITIONING TO MORE WEST NORTHWESTERLY...SNOWS WILL CONTINUE OVER
THE CENTRAL MOUNTAINS. 4-8" WILL FALL IN THE SAN JUANS S OF WOLF
CREEK...AND 3-7" WILL FALL IN THE C MTNS. A FEW MORE INCHES WILL
FALL ON TOP OF THE SANGRES.
THE PLAINS WILL SEE SNOW BUT OVERALL ACCUMS WILL GENERALLY BE LESS
THAN AN INCH. THE HEAVIEST AMOUNTS WILL OCCUR OVER FAR SE CO. THE
ENTIRE PLAINS WILL BE IN THE COLD UPSLOPE AND EXPECT CLOUDY SKIES
WITH SINGLE DIGIT TEMPS OVER THE FAR E PLAINS AND TEENS ELSEWHERE.
THE MTNS/VALLEYS WILL BE IN THE MID TEENS/20S FOR LOWS TONIGHT.
/HODANISH
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 405 AM MST SAT MAR 1 2014
...COLD SUNDAY...
THE UPPER TROUGH AXIS WILL BE THROUGH CENTRAL CO AT 12Z SUN...AND NR THE
KS BORDER BY 18Z. EXPECT RAPID DECREASE IN PRECIP ACROSS THE MT AREAS
SUN MORNING...MAYBE EVEN SOME BREAKS IN THE CLOUDS...BUT SOME LIGHT
ONGOING SNOW SHOWERS WILL BE LIKELY GIVEN INCREASED INSTABILITY. IF
THERE ARE ANY BREAKS...THERE WILL BE RAPID REDEVELOPMENT OF CONVECTION
OVER THE PEAKS SO CONTINUED HIGH POPS LOOK REASONABLE. ADDITIONAL
ACCUMS WILL BE LIGHT FOR THE MTS...MAYBE AN INCH OR TWO.
MAIN QUESTION SUNDAY WILL BE PRECIP FOR THE PLAINS. GIVEN THE TREND FOR
A FASTER TROUGH PASSAGE...IT LOOKS LIKE THE MODELS ARE SHIFTING THE
POTENTIAL FOR SNOW OVER THE PLAINS EWD...MAINLY INTO KS AND THE
PANHANDLES SUN MORNING. THE NAM CONTINUES TO SHOW A MOSTLY DRY
FORECAST EXCEPT NR THE KS BORDER. STILL SEE SOME POTENTIAL FOR
BANDED SNOW OVR THE PLAINS...ESPECIALLY GIVEN THE CONVECTIVE NATURE
OF THIS SYSTEM...SO WILL MAINTAIN CHANCE POPS MAINLY FOR THE MORNING
HOURS AND AREAS E OF I-25. NOT READY TO THROW IN THE TOWEL QUITE YET
FOR SN OVER THE I-25 ZONES. IT WILL DEFINITELY BE COLD ENOUGH...WITH
SHALLOW COLD AIR FIRMLY IN PLACE AND TEMPS NOT LIKELY TO MAKE IT
ABOVE FREEZING ANYWHERE OVER THE ERN PLAINS. WARMEST WX WILL BE IN
THE HIGH VALLEYS WHICH COULD SEE SOME MID 40S.
WE DRY OUT MON-TUE AS QUASI-ZONAL FLOW RESUMES OVER OUR AREA. A
COUPLE WEAK DISTURBANCES MOVE THROUGH THE FLOW...THE FIRST MON
AFTERNOON AND A SECOND TUE NIGHT. THESE COULD BRING SOME RENEWED
SHSN TO THE MTS...ESPECIALLY THE CENTRAL MTS. THE GFS EVEN HINTS AT
THE POSSIBILITY OF SOME LIGHT PRECIP OVER THE PLAINS LATE TUE OR
EARLY WED...BUT WILL KEEP POPS SILENT FOR NOW.
AFTER A DRY AND WARM THU...WITH TEMPS IN THE MID 60S OVER THE
PLAINS...NEXT STORM SYSTEM ARRIVES FRI FROM THE NW. LOOKS LIKE
ANOTHER FRONTAL PUSH IS POSSIBLE ACROSS THE PLAINS. IT IS STILL
QUITE A WAYS OUT...SO WILL MAINTAIN POPS IN THE 20-30 PERCENT RANGE
FOR THIS TIME PERIOD. THEN A HIGH AMPLITUDE RIDGE BUILDS...GIVING
US A WARMER AND DRY NEXT WEEKEND. ROSE
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 405 AM MST SAT MAR 1 2014
VFR CONDITIONS WILL OCCUR ACROSS THE 3 TAF SITES...KPUB...KCOS
AND KALS NEXT 24H. MAIN CONCERN TODAY AT KCOS AND ESPECIALLY KPUB
WILL BE GUSTY WEST TO NORTHWEST WINDS AT 15 TO 30 KNOTS. KALS MAY
HAVE -SN VCNTY TOWARDS SUNRISE TOMORROW. THERE IS A VERY LOW
CHANCE THAT SOME FOG COULD DEVELOP AT KCOS AND KPUB AROUND SUNRISE
TOMORROW.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 11 AM MST THIS MORNING FOR COZ084-085.
WINTER WEATHER ADVISORY UNTIL 5 AM MST SUNDAY FOR COZ059-061-064-
067-073-075.
WINTER STORM WARNING UNTIL 5 AM MST SUNDAY FOR COZ058-060-066-
068.
&&
$$
UPDATE...KT
SHORT TERM...HODANISH
LONG TERM...ROSE
AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1026 AM CST SAT MAR 1 2014
.DISCUSSION...
400 AM CST
MAIN CONCERN FOR THE FORECAST PERIOD WILL BE THE POTENTIAL FOR HEAVY
SNOW THROUGH THE WEEKEND.
FOR THE REMAINDER OF THE OVERNIGHT HOURS...A WEAK SHORTWAVE INVOF
THE LEFT EXIT REGION OF A STRONG UPPER LEVEL JET IS PROVIDING THE
DYNAMICS TO GENERATE A QUICK ROUND OF SNOW EARLY THIS MORNING. WITH
ONLY WEAK SFC TROUGHING AND VERY MODEST LOW LEVEL FORCING...THE SNOW
IS ALMOST ENTIRELY RELYING ON UPPER LEVEL DYNAMICS TO SUPPORT THE
SNOW GENERATION. LATEST RADAR TRENDS INDICATE THAT THE BAND OF SNOW
EXTENDS FROM WAUKEGAN TO PERU AND IS MOVING VERY QUICKLY TO THE
EAST. THE SNOW WILL END SHORTLY IN THE ROCKFORD AREA AND WILL
QUICKLY PUSH PAST THE CHICAGO METRO AREA SHORTLY AFTER
DAYBREAK...AND EVEN ENDING OVER THE FAR EASTERN PORTIONS OF THE CWA
BY LATE THIS MORNING. SINCE THE SYSTEM IS MOVING SO QUICKLY...ONLY
AROUND AN INCH OF ACCUMULATION IS EXPECTED.
THE MAIN SNOW CONCERN IS SETTING UP FOR LATE THIS AFTERNOON...AND
PERSISTING ACROSS PORTIONS OF THE REGION UNTIL LATE SUNDAY NIGHT.
GIVEN THE LONG DURATION OF THE EVENT...HAVE OPTED TO ISSUE A WINTER
WEATHER ADVISORY FOR THE ENTIRE CWA. THE ADVISORY WILL BE IN 2
SEGMENTS...BEGINNING EARLIER FOR LOCATIONS NORTH OF THE ILLINOIS AND
KANKAKEE RIVERS...AND THEN SPREADING SOUTH OVERNIGHT TONIGHT.
THE MAIN FEATURE OF CONCERN IS A STRONG CLOSED UPPER LOW OFF THE
CENTRAL CALIFORNIA COAST. THE GUIDANCE HAS CONVERGED INTO
RELATIVELY GOOD AGREEMENT IN THE LARGER SCALE DETAILS WITH THE
SYSTEM EVOLVING INTO AN OPEN WAVE AS THE SYSTEM MOVES ON SHORE LATE
THIS AFTERNOON. THIS WILL SET UP A STREAM OF SWLY FLOW ALOFT AS
WEAK UPPER RIDGING BUILDS OVER THE CENTRAL CONUS AND THE UPPER
TROUGH DIGS OVER THE WEST. A BROAD UPPER LOW CENTERED OVER HUDSON
BAY...WITH TROUGHING THROUGH THE UPPER GREAT LAKES WILL SQUEEZE THE
UPPER LEVEL FLOW...SETTING UP VERY FAST FLOW ALOFT RIPPLES OF SHORT
WAVE ENERGY EJECTING OUT OF THE SOUTHERN ROCKIES WITH A DIRECT
TRAJECTORY ACROSS THE MIDDLE MISSISSIPPI VALLEY TO THE GREAT LAKES.
AT THE SURFACE...POLAR HIGH PRESSURE WILL BUILD OUT OF CANADA AND
SPREAD ACROSS THE NORTHERN PLAINS AND INTO THE MIDDLE AND UPPER
MISSISSIPPI VALLEY TODAY. AFTER A RELATIVELY MILD FRIDAY...THIS
AREA OF HIGH PRESSURE WILL BRING AN ARCTIC AIRMASS BACK TO THE REGION
AT THE SFC. THE SNOW WILL AGAIN LARGELY BE DRIVEN BY UPPER LEVEL
DYNAMICS...WITH THE BAND OF STRONGEST FORCING SAGGING SOUTHWARD
THROUGH THE CWA. CURRENTLY...ANTICIPATE THAT THE SNOW WILL BEGIN
OVER THE NWRN PORTIONS OF THE CWA...INCLUDING THE ROCKFORD METRO
AREA BY AROUND 3PM THIS AFTERNOON AND GRADUALLY SPREAD SOUTH AND
EAST...WITH HEAVIER SNOW REACHING THE CHICAGO METRO AREA DURG THE
EARLY EVENING HOURS. AS THE UPPER LEVEL TROUGHING EXTENDING FROM
HUDSON BAY BACK TOWARD SOUTH CENTRAL CANADA BEGINS TO DIG SOUTHWARD
ACROSS THE UPPER GREAT LAKES LATE TONIGHT AND EARLY SUNDAY...THE
AREA OF SNOW WILL BE QUICKLY FORCED SOUTH...WITH SNOW ENDING OVER
THE NORTHERN TIER COUNTIES BY EARLY SUNDAY MORNING. HOWEVER...THE
MAIN SHORTWAVE TROUGH ASSOCIATED WITH THE PACIFIC SYSTEM WILL EJECT
OUT OF THE SOUTHERN ROCKIES BY SUNDAY MORNING AND TRACK ACROSS THE
PLAINS TO THE MIDDLE MISSISSIPPI VALLEY BY SUNDAY NIGHT...AND THEN
PUSH QUICKLY EAST OF THE AREA BY EARLY MONDAY MORNING. WHILE THE
CANADIAN TROUGH WILL FORCE AN END TO THE SYNOPTIC SNOW OVER THE NRN
PORTIONS OF THE BY EARLY SUNDAY MORNING...THE PACIFIC SHORTWAVE
ENERGY WILL KEEP THE SNOW POTENTIAL GOING OVER THE SRN PORTIONS OF
THE CWA THROUGH LATE SUNDAY NIGHT. ALL TOTAL...EXPECT AROUND 3 TO 5
INCHES ACCUMULATION OF RELATIVELY DRIER SNOW OVER THE NORTHERN
PORTIONS OF THE CWA...AND 5 TO 7 INCHES OVER THE SOUTHERN PORTIONS
OF THE CWA...THOUGH THE SNOW OVER THE SOUTHERN LOCATIONS MAY LIKELY
CONTAIN SLIGHTLY HIGHER LIQUID WATER CONTENT DUE TO THE LONGER
DURATION OF THE PACIFIC SYSTEM IMPACTING THE REGION.
AS THE SYNOPTIC SNOW TAPERS OFF OVER THE NORTHERN PORTIONS OF THE
CWA EARLY SUNDAY MORNING...THE SFC HIGH PRESSURE WILL SPREAD EAST
ACROSS THE UPPER MISSISSIPPI VALLEY AND THE GREAT LAKES REGION. THE
LARGER SCALE MODELS...IN PARTICULAR...THE GFS...HAVE BEEN
ADVERTISING THE POTENTIAL FOR A LAKE EFFECT BAND OF SNOW TO DEVELOP
OVER LAKE MICHIGAN BY SUNDAY MORNING. THE SHORTER RANGE HIGH RES
GUIDANCE IS NOW SHOWING A SIMILAR SETUP WITH SFC CONVERGENCE SETTING
UP OVER WESTERN LAKE MICHIGAN. THIS COULD BRING PERIODS OF LAKE
EFFECT SNOW SHOWERS TO FAR NERN IL...AND EVENTUALLY FAR NWRN INDIANA
AS THE LAKE PLUME MIGRATES EWD INTO EARLY MONDAY MORNING. GIVEN THE
EXTENSIVE ICE COVER ON LAKE MICHIGAN AND RELATIVELY COLD SFC WATER
TEMPERATURES...INVERSION HEIGHTS WILL BE RELATIVELY SHALLOW AND
EQUILIBRIUM LEVELS ONLY AROUND 5-6KFT AND CAPE VALUES OF 300-400
J/KG. THE MODEST CONVECTIVE DEPTH AND INSTABILITY WOULD SUGGEST
THAT SIGNIFICANT LAKE EFFECT SNOW IS NOT LIKELY...BUT PERIODS OF
LAKE EFFECT SNOW SHOWERS PRODUCING ADDITIONAL LIGHT ACCUMULATIONS
OVER THE CHICAGO METRO AREA ARE CERTAINLY POSSIBLE SUNDAY AND SUNDAY
NIGHT.
AS THE COLD HIGH PRESSURE SETTLES OVER THE REGION EARLY NEXT
WEEK...THE REGION CAN EXPECT A FEW MORE DAYS WITH LOW TEMPERATURES
RANGING FROM THE SINGLE DIGITS ABOVE ZERO TO THE SINGLE DIGITS BELOW
ZERO. BRISK NORTH WINDS SHOULD DRIVE WIND CHILL READING TO AROUND 5
TO 15 BELOW ZERO FOR SUNDAY MORNING. AS THE CENTER OF THE HIGH
SETTLES OVER IOWA BY MONDAY MORNING...COLD ADVECTION WILL DRIVE
TEMPERATURES BELOW ZERO FOR PORTIONS OF THE AREA GENERALLY WEST OF
THE I-57 CORRIDOR AND THE FOX VALLEY...WHERE TEMPERATURES COULD DIP
TO AROUND 5 BELOW ZERO...WITH WIND CHILLS TO 20 BELOW ZERO. THE
CENTER OF THE HIGH WILL MOVE OVER THE AREA FOR TUESDAY MORNING...SO
CLEAR SKIES...LIGHT WINDS AND FRESH SNOW COVER WILL ALLOW FOR MORE
WIDESPREAD LOWS BELOW ZERO DUE TO RADIATIVE COOLING.
FOR THE EXTENDED FORECAST PERIOD...FOR TUESDAY THROUGH FRIDAY...THE
LONGER RANGE GUIDANCE CONTINUES TO ADVERTISE A GRADUAL WARMING TREND
BY THE END OF THE PERIOD. WEDNESDAY SHOULD REMAIN RELATIVELY COOL
WITH HIGHS STILL ONLY IN THE MIDDLE 20S...BUT AS THE ARCTIC HIGH MOST
WELL TO THE EAST BY THURSDAY...SETTING UP A WARM ADVECTIVE
PATTERN...TEMPERATURES SHOULD REBOUND INTO THE LOWER 30S BY THURSDAY
AND COULD EVEN PEG 40F BY FRIDAY. A SERIES OF MID LEVEL SHORTWAVES
COULD BRING PERIODIC CHANCES FOR SOME LIGHT SNOW ON WEDNESDAY AND
THURSDAY...BUT NOTHING SIGNIFICANT IS LIKELY.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* NORTH WINDS LATE THIS MORNING WITH LINGERING POCKETS OF MVFR
CIGS. EXPECT A PERIOD OF VFR BEFORE SNOW ARRIVES.
* SNOW ARRIVING THIS AFTERNOON. MOVED UP START TIME BY AN HOUR AND
LOWERED INITIAL VSBYS TO MVFR. ALSO MOVED UP START TIME OF
HEAVIER SNOW. IFR LIKELY AND LIFR POSSIBLE THIS EVENING.
LENNING
//DISCUSSION...UPDATED 12Z...
LAST OF THE LIGHT SNOW CONTINUES TO EXIT THE TERMINALS EARLY THIS
MORNING. A BAND OF IFR CIGS HAS DEVELOPED IN THE WAKE OF THE BAND
BUT SHOULD BE PROGRESSING EAST AWAY FROM THE TERMINALS IN THE NEXT
FEW HOURS. VARIABLE MVFR/VFR CIGS EXTEND BACK TO THE MISSISSIPPI
RIVER OR SO WITH STEADIER VFR TO THE WEST. WINDS HAVE OR WILL BE
TURNING NORTHERLY SHORTLY AND EXPECT THAT THERE WILL BE
FLUCTUATIONS BETWEEN NW AND NNE THROUGH THE DAY.
ATTENTION TURNS TO THE NEXT ROUND OF MORE SIGNIFICANT SNOW WHICH
WILL ARRIVE LATER THIS AFTERNOON FROM WEST TO EAST. SNOW SHOULD
QUICKLY INCREASE IN INTENSITY LATE THIS AFTERNOON AT RFD AND RIGHT
AROUND 00Z IN THE CHICAGO AREA...THOUGH LIGHT SNOW MAY DEVELOP
JUST PRIOR TO THAT. TIMING MAY STILL NEED SOME TWEAKING BUT HAVE
GOOD CONFIDENCE OVERALL. PERIOD OF MODERATE TO EVEN BRIEFLY HEAVY
SNOW ARE EXPECTED FROM LATE THIS AFTERNOON INTO MID EVENING AT RFD
AND PRIMARILY DURING THE EVENING IN THE CHICAGO AREA. PREVAILING
VSBY OF 1 TO 1.5SM IS LIKELY WITH PERIODS OF 1/2 TO 3/4SM VSBY
POSSIBLE AS WELL. CANNOT RULE OUT SOME BRIEF PERIODS OF 1/4SM AS
WELL. ACCUMULATION RATES OF 0.5 TO 1 INCH PER HOUR ARE ALSO LIKELY
AT TIMES. THE MAIN FORCING FOR THE SNOW WILL PUSH SOUTHWARD FROM
LATE EVENING INTO THE OVERNIGHT ALLOWING SNOW INTENSITY TO TAPER
OFF AT THE TERMINALS...THOUGH SOME LIGHT SNOW MAY CONTINUE THROUGH
DAYBREAK. LAKE EFFECT PROCESSES WILL THEN TRY TO TAKE OVER WHICH
SHOULD LEAD TO LAKE EFFECT SNOW SHOWERS. THE CHALLENGE WILL BE
DETERMINING THE LOCATION AND INTENSITY DETAILS. WITH A SLIGHT
NORTHEAST WIND COMPONENT TO THE WINDS SOME OF THIS ACTIVITY MAY
DRIFT TOWARD OR OVER ORD/MDW DURING THE DAY SUNDAY. SHOULD THIS
OCCUR THEN PERIODIC BURSTS OF MORE INTENSE SNOW WILL BE POSSIBLE
WITH GREATLY REDUCED VSBY. GYY IS PROBABLY THE MOST FAVORED FOR
LAKE EFFECT ACTIVITY GIVEN THE PRIMARILY NORTH WIND BU OVERALL
CONFIDENCE IS LIMITED SO CONTINUE TO MONITOR FOR THE LATEST
THINKING.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE ON WINDS REMAINING NORTHERLY.
* MEDIUM CONFIDENCE ON TIMING OF SNOW AND CIG/VSBY TRENDS. HIGH
CONFIDENCE OF IFR PERIODS THIS EVENING.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE FOR SNOW SHOWERS WITH IFR/MVFR POSSIBLE.
MONDAY THROUGH FRIDAY...MAINLY VFR WITH PERIODIC LOW CHANCES FOR
LIGHT SNOW.
MDB
&&
.MARINE...
302 AM CST
LOW PRESSURE JUST EAST OF NORTHERN LAKE SUPERIOR WILL MOVE EASTWARD
INTO WESTERN QUEBEC INTO THE EARLY AFTERNOON HOURS. A COLD FRONT IS
TRAILING THIS LOW AND IS PUSHING ACROSS LAKE MICHIGAN EARLY THIS
MORNING BRINGING A SHIFT TO NORTH AND NORTHWEST WINDS. SPEEDS WILL
INCREASE INTO THE 15 TO 25 KT RANGE BEHIND THE FRONT THIS MORNING
THEN EASE UP A BIT THIS EVENING. NORTHERLY WINDS WILL CONTINUE
THROUGH SUNDAY WITH SOME CONVERGENCE LIKELY SETTING UP ACROSS
CENTRAL AND SOUTHERN SECTIONS OF THE LAKE AS LAKE EFFECT PROCESSES
TAKE OVER. AS THIS OCCURS AN INVERTED TROUGH WILL DEVELOP FROM
SOUTHWEST TO NORTHEAST ACROSS THE OHIO VALLEY THEN SHIFT SOUTHWARD
SUNDAY AND MONDAY. STRONG HIGH PRESSURE CENTERED OVER ALBERTA AND
ITS ASSOCIATED RIDGE EXTENDING SOUTHEASTWARD INTO THE CENTRAL PLAINS
WILL DRIFT SOUTHEAST OVER THE NEXT SEVERAL DAYS. THE RIDGE AXIS WILL
RE-ORIENT SOMEWHAT AND POSITION ITSELF ACROSS THE WESTERN GREAT
LAKES LATER TONIGHT...BEFORE THE HIGH BECOMES CENTERED OVER THE
PLAINS AND MID AND UPPER MISSISSIPPI RIVER VALLEY LATER SUNDAY. THE
PRESSURE GRADIENT LOOKS TO TIGHTEN ACROSS LAKE MICHIGAN SUNDAY NIGHT
ALLOWING NORTHERLY WINDS TO INCREASE ONCE AGAIN. THE HIGH WILL MOVE
EASTWARD MONDAY ALLOWING WINDS TO DROP OFF AND BECOME VARIABLE. AS
THE HIGH PASSES WINDS SHIFT TO THE EAST AND SOUTHEAST FOR MID WEEK
BEFORE TURNING SOUTHERLY LATE IN THE WEEK.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-
ILZ022...3 PM SATURDAY TO 9 AM SUNDAY.
WINTER WEATHER ADVISORY...ILZ023-ILZ032-ILZ033-ILZ039...9 PM
SATURDAY TO MIDNIGHT MONDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...9
PM SATURDAY TO MIDNIGHT MONDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
1013 AM CST Sat Mar 1 2014
.DISCUSSION...
ISSUED 1011 AM CST Sat Mar 1 2014
Cold front has reached the I-70 corridor as of 10 am, and will
continue to move through the southeast CWA into early afternoon.
High temperatures further northwest have already occurred, and
falling temperatures will be the trend through the afternoon as
Arctic air upstream pushes southeastward. Large area of light
snow has set up over the north half of Iowa and will be tracking
eastward much of the day, before taking a southeast nudge later
this afternoon. Have adjusted PoP`s for the afternoon to focus
them on the 3-6 pm time frame as a result. Other adjustments to
hourly temperature trends have been sent.
Will hold onto the Winter Storm Watch until all of the 12Z model
guidance has arrived, before making the decision on how to convert
it.
Geelhart
&&
.AVIATION...
ISSUED 510 AM CST Sat Mar 1 2014
IFR CIGs behind cold front beginning to work into central Illinois
from the northwest. KGBG has dropped to OVC007 and large area of
CIGs between 007 and 012 extends approximately 100 nm behind the
cold front. Although diurnal influence may raise the CIGs slightly
as they work southeast, latest HRRR suggest the band will hold
together much of the day. Have translated the IFR/MVFR clouds into
the terminals this morning as front pushes through. So far only
minor reductions in VSBYs and will leave as P6SM for now.
Jet streak induced broad area of snow is expected to develop
across the upper Mississippi Valley this afternoon and advect
southward into the terminals this evening. Will likely be
occasional VSBYs lower, will currently broad brush with 2 nm. As
the area develops later packages can hone the details on exactly
when LIFR VSBYs might occur.
Barker
&&
.PREV DISCUSSION...
ISSUED 328 AM CST Sat Mar 1 2014
SHORT TERM...Today through Sunday
At 08Z/2AM Arctic cold front was just entering the NW CWA
accompanied by a narrow band of light snow, which has briefly
dropped vsbys to 3-5 miles. Latest trends and short range models
indicate what snow there is will dissipate as the front continues
to shift southeast this morning. Did include low chance pops this
afternoon across the northern third where models show weak omega
behind front off weak dpva.
As the Arctic front shifts south towards the Ohio Valley this
evening, a strong 140+ kt 300mb jet sets up over the Great Lakes.
This in conjunction with a tightening mid-level baroclinic zone to
our south sets up good moisture transport into a region of strong
frontogenesis over Iowa and northern IL. As this zone gradually
shifts south this evening, expect snow to increase in coverage and
intensity. Given the strength of projected frontogenesis and a
hint of negative EPV above this zone would expect some banding and
enhance snowfall rates overnight. 00Z guidance has trended more
progressive the the band of stronger forcing, shifting this south
of I-72 Sunday morning. This seems reasonable given the fact this
is an open wave at 850/700 mb. Snow will likely continue over the
southern half Sunday afternoon, and into Sunday night far SE, as
additional shortwave energy ejects from southern plains trough.
Thermal profiles off consistent GFS/ECMWF show snow for much of
the CWA, except south of I-70 where a sleet/freezing rain mix is
possible for several hours after onset. Have discounted aggressive
warmer NAM thermal structure (which would bring mixed precip north
of I-72) due to open wave feature. This does lead to lower overall
confidence in p-type than would be desired at 24 hrs. Given
precipitable water values 0.6-0.9 and projected forcing, model qpf
raning from 0.3 NW to 0.75 SE looks reasonable. Used 12:1
snow:liquid ratio, except 10:1 south of I-70 due to thermal
profiles. For the northwest half of the CWA projected totals of 4-6"
in 18+ hours fall short of warning criteria (6"+ in 12 hours or
8"+ in 24 hours) and have issued winter wx advisory for 6 PM
tonight through 6 PM Sunday. For areas southeast of a Shebyville
to Monticello to Rantoul line, 5-8" forecast over a 24+ hour period
also falls short of warning criteria. The potential for mixed
precip does complicate things, as warning sleet/ice accums would
be possible under NAM solution. With uncertainty remaining in
this area will keep winter storm watch going (midnight tonight
through 6 AM Monday morning), and let day shift make the call
after looking over 12Z data.
LONG TERM...Monday through Friday
Bitterly cold air moves into the region behind the departing
storm. Late season Arctic high pressure will produce temps 20-25
degrees below normal, with lows likely dropping below zero across
the north Monday and Tuesday mornings. A weak shortwave dropping
through in northwest flow behind the high, will bring a chance of
light snow to the northern half of the CWA Tuesday. With low
moisture availability have kept pops to slight chance. While temps
will remain below normal through the week, readings will gradually
moderate as mid level flow flattens. Dry weather is expected as
split flow keeps major systems well to our north and south.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH from late tonight through late Sunday night
FOR ILZ044>046-054>057-061>063-066>068-071>073.
WINTER WEATHER ADVISORY from 6 PM this evening to 6 PM CST
Sunday FOR ILZ027>031-036>038-040>043-047>053.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
102 PM MST SAT MAR 1 2014
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 419 AM MST SAT MAR 1 2014
MAIN FORECAST CONCERNS...AMONG VERY MANY...WILL BE PHASE OF
PRECIPITATION AND AMOUNT OF ICE AND SNOW ACCUMULATION INTO TOMORROW
SATELLITE CONTINUING TO SHOW AN AMPLIFIED/COMPLEX AND EVEN
RETROGRESSIVE PATTERN FROM THE PACIFIC INTO CANADA. HIGH AMPLITUDE
RIDGE RESIDES ALONG THE WEST COAST OF NORTH AMERICA WITH BROAD AND
COLD UPPER TROUGH OVER CANADA. WEAKENING/FILLING SYSTEM IS MOVING
TOWARD THE CALIFORNIA COAST WITH A LARGE AMOUNT OF MID AND UPPER
LEVEL MOISTURE STREAMING OUT AHEAD OF IT. A SIGNIFICANT LOBE ROTATING
AROUND THE CANADIAN TROUGH IS PUSHING SOUTH.
AT JET LEVEL...MODELS INITIALIZED POORLY WITH JET SEGMENT IN
ADVANCE OF SYSTEM OFF THE CALIFORNIA COAST. THE UKMET AND NAM WERE
DOING THE BEST BUT WERE STILL OFF. AT MID LEVELS...THE GFS...ECMWF
...CANADIAN AND SREF WERE DOING ABOUT THE SAME AND THE BEST OF THE
AVAILABLE OUTPUT. THE ECMWF WAS DOING A LITTLE BETTER THAN THE
SREF ON THE SURFACE WIND AND PRESSURE FIELD. THE UKMET...GFS...NAM
AND CANADIAN WERE DOING WELL ON THE LOW LEVEL THERMAL FIELD.
EVEN THOUGH THEY ARE NOT PRODUCING A LOT OF QPF...THEY ARE TENDING
TO OVERDO IT WITH THE GFS...NAM...AND SREF THE WORST.
THIS WILL CONTINUE TO BE A VERY LOW CONFIDENCE FORECAST DUE TO POOR
INITIAL ANALYSIS ON MID AND UPPER LEVEL FEATURES...MODEL
DIFFERENCES IN THERMAL AND MOISTURE PROFILES...AND MODELS CHANGING
FROM THEIR SOLUTIONS...SOMETIMES DRAMATICALLY...FROM 24 HOURS AGO.
SAYING ALL THAT...THE WINTER WEATHER ADVISORY DOES STILL LOOK ON
TRACK DUE TO THE VARIABLE PHASES...VARIABLE ICE AND SNOW AMOUNTS.
IN GENERAL DID INCREASE ICE AMOUNTS...STILL BELOW A TENTH OF AN
INCH...DUE TO A LONGER TIME FOR ICE ACCUMULATION...AND LOWERED
SNOW AMOUNTS SLIGHTLY DUE TO NOT VERY MUCH SNOW ACCUMULATION UNTIL
TONIGHT.
TODAY/TONIGHT...JET SETUP BY THE END OF THE DAY IS DIFFERENT THAN
WHAT WAS DEPICTED YESTERDAY. BY LATE IN THE DAY THE MAIN JET
SEGMENT IS STILL TO THE WEST OF MY AREA WITH THE RIGHT FRONT
QUADRANT OVER THE AREA. SO AT FIRST GLANCE THERE DOES NOT APPEAR TO
BE A LOT TO DRIVE PRECIPITATION DEVELOPMENT DUE TO ANY STRONG
FEATURES. HOWEVER...MODELS DO CONTINUE TO PRODUCE LIGHT AMOUNTS OF
QPF. THE LIFT IS BEING GENERATED BY LOW LEVEL UPSLOPE AND
ISENTROPIC LIFT ABOVE THIS DOME OF COLD AIR.
PRECIPITATION HAS BEEN SLOWER TO START THAN WHAT WAS PREVIOUSLY
EXPECTED. SURFACE OBSERVATIONS ARE STARTING TO SHOW SOME
PRECIPITATION. SO BELIEVE WILL HAVE LIGHT PRECIPITATION AROUND FOR
MOST OF THE DAY. SO QUESTION BECOMES PHASE. 00Z SOUNDINGS SHOW
EITHER A DRY AIR MASS OR ONLY A SATURATED SHALLOW AIR MASS AND
THAT WAS EVIDENT IN SOME FOG DEVELOPMENT WHICH I WILL ADD. GFS HAS
CHANGED ITS TUNE FROM YESTERDAY. IT IS NOT AS AGGRESSIVE IN
SATURATING THE COLUMN TO A DEEPER DEPTH. THE NAM ALSO CHANGED ITS
TUNE AND SATURATED TO GREATER DEPTH...AT LEAST IN THE BEGINNING...IN
A SIMILAR FASHION AS THE GFS WHICH IS SLIGHTLY DRIER ALOFT THAN
THE NAM.
WARM LAYER APPEARS IN ALL AREAS OR ALMOST ALL AREAS AT THE BEGINNING
WITH THE GFS SHOWING WARMER TEMPERATURES ALOFT. NORTHERN AREAS
SHOULD SEE ALL SNOW ONLY BECAUSE THE DENDRITIC ZONE IS AT THE
SURFACE. FOR A FEW COUNTIES SOUTH AND WEST OF THAT A MIXTURE OF
FREEZING DRIZZLE...SNOW AND SLEET IS INDICATED WITH THE FAR SOUTH
AND WEST INDICATING SLEET AND FREEZING DRIZZLE. THIS AREA WORKS ITS
WAY SOUTH GRADUALLY THROUGH THE DAY. ALL IN ALL THE PREVIOUS
FORECAST HAD THE POP AND PHASE LAYOUT IN GOOD SHAPE AND ONLY MADE
MINOR ADJUSTMENTS. WITH NOT VERY STRONG LIFT...DID REDUCE THE
ALREADY LIGHT SNOW AMOUNTS A LITTLE.
RIGHT REAR QUADRANT OF THE JET MOVES ACROSS THE AREA DURING THE
NIGHT. AT THE SAME A SHORTWAVE TROUGH MOVES ACROSS THE AREA WITH
ISENTROPIC LIFT STILL IN PLACE. GFS CONTINUES TO NOT HAVE A DEEP OF
A SATURATED LAYER AS YESTERDAY. HOWEVER...THE DENDRITIC ZONE REMAINS
NEAR OR AT THE SURFACE. WHAT IS ALSO DIFFERENT FROM YESTERDAY IS
THAT THE GFS IS DOING WHAT THE NAM WAS DOING YESTERDAY WHICH IS
KEEPING A MIXTURE IN PLACE FOR MUCH LONGER. IF SOUNDINGS ARE
CORRECT THE FAR SOUTH AND WEST MAY NOT DO A COMPLETE CHANGE OVER TO
SNOW UNTIL AFTER MIDNIGHT.
AM CONCERNED THAT THE MODELS MAY BE UNDERDOING PRECIPITATION/SNOW
AMOUNTS DUE TO THE STRONG LIFT FROM THE JET/UPPER DEFORMATION MOVING
ACROSS. BY MIDNIGHT THE MAIN AREA OF SNOW WILL HAVE MOVED INTO THE
SOUTHEAST HALF AND THAT IS WHERE WE WILL HAVE TO WATCH AMOUNTS
CAREFULLY.
FOR MAXES...MODEL GUIDANCE IS WARMER AND THAT LOOKS TO BE MAINLY
DUE TO THE MODELS NOT COOLING OFF TEMPERATURES AS MUCH FOR THIS
MORNING. MAXES MAY BE EARLY. USED A COMBINATION OF HRRR AND MAV TO
ADJUST THE MAXES. KEPT MINS WARMER AND ABOVE THE COLDEST GUIDANCE
DUE TO THE CLOUDS AND UPSLOPE WINDS. CONSEQUENTLY THE WIND CHILL
READINGS ARE NOT AS LOW AS PREVIOUS FEW DAYS WITH MARGINAL WIND
CHILL ADVISORY CRITERIA ALONG AND EAST OF THE COLORADO BORDER.
SUNDAY/SUNDAY NIGHT...MODELS DIFFERING ON THE SPEED/POSITION A
LITTLE BUT IN GENERAL THEY SHOW THE RIGHT REAR QUADRANT AFFECTING
THE SOUTHEAST HALF OF THE AREA AT THE BEGINNING OF THE DAY. THIS IS
TO THE EAST OF THE AREA BY 18Z. IT IS ALSO BY THIS TIME THAT
DOWNGLIDE IS OCCURRING ON 290 SURFACE. PRECIPITATION BE HIGHEST IN
THE SOUTHEAST HALF OF THE FORECAST AREA DUE TO THE JET AND SHORTWAVE
TROUGH. SO KEPT HIGHER POPS THERE AND LOWERED THEM OVER THE REST OF
THE AREA. SNOW WILL GRADUALLY DECREASE DURING THE DAY WITH FLURRIES
EXPECTED DURING THE EVENING. BASED ON SATURATED LOW LEVELS DID TOSS
IN SOME PATCHY FREEZING FOG DURING THE OVERNIGHT HOURS.
CLOUDS...UPSLOPE WINDS AND COLD AIR ADVECTION WILL BE PLACE FOR THE
ENTIRE DAY. NOT SURE WHY MODEL GUIDANCE IS WARMING UP MAXES SO
MUCH. KEPT THE MAXES NEAR THE COLDER SIDE AND NEAR THE BETTER
PERFORMING GUIDANCE. MINS WILL BE WARMER THAN THE PREVIOUS NIGHT
WHICH AGAIN MEANS WIND CHILL READINGS NOT GETTING AS COLD. AGAIN
REACHING MARGINAL ADVISORY VALUES.
MONDAY/MONDAY NIGHT...WEAK RIGHT REAR QUADRANT OF THE JET DEVELOPS
OVER THE AREA BY THE MIDDLE OF THE DAY AND AFFECTS THE AREA AT
LEAST THROUGH THE EVENING. THERE WILL BE A DEEP DRY LAYER SO ONLY
CLOUDS WILL RESULT. SO THIS PERIOD WILL JUST END UP BEING A
TEMPERATURE FORECAST. DEPENDING ON HOW MUCH SNOW FALLS AND WHERE...
THAT COULD CAUSE IN THE TEMPERATURE LAYOUT I HAVE IN THERE. MODELS
ARE BRINGING IN WARMER AIR FURTHER EAST AND FOR THE MOST PART I
BELIEVE THEY ARE TOO AGGRESSIVE. SINCE THE ECMWF HAS A BETTER
DEPICTION OF THE SURFACE...DO LIKE ITS TEMPERATURES A LITTLE
BETTER. HOWEVER...MODELS HAVE HAD A TENDENCY TO HOLD TO COLD
TEMPERATURES TOO LONG IN THIS PATTERN WHICH BECOMES STRONG ZONAL.
WARM AIR ADVECTION PATTERN DEVELOPS IN ERNEST DURING THE NIGHT AND
MAY END UP HAVING WARMING TEMPERATURES DURING THE OVERNIGHT HOURS.
.LONG TERM...(TOMORROW NIGHT THROUGH NEXT SATURDAY)
ISSUED AT 1248 PM MST SAT MAR 1 2014
RIDGING WILL GENERALLY BE IN PLACE OVER THE CENTRAL ROCKIES
LEADING TO NORTHWEST FLOW OVER THE CENTRAL PLAINS THROUGH THE
PERIOD. A SERIES OF EMBEDDED SHORTWAVE TROUGHS WILL BRING
OCCASIONAL CHANCES FOR LIGHT PRECIPITATION LATER IN THE MID TO
LATE WEEK TIMEFRAME. TEMPERATURES WILL START OUT BELOW NORMAL TO
START BUT THE ARCTIC AIR WILL QUICKLY RETREAT AND FROM TUESDAY AND
BEYOND TEMPERATURES WILL BE ABOVE NORMAL UNDER THE INFLUENCE OF
THE RIDGE.
AS FOR PRECIPITATION...MONDAY AND TUESDAY WILL BE DRY. SHORTWAVE
TROUGH COMING OVER THE RIDGE TUESDAY NIGHT WILL BRING LOW CHANCES
OF LIGHT PRECIPITATION WITH MAIN ENERGY GOING SOUTH. FORECAST
POINT SOUNDINGS SHOW DRY AIR IN THE MID LEVELS AND MOST
PRECIPITATION WILL PROBABLY NOT MAKE IT TO THE GROUND. A
SUFFICIENT WARM LAYER WILL EXIST TO MELT ANY ICE...SO
PRECIPITATION TYPE WILL BE DETERMINED BY SURFACE TEMPERATURES
WHICH WILL BE IN THE LOWER TO MIDDLE 30S. WILL CARRY SLIGHT
CHANCES OF -RA/-FZRA WITH LOW CONFIDENCE EITHER WILL PAN OUT. THAT
SCENARIO CARRIES OVER INTO WEDNESDAY MORNING...THEN A CHANCE OF
RAIN WEDNESDAY AFTERNOON SURFACE TEMPERATURES WARM. SHORTWAVE
RIDGING WILL KEEP IT DRY WEDNESDAY NIGHT THROUGH THURSDAY NIGHT.
NEXT SHORTWAVE TROUGH ARRIVES ON FRIDAY. MOISTURE LOOKS BETTER IN
DENDRITIC LAYER BUT SURFACE WILL BE WARM TO START. COLDER AIR
ARRIVES FRIDAY AFTERNOON WITH COLD FRONT. GIVEN THERE WILL BE ICE
IN THE COLUMN BUT UNCERTAINTY ON EXTENT OF SURFACE BASED WARM
LAYER WILL CARRY RAIN/SNOW AS PRECIPITATION TYPE THROUGH FRIDAY
NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1103 AM MST SAT MAR 1 2014
IFR CONDITIONS SHOULD CONTINUE THROUGH AT LEAST THIS EVENING AT
KGLD AND KMCK. CEILINGS WILL LIKELY REMAIN IN THE MVFR CATEGORY
BUT LIGHT SNOW IS CAUSING VISIBILITY REDUCTIONS TO IFR.
EARLIER THIS MORNING KGLD DROPPED BRIEFLY TO LIFR DUE TO 3/4 SM
VISIBILITY BUT SNOW INTENSITY IS EXPECTED TO REMAIN LIGHT ENOUGH
THAT VISIBILITY REMAINS IN THE IFR CATEGORY. IF A PERIOD OF GREATER
SNOW INTENSITIES AT EITHER TERMINAL WERE TO OCCUR CAUSING A
REDUCTION IN VISIBILITY TO LIFR...IT WOULD LIKELY BE DURING THE
EVENING WHEN SHORT TERM MODEL GUIDANCE SUGGEST SLIGHTLY STRONGER
FRONTOGENESIS/LIFT MAY BE PRESENT. OTHERWISE EXPECT FLUCTUATIONS
IN VISIBILITY TO CONTINUE FROM AROUND 1 SM TO AROUND 3 SM. TOWARD
TOMORROW MORNING...MOISTURE BECOMES SHALLOWER AND SNOW INTENSITIES
SHOULD DECREASE SUFFICIENTLY FOR MVFR CONDITIONS. SOME LIGHT
FREEZING DRIZZLE HAS OCCASIONALLY BEEN MIXED IN WITH THE SNOW BUT
ICE ACCUMULATION HAS BEEN VERY MINOR TO NON-EXISTENT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY UNTIL 5 PM MST /6 PM CST/ SUNDAY FOR
KSZ001>004-013>016-027>029-041-042.
CO...WINTER WEATHER ADVISORY UNTIL 5 PM MST SUNDAY FOR COZ090>092.
NE...WINTER WEATHER ADVISORY UNTIL 5 PM MST /6 PM CST/ SUNDAY FOR
NEZ079>081.
&&
$$
SHORT TERM...BULLER
LONG TERM...024
AVIATION...BRB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1103 AM MST SAT MAR 1 2014
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 419 AM MST SAT MAR 1 2014
MAIN FORECAST CONCERNS...AMONG VERY MANY...WILL BE PHASE OF
PRECIPITATION AND AMOUNT OF ICE AND SNOW ACCUMULATION INTO TOMORROW
SATELLITE CONTINUING TO SHOW AN AMPLIFIED/COMPLEX AND EVEN
RETROGRESSIVE PATTERN FROM THE PACIFIC INTO CANADA. HIGH AMPLITUDE
RIDGE RESIDES ALONG THE WEST COAST OF NORTH AMERICA WITH BROAD AND
COLD UPPER TROUGH OVER CANADA. WEAKENING/FILLING SYSTEM IS MOVING
TOWARD THE CALIFORNIA COAST WITH A LARGE AMOUNT OF MID AND UPPER
LEVEL MOISTURE STREAMING OUT AHEAD OF IT. A SIGNIFICANT LOBE ROTATING
AROUND THE CANADIAN TROUGH IS PUSHING SOUTH.
AT JET LEVEL...MODELS INITIALIZED POORLY WITH JET SEGMENT IN
ADVANCE OF SYSTEM OFF THE CALIFORNIA COAST. THE UKMET AND NAM WERE
DOING THE BEST BUT WERE STILL OFF. AT MID LEVELS...THE GFS...ECMWF
...CANADIAN AND SREF WERE DOING ABOUT THE SAME AND THE BEST OF THE
AVAILABLE OUTPUT. THE ECMWF WAS DOING A LITTLE BETTER THAN THE
SREF ON THE SURFACE WIND AND PRESSURE FIELD. THE UKMET...GFS...NAM
AND CANADIAN WERE DOING WELL ON THE LOW LEVEL THERMAL FIELD.
EVEN THOUGH THEY ARE NOT PRODUCING A LOT OF QPF...THEY ARE TENDING
TO OVERDO IT WITH THE GFS...NAM...AND SREF THE WORST.
THIS WILL CONTINUE TO BE A VERY LOW CONFIDENCE FORECAST DUE TO POOR
INITIAL ANALYSIS ON MID AND UPPER LEVEL FEATURES...MODEL
DIFFERENCES IN THERMAL AND MOISTURE PROFILES...AND MODELS CHANGING
FROM THEIR SOLUTIONS...SOMETIMES DRAMATICALLY...FROM 24 HOURS AGO.
SAYING ALL THAT...THE WINTER WEATHER ADVISORY DOES STILL LOOK ON
TRACK DUE TO THE VARIABLE PHASES...VARIABLE ICE AND SNOW AMOUNTS.
IN GENERAL DID INCREASE ICE AMOUNTS...STILL BELOW A TENTH OF AN
INCH...DUE TO A LONGER TIME FOR ICE ACCUMULATION...AND LOWERED
SNOW AMOUNTS SLIGHTLY DUE TO NOT VERY MUCH SNOW ACCUMULATION UNTIL
TONIGHT.
TODAY/TONIGHT...JET SETUP BY THE END OF THE DAY IS DIFFERENT THAN
WHAT WAS DEPICTED YESTERDAY. BY LATE IN THE DAY THE MAIN JET
SEGMENT IS STILL TO THE WEST OF MY AREA WITH THE RIGHT FRONT
QUADRANT OVER THE AREA. SO AT FIRST GLANCE THERE DOES NOT APPEAR TO
BE A LOT TO DRIVE PRECIPITATION DEVELOPMENT DUE TO ANY STRONG
FEATURES. HOWEVER...MODELS DO CONTINUE TO PRODUCE LIGHT AMOUNTS OF
QPF. THE LIFT IS BEING GENERATED BY LOW LEVEL UPSLOPE AND
ISENTROPIC LIFT ABOVE THIS DOME OF COLD AIR.
PRECIPITATION HAS BEEN SLOWER TO START THAN WHAT WAS PREVIOUSLY
EXPECTED. SURFACE OBSERVATIONS ARE STARTING TO SHOW SOME
PRECIPITATION. SO BELIEVE WILL HAVE LIGHT PRECIPITATION AROUND FOR
MOST OF THE DAY. SO QUESTION BECOMES PHASE. 00Z SOUNDINGS SHOW
EITHER A DRY AIR MASS OR ONLY A SATURATED SHALLOW AIR MASS AND
THAT WAS EVIDENT IN SOME FOG DEVELOPMENT WHICH I WILL ADD. GFS HAS
CHANGED ITS TUNE FROM YESTERDAY. IT IS NOT AS AGGRESSIVE IN
SATURATING THE COLUMN TO A DEEPER DEPTH. THE NAM ALSO CHANGED ITS
TUNE AND SATURATED TO GREATER DEPTH...AT LEAST IN THE BEGINNING...IN
A SIMILAR FASHION AS THE GFS WHICH IS SLIGHTLY DRIER ALOFT THAN
THE NAM.
WARM LAYER APPEARS IN ALL AREAS OR ALMOST ALL AREAS AT THE BEGINNING
WITH THE GFS SHOWING WARMER TEMPERATURES ALOFT. NORTHERN AREAS
SHOULD SEE ALL SNOW ONLY BECAUSE THE DENDRITIC ZONE IS AT THE
SURFACE. FOR A FEW COUNTIES SOUTH AND WEST OF THAT A MIXTURE OF
FREEZING DRIZZLE...SNOW AND SLEET IS INDICATED WITH THE FAR SOUTH
AND WEST INDICATING SLEET AND FREEZING DRIZZLE. THIS AREA WORKS ITS
WAY SOUTH GRADUALLY THROUGH THE DAY. ALL IN ALL THE PREVIOUS
FORECAST HAD THE POP AND PHASE LAYOUT IN GOOD SHAPE AND ONLY MADE
MINOR ADJUSTMENTS. WITH NOT VERY STRONG LIFT...DID REDUCE THE
ALREADY LIGHT SNOW AMOUNTS A LITTLE.
RIGHT REAR QUADRANT OF THE JET MOVES ACROSS THE AREA DURING THE
NIGHT. AT THE SAME A SHORTWAVE TROUGH MOVES ACROSS THE AREA WITH
ISENTROPIC LIFT STILL IN PLACE. GFS CONTINUES TO NOT HAVE A DEEP OF
A SATURATED LAYER AS YESTERDAY. HOWEVER...THE DENDRITIC ZONE REMAINS
NEAR OR AT THE SURFACE. WHAT IS ALSO DIFFERENT FROM YESTERDAY IS
THAT THE GFS IS DOING WHAT THE NAM WAS DOING YESTERDAY WHICH IS
KEEPING A MIXTURE IN PLACE FOR MUCH LONGER. IF SOUNDINGS ARE
CORRECT THE FAR SOUTH AND WEST MAY NOT DO A COMPLETE CHANGE OVER TO
SNOW UNTIL AFTER MIDNIGHT.
AM CONCERNED THAT THE MODELS MAY BE UNDERDOING PRECIPITATION/SNOW
AMOUNTS DUE TO THE STRONG LIFT FROM THE JET/UPPER DEFORMATION MOVING
ACROSS. BY MIDNIGHT THE MAIN AREA OF SNOW WILL HAVE MOVED INTO THE
SOUTHEAST HALF AND THAT IS WHERE WE WILL HAVE TO WATCH AMOUNTS
CAREFULLY.
FOR MAXES...MODEL GUIDANCE IS WARMER AND THAT LOOKS TO BE MAINLY
DUE TO THE MODELS NOT COOLING OFF TEMPERATURES AS MUCH FOR THIS
MORNING. MAXES MAY BE EARLY. USED A COMBINATION OF HRRR AND MAV TO
ADJUST THE MAXES. KEPT MINS WARMER AND ABOVE THE COLDEST GUIDANCE
DUE TO THE CLOUDS AND UPSLOPE WINDS. CONSEQUENTLY THE WIND CHILL
READINGS ARE NOT AS LOW AS PREVIOUS FEW DAYS WITH MARGINAL WIND
CHILL ADVISORY CRITERIA ALONG AND EAST OF THE COLORADO BORDER.
SUNDAY/SUNDAY NIGHT...MODELS DIFFERING ON THE SPEED/POSITION A
LITTLE BUT IN GENERAL THEY SHOW THE RIGHT REAR QUADRANT AFFECTING
THE SOUTHEAST HALF OF THE AREA AT THE BEGINNING OF THE DAY. THIS IS
TO THE EAST OF THE AREA BY 18Z. IT IS ALSO BY THIS TIME THAT
DOWNGLIDE IS OCCURRING ON 290 SURFACE. PRECIPITATION BE HIGHEST IN
THE SOUTHEAST HALF OF THE FORECAST AREA DUE TO THE JET AND SHORTWAVE
TROUGH. SO KEPT HIGHER POPS THERE AND LOWERED THEM OVER THE REST OF
THE AREA. SNOW WILL GRADUALLY DECREASE DURING THE DAY WITH FLURRIES
EXPECTED DURING THE EVENING. BASED ON SATURATED LOW LEVELS DID TOSS
IN SOME PATCHY FREEZING FOG DURING THE OVERNIGHT HOURS.
CLOUDS...UPSLOPE WINDS AND COLD AIR ADVECTION WILL BE PLACE FOR THE
ENTIRE DAY. NOT SURE WHY MODEL GUIDANCE IS WARMING UP MAXES SO
MUCH. KEPT THE MAXES NEAR THE COLDER SIDE AND NEAR THE BETTER
PERFORMING GUIDANCE. MINS WILL BE WARMER THAN THE PREVIOUS NIGHT
WHICH AGAIN MEANS WIND CHILL READINGS NOT GETTING AS COLD. AGAIN
REACHING MARGINAL ADVISORY VALUES.
MONDAY/MONDAY NIGHT...WEAK RIGHT REAR QUADRANT OF THE JET DEVELOPS
OVER THE AREA BY THE MIDDLE OF THE DAY AND AFFECTS THE AREA AT
LEAST THROUGH THE EVENING. THERE WILL BE A DEEP DRY LAYER SO ONLY
CLOUDS WILL RESULT. SO THIS PERIOD WILL JUST END UP BEING A
TEMPERATURE FORECAST. DEPENDING ON HOW MUCH SNOW FALLS AND WHERE...
THAT COULD CAUSE IN THE TEMPERATURE LAYOUT I HAVE IN THERE. MODELS
ARE BRINGING IN WARMER AIR FURTHER EAST AND FOR THE MOST PART I
BELIEVE THEY ARE TOO AGGRESSIVE. SINCE THE ECMWF HAS A BETTER
DEPICTION OF THE SURFACE...DO LIKE ITS TEMPERATURES A LITTLE
BETTER. HOWEVER...MODELS HAVE HAD A TENDENCY TO HOLD TO COLD
TEMPERATURES TOO LONG IN THIS PATTERN WHICH BECOMES STRONG ZONAL.
WARM AIR ADVECTION PATTERN DEVELOPS IN ERNEST DURING THE NIGHT AND
MAY END UP HAVING WARMING TEMPERATURES DURING THE OVERNIGHT HOURS.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 419 AM MST SAT MAR 1 2014
NEAR TO ABOVE NORMAL TEMPERATURES WILL START OUT THIS PERIOD AS THE
COLD FRONT FROM THE WEEKEND CONTINUES TO MOVE EAST OUT OF THE AREA.
THE NEXT CHANCE FOR PRECIPITATION WILL BE WEDNESDAY AS AN UPPER
LEVEL SHORT WAVE TROUGH MOVES ACROSS THE AREA BRINGING A BRIEF SHOT
FOR SOME RAIN/SNOW. TEMPERATURES CONTINUE TO WARM THURSDAY AS A
SHORT WAVE RIDGE BUILDS OVER THE AREA. HIGHS WILL BE IN THE 60S AND
LOWS WILL BE IN THE 30S. FRIDAY ANOTHER STRONGER UPPER LEVEL SHORT
WAVE TROUGH MOVES OVER THE AREA...REMAINING OVER THE AREA UNTIL
SATURDAY. LATE FRIDAY AFTERNOON AND FRIDAY EVENING A COLD FRONT
WILL MOVE THROUGH THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1103 AM MST SAT MAR 1 2014
IFR CONDITIONS SHOULD CONTINUE THROUGH AT LEAST THIS EVENING AT
KGLD AND KMCK. CEILINGS WILL LIKELY REMAIN IN THE MVFR CATEGORY
BUT LIGHT SNOW IS CAUSING VISIBILITY REDUCTIONS TO IFR.
EARLIER THIS MORNING KGLD DROPPED BRIEFLY TO LIFR DUE TO 3/4 SM
VISIBILITY BUT SNOW INTENSITY IS EXPECTED TO REMAIN LIGHT ENOUGH
THAT VISIBILITY REMAINS IN THE IFR CATEGORY. IF A PERIOD OF GREATER
SNOW INTENSITIES AT EITHER TERMINAL WERE TO OCCUR CAUSING A
REDUCTION IN VISIBILITY TO LIFR...IT WOULD LIKELY BE DURING THE
EVENING WHEN SHORT TERM MODEL GUIDANCE SUGGEST SLIGHTLY STRONGER
FRONTOGENESIS/LIFT MAY BE PRESENT. OTHERWISE EXPECT FLUCTIATIONS
IN VISIBILITY TO CONTINUE FROM AROUND 1 SM TO AROUND 3 SM. TOWARD
TOMORROW MORNING...MOISTURE BECOMES SHALLOWER AND SNOW INTENSITIES
SHOULD DECREASE SUFFICIENTLY FOR MVFR CONDITIONS. SOME LIGHT
FREEZING DRIZZLE HAS OCCASIONALLY BEEN MIXED IN WITH THE SNOW BUT
ICE ACCUMULATION HAS BEEN VERY MINOR TO NON-EXISTIENT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY UNTIL 5 PM MST /6 PM CST/ SUNDAY FOR
KSZ001>004-013>016-027>029-041-042.
CO...WINTER WEATHER ADVISORY UNTIL 5 PM MST SUNDAY FOR COZ090>092.
NE...WINTER WEATHER ADVISORY UNTIL 5 PM MST /6 PM CST/ SUNDAY FOR
NEZ079>081.
&&
$$
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...BRB
AREA FORECAST DISCUSSION
NWS GRAY ME
244 PM EST SAT MAR 1 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST TONIGHT THEN PUSH
SOUTHEAST OF THE REGION SUNDAY. LOW PRESSURE WILL TRACK EAST
ALONG THIS FRONT WELL SOUTH OF THE REGION SUNDAY NIGHT AND MONDAY. COLD
HIGH PRESSURE WILL BUILD IN BEHIND THE LOW MONDAY INTO TUESDAY.
ANOTHER COLD FRONT WILL CROSS THE AREA TUESDAY NIGHT FOLLOWED BY
COLD HIGH PRESSURE. THE HIGH WILL MOVE OFF THE COAST THURSDAY
NIGHT AND FRIDAY ALLOWING MILDER AIR TO FLOW INTO THE REGION WITH
AN INCREASING CHANCE OF PRECIPITATION.
&&
.NEAR TERM /THROUGH TONIGHT/...
CLOUDS WILL CONTINUE TO THICKEN DURING THE OVERNIGHT HOURS AHEAD
OF ATHE PPROACHING FRONT. LIGHT SNOW SHOWERS WILL BE MOST FREQUENT
TONIGHT IN THE NORTH AND MOUNTAINS WHERE ELEVATED TERRAIN WILL
ALLOW FOR LIGHT ACCUMULATIONS OF SNOW. MESOSCALE MODELS CONSISTENT
WITH THIS IDEA...HOWEVER THE LASTEST HRRR RUN APPEARS TO BE
OVERDONE WITH PRECIP FOR THE COASTAL REGIONS OVERNIGHT.
MIN TEMPS WILL BE MUCH WARMER OVERNIGHT THAN LAST NIGHT WITH CLOUD
COVER AND RADIATIONAL COOLING. SOME OF OUR COLDEST SPOTS LAST
NIGHT REACHED 20 BELOW ZERO.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
THE FRONT WILL SAG WELL SOUTH OF OUR FORECAST AREA AFTER IS PASSES
THROUGH NEW ENGLAND SUNDAY MORNING. 12Z MODEL SUITE NOW EVEN
FURTHER SOUTH WITH THIS SYSTEM WITH THE TRACK OF THE SURFACE LOW
NEAR THE CAROLINAS.
TEMPERATURES WILL BE NEAR 32 DEGREES IN PORTLAND TOMORROW. IF WE
DO BREAK THE FREEZING POINT...IT WILL BE AFTER QUITE A PROLONGED
PERIOD OF BELOW FREEZING WEATHER. THEREAFTER...WE ARE BACK INTO
THE DEEP FREEZE WITH TEMPERATURES NEAR OR BELOW ZERO...EVEN ALONG
THE COAST AS WE MOVE INTO THE LONG RANGE PORTION OF THE FORECAST.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
QUIET BUT COLD WEATHER EXPECTED FOR MUCH OF THE LONG TERM PERIOD.
COLD HIGH PRESSURE WILL BUILD INTO THE REGION BEHIND THE DEPARTING
LOW WELL SOUTH OF THE REGION. MODELS CONTINUE TO TREND FARTHER
SOUTH WITH THIS SYSTEM WITH NO SNOW PREDICTED FOR OUR AREA MONDAY.
A SECOND FRONT CROSSES THE AREA TUESDAY. ONLY MINIMAL MOISTURE
WITH THIS FRONT SO EXPECT ONLY A SLIGHT CHANCE OF SNOW
SHOWERS...MOSTLY IN THE MOUNTAINS. ANOTHER COLD HIGH BUILDS IN FOR
WEDNESDAY AND THURSDAY. THE RETURN FLOW ON THE BACK SIDE OF THE
HIGH WILL BRING WARMER TEMPS IN FOR FRIDAY AND POSSIBLY UNSETTLED
WEATHER FOR NEXT WEEKEND.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
SHORT TERM...
MAINLY VFR CONDITIONS...HOWEVER AREAS OF MVFR CONDITIONS IN THE
NORTH AND MOUNTAINS IN SNOW SHOWERS OVERNIGHT.
LONG TERM...
NO SIGNIFICANT WEATHER EXPECTED. WIDELY SCATTERED SNOW SHOWERS
TUESDAY NIGHT.
&&
.MARINE...
SHORT TERM...
SOUTHWEST GRADIENT WILL BE ON THE INCREASE OVERNIGHT...HENCE SCAS
REMAIN IN EFFECT OVERNIGHT.
LONG TERM...
WINDS AND SEAS AT OR BELOW SCA THROUGH THE FRIDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST SUNDAY FOR ANZ150>152-154.
&&
$$
SYNOPSIS...
NEAR TERM...JC
SHORT TERM...JC
LONG TERM...JENSENIUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
401 PM EST SAT MAR 1 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 349 PM EST SAT MAR 1 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A PERSISTENT TROF
OVER CANADA WITH CORE OF COLDEST AIR/CLOSED UPR LO OVER HUDSON BAY.
12Z H85 TEMPS UNDER THE LOWEST HGTS ARE AOB -30C...INDLUDING -30C AT
INL AND -33C AT YPL. WITH A LLVL NW FLOW E OF ARCTIC HI PRES OVER
THE CNDN PRAIRIES BLDG INTO THE NRN PLAINS...THIS COLD AIR IS
ADVECTING INTO UPR MI. ALTHOUGH LATEST VSBL STLT IMAGERY SHOWS LK
SUP IS MAINLY ICE COVERED...THERE ARE STILL SOME CLD/SHSN BANDS
STREAMING INTO THE AREA AS THE UPSTREAM 12Z INL/YPL RAOBS SHOWED A
RELATIVELY MOIST LLVL AIRMASS. BUT ANY PCPN HAS BEEN ON THE LGT
SIDE...WITH EXTENSIVE ICE AND LLVL ACYC FLOW TENDING TO LIMIT THE
INTENSITY OF THE SHSN. ONSET OF DAYTIME HEATING WITH INCRSG EARLY
MARCH SUN ANGLE HAS ALSO RESULTED IN MORE INSTABILITY CU/SC OVER
LAND AS WELL. SOME THICKER MID/HI CLDS ARE IMPACTING WI AND SRN UPR
MI ON THE NRN FLANK OF DISTURBANCE/DEEPER MSTR TO THE S. SN UNDER
SOME UPR DVGC IN RRQ OF 140KT H3 JET MAX STREAKING ACRS NRN MN/LK
SUP IS AS FAR N AS SRN MN.
MAIN FCST CONCERNS IN THE SHORT TERM ARE CLD TRENDS/CONTINUED BLO
NORMAL TEMPS.
TNGT...AS CNDN HI PRES CONTINUES TO BLD INTO THE NRN PLAINS...AN
ACYC NW FLOW WL DOMINATE THE UPR LKS. ALTHOUGH SOME UPR DVGC
ASSOCIATED WITH JET STREAK MOVING THRU THE UPR LKS WL PASS ACRS THE
SCENTRAL THIS EVNG...GENERAL DRY ADVECTION IN THE H85-7 LYR SHOULD
SUPPRESS NRN EDGE OF PCPN SHIELD TO THE S OF MENOMINEE. ALTHOUGH
SOME LK CLDS/A FEW SN SHOWERS OFF LK SUP MAY LINGER UNDER THE COLD
FLOW IN THE EVNG...LOSS OF DAYTIME HEATING AS WELL AS ACYC FLOW/
LOWERING SUBSIDENCE INVRN TOWARD 2K FT SHOWN ON FCST SDNGS SHOULD
RESULT IN ALMOST COMPLETE SUPPRESSION OF CLDS/SN SHOWERS OVERNGT.
WITH SKIES TURNING MOCLR AND PWAT UNDER 0.10 INCH...EXPECT SFC TEMPS
TO TUMBLE AOB -20F AT MANY OF THE INTERIOR COLD SPOTS. GIVEN THE
EXTENSIVE ICE COVER OF THE LK THAT WL TEND TO RESULT IN LOWER TEMPS
OVER THE CWA...TRENDED TOWARD THE LO END OF GUIDANCE FOR MIN TEMPS
FCST. LOWERING INVRN BASE/INCRSG STABILITY SHOULD KEEP SFC WINDS
UNDER THE 10 MPH THRESHOLD FOR WIND CHILL HEADLINES...BUT ISSUED AN
SPS TO HIGHLIGHT THE RESULTING VERY LO APRNT/WIND CHILL TEMPS THAT
WL FALL AS LO AS -35F AT SOME PLACES.
SUN...THERE WL BE A SHRTWV TRACKING SEWD TO THE NE OF UPR MI AND
THRU ONTARIO...BUT BULK OF ASSOCIATED UPR FORCING WL REMAIN TO THE
NE OF UPR MI. ALTHOUGH DAYTIME HEATING AND PASSAGE OF ATTENDANT WEAK
SFC LO PRES TROF MAY RESULT IN SOME CLDS AND EVEN A FEW LGT SN
SHOWERS MAINLY OVER THE NE HALF OF THE CWA TOWARD THE ACCOMPANYING
DYANMIC FORCING...LO INVRN BASES SHOULD LIMIT THIS POTENTIAL. H85
TEMPS ARE FCST TO RANGE FM NEAR -20C OVER THE SCENTRAL TO AS LO AS
-24C OR -25C OVER THE N. WITH THE EXTENSIVE ICE COVER...TEMPS WL
REMAIN WELL BLO NORMAL DESPITE A GOOD DEAL OF SUNSHINE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 359 PM EST SAT MAR 1 2014
MODELS SUGGEST THAT THE OVERALL PATTERN WILL UNDERGO A GRADUAL
TRANSITION AWAY FROM THE VERY COLD AIR AS THE HIGH LATITUDE RIDGING
INTO ERN AK SHIFTS WESTWARD INTO ERN SIBERIA. THE RESULTING
DOWNSTREAM PATTERN WILL ALLOW THE SEVERE ARCTIC AIRMASS TO SHIFT OFF
TO THE NE AND MORE MODERATE PACIFIC AIR INTO THE CNTRL CONUS.
HOWEVER...A TREND BACK TOWARD RIDING ALONG THE WEST COAST WITH NW
FLOW INTO THE NRN LAKES WILL KEEP ENOUGH COLD AIR IN THE REGION FOR
BELOW NORMAL TEMPS AGAIN BY NEXT WEEKEND.
SUN NIGHT...FAVORABLE RADIATIONAL COOLING CONDITIONS WITH THE SFC
RIDGE AXIS INTO UPPER MICHIGAN WILL ALLOW TEMPS TO AGAIN DROP TO THE
LOWER END OF GUIDANCE...INTO THE -20F TO -30F RANGE INLAND WITH
TEENS BELOW READINGS CLOSER TO THE LAKES. THERE MAY BE ENOUGH OPEN
WATER PATCHES OVER THE S CNTRL LAKE FOR SOME ISOLD -SHSN INTO THE NE
CWA. HOWEVER...LITTLE OR NO ACCUMULATION IS EXPECTED.
MON INTO TUE...PARTLY TO MOSTLY SUNNY SKIES MON SHOULD ALLOW TEMPS
TO REBOUND INTO THE 10F TO 15F RANGE. WNW TO W WINDS SHOULD KEEP ANY
LIGHT LES NEAR THE SHORE IN THE NE CWA. A CLIPPER SHORTWAVE TROUGH
COULD BRING AN AREA OF MORE WIDESPREAD LIGHT SNOW TO THE AREA MON
NIGHT INTO EARLY TUE. SINCE THE MODELS STILL SHOWED DIFFERENCES WITH
THE GFS FARTHER SOUTH WITH THIS FEATURE COMPARED TO THE
ECMWF/GEM...ONLY SLIGHT CHANCE POPS WERE MENTIONED. EVEN THE MORE
NRN TRACK WOULD ONLY SUPPORT LIGHT ACCUMULATIONS OF AN INCH OR LESS.
WED...MODELS WERE IN AGREEMENT THAT HIGH PRES WILL DOMINATE THE AREA
WITH DRY WEATHER AND MORE MODERATE BUT STILL BELOW NORMAL
TEMPERATURES INTO THE TEENS.
THU-SAT...ANOTHER STRONGER SHORTWAVE IS EXPECTED TO MOVE THROUGH THE
NRN LAKES BY THU NIGHT INTO FRI. THERE IS A BETTER CHANCE FOR SOME
ACCUMULATING SNOW WITH THIS SYSTEM WITH BETTER MOISTURE
AVAILABILITY. CHANCE POPS WERE MENTIONED GIVE TIMING/STRENGTH
DIFFERENCES. THE WARMEST CONDITONS OF THE WEEK ARE POSSIBLE BY THU
WITH TEMPS NEAR 30F. HIGH PRES IN THE WAKE OF THE SHRTWVM
SHOULD BRING IN SLIGHTLY COOLER AIR WITH READINGS BACK INTO THE
LOWER 20S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1225 PM EST SAT MAR 1 2014
EXPECT HI END MVFR TO VFR CONDITIONS THIS AFTN TO GIVE WAY TO JUST
VFR WX THIS EVNG THRU SUN AS STRONG SUBSIDENCE TO THE E OF HI PRES
BLDG INTO THE NRN PLAINS BRINGS MOCLR SKIES. DESPITE COLD NW FLOW
THAT MIGHT RESULT IN SOME GUSTY WINDS THRU THIS AFTN...EXTENSIVE ICE
COVER ON LK SUP AND THE STRONG SUBSIDENCE WL PREVENT ANY LK EFFECT
SHSN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 349 PM EST SAT MAR 1 2014
EXPECT NW WINDS UP TO 15 TO 25 KTS TO THE E OF HI PRES BUILDING INTO
THE NORTHERN PLAINS TO DIMINISH TO UNDER 20 KTS AFTER MON NIGHT AS
THE HI CENTER PASSES OVER THE UPPER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLB
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
356 PM EST SAT MAR 1 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 349 PM EST SAT MAR 1 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A PERSISTENT TROF
OVER CANADA WITH CORE OF COLDEST AIR/CLOSED UPR LO OVER HUDSON BAY.
12Z H85 TEMPS UNDER THE LOWEST HGTS ARE AOB -30C...INDLUDING -30C AT
INL AND -33C AT YPL. WITH A LLVL NW FLOW E OF ARCTIC HI PRES OVER
THE CNDN PRAIRIES BLDG INTO THE NRN PLAINS...THIS COLD AIR IS
ADVECTING INTO UPR MI. ALTHOUGH LATEST VSBL STLT IMAGERY SHOWS LK
SUP IS MAINLY ICE COVERED...THERE ARE STILL SOME CLD/SHSN BANDS
STREAMING INTO THE AREA AS THE UPSTREAM 12Z INL/YPL RAOBS SHOWED A
RELATIVELY MOIST LLVL AIRMASS. BUT ANY PCPN HAS BEEN ON THE LGT
SIDE...WITH EXTENSIVE ICE AND LLVL ACYC FLOW TENDING TO LIMIT THE
INTENSITY OF THE SHSN. ONSET OF DAYTIME HEATING WITH INCRSG EARLY
MARCH SUN ANGLE HAS ALSO RESULTED IN MORE INSTABILITY CU/SC OVER
LAND AS WELL. SOME THICKER MID/HI CLDS ARE IMPACTING WI AND SRN UPR
MI ON THE NRN FLANK OF DISTURBANCE/DEEPER MSTR TO THE S. SN UNDER
SOME UPR DVGC IN RRQ OF 140KT H3 JET MAX STREAKING ACRS NRN MN/LK
SUP IS AS FAR N AS SRN MN.
MAIN FCST CONCERNS IN THE SHORT TERM ARE CLD TRENDS/CONTINUED BLO
NORMAL TEMPS.
TNGT...AS CNDN HI PRES CONTINUES TO BLD INTO THE NRN PLAINS...AN
ACYC NW FLOW WL DOMINATE THE UPR LKS. ALTHOUGH SOME UPR DVGC
ASSOCIATED WITH JET STREAK MOVING THRU THE UPR LKS WL PASS ACRS THE
SCENTRAL THIS EVNG...GENERAL DRY ADVECTION IN THE H85-7 LYR SHOULD
SUPPRESS NRN EDGE OF PCPN SHIELD TO THE S OF MENOMINEE. ALTHOUGH
SOME LK CLDS/A FEW SN SHOWERS OFF LK SUP MAY LINGER UNDER THE COLD
FLOW IN THE EVNG...LOSS OF DAYTIME HEATING AS WELL AS ACYC FLOW/
LOWERING SUBSIDENCE INVRN TOWARD 2K FT SHOWN ON FCST SDNGS SHOULD
RESULT IN ALMOST COMPLETE SUPPRESSION OF CLDS/SN SHOWERS OVERNGT.
WITH SKIES TURNING MOCLR AND PWAT UNDER 0.10 INCH...EXPECT SFC TEMPS
TO TUMBLE AOB -20F AT MANY OF THE INTERIOR COLD SPOTS. GIVEN THE
EXTENSIVE ICE COVER OF THE LK THAT WL TEND TO RESULT IN LOWER TEMPS
OVER THE CWA...TRENDED TOWARD THE LO END OF GUIDANCE FOR MIN TEMPS
FCST. LOWERING INVRN BASE/INCRSG STABILITY SHOULD KEEP SFC WINDS
UNDER THE 10 MPH THRESHOLD FOR WIND CHILL HEADLINES...BUT ISSUED AN
SPS TO HIGHLIGHT THE RESULTING VERY LO APRNT/WIND CHILL TEMPS THAT
WL FALL AS LO AS -35F AT SOME PLACES.
SUN...THERE WL BE A SHRTWV TRACKING SEWD TO THE NE OF UPR MI AND
THRU ONTARIO...BUT BULK OF ASSOCIATED UPR FORCING WL REMAIN TO THE
NE OF UPR MI. ALTHOUGH DAYTIME HEATING AND PASSAGE OF ATTENDANT WEAK
SFC LO PRES TROF MAY RESULT IN SOME CLDS AND EVEN A FEW LGT SN
SHOWERS MAINLY OVER THE NE HALF OF THE CWA TOWARD THE ACCOMPANYING
DYANMIC FORCING...LO INVRN BASES SHOULD LIMIT THIS POTENTIAL. H85
TEMPS ARE FCST TO RANGE FM NEAR -20C OVER THE SCENTRAL TO AS LO AS
-24C OR -25C OVER THE N. WITH THE EXTENSIVE ICE COVER...TEMPS WL
REMAIN WELL BLO NORMAL DESPITE A GOOD DEAL OF SUNSHINE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 439 AM EST SAT MAR 1 2014
CURRENT HIGHLY AMPLIFIED PATTERN FEATURING A STRONG RIDGE EXTENDING
N THRU AK/YUKON AND A DEEP TROF DOWNSTREAM OVER MUCH OF CANADA INTO
THE ADJACENT CONUS WILL BE BREAKING DOWN DURING THE LONG TERM. AS
HAPPENED WITH THE LAST OCCURRENCE OF THIS HIGHLY AMPLIFIED PATTERN A
FEW WEEKS AGO...THE NRN END OF THE WRN RIDGE IS STILL FCST TO CLOSE
OFF AND RETROGRADE TO SIBERIA...ALLOWING PACIFIC FLOW TO STRENGTHEN
INTO THE CONUS. THIS WILL RESULT IN SLOW MODERATION OF THE COLD
DURING THE UPCOMING WEEK. HOWEVER...MEDIUM RANGE GUIDANCE CONTINUES
TO SHOW A TENDENCY FOR SOME DEGREE OF WRN RIDGING WHICH SHOULD
ENSURE BELOW NORMAL TEMPS PREVAIL ON MOST DAYS ACROSS UPPER MI
DURING THE NEXT COUPLE OF WEEKS. PATTERN OVER THE NEXT 7 DAYS IS NOT
REALLY FAVORABLE FOR MUCH IN THE WAY OF SYNOPTIC PCPN. HOWEVER...
SHORTWAVES SWEEPING ONSHORE OFF THE PACIFIC AND TRACKING E IN A MORE
PROGRESSIVE LOWER AMPLITUDE FLOW REGIME WILL BRING SOME
OPPORTUNITIES FOR PCPN DURING THE MIDDLE AND END OF THE WEEK...BUT
AT THIS TIME...NOTHING LOOKS SIGNIFICANT. NORMALLY WOULD BE DEALING
WITH LES OFF LAKE SUPERIOR IN THIS LINGERING VERY COLD AIR MASS...
BUT WITH EXTENSIVE ICE COVER THAT IS NEARING 100PCT...LES WILL
ALMOST BE NONEXISTENT THRU THIS FCST PERIOD.
BEGINNING SUN/MON...WHILE A SHORTWAVE SWINGING AROUND VORTEX IN THE
VCNTY OF HUDSON BAY/NRN QUEBEC WILL BRUSH THE AREA SUN...AIR MASS IS
TOO DRY TO SUPPORT ANY -SN...ESPECIALLY SINCE STRONGER FORCING
PASSES BY TO THE N AND NE. IN ADDITION...WITH NEAR 100PCT ICE COVER
ON LAKE SUPERIOR...THERE REALLY WON`T BE ANY LAKE COMPONENT. SINCE
RATHER BRISK W TO NW WINDS WILL BE OCCURRING OVER THE LAKE...ICE MAY
BE PUSHED ENOUGH TO EITHER MAINTAIN OR OPEN UP A LITTLE OPEN WATER
ALONG THE IMMEDIATE MN N SHORE UP PAST ISLE ROYALE AND ALSO TO THE
LEE OF THE KEWEENAW PENINSULA. IF SO...THERE WILL BE A FEW -SHSN OR
FLURRIES...AND THUS SCHC POPS WILL BE UTILIZED IN THE AREAS FAVORED
BY W TO NW WINDS. OTHERWISE...WILL CARRY DRY WEATHER ACROSS THE
BOARD SUN AND ON INTO MON AS CANADIAN HIGH PRES SETTLES SE INTO THE
PLAINS AND EXTENDS WEAK RIDGING INTO THE GREAT LAKES. TEMPS SUN/MON
AFTN WILL STILL BE VERY COLD FOR THIS TIME OF YEAR EVEN THOUGH AIR
MASS WILL BE SLOWLY MODERATING. EXPECT HIGHS IN THE SINGLE DIGITS TO
AROUND 10F SUN AND A FEW DEGREES HIGHER FOR MON. SHOULD BE A
BITTERLY COLD NIGHT SUN NIGHT UNDER MOSTLY CLEAR SKIES AS WINDS
SHOULD DECOUPLE SUFFICIENTLY. A VERY DRY AIR MASS (PRECIPITABLE
WATER JUST 15-20PCT OF NORMAL) WILL ENHANCE THE COOLING POTENTIAL.
FAVORED MIN TEMPS AT OR BLO THE LOWEST GUIDANCE IN THE INTERIOR...
ESPECIALLY AT TRADITIONAL COLD SPOTS WHICH SHOULD EASILY FALL WELL
DOWN INTO THE -20S AND PERHAPS REACH -30F AT A LOCATION OR TWO.
MON NIGHT INTO TUE...THERE REMAINS UNCERTAINTY IN WHETHER A WEAK
SHORTWAVE MOVING ACROSS THE NRN ROCKIES AND THEN ESE WILL BRING SOME
-SN TO THE AREA. THE ECMWF HAD BEEN GENERALLY FARTHER N...BUT THE
12Z TRENDED S...RESULTING IN DRY WEATHER HERE. THE 00Z RUN IS BACK
TO BRUSHING THE AREA WITH SOME -SN. THE GFS AND GEM HAVE TRENDED
N...AND BRING THE POSSIBILITY OF SOME -SN...ESPECIALLY THE GEM. WILL
INCLUDE SCHC POPS ACROSS THE SW LATE MON NIGHT AND ACROSS MUCH OF
THE AREA TUE. THERE MAY BE ENOUGH TIME BEFORE CLOUDS ARRIVE TO
RESULT IN A QUICK TEMP DROP MON EVENING. LEANED TOWARD THE COLD SIDE
OF GUIDANCE MON NIGHT...ESPECIALLY E WHERE CLOUDS WILL ARRIVE LATEST
(-TEENS IN THE USUAL COLD SPOTS E). TEMPS TUE WILL RISE INTO THE
TEENS. TUE NIGHT HAS THE POTENTIAL TO BE VERY COLD ONCE AGAIN AS THE
CENTER OF STRONG HIGH PRES PASSES JUST TO THE N AND NE OF LAKE
SUPERIOR. LIGHT WIND AND DRY AIR MASS WILL SUPPORT GOOD RADIATIONAL
COOLING...ESPECIALLY OVER THE ERN FCST AREA WHERE COLUMN WILL BE
DRIEST (PRECIPITABLE WATER 25PCT OF NORMAL). MINS IN THE USUAL COLD
SPOTS OVER THE E SHOULD FALL INTO THE -TEENS.
DRY WEATHER WILL CONTINUE INTO WED AS HIGH PRES CENTER DRIFTS E. E
TO SE WINDS WON`T FAVOR MUCH OF A WARM UP OVER TUE. HIGH TEMPS WED
SHOULD BE IN THE TEENS...COLDEST E CLOSER TO CORE OF COLDER AIR
ASSOCIATED WITH HIGH.
MEDIUM RANGE GUIDANCE FOR A FEW DAYS HAS BEEN INDICATING ONE OR TWO
SHORTWAVES AFFECTING THE UPPER LAKES AT SOME POINT THU/FRI. FOR
NOW...UTILIZED A SIMPLE CONSENSUS OF RECENT MODEL RUNS WHICH RESULTS
IN SCHC/CHC POPS THU/FRI. TEMPS SHOULD RISE INTO THE 20S THU IN WAA
REGIME AND MAY TOP OUT AROUND 30F FRI...DEPENDING ON TIMING OF
FRONTAL PASSAGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1225 PM EST SAT MAR 1 2014
EXPECT HI END MVFR TO VFR CONDITIONS THIS AFTN TO GIVE WAY TO JUST
VFR WX THIS EVNG THRU SUN AS STRONG SUBSIDENCE TO THE E OF HI PRES
BLDG INTO THE NRN PLAINS BRINGS MOCLR SKIES. DESPITE COLD NW FLOW
THAT MIGHT RESULT IN SOME GUSTY WINDS THRU THIS AFTN...EXTENSIVE ICE
COVER ON LK SUP AND THE STRONG SUBSIDENCE WL PREVENT ANY LK EFFECT
SHSN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 349 PM EST SAT MAR 1 2014
EXPECT NW WINDS UP TO 15 TO 25 KTS TO THE E OF HI PRES BUILDING INTO
THE NORTHERN PLAINS TO DIMINISH TO UNDER 20 KTS AFTER MON NIGHT AS
THE HI CENTER PASSES OVER THE UPPER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...ROLFSON
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1210 PM CST SAT MAR 1 2014
.UPDATE...
ISSUED AT 1210 PM CST SAT MAR 1 2014
...WINTER WX ADVISORY CANCELLED...
NO SUBSTANTIAL CHANGES NEEDED FOR THE NEXT 3- 6 HRS. HOWEVER...
THE ADVISORY WAS CANCELLED AS WEBCAMS SHOW NO MORE THAN A
GLORIFIED DUSTING OVER THE ADVISORY AREA. PERIODS OF -SN WILL
CONTINUE AND WE ARE NOTING A HEALTHY BAND OVER THE SANDHILLS
WHICH WAS NAILED BY THE HI-RES NAM-ARW ON YESTERDAY`S SHIFT. THIS
BAND WILL PROBABLY CROSS THE FCST AREA N OF I-80...WITH BRIEF BUT
DRASTIC REDUCTION IN VISIBILITY POSSIBLE. WE ARE NOTING THEDFORD
DOWN TO 1/4SM AT 18Z.
NONETHELESS...THE PROGRESSIVE NATURE OF THIS BAND WILL LIMIT
ACCUMS.
IF THIS BAND MAINTAINS ITS STRENGTH WE WILL HANDLE IT WITH AN SPS
/SPECIAL WX STATEMENT/.
WIND CHILL WATCH REMAINS AS POSTED FROM 4 AM.
UPDATE ISSUED AT 959 AM CST SAT MAR 1 2014
RADAR AND SURFACE OBS SHOW BLOSSOMING LIGHT SNOW /-SN/ PRIMARILY
WITHIN THE LOW-LEVEL DECK OF STRATUS THAT RESIDES WITHIN THE
DENDRITIC GROWTH ZONE /DGZ/. EVEN THOUGH I AM NOT CONFIDENT ALL
AREAS WILL MELT .01" LIQUID EQUIVALENT...POPS WERE INCREASED TO
80% THRU 20Z FOR THE ENTIRE FCST AREA. THIS WAS DONE TO TO FORCE
THE FCST TO BEST DEPICT WHAT WILL PROBABLY CONT THRU THE
AFTERNOON. THERE IS NO WAY WE CAN PINPOINT WHERE AND WHEN IT WILL
SNOW. SO FCST WILL NOW READ AS PERIODS OF -SN. AM NOT EXPECTING
MUCH MORE THAN A GOOD DUSTING HERE AND THERE TO THE S OF I-80.
N OF I-80 THE SAME APPLIES BUT WITH A SOMEWHAT BETTER CHANCE FOR
MODEST ACCUM.
IT WILL BE INTERESTING TO SEE WHAT UNFOLDS THIS AFTERNOON. MODEL
GUIDANCE IS ALL OVER THE PLACE...RESULTING IN ABOVE NORMAL
UNCERTAINTY. SOME GUIDANCE INDICATES WE COULD SEE A REDEVELOPMENT
OF MORE ROBUST SNOWFALL FOR A TIME...MAINLY OVER PARTS OF S-CNTRL
NEB.
UPDATE ISSUED AT 742 AM CST SAT MAR 1 2014
SENT AN EARLY ENHANCED SHORT-TERM FCST /ESTF/ UPDATE AS OUR
HOURLY FCST TEMPS WERE RUNNING A LITTLE COLDER THAN REALITY. WE
WILL STILL SEE A SLOW DOWNWARD SLIDE TODAY...BUT CURRENT TEMPS
WERE MERGED WITH THE 11Z HRRR THRU MIDDAY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 336 AM CST SAT MAR 1 2014
THE FOCUS DURING THE SHORT TERM PERIODS IS ON DEVELOPING SNOW...SNOW
AMOUNTS...BITTER COLD TEMPS/WIND CHILLS AND ASSOCIATED WINTER
HEADLINES.
AN ARCTIC AIRMASS HAD SETTLED ACROSS THE PLAINS STATES WITH EARLY
MORNING TEMPS AVERAGING IN THE SINGLE DIGITS AND TEENS. SNOW HAS
BEEN DEVELOPING/FALLING ACROSS NW/NORTHERN NEB THROUGH MUCH OF THE
PRE DAWN HOURS WITH VSBYS AS LOW AS 3/4SM AT TIMES. THE SNOW IS IN
ASSOCIATION WITH ISENTROPIC LIFT AHEAD OF AN APPROACHING WAVE MOVING
OUT OF THE CENTRAL ROCKIES...AND IN FAVORABLE UPPER JET DYNAMICS.
THE SNOW WILL DEVELOP IN BANDS WITH THE GREATEST ACCUMULATIONS TODAY
OCCURRING ACROSS NORTHERN NEBRASKA WITH OUR NORTHERN CWA ON THE
PERIPHERY OF THE HIGHEST ACCUMULATIONS. SHORT TERM MODELS INDICATE
THAT A DECENT SNOW BAND SHOULD ESTABLISH ACROSS VALLEY AND GREELEY
COUNTIES AND SNOW AMOUNTS WILL BE DEPENDENT UPON WHERE THE BANDS
SET UP. HAVE WENT WITH SNOWFALL ACCUMULATIONS OF 2 TO 4 INCHES
WHERE OUR CURRENT WINTER WEATHER ADVISORY IS IN EFFECT...GENERALLY
ALONG AND NORTH OF A LINE FROM LOUP CITY TO OSCEOLA NEB. FARTHER
SOUTH...AREAS OF LIGHTER SNOW SHOULD DEVELOP/SPREAD EASTWARD BY
MID DAY. HEADING INTO THE EVENING...THE SNOW SHOULD BEGIN TO TAPER
OFF IN OUR NW ZONES FIRST AS A 1042MB SFC RIDGE BUILDS SOUTH FM
THE DAKOTAS. NEXT ISSUE IS WHERE A SECOND ROUND/BAND OF SNOW WILL
SET UP ACROSS KANSAS SATURDAY NIGHT INTO SUNDAY AS NEXT SYSTEM
CROSSES THE SOUTHERN/CENTRAL PLAINS. THE 00Z MODELS KEPT THE BRUNT
OF THIS NEXT SYSTEM TO OUR SOUTH WHERE THE POTENTIAL EXISTS FOR A
SWATH OF HEAVY SNOWFALL IN GOOD DYNAMICS/ISENTROPIC
LIFT/JET/FRONTOGENESIS WITH THIS STRONGER WAVE. OF CONCERN IS THAT
THE 06Z NAM IS TRENDING FARTHER NORTH WITH THE BAND AND CLIPS OUR
SE KS COUNTIES IN A BAND OF POTENTIAL HEAVY SNOW. DO NOT WANT TO
JUMP ON ONE MODEL RUN AS TRENDS HAVE BEEN FARTHER SOUTH WITH THE
BAND...AND SREF SNOW PLUMES DO NOT SUPPORT SNOWFALL AS HIGH AS
LATEST NAM INDICATES IN THIS AREA. FOR SOME LOCATIONS IT COULD BE
AN ALL OR NOTHING TYPE OF EVENT BUT DID INCLUDED THE POTENTIAL FOR
A COUPLE TO SEVERAL INCHES ACROSS PORTIONS OF NC KANSAS AND WILL
NEED TO CLOSELY MONITOR HOW THIS SYSTEM EVOLVES AS IT MOVES INLAND
TODAY.
FOR HEADLINES...AGAIN THE CURRENT WINTER WX ADVISORY WILL COVER THE
SNOWFALL ACROSS OUR NORTHERN COUNTIES TODAY. CURRENT SNOWFALL
FORECAST ACROSS THE REMAINDER OF OUR CWA DOES NOT SUPPORT A WINTER
WX ADVISORY YET...AND ENOUGH UNCERTAINTY REMAINS IN KS TONIGHT TO
HOLD OFF ON SNOW HEADLINE IN THIS AREA. NEXT CONCERN IS THE FRIGID
WIND CHILLS EXPECTED THE COUPLE OF NIGHTS...AND WIND CHILLS FOR
TONIGHT/SATURDAY NIGHT ARE EXPECTED TO DROP TO 25 TO 35 BELOW ZERO IN
OUR NORTHERN ZONES. RATHER THAN ISSUE A WIND CHILL WARNING FOR
TONIGHT IN THE SAME AREA THAT HAS THE WINTER WEATHER ADVISORY FOR
TODAY...WILL GO WITH A WIND CHILL WATCH FOR TONIGHT AND LOCATIONS
FARTHER SOUTH CAN BE INCLUDED IN A WIND CHILL ADVISORY IF THE
GREATER SNOW REMAINS SOUTH...OR A WINTER WEATHER ADVISORY IF SNOW
AMOUNTS LOOK HIGHER THAN CURRENT FORECAST.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 336 AM CST SAT MAR 1 2014
ON THE LARGE SCALE...ZONAL TO NORTHWEST FLOW REGIME WILL BE THE RULE
THROUGH THE PERIOD. THERE WILL BE A FEW SHORT WAVES MOVING THROUGH
THE FLOW...WITH THE MOST ORGANIZED WAVE FORECAST OVER THE AREA ON
WEDNESDAY.
SPECIFICALLY...EXPECT DRY WEATHER SUNDAY NIGHT THROUGH TUESDAY NIGHT
WITH A GRADUAL WARMING TREND. WEDNESDAY LEFT A LOW CHANCE OF
PRECIP...SNOW NORTHEAST AND RAIN SOUTHWEST. LOOKS LIKE THERE WILL BE
ENOUGH LIFT BUT MOISTURE WILL BE LIMITED AS THE SYSTEM DEVELOPS OVER
THE AREA. THE SYSTEM IS FORECAST TO DEEPEN AS IT MOVES EAST OF THE
AREA AND THIS CYCLOGENESIS WILL FORCE INCREASED MOISTURE ADVECTION.
SO RIGHT NOW IT APPEARS PRECIP AMOUNTS WILL BE ON THE LOW END. WE
WILL HAVE TO CONTINUE TO MONITOR... THURSDAY AND FRIDAY APPEAR TO BE
DRY...AS THE NEXT SHORT WAVE AND APPROACHES FROM THE NORTHWEST.
AS MENTIONED...WE EXPECT A GRADUAL WARMING TREND MONDAY THROUGH
FRIDAY AS THE ARCTIC AIR MASS CURRENTLY ON TOP OF US IS GRADUALLY
MODIFIED AND PUSHED EAST. A SOUTHERLY FLOW WILL MIX IN WARMER TEMPS
MONDAY AND TUESDAY. THE POTENTIAL DEVELOPING LOW PRESSURE AREA WILL
NOT BRING A SIGNIFICANT TEMPERATURE CHANGE BEHIND IT...AS A MATTER
OF FACT...IT IS FORECAST TO MOVE OFF FAST ENOUGH THAT WINDS WILL
QUICKLY REBOUND TO THE SOUTH ON THURSDAY AND FRIDAY AND BRING NEAR
NORMAL TEMPS TO THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1210 PM CST SAT MAR 1 2014
THIS AFTERNOON: VFR IN PERIODS OF -SN EXCEPT TEMPO MVFR CIGS/VSBYS
IN HEALTHIER SNOW BANDS. THEY WILL BE TRANSIENT. NE WINDS MAY
OCCASIONALLY GUST TO 20 KTS...BUT OVERALL GUSTINESS IS DONE.
CONFIDENCE: MEDIUM
TONIGHT: VFR STRATUS CIGS AROUND 5K FT. NNE WINDS AROUND 10 KTS.
CONFIDENCE: MEDIUM
SUN: VFR STRATUS CIGS AROUND 5K FT...BUT COULD BECOME SCT
REVEALING HIGH CLOUDS. NNE WINDS 5-10 KTS. CONFIDENCE: MEDIUM
&&
.CLIMATE...
ISSUED AT 1210 PM CST SAT MAR 1 2014
FOLLOWING BELOW IS A RECAP OF THE DAILY RECORD COLDEST HIGH
TEMPS FOR GRAND ISLAND AND HASTINGS THAT WILL BE IN JEOPARDY
SUNDAY. ITS NOT OUT OF THE REALM OF POSSIBILITY THAT SUNDAY COULD
COME VERY CLOSE TO THE COLDEST MAXIMUM (HIGH) TEMPERATURE ON
RECORD FOR ANY DAY IN MARCH:
THE DAILY RECORDS FOR COLDEST HIGH TEMP STAND AS FOLLOWS:
MARCH 2: GRAND ISLAND...10 IN 2002
HASTINGS...11 IN 2002
MARCH 3: GRAND ISLAND...8 IN 1916
HASTINGS...10 IN 2002
ALL-TIME COLDEST HIGH TEMP ON RECORD FOR ANY DAY IN MARCH:
GRAND ISLAND: 4 DEGREES ON 3-10-1948
HASTINGS: 3 DEGREES ON 3-11-1948
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND CHILL WATCH FROM 10 PM CST THIS EVENING THROUGH SUNDAY
MORNING FOR NEZ039>041-046>049.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...FAY
LONG TERM...EDDY
AVIATION...HALBLAUB
CLIMATE...PFANNKUCH/HALBLAUB
AREA FORECAST DISCUSSION...CORRECTED
NWS ALBUQUERQUE NM
328 PM MST SAT MAR 1 2014
.SYNOPSIS...
WIDESPREAD RAIN AND HIGH ELEVATION SNOW TODAY WILL GRADUALLY CHANGE
OVER TO SNOW DOWN TO NEAR 6000 FEET TONIGHT BEFORE MIXING WITH RAIN
AGAIN SUNDAY. SIGNIFICANT ACCUMULATIONS WILL OCCUR IN THE HIGHER
TERRAIN OF THE NORTHERN AND WESTERN MOUNTAINS. STRONG WINDS OVER
MUCH OF EASTERN NEW MEXICO WILL TAPER OFF THROUGH THE EVENING. A
POTENT COLD FRONT OVER THE NORTHEAST PLAINS WILL ALLOW RAIN TO
CHANGE OVER TO A MIX OF SNOW...SLEET...AND FREEZING RAIN THROUGH
SUNDAY. THIS STORM SYSTEM WILL MOVE OUT OF THE AREA SUNDAY...
LEAVING BEHIND COOLER TEMPERATURES THROUGH MONDAY. THE REMAINDER
OF THE WEEK WILL BE NEAR NORMAL FOR EARLY MARCH AS A COUPLE WEAK
DISTURBANCES MOVE OVER THE STATE. PERIODIC BREEZY CONDITIONS WILL
IMPACT THE PLAINS AND PATCHY CLOUD COVER WITH EVEN A FEW SHOWERS
WILL AFFECT THE HIGH TERRAIN.
&&
.DISCUSSION...
WHAT A WELCOME SITE IT IS AS A DEEP FETCH OF RAIN AND HIGH TERRAIN
SNOW IMPACTS CENTRAL AND WESTERN NM. THE WATER VAPOR LOOP STILL
SHOWS THE CORE OF A WELL-DEFINED STORM SYSTEM CRASHING ONSHORE
SOUTHERN CALIFORNIA WITH A MASSIVE FETCH OF MOIST SW FLOW SHIFTING
INTO AZ AND NM. CIRA TOTAL PWAT VALUES ARE ABOVE 200PCT OF NORMAL IN
THIS PLUME AND IT WILL SHIFT DIRECTLY OVER NM THRU THIS EVENING. SFC
AND MID LEVEL TEMPS ARE TRENDING DOWN WITH THE AID OF EVAPORATIONAL
COOLING AND SOME WEAK COLD AIR ADVECTION. SNOW REPORTS SO FAR RANGE
FROM ABOUT 1 TO 4 INCHES ABOVE 7500 FT. THE LATEST HRRR SOLUTION
AGREES THE CURRENT PLUME WILL SHIFT SE OVER CENTRAL NM THRU THIS
EVENING THEN INTO SOUTHERN NM LATE TONIGHT.
A SECONDARY VORT MAX AHEAD OF THE MAIN UPPER COLD CORE WILL SHIFT
OVER THE REGION TONIGHT AND EARLY SUNDAY...DELIVERING A SECONDARY
PEAK IN PRECIP COVERAGE LATE TONIGHT AND EARLY SUNDAY. MODELS HAVE
STRUGGLED WITH THE LOCATION AND INTENSITY OF THIS SECONDARY PRECIP
MAX. HOWEVER...BASED ON TREND OF LATEST HRRR AFTER 06Z CONFIDENCE
IS INCREASING THAT THE 12Z GFS AND ECMWF WILL VERIFY THIS MAX ALONG
THE I-40/CONT DVD CORRIDOR INTO THE MIDDLE RIO GRANDE VALLEY AND
NORTHERN MTS LATE TONIGHT.
THE NE PLAINS WILL BE A TRICKY AREA AS WELL WITH SOME INCREDIBLE
SPATIAL TEMPERATURE DIFFERENCES ON THE LATEST 21Z OBS. THE FRONT HAS
PUSHED THROUGH TRINIDAD WHERE THE TEMP IS 21F WHILE RATON IS WINDY
WITH A TEMP OF 61F! MODELS ARE TRENDING THE FRONT A LITTLE FARTHER
SOUTH AND WEST BY EARLY SUNDAY SO EVENING SHIFT WILL NEED TO MONITOR
FOR POSSIBLE EXPANSION OF ADVISORY SOUTH AND WEST. FOR THIS UPDATE
WILL EXPAND ADVISORY INTO RATON RIDGE ZONE. MODEL PROFILES OVER
THE NE SUGGEST A MIX OF SLEET...FREEZING RAIN...AND SNOW THRU AT
LEAST EARLY SUNDAY MORNING BEFORE MID LEVEL COLDER AIR SLIDES OVER
AND CHANGES ALL ACTIVITY TO SNOW.
BEYOND SUNDAY...THERE ARE SEVERAL WEAK PERTURBATIONS IN WEST TO NW
FLOW THAT WILL SLIDE QUICKLY OVER THE AREA. THIS WILL KEEP TEMPS
NEAR SEASONAL AVERAGES WHILE WINDS ARE PERIODICALLY BREEZY OUT
EAST. A FEW PERIODS OF THICK CLOUD COVER AND PERHAPS EVEN SOME
SHOWERS ARE POSSIBLE FOR THE HIGH TERRAIN.
GUYER
&&
.FIRE WEATHER...
MOIST PACIFIC TROUGH TO GRADUALLY CROSS THIS WEEKEND WITH WETTING
PRECIPITATION CONTINUING TONIGHT AND SUNDAY. SNOW LEVELS HAVE
ALREADY SHOWN SIGNS OF BEGINNING A DOWNWARD TREND THIS
AFTERNOON...AND THESE WILL CONTINUE TO LOWER TO AROUND 6000 FEET
ACROSS THE CONTINENTAL DIVIDE REGION AND UPPER RIO GRANDE VALLEY
TONIGHT. A BAND OF MAINLY WINTER PRECIPITATION IS EXPECTED TO SET UP
TONIGHT ACROSS THE CONTINENTAL DIVIDE REGION OF NW NM...BRINGING
ACCUMULATING SNOW TO THAT AREA. FARTHER SOUTHEAST ACROSS THE
SOUTHWEST MOUNTAINS AND CENTRAL MOUNTAIN CHAIN...THE SNOW
ACCUMULATION LEVEL MAY ONLY DROP TO ABOUT 7000 FEET TONIGHT INTO
SUNDAY MORNING. THE HIGH TERRAIN WILL REALLY BENEFIT FROM THE DWELL
TIME OF ALL THIS MOISTURE WITH SEVERAL INCHES OF SNOW ACCUMULATION
EXPECTED IN ALL NORTHERN AND CENTRAL NM MOUNTAINS ABOVE 7500 FEET.
THE SAN JUAN MOUNTAINS SHOULD GET THE MOST SNOW WITH NEARLY 20
INCHES.
A SECONDARY LOCATION FAVORED FOR ACCUMULATING WINTRY PRECIPITATION
WILL BE THE NORTHEAST PLAINS AND QUAY COUNTY...WHERE A POTENT BACK
DOOR COLD FRONT WILL PROVIDE A FOCUS FOR LIFT AS THE MOIST UPPER
LEVEL TROUGH CROSSES. A FEW INCHES OF SNOW WITH SLEET AND EVEN SOME
FREEZING RAIN ARE POSSIBLE THERE. HIGH TEMPERATURES ACROSS NORTHEAST
AREAS WILL FALL 35 TO 40 DEGREES SUNDAY FROM TODAYS READINGS LEAVING
HIGH TEMPERATURES IN THE MID 20S.
STRONG WINDS ALONG AND EAST OF THE CENTRAL MOUNTAIN CHAIN THIS
AFTERNOON WILL DIMINISH WITH SUNSET...EXCEPT FOR THE HIGHER PEAKS OF
THE CENTRAL MOUNTAIN CHAIN WHERE GUSTY WINDS SHOULD LINGER THROUGH
TONIGHT AS STRONGER FLOW ALOFT GRADUALLY SHIFTS EAST OF THE FORECAST
AREA.
TEMPERATURES WILL GENERALLY REBOUND THROUGH THURSDAY...WITH A
NOTABLE EXCEPTION BEING SOME COOLER READINGS ACROSS THE NORTHEAST ON
WEDNESDAY DUE TO A BACK DOOR COLD FRONT. MODELS ARE NOT AGREEING
VERY WELL ON A WEAKER UPPER LEVEL TROUGH THAT MAY DIVE SOUTHEASTWARD
OVER THE FORECAST AREA ON TUESDAY OR WEDNESDAY. AS HAS BEEN THE CASE
THIS WINTER...THE ECMWF IS DEEPER/WETTER/SLOWER WHILE THE GFS IS
SHALLOWER/DRIER/FASTER. GRIDS ARE ALIGNED WITH THE GFS SOLUTION FOR
NOW.
A WEAK RIDGE OF HIGH PRESSURE PROGGED TO CROSS THE FORECAST AREA
WEDNESDAY NIGHT MAY QUICKLY TRANSITION TO GUSTY ZONAL FLOW ALOFT AS
AN UPPER LEVEL TROUGH TRACKS SOUTHEASTWARD ACROSS THE CENTRAL
ROCKIES. THIS SHOULD BE OUR NEXT DAY WITH WIND AND FIRE WEATHER
CONCERNS. FORECAST GRIDS CURRENTLY SHOW THE TYPICAL PATCH OF
CRITICAL CONDITIONS IN WESTERLY DOWNSLOPE FLOW AROUND CLINES CORNERS
AND SANTA ROSA. HIGH TEMPERATURES SHOULD PEAK FROM 3 TO 8 DEGREES
ABOVE NORMAL THURSDAY.
VENTILATION-WISE...WATCH FOR POOR READINGS IN THE VICINITY OF THE
BACK DOOR COLD FRONT ACROSS THE NORTHEAST TOMORROW...SUNDAY.
ALSO...IN THE WAKE OF THIS WEEKENDS STORM SYSTEM...AREAS OF POOR
VENTILATION WILL BE POSSIBLE FROM ALBUQUERQUE AND SANTA FE
NORTHWESTWARD TO GALLUP AND FARMINGTON. FURTHER...THE UPPER LEVEL
TROUGH TUESDAY/WEDNESDAY SHOULD BRING IN ENOUGH COOL AND SETTLED AIR
FOR AREAS OF POOR VENTILATION ALONG AND WEST OF THE RIO GRANDE
WEDNESDAY.
44
&&
.AVIATION...
18Z TAF CYCLE
RAIN AND HIGH TERRAIN SNOW ALONG AND W OF THE CENTRAL MTN CHAIN
TODAY WITH PERIODS OF MVFR AND BRIEF/LCL IFR CONDITIONS. SPOTTIER RAIN
SHOWERS POSSIBLE FARTHER E...EXCEPT DRY ALONG/E OF A LINE FROM
KROW TO KCVN. SNOW LEVEL SHOULD LOWER TO NEAR 8500 FEET DURING THE
AFTN W OF THE RIO GRANDE. SNOW LEVEL WILL KEEP DROPPING
TONIGHT...REACHING NEAR 6000 FT BY MORNING. AN EXCEPTION WILL BE
LATE TONIGHT ACROSS NE/E CENTRAL AREAS WHERE A COLD FRONT WILL BRING
MUCH COLDER TEMPERATURES AND A MIX OF SNOW...SLEET AND POSSIBLY
-FZRA FM KTCC N TO THE CO BORDER. THIS SHOULD CHANGE OVER TO ALL
SNOW ACROSS NE/E CENTRAL AREAS AFT SUNRISE.
44
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 34 50 27 57 / 70 30 0 5
DULCE........................... 30 43 19 53 / 100 40 10 5
CUBA............................ 32 44 24 53 / 100 60 10 5
GALLUP.......................... 31 47 23 56 / 70 40 5 5
EL MORRO........................ 29 42 22 49 / 70 60 5 5
GRANTS.......................... 31 47 22 56 / 60 50 0 5
QUEMADO......................... 32 45 28 52 / 70 60 5 5
GLENWOOD........................ 38 56 24 63 / 90 30 0 5
CHAMA........................... 25 37 15 45 / 100 50 20 10
LOS ALAMOS...................... 32 45 32 51 / 90 70 10 5
PECOS........................... 31 45 24 48 / 80 70 10 5
CERRO/QUESTA.................... 27 41 16 51 / 80 60 10 5
RED RIVER....................... 23 32 17 40 / 90 70 20 5
ANGEL FIRE...................... 27 39 19 45 / 80 70 10 5
TAOS............................ 31 44 22 53 / 70 60 10 5
MORA............................ 31 43 21 50 / 80 70 10 5
ESPANOLA........................ 32 49 25 56 / 70 50 0 5
SANTA FE........................ 32 45 27 51 / 80 70 5 5
SANTA FE AIRPORT................ 34 48 28 55 / 70 60 5 5
ALBUQUERQUE FOOTHILLS........... 35 52 34 58 / 70 60 0 5
ALBUQUERQUE HEIGHTS............. 39 55 34 59 / 60 60 0 5
ALBUQUERQUE VALLEY.............. 42 56 29 61 / 60 50 0 0
ALBUQUERQUE WEST MESA........... 40 55 32 62 / 60 50 0 5
LOS LUNAS....................... 44 58 26 62 / 60 50 0 0
RIO RANCHO...................... 39 54 31 61 / 60 50 0 5
SOCORRO......................... 43 60 36 64 / 60 30 0 0
SANDIA PARK/CEDAR CREST......... 34 52 32 57 / 90 70 10 5
TIJERAS......................... 36 50 36 55 / 80 70 5 5
MORIARTY/ESTANCIA............... 34 52 28 54 / 80 70 5 0
CLINES CORNERS.................. 34 49 26 52 / 80 80 5 0
GRAN QUIVIRA.................... 37 55 31 54 / 90 50 5 5
CARRIZOZO....................... 40 55 32 58 / 90 50 0 5
RUIDOSO......................... 37 53 34 52 / 90 60 5 5
CAPULIN......................... 31 39 17 50 / 60 70 10 5
RATON........................... 30 45 18 56 / 50 60 10 5
SPRINGER........................ 31 47 19 57 / 40 60 5 0
LAS VEGAS....................... 32 45 21 54 / 70 60 10 0
CLAYTON......................... 18 25 14 49 / 60 60 5 5
ROY............................. 34 37 17 50 / 60 60 5 0
CONCHAS......................... 38 43 20 55 / 60 60 5 0
SANTA ROSA...................... 42 53 22 55 / 60 60 5 5
TUCUMCARI....................... 34 37 17 53 / 60 60 5 5
CLOVIS.......................... 40 45 16 50 / 50 60 5 0
PORTALES........................ 42 47 18 51 / 50 60 5 0
FORT SUMNER..................... 43 55 22 51 / 50 60 5 0
ROSWELL......................... 48 67 26 51 / 50 30 0 0
PICACHO......................... 43 61 26 53 / 50 40 5 0
ELK............................. 45 58 30 51 / 50 50 5 0
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 4 PM MST SUNDAY FOR THE FOLLOWING
ZONES...NMZ502-508-510>515.
WIND ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR THE FOLLOWING
ZONES...NMZ521>524-526-528-529-532>537-539-540.
WINTER WEATHER ADVISORY UNTIL 4 PM MST SUNDAY FOR THE FOLLOWING
ZONES...NMZ527-528-530-531-534.
WINTER WEATHER ADVISORY UNTIL 4 PM MST SUNDAY FOR THE FOLLOWING
ZONES...NMZ503-504-506-516.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 4 PM MST SUNDAY
FOR THE FOLLOWING ZONES...NMZ505-507.
WINTER STORM WARNING FROM 6 PM THIS EVENING TO 4 PM MST SUNDAY FOR
THE FOLLOWING ZONES...NMZ521-526.
&&
$$
CORRECTED START TIME OF WINTER WEATHER ADVISORY FOR NORTHEAST
ZONES
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
303 PM MST SAT MAR 1 2014
.SYNOPSIS...
WIDESPREAD RAIN AND HIGH ELEVATION SNOW TODAY WILL GRADUALLY CHANGE
OVER TO SNOW DOWN TO NEAR 6000 FEET TONIGHT BEFORE MIXING WITH RAIN
AGAIN SUNDAY. SIGNIFICANT ACCUMULATIONS WILL OCCUR IN THE HIGHER
TERRAIN OF THE NORTHERN AND WESTERN MOUNTAINS. STRONG WINDS OVER
MUCH OF EASTERN NEW MEXICO WILL TAPER OFF THROUGH THE EVENING. A
POTENT COLD FRONT OVER THE NORTHEAST PLAINS WILL ALLOW RAIN TO
CHANGE OVER TO A MIX OF SNOW...SLEET...AND FREEZING RAIN THROUGH
SUNDAY. THIS STORM SYSTEM WILL MOVE OUT OF THE AREA SUNDAY...
LEAVING BEHIND COOLER TEMPERATURES THROUGH MONDAY. THE REMAINDER
OF THE WEEK WILL BE NEAR NORMAL FOR EARLY MARCH AS A COUPLE WEAK
DISTURBANCES MOVE OVER THE STATE. PERIODIC BREEZY CONDITIONS WILL
IMPACT THE PLAINS AND PATCHY CLOUD COVER WITH EVEN A FEW SHOWERS
WILL AFFECT THE HIGH TERRAIN.
&&
.DISCUSSION...
WHAT A WELCOME SITE IT IS AS A DEEP FETCH OF RAIN AND HIGH TERRAIN
SNOW IMPACTS CENTRAL AND WESTERN NM. THE WATER VAPOR LOOP STILL
SHOWS THE CORE OF A WELL-DEFINED STORM SYSTEM CRASHING ONSHORE
SOUTHERN CALIFORNIA WITH A MASSIVE FETCH OF MOIST SW FLOW SHIFTING
INTO AZ AND NM. CIRA TOTAL PWAT VALUES ARE ABOVE 200PCT OF NORMAL IN
THIS PLUME AND IT WILL SHIFT DIRECTLY OVER NM THRU THIS EVENING. SFC
AND MID LEVEL TEMPS ARE TRENDING DOWN WITH THE AID OF EVAPORATIONAL
COOLING AND SOME WEAK COLD AIR ADVECTION. SNOW REPORTS SO FAR RANGE
FROM ABOUT 1 TO 4 INCHES ABOVE 7500 FT. THE LATEST HRRR SOLUTION
AGREES THE CURRENT PLUME WILL SHIFT SE OVER CENTRAL NM THRU THIS
EVENING THEN INTO SOUTHERN NM LATE TONIGHT.
A SECONDARY VORT MAX AHEAD OF THE MAIN UPPER COLD CORE WILL SHIFT
OVER THE REGION TONIGHT AND EARLY SUNDAY...DELIVERING A SECONDARY
PEAK IN PRECIP COVERAGE LATE TONIGHT AND EARLY SUNDAY. MODELS HAVE
STRUGGLED WITH THE LOCATION AND INTENSITY OF THIS SECONDARY PRECIP
MAX. HOWEVER...BASED ON TREND OF LATEST HRRR AFTER 06Z CONFIDENCE
IS INCREASING THAT THE 12Z GFS AND ECMWF WILL VERIFY THIS MAX ALONG
THE I-40/CONT DVD CORRIDOR INTO THE MIDDLE RIO GRANDE VALLEY AND
NORTHERN MTS LATE TONIGHT.
THE NE PLAINS WILL BE A TRICKY AREA AS WELL WITH SOME INCREDIBLE
SPATIAL TEMPERATURE DIFFERENCES ON THE LATEST 21Z OBS. THE FRONT HAS
PUSHED THROUGH TRINIDAD WHERE THE TEMP IS 21F WHILE RATON IS WINDY
WITH A TEMP OF 61F! MODELS ARE TRENDING THE FRONT A LITTLE FARTHER
SOUTH AND WEST BY EARLY SUNDAY SO EVENING SHIFT WILL NEED TO MONITOR
FOR POSSIBLE EXPANSION OF ADVISORY SOUTH AND WEST. FOR THIS UPDATE
WILL EXPAND ADVISORY INTO RATON RIDGE ZONE. MODEL PROFILES OVER
THE NE SUGGEST A MIX OF SLEET...FREEZING RAIN...AND SNOW THRU AT
LEAST EARLY SUNDAY MORNING BEFORE MID LEVEL COLDER AIR SLIDES OVER
AND CHANGES ALL ACTIVITY TO SNOW.
BEYOND SUNDAY...THERE ARE SEVERAL WEAK PERTURBATIONS IN WEST TO NW
FLOW THAT WILL SLIDE QUICKLY OVER THE AREA. THIS WILL KEEP TEMPS
NEAR SEASONAL AVERAGES WHILE WINDS ARE PERIODICALLY BREEZY OUT
EAST. A FEW PERIODS OF THICK CLOUD COVER AND PERHAPS EVEN SOME
SHOWERS ARE POSSIBLE FOR THE HIGH TERRAIN.
GUYER
&&
.FIRE WEATHER...
MOIST PACIFIC TROUGH TO GRADUALLY CROSS THIS WEEKEND WITH WETTING
PRECIPITATION CONTINUING TONIGHT AND SUNDAY. SNOW LEVELS HAVE
ALREADY SHOWN SIGNS OF BEGINNING A DOWNWARD TREND THIS
AFTERNOON...AND THESE WILL CONTINUE TO LOWER TO AROUND 6000 FEET
ACROSS THE CONTINENTAL DIVIDE REGION AND UPPER RIO GRANDE VALLEY
TONIGHT. A BAND OF MAINLY WINTER PRECIPITATION IS EXPECTED TO SET UP
TONIGHT ACROSS THE CONTINENTAL DIVIDE REGION OF NW NM...BRINGING
ACCUMULATING SNOW TO THAT AREA. FARTHER SOUTHEAST ACROSS THE
SOUTHWEST MOUNTAINS AND CENTRAL MOUNTAIN CHAIN...THE SNOW
ACCUMULATION LEVEL MAY ONLY DROP TO ABOUT 7000 FEET TONIGHT INTO
SUNDAY MORNING. THE HIGH TERRAIN WILL REALLY BENEFIT FROM THE DWELL
TIME OF ALL THIS MOISTURE WITH SEVERAL INCHES OF SNOW ACCUMULATION
EXPECTED IN ALL NORTHERN AND CENTRAL NM MOUNTAINS ABOVE 7500 FEET.
THE SAN JUAN MOUNTAINS SHOULD GET THE MOST SNOW WITH NEARLY 20
INCHES.
A SECONDARY LOCATION FAVORED FOR ACCUMULATING WINTRY PRECIPITATION
WILL BE THE NORTHEAST PLAINS AND QUAY COUNTY...WHERE A POTENT BACK
DOOR COLD FRONT WILL PROVIDE A FOCUS FOR LIFT AS THE MOIST UPPER
LEVEL TROUGH CROSSES. A FEW INCHES OF SNOW WITH SLEET AND EVEN SOME
FREEZING RAIN ARE POSSIBLE THERE. HIGH TEMPERATURES ACROSS NORTHEAST
AREAS WILL FALL 35 TO 40 DEGREES SUNDAY FROM TODAYS READINGS LEAVING
HIGH TEMPERATURES IN THE MID 20S.
STRONG WINDS ALONG AND EAST OF THE CENTRAL MOUNTAIN CHAIN THIS
AFTERNOON WILL DIMINISH WITH SUNSET...EXCEPT FOR THE HIGHER PEAKS OF
THE CENTRAL MOUNTAIN CHAIN WHERE GUSTY WINDS SHOULD LINGER THROUGH
TONIGHT AS STRONGER FLOW ALOFT GRADUALLY SHIFTS EAST OF THE FORECAST
AREA.
TEMPERATURES WILL GENERALLY REBOUND THROUGH THURSDAY...WITH A
NOTABLE EXCEPTION BEING SOME COOLER READINGS ACROSS THE NORTHEAST ON
WEDNESDAY DUE TO A BACK DOOR COLD FRONT. MODELS ARE NOT AGREEING
VERY WELL ON A WEAKER UPPER LEVEL TROUGH THAT MAY DIVE SOUTHEASTWARD
OVER THE FORECAST AREA ON TUESDAY OR WEDNESDAY. AS HAS BEEN THE CASE
THIS WINTER...THE ECMWF IS DEEPER/WETTER/SLOWER WHILE THE GFS IS
SHALLOWER/DRIER/FASTER. GRIDS ARE ALIGNED WITH THE GFS SOLUTION FOR
NOW.
A WEAK RIDGE OF HIGH PRESSURE PROGGED TO CROSS THE FORECAST AREA
WEDNESDAY NIGHT MAY QUICKLY TRANSITION TO GUSTY ZONAL FLOW ALOFT AS
AN UPPER LEVEL TROUGH TRACKS SOUTHEASTWARD ACROSS THE CENTRAL
ROCKIES. THIS SHOULD BE OUR NEXT DAY WITH WIND AND FIRE WEATHER
CONCERNS. FORECAST GRIDS CURRENTLY SHOW THE TYPICAL PATCH OF
CRITICAL CONDITIONS IN WESTERLY DOWNSLOPE FLOW AROUND CLINES CORNERS
AND SANTA ROSA. HIGH TEMPERATURES SHOULD PEAK FROM 3 TO 8 DEGREES
ABOVE NORMAL THURSDAY.
VENTILATION-WISE...WATCH FOR POOR READINGS IN THE VICINITY OF THE
BACK DOOR COLD FRONT ACROSS THE NORTHEAST TOMORROW...SUNDAY.
ALSO...IN THE WAKE OF THIS WEEKENDS STORM SYSTEM...AREAS OF POOR
VENTILATION WILL BE POSSIBLE FROM ALBUQUERQUE AND SANTA FE
NORTHWESTWARD TO GALLUP AND FARMINGTON. FURTHER...THE UPPER LEVEL
TROUGH TUESDAY/WEDNESDAY SHOULD BRING IN ENOUGH COOL AND SETTLED AIR
FOR AREAS OF POOR VENTILATION ALONG AND WEST OF THE RIO GRANDE
WEDNESDAY.
44
&&
.AVIATION...
18Z TAF CYCLE
RAIN AND HIGH TERRAIN SNOW ALONG AND W OF THE CENTRAL MTN CHAIN
TODAY WITH PERIODS OF MVFR AND BRIEF/LCL IFR CONDITIONS. SPOTTIER RAIN
SHOWERS POSSIBLE FARTHER E...EXCEPT DRY ALONG/E OF A LINE FROM
KROW TO KCVN. SNOW LEVEL SHOULD LOWER TO NEAR 8500 FEET DURING THE
AFTN W OF THE RIO GRANDE. SNOW LEVEL WILL KEEP DROPPING
TONIGHT...REACHING NEAR 6000 FT BY MORNING. AN EXCEPTION WILL BE
LATE TONIGHT ACROSS NE/E CENTRAL AREAS WHERE A COLD FRONT WILL BRING
MUCH COLDER TEMPERATURES AND A MIX OF SNOW...SLEET AND POSSIBLY
-FZRA FM KTCC N TO THE CO BORDER. THIS SHOULD CHANGE OVER TO ALL
SNOW ACROSS NE/E CENTRAL AREAS AFT SUNRISE.
44
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 34 50 27 57 / 70 30 0 5
DULCE........................... 30 43 19 53 / 100 40 10 5
CUBA............................ 32 44 24 53 / 100 60 10 5
GALLUP.......................... 31 47 23 56 / 70 40 5 5
EL MORRO........................ 29 42 22 49 / 70 60 5 5
GRANTS.......................... 31 47 22 56 / 60 50 0 5
QUEMADO......................... 32 45 28 52 / 70 60 5 5
GLENWOOD........................ 38 56 24 63 / 90 30 0 5
CHAMA........................... 25 37 15 45 / 100 50 20 10
LOS ALAMOS...................... 32 45 32 51 / 90 70 10 5
PECOS........................... 31 45 24 48 / 80 70 10 5
CERRO/QUESTA.................... 27 41 16 51 / 80 60 10 5
RED RIVER....................... 23 32 17 40 / 90 70 20 5
ANGEL FIRE...................... 27 39 19 45 / 80 70 10 5
TAOS............................ 31 44 22 53 / 70 60 10 5
MORA............................ 31 43 21 50 / 80 70 10 5
ESPANOLA........................ 32 49 25 56 / 70 50 0 5
SANTA FE........................ 32 45 27 51 / 80 70 5 5
SANTA FE AIRPORT................ 34 48 28 55 / 70 60 5 5
ALBUQUERQUE FOOTHILLS........... 35 52 34 58 / 70 60 0 5
ALBUQUERQUE HEIGHTS............. 39 55 34 59 / 60 60 0 5
ALBUQUERQUE VALLEY.............. 42 56 29 61 / 60 50 0 0
ALBUQUERQUE WEST MESA........... 40 55 32 62 / 60 50 0 5
LOS LUNAS....................... 44 58 26 62 / 60 50 0 0
RIO RANCHO...................... 39 54 31 61 / 60 50 0 5
SOCORRO......................... 43 60 36 64 / 60 30 0 0
SANDIA PARK/CEDAR CREST......... 34 52 32 57 / 90 70 10 5
TIJERAS......................... 36 50 36 55 / 80 70 5 5
MORIARTY/ESTANCIA............... 34 52 28 54 / 80 70 5 0
CLINES CORNERS.................. 34 49 26 52 / 80 80 5 0
GRAN QUIVIRA.................... 37 55 31 54 / 90 50 5 5
CARRIZOZO....................... 40 55 32 58 / 90 50 0 5
RUIDOSO......................... 37 53 34 52 / 90 60 5 5
CAPULIN......................... 31 39 17 50 / 60 70 10 5
RATON........................... 30 45 18 56 / 50 60 10 5
SPRINGER........................ 31 47 19 57 / 40 60 5 0
LAS VEGAS....................... 32 45 21 54 / 70 60 10 0
CLAYTON......................... 18 25 14 49 / 60 60 5 5
ROY............................. 34 37 17 50 / 60 60 5 0
CONCHAS......................... 38 43 20 55 / 60 60 5 0
SANTA ROSA...................... 42 53 22 55 / 60 60 5 5
TUCUMCARI....................... 34 37 17 53 / 60 60 5 5
CLOVIS.......................... 40 45 16 50 / 50 60 5 0
PORTALES........................ 42 47 18 51 / 50 60 5 0
FORT SUMNER..................... 43 55 22 51 / 50 60 5 0
ROSWELL......................... 48 67 26 51 / 50 30 0 0
PICACHO......................... 43 61 26 53 / 50 40 5 0
ELK............................. 45 58 30 51 / 50 50 5 0
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 4 PM MST SUNDAY FOR THE FOLLOWING
ZONES...NMZ502-508-510>515.
WIND ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR THE FOLLOWING
ZONES...NMZ521>524-526-528-529-532>537-539-540.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 4 PM MST SUNDAY
FOR THE FOLLOWING ZONES...NMZ527-528-530-531-534.
WINTER WEATHER ADVISORY UNTIL 4 PM MST SUNDAY FOR THE FOLLOWING
ZONES...NMZ503-504-506-516.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 4 PM MST SUNDAY
FOR THE FOLLOWING ZONES...NMZ505-507.
WINTER STORM WARNING FROM 6 PM THIS EVENING TO 4 PM MST SUNDAY FOR
THE FOLLOWING ZONES...NMZ521-526.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
101 PM CST SAT MAR 1 2014
.UPDATE...
ISSUED AT 101 PM CST SAT MAR 1 2014
TEMPS ARE FINALLY RISING A LITTLE BUT NOT LOOKING LIKE ANY
LOCATION WILL GET ABOVE ZERO. ONLY POSSIBLE EXCEPTION MAY BE
ACROSS THE FAR SOUTHWEST WHICH HAS THE LEAST AMOUNT OF SNOW. STILL
SEEING THE MOST CLOUD COVER ACROSS THE SOUTH WITH A LOT OF SUN IN
THE NORTH. NOT PLANNING ON ANY CHANGES FOR NOW.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 345 AM CST SAT MAR 1 2014
WIND CHILLS WILL BE THE MAIN CONCERN THIS PERIOD. 00Z MODELS ARE
IN GOOD AGREEMENT AND WILL USE A BLEND FOR DETAILS.
TODAY...A VERY COLD AIRMASS WITH 925MB TEMPS -30C TO -32C WILL
SETTLE OVER THE REGION AS SFC HIGH PRESSURE BUILDS. MAX TEMPS
TODAY WILL STRUGGLE TO REACH -10F TO -15F MOST AREAS. WINDS WILL
BE LIGHTER...BUT STILL 5-10 KNOTS. ALTHOUGH WE LIKELY WILL NEED TO
EXTEND THE WIND CHILL HEADLINES INTO THIS AFTERNOON AND
TONIGHT...WILL PASS THIS DUTY TO THE DAY SHIFT. THERE IS AN AREA
OF CLOUDS AND FLURRIES ACROSS SOUTHWEST MANITOBA ASSOCIATED WITH
AN UPPER JET STREAK. RAP GUIDANCE INDICATES THESE CONDITIONS WILL
PROPAGATE SOUTHEAST THROUGH THE DAY...ADJUSTED SKY GRIDS
ACCORDINGLY (AND ADDED FLURRIES).
TONIGHT-SUNDAY...HIGH PRESSURE CONTINUES TO ESTABLISH ITSELF. THIS
SHOULD END WIND CHILL HEADLINES BY LATER SUNDAY AFTERNOON AS WINDS
BECOME CALM. TEMPERATURES MAY BE SLIGHTLY WARMER ON SUNDAY...BUT
STILL BELOW ZERO MOST AREAS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 345 AM CST SAT MAR 1 2014
SUNDAY NIGHT-MONDAY NIGHT...HIGH PRESSURE MOVES EAST AS A WEAK
SHORTWAVE FROM THE PAC NW APPROACHES AND MOVES THROUGH THE REGION.
TIMING AND QPF AMOUNTS STILL A BIT UNCERTAIN...BUT MOST GUIDANCE
DOES INDICATE SOMETHING LATER MONDAY AFTERNOON INTO THE EVENING.
SNOW AMTS APPEAR TOWARD THE LIGHTER SIDE. TEMPERATURES SHOULD
CONTINUE THE GRADUAL WARMING TREND (BUT STILL WELL BELOW NORMAL
VALUES).
TUESDAY-FRIDAY...LONG WAVE PATTERN IS SPLIT WITH ZONAL FLOW
ACROSS THE STATES. LONG WAVE UPPER LOW OVER THE CANADIAN
ARCHIPELAGO MOVES TO THE NORTHWEST BY THE END OF THE PERIOD. LONG
WAVE PATTERN AMPLIFIES BY THE END OF THE PERIOD WITH AN UPPER
LEVEL RIDGE OVER THE WEST COAST AND LONG WAVE TROUGH OVER EASTERN
NORTH AMERICA.
THE GFS WAS FASTER THAN THE ECMWF THROUGH WED. THEN THE GFS WAS
SLOWER WITH THE NEXT SHORT WAVE ACROSS SOUTHERN CANADA FOR THU AND
FRI. THE ECMWF HAS BEEN TRENDING FASTER WHILE THE GFS HAS TRENDED
SLOWER. WILL BLEND THE TWO MODELS.
WILL KEEP YESTERDAY POPS FOR TUE. WILL KEEP YESTERDAYS POPS IN THE
WEST FOR TUE NIGHT. WILL EXPAND POPS FARTHER WEST ON WED NIGHT. WILL
TRIM BACK POPS IN THE SOUTH FOR THU NIGHT.
HIGH TEMPS WERE INCREASED 3 TO 4 DEGREES FOR THU...A DEGREE OR SO
FOR WED AND FRI AND NO CHANGE TO THU FROM YESTERDAYS RUN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 101 PM CST SAT MAR 1 2014
GOOD FLYING WEATHER WITH THE EXCEPTION OF THE COLD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY UNTIL NOON CST SUNDAY FOR NDZ038-039-049-052-
053.
WIND CHILL WARNING UNTIL NOON CST SUNDAY FOR NDZ006>008-014>016-
024-026>030-054.
MN...WIND CHILL ADVISORY UNTIL NOON CST SUNDAY FOR MNZ003-024-027>032-
040.
WIND CHILL WARNING UNTIL NOON CST SUNDAY FOR MNZ001-002-004>009-
013>017-022-023.
&&
$$
UPDATE...GODON
SHORT TERM...TG
LONG TERM...TG/HOPPES
AVIATION...GUST
AREA FORECAST DISCUSSION
NWS TULSA OK
1126 AM CST SAT MAR 1 2014
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
WIDESPREAD MVFR/OCCASIONAL IFR CIGS WILL PERSIST THROUGH
THE AFTERNOON...ALTHOUGH COULD SEE A FEW BREAKS FROM
TIME TO TIME. IFR CIGS WILL PREVAIL THIS EVENING THROUGH
SUNDAY MORNING...WITH FREEZING RAIN/SLEET DEVELOPING AFTER
06Z ACROSS NE OK/NW AR...THEN INTO SE OK/WCNTRL AR TOWARD
12Z.
&&
.PREV DISCUSSION... /ISSUED 1104 AM CST SAT MAR 1 2014/
..UPDATE...
DISCUSSION...
LEAD COLD FRONT HAS PUSHED INTO NRN TX...WITH AN
EXPANSIVE AREA OF LOW CLOUDS TO THE N OF THE FRONT
ACROSS OUR FORECAST AREA. HRRR SUGGESTS CLOUD DECK
WILL PERSIST THROUGH THE AFTERNOON...ESPECIALLY
ACROSS SE OK...SO HAVE LOWERED HIGH TEMPERATURES
SEVERAL DEGREES ACROS THIS AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 49 20 20 7 / 10 60 80 60
FSM 55 38 38 18 / 10 40 80 60
MLC 54 29 29 13 / 10 30 70 20
BVO 37 13 16 4 / 10 70 80 60
FYV 55 28 28 8 / 10 60 90 80
BYV 54 25 25 6 / 10 60 90 80
MKO 55 25 25 10 / 10 50 80 60
MIO 45 16 17 2 / 10 70 80 70
F10 50 24 24 9 / 10 50 70 50
HHW 57 42 42 19 / 10 20 70 20
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WINTER STORM WARNING FROM 6 PM SATURDAY TO MIDNIGHT MONDAY FOR
OKZ049-OKZ054-OKZ055-OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-
OKZ061-OKZ062-OKZ063-OKZ067-OKZ068-OKZ069-OKZ070-OKZ071-
OKZ072-OKZ073-OKZ074-OKZ075-OKZ076.
WINTER WEATHER ADVISORY FROM 6 AM SUNDAY TO MIDNIGHT MONDAY FOR
OKZ053.
WINTER STORM WATCH FROM 6 PM SATURDAY TO MIDNIGHT MONDAY FOR
OKZ064-OKZ065-OKZ066.
AR...WINTER STORM WARNING FROM 6 PM SATURDAY TO MIDNIGHT MONDAY FOR
ARZ001-ARZ002-ARZ010-ARZ011-ARZ019-ARZ020-ARZ029.
&&
$$
AVIATION...18
AREA FORECAST DISCUSSION
NWS TULSA OK
1104 AM CST SAT MAR 1 2014
...UPDATE...
.DISCUSSION...
LEAD COLD FRONT HAS PUSHED INTO NRN TX...WITH AN
EXPANSIVE AREA OF LOW CLOUDS TO THE N OF THE FRONT
ACROSS OUR FORECAST AREA. HRRR SUGGESTS CLOUD DECK
WILL PERSIST THROUGH THE AFTERNOON...ESPECIALLY
ACROSS SE OK...SO HAVE LOWERED HIGH TEMPERATURES
SEVERAL DEGREES ACROS THIS AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 49 20 20 7 / 10 60 80 60
FSM 55 38 38 18 / 10 40 80 60
MLC 54 29 29 13 / 10 30 70 20
BVO 37 13 16 4 / 10 70 80 60
FYV 55 28 28 8 / 10 60 90 80
BYV 54 25 25 6 / 10 60 90 80
MKO 55 25 25 10 / 10 50 80 60
MIO 45 16 17 2 / 10 70 80 70
F10 50 24 24 9 / 10 50 70 50
HHW 57 42 42 19 / 10 20 70 20
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WINTER STORM WARNING FROM 6 PM SATURDAY TO MIDNIGHT MONDAY FOR
OKZ049-OKZ054-OKZ055-OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-
OKZ061-OKZ062-OKZ063-OKZ067-OKZ068-OKZ069-OKZ070-OKZ071-
OKZ072-OKZ073-OKZ074-OKZ075-OKZ076.
WINTER WEATHER ADVISORY FROM 6 AM SUNDAY TO MIDNIGHT MONDAY FOR
OKZ053.
WINTER STORM WATCH FROM 6 PM SATURDAY TO MIDNIGHT MONDAY FOR
OKZ064-OKZ065-OKZ066.
AR...WINTER STORM WARNING FROM 6 PM SATURDAY TO MIDNIGHT MONDAY FOR
ARZ001-ARZ002-ARZ010-ARZ011-ARZ019-ARZ020-ARZ029.
&&
$$
SHORT TERM...18
LONG TERM....21
AREA FORECAST DISCUSSION
NWS PORTLAND OR
1002 AM PST SAT MAR 1 2014
.SYNOPSIS...STRONG LOW PRESSURE IS DRIFTING INTO SOUTHERN CALIFORNIA
THIS MORNING. LEFTOVER MOISTURE FROM AN ASSOCIATED FRONT CONTINUES TO
BRING RAIN AND HIGH ELEVATION SNOW TO PORTIONS OF LANE AND LINN
COUNTIES. OTHERWISE THE BIG STORY TODAY WILL BE A STRONG PUSH OF COLD
AIR COMING DOWN FROM THE CANADIAN ROCKIES. A BACKDOOR COLD FRONT HAS
PUSHED SOUTHWEST ACROSS THE COLUMBIA BASIN...AND HAS ARRIVED ALONG
THE EAST SLOPES OF THE CASCADES. THIS FRONT WILL PUSH WESTWARD
THROUGH THE GORGE AND ACROSS THE PORTLAND METRO AREA TODAY WITH COLD
EAST WINDS TO FOLLOW LATER TODAY THROUGH SUNDAY. WHILE IT DOES NOT
APPEAR IT WILL BE COLD ENOUGH FOR WINTRY PRECIP IN THE PORTLAND METRO
AREA...THERE IS A THREAT FOR SIGNIFICANT SNOW AND ICE IN THE GORGE
AND HOOD RIVER VALLEY TONIGHT UNTIL THE COLD AIR SCOURS OUT SUNDAY
NIGHT OR MONDAY. OTHERWISE...A SERIES OF PACIFIC STORM SYSTEMS WILL
BRING PERIODS OF RAIN...MOUNTAIN SNOW...AND COASTAL WIND FOR MUCH OF
THE UPCOMING WEEK.
&&
.MORNING UPDATE...COMPLICATED FORECAST WITH CLASH OF MARINE AND
CONTINENTAL AIR UNDERWAY. THE HIGHEST IMPACT EVENT IN THE NEXT FEW
DAYS IS THE POTENTIAL FOR ICE ACCUMULATIONS IN THE COLUMBIA RIVER
GORGE AND THE UPPER HOOD RIVER VALLEY. SINCE NAM SOUNDINGS ARE NOT
HELPFUL AT THE MOMENT WILL RELY ON 4KM WRFGFS A BIT MORE HEAVILY
TODAY AS IT HAS A DECENT HANDLE AT LEAST ON HOOD RIVER CURRENTLY
UNTIL OBSERVATIONS SUPPORT OTHERWISE.
OBSERVATIONS CURRENTLY SUGGEST PROFILES ARE COLD ENOUGH FOR SNOW TO
FALL IN UPPER HOOD RIVER VALLEY...AND SURFACE TEMPERATURES NEAR HOOD
RIVER ARE NOW IN THE LOWER TO MID 30S. WHILE TEMPERATURES ARE
EXPECTED TO FALL SOME MORE TODAY...PRECIPITATION AMOUNTS ARE NOT
EXPECTED TO BE TOO HIGH THROUGH THE DAY GIVEN THE SHALLOW MOISTURE
PROFILES. ADVISORY LEVEL SNOWS IN THE UPPER HOOD RIVER VALLEY ARE 3-6
INCHES IN 12 HOURS...WITH 1 INCH PLUS IN THE GORGE. WITH BORDERLINE
TEMPS ONGOING NEAR HOOD RIVER CURRENTLY EXPECT THAT RATES WON`T BE
SUFFICIENT TODAY BUT...
CURRENT ADVISORY IS BUMPED UP AS SNOW IS STICKING FROM CASCADE LOCKS
TO CARSON.I DO NOT THINK THE UPPER HOOD RIVER VALLEY WILL GET 3-6" OF
SNOW BASED ON EXPECTED QPF BUT THE GORGE 1" CRITERIA WILL BE EASIER
TO BE FOUND EVEN THOUGH THE PRECIP SHIELD IS NOT COMPLETELY FILLED
IN. EXPECT IT WILL BE MORE SQUALLY IN NATURE IS OCCURRING WHICH CAN
CAUSE TRICKY TRAVEL QUICKLY...THUS THE REASON FOR BUMPING UP THE
START TIME.
SOUNDING PROFILES SUGGEST SNOW IS THE DOMINANT P-TYPE OVERNIGHT
CLOSER TO HOOD RIVER...WITH A TRANSITION EARLIER IN THE WESTERN
COLUMBIA RIVER GORGE...BUT STILL SOME UNCERTAINTY THERE WITH SEVERAL
MODELS WHILE STRUGGLING WITH SURFACE TEMPS STILL SUGGEST A WARM NOSE
RIDING OVER THE LOWER LEVEL COLD AIR. THEREFORE WILL HOLD ONTO THE
ADVISORY FOR ALL LOCATIONS. WITH SOME NEAR SURFACE WET BULBING IT IS
POSSIBLE THAT SOME FROZEN PRECIPITATION (SLEET/SNOW GRAINS) MAY GET
IN TO NEAR TTD/EAST PDX BUT NOT THE MOST LIKELY SCENARIO AT THIS
POINT AS EVEN THE DALLES RAPID TEMPERATURE DROPS HAVE EASED SOME.
OUR TEMPERATURE AT THE OFFICE 3 MILES WEST OF PDX CONTINUES TO
FALL...CURRENTLY APPROACHING 36 DEGREES.
QPF COMPARISONS FOR 12Z-18Z TOMORROW MORNING RANGE FROM 0.1 TO 0.4
OVER THE GORGE AND UPPER HOOD VALLEY. SOUNDINGS SUGGEST THAT THIS IS
THE MOST LIKELY PERIOD OF TRANSITION TO A SLEET AND FREEZING RAIN
PROFILE FOR THE CENTRAL GORGE.
EVEN THE COLD BIASED NAM HAS TEMPERATURES WARMING ABOVE FREEZING IN
THE GORGE SOMETIME LATE TOMORROW AFTERNOON. IT IS THIS KEY TRANSITION
PERIOD WHEN SIGNIFICANT PRECIPITATION IS EXPECTED TO BE COMING IN.
WILL TRIM BACK THE END OF THE WATCH SOME. IT IS LIKELY TO TRANSITION
MUCH SOONER THAN CURRENT EXPIRATION TIME WEST OF CASCADE LOCKS...BUT
WILL HANDLE THAT LATER TODAY WHEN WE DECIDE WHAT TO DO WITH THE
WATCH.
WITH THE WIND ADVISORY...THIS IS JUST AN EAST COUNTY SITUATION AT
BEST. PEAK WINDS LOOK TO BE TODAY SO THE ADVISORY MAY BE A BIT A
LONG. /KMD
&&
.SHORT TERM...TODAY THROUGH MONDAY...LET ME START OFF BY SAYING THIS
IS ONE OF THE MOST CHALLENGING FORECASTS THUS FAR IN MY CAREER...AS
IT IS A VERY ODD PATTERN WHERE A MAJOR SURGE OF COLD AIR MAY OR MAY
NOT BE SUCCESSFUL PUSHING ALL THE WAY SOUTHWEST FROM THE CANADIAN
PRAIRIE PROVINCES ACROSS BOTH THE ROCKIES AND CASCADES. THIS IS VERY
TOUGH FOR COLD AIR TO DO SUCCESSFULLY...BUT IT IS POSSIBLE AND MOST
MODELS HAVE BEEN FAIRLY CONSISTENT IN SUGGESTING IT WILL. SOME MODELS
SUCH AS THE NAM STILL SUGGEST THERE COULD BE WINTRY PRECIPITATION IN
THE PORTLAND METRO AREA LATER TODAY INTO EARLY SUNDAY...WHILE OTHERS
SUCH AS THE RAP ARE NOT EVEN BRINGING ENOUGH COLD AIR TO CREATE A
SIGNIFICANT SNOW/ICE EVENT IN THE GORGE OR HOOD RIVER VALLEY. TO GIVE
AN EXAMPLE OF THE UNCERTAINTY HERE...THE 06Z NAM BUFR SOUNDING
SUGGESTED TEMPS WILL BE IN THE LOW 20S IN HOOD RIVER AT 3 PM THIS
AFTERNOON. MEANWHILE THE 06Z RAP SUGGESTS TEMPS WILL BE IN THE UPPER
40S AT THE SAME PLACE AT THE SAME TIME. I BELIEVE BOTH ARE
WRONG...STICKING TO THE TYPICAL BIASES OF THE NAM BEING TOO COLD AND
THE RAP BEING TOO WARM. THE REALITY WILL MOST LIKELY SOMEWHERE IN
BETWEEN THESE EXTREMES. NEEDLESS TO SAY CONFIDENCE IN ANY
DETERMINISTIC FORECAST IS UNUSUALLY LOW IN THIS SITUATION...BUT WE
WILL DO OUR BEST.
LETS START WITH THE TWO MODELS I MENTIONED EARLIER...THE NAM AND THE
RAP. THE COLD AIR IS ALREADY WELL BEHIND THE 00Z NAM FORECAST AND
EVEN THE 06Z INITIALIZATION. CHECKING SFC PRESSURES...THE 09Z NAM
FORECAST FOR CENTRAL WA ARE ALREADY 4-6 MB TOO HIGH. TEMPS REMAIN
ABOVE FREEZING FOR ALL BUT THE EASTERN THIRD OF WASHINGTON...EXCEPT
MOSES LAKE AND EPHRATA. THE 06Z NAM BUFR SOUNDING FOR KDLS SAID IT
WOULD BE 28 DEG F BY NOW...THE 11Z OB FOR KDLS SAYS IT IS STILL 42.
THIS MARKS LITTLE CHANGE FROM WHERE THE TEMP HAS BEEN SITTING AT KDLS
MUCH OF THE NIGHT. HOWEVER THE COLD ADVECTION HAS JUST STARTED...
EAST WINDS AT 10 KT HAVE PICKED UP AND THE DEWPOINT FELL 7 DEG F IN
ONE HOUR. SO IT IS SAFE TO SAY OUR BACKDOOR COLD FRONT HAS PUSHED
W-SW INTO THE COLUMBIA GORGE...BUT IS DOING SO MUCH SLOWER AND WITH
MUCH LESS BLUSTER THAN THE NAM SUGGESTED. MEANWHILE THE RAP HAS BEEN
DOING MUCH BETTER WITH THE HANDLING OF THE COLD AIR...BEING MUCH
SLOWER AS IT HAS THE BENEFIT OF BEING REINITIALIZED EACH HOUR. WHERE
THE RAP LIKELY GOES WRONG IS WHAT IT DOES WITH THE COLD AIR LATER
TODAY. STRANGELY...THE RAP HAS THE EASTSIDE COLD POOL ESSENTIALLY
SURRENDERING LATER TODAY DUE TO INCREASING WESTERLY FLOW ALOFT AND
SUPPOSED WARM ADVECTION IN BRITISH COLUMBIA ASSOCIATED WITH A
DISTURBANCE SLIDING DOWN THE COAST. THIS DISTURBANCE APPEARS FAR TOO
WEAK TO DEFEAT A FULL-ON PUSH OF ARCTIC AIR...AND THE RAP IS OUT ON
ITS OWN WITH THIS IDEA. SUSPECT THE EASTSIDE COLD POOL WILL CONTINUE
TO STRENGTHEN OVER THE NEXT 12-24 HRS AS THE NAM/GFS/UKMET/ ECMWF/GEM
ALL INDICATE TO SOME DEGREE.
THE 00Z/06Z GFS ALSO HAS DONE MUCH BETTER WITH ITS INITIALIZATION...
BOTH WITH SFC PRESSURES AND THE MAGNITUDE/PROGRESS OF THE COLD AIR.
IT ALSO SEEMS TO BE HANDLING THE STRONG LOW OFF CALIFORNIA AND
ACTIVITY FURTHER OUT INTO THE PACIFIC FAIRLY WELL. THEREFORE THE
LATEST RUNS OF THE GFS ARE PREFERRED...AND ESSENTIALLY OUR FORECAST
IS A BLEND BETWEEN THE PREVIOUS FORECAST AND THE GFS/WRFGFS.
WE DECIDED TO PUSH BACK THE START OF THE WINTER WX ADVISORY IN THE
GORGE TO 6 PM FOR SEVERAL REASONS. FIRST...THE DELAY IN ARRIVAL OF
COLD AIR. SECOND...THE UNCERTAINTY IN THE AMOUNT OF QPF EXPECTED
TODAY. AND THIRD...THE EARLY MARCH SUN AND ITS IMPACT ON SURFACE
TEMPS. TEMPS HAVE GENERALLY BEEN IN THE 40S ALL NIGHT...SO SURFACES
TAKE SOME TIME TO COOL OFF ENOUGH TO ALLOW ICE ACCRETION. THE
STRONGER EARLY MARCH SUN WILL BE FIGHTING THE COLD AIR...EVEN THOUGH
IT WILL LIKELY BE CLOUDY THROUGHOUT THE DAY THERE WILL LIKELY BE
ENOUGH SOLAR ENERGY TO KEEP MOST SURFACES ABOVE FREEZING THROUGHOUT
THE DAY. OUTSIDE OF THE GORGE...TODAY WILL SEE RAIN GRADUALLY
INCREASING ACROSS THE AREA DUE TO LOW AND MID-LEVEL FRONTOGENESIS
ASSOCIATED WITH THE BACKDOOR COLD FRONT MEETING THE MILD AND MOIST
AIR MASS IN PLACE.
AS COLD HIGH PRESSURE BUILDS EAST OF THE CASCADES...EASTERLY PRES
GRADIENTS AND THUS EAST WINDS WILL INCREASE THROUGH THE GORGE. THIS
SHOULD CAUSE TEMPS TO STAY STEADY OR SLOWLY FALL THROUGH THE DAY IN
THE PDX METRO AREA...WHILE AREAS OUTSIDE OF THE GORGE OUTFLOW ONCE
AGAIN AIM FOR THE 50S. IT APPEARS VERY QUESTIONABLE WINDS WILL BE
STRONG ENOUGH FOR AN ADVISORY...BUT THERE IS ENOUGH UNCERTAINTY IN
THIS SITUATION TO KEEP THE EXISTING WIND ADVISORY IN PLACE FOR THE
EAST PORTLAND METRO. NORTHEAST WINDS ASSOCIATED WITH THE COLD
ADVECTION ARE RATHER STRONG IN THE COLUMBIA BASIN...IT WILL BE
INTERESTING TO SEE WHAT THEY DO THIS MORNING WHEN THEY REACH THE
CASCADES. THE COLD POOL WILL LIKELY BE DEEP ENOUGH TO SUPPORT A WINDY
DAY FOR MUCH OF THE METRO...RATHER THAN CONFINE STRONGER WINDS TO THE
GORGE. EXPECT MANY SPOTS IN AND AROUND PORTLAND/VANCOUVER WILL SEE
GUSTS IN THE 30-40 MPH RANGE...WITH PERHAPS AN ISOLATED 45 MPH GUST
OR TWO.
THE RESULTING DOWNSLOPING OF THE BROADER EAST WIND MAY ALSO TAKE A
BIT OF THE EDGE OFF THE MAGNITUDE OF THE COLD AIR TRYING TO SPILL
WEST OF THE CASCADES. AS A RESULT WE BUMPED TEMPS UP SLIGHTLY
TODAY...AND LEFT ONLY A SLIGHT CHANCE OF FZRA AROUND TROUTDALE
TONIGHT. KEEP IN MIND THE NAM BUFR SOUNDINGS CONTINUE TO SUGGEST A
HIGH IMPACT ICE EVENT THROUGHOUT THE METRO THIS AFTERNOON THROUGH
SUNDAY MORNING...BUT AGAIN THE NAM HAS BEEN DISCOUNTED DUE TO THE
FACT IT IS FAR TOO FAST AND STRONG WITH THE EASTSIDE COLD AIR.
A PACIFIC DISTURBANCE WILL BEGIN TO SPREAD MORE RAIN ACROSS THE
DISTRICT SUNDAY. AS THE LOW PRESSURE SYSTEM APPROACHES...THERE MAY BE
A BIT OF A COASTAL JET WHICH WOULD ALLOW BRIEF WINDS GUSTING 40-50
MPH ALONG THE BEACHES AND HEADLANDS. ANOTHER SIMILAR SYSTEM IS
EXPECTED FOR MONDAY...AND THESE SYSTEMS WILL HAVE AN INCREASING TAP
OF SUBTROPICAL MOISTURE. THIS MOISTURE WILL BE OVERRUNNING THE COLD
AIR IN THE GORGE AND HOOD RIVER VALLEY... POSSIBLY RESULTING IN
SUBSTANTIAL SNOW AND ICE ACCUMULATIONS BEFORE THE COLD AIR FINALLY
SCOURS OUT MONDAY. AT THIS MOMENT OUR HUNCH IS THAT TEMPS WILL
MODERATE JUST ENOUGH SUNDAY TO ALLOW THE SECOND SURGE OF MOISTURE TO
FALL AS PLAIN RAIN IN THE GORGE AND NEAR HOOD RIVER. AGAIN...LEFT THE
EXISTING WINTER STORM WATCH IN PLACE DUE TO THE UNCERTAINTY... BUT IT
APPEARS THE BEST CHANCE FOR WINTRY PRECIP SUN NIGHT/MON WILL BE IN
UPPER PORTIONS OF THE HOOD RIVER VALLEY AND POSSIBLY EASTERN SKAMANIA
COUNTY.
TEMPS WARM WELL INTO THE 50S ON GUSTY SOUTH WINDS THROUGH THE
WILLAMETTE VALLEY MONDAY...POSSIBLY INTO THE 40S AND LOWER 50S IN THE
GORGE BY MONDAY AFTERNOON OR EVENING. AN ACTIVE PACIFIC STORM TRACK
WILL KEEP THINGS WET WELL INTO THE UPCOMING WEEK...BUT TEMPS WILL
WARM UP JUST ENOUGH TO GIVE MANY OF US A HINT OF SPRING TO THE AIR BY
MIDWEEK. WEAGLE
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
MONDAY NIGHT THROUGH FRIDAY...MILD BUT WET CONDITIONS ARE EXPECTED
NEXT WEEK AS STRONG WESTERLY FLOW PREVAILS. A MOIST PACIFIC FRONTAL
SYSTEM WILL MOVE ONSHORE LATE MONDAY...LIFTING SNOW LEVELS ABOVE PASS
LEVEL. STRONG OROGRAPHIC LIFT WILL ALLOW ABUNDANT PRECIPITATION OVER
THE CASCADES AND COAST RANGE MONDAY NIGHT INTO TUESDAY. BOTH THE 12Z
GFS AND ECMWF ARE STILL IN GOOD AGREEMENT SHOWING BACK TO BACK
SYSTEMS MOVING THROUGH WEDNESDAY AND THURSDAY. THEY BOTH SETUP AN
UPPER LOW IN THE GULF OF ALASKA AND ANOTHER JUST OFF THE
OREGON/CALIFORNIA BORDER. THE 12Z ECMWF HAS A 985 MB SURFACE LOW
DEVELOPING LATE WEDNESDAY NIGHT AND HAS IT SETUP A LITTLE FURTHER
SOUTH OF THE GFS SOLUTION. MAY SEE SOME DECENT COASTAL WINDS WITH
THIS SETUP AS THE LOW LIFTS NORTH ALONG THE COAST THROUGH THURSDAY
MORNING. POST FRONTAL SHOWERS CONTINUE INTO LATE NEXT WEEK AS MODELS
SUGGEST AN AMPLIFYING TROUGH OVER THE PACIFIC NORTHWEST. /27
&&
.AVIATION...CONDITIONS ARE SLOWLY DETERIORATING THIS MORNING AS
MOISTURE SPREADS INTO THE REGION FROM A STORM SYSTEM OFF THE
CALIFORNIA COAST. AT CURRENT MOST COAST SITES SIT AT MVFR WITH
SOME LOCALIZED IFR OR LOWER...WHILE IN THE WILLAMETTE VALLEY MVFR
RULES ROUGHLY SOUTH OF KSLE WITH VFR TO THE NORTH. EXPECT THE MVFR
CIGS TO CONTINUE SPREADING NORTH LATER THIS MORNING WITH SHOWER
ACTIVITY INCREASING. PERSISTENT OFFSHORE FLOW WILL CONTINUE
THROUGH THE REST OF TODAY OVER W WASHINGTON AND NW OREGON...WITH
BREEZY TO GUSTY WINDS FOR AREAS N OF A KTMK TO KUAO LINE.
KPDX AND APPROACHES...VFR AT CURRENT SHOULD LOWER TO MVFR LATER
THIS MORNING. EXPECT GUSTY E WINDS THROUGH THE DAY...WITH THE
STRONGEST WINDS AFFECTING THE EASTERN PART OF THE METRO AREA
TOWARD THE COLUMBIA RIVER GORGE. PYLE
&&
.MARINE...CONDITIONS WILL REMAIN FAIRLY BENIGN ACROSS THE
COASTAL WATERS TODAY INTO EARLY SUN. LIGHT TO MODERATE OFFSHORE
FLOW MAY BECOME GUSTY AT TIMES THIS AFTERNOON...WITH A FEW GUSTS
UP TO 25 KT POSSIBLE...MAINLY BELOW THE COASTAL GAPS AND THROUGH
THE COLUMBIA RIVER.
A MORE ACTIVE WEATHER PATTERN LOOKS TO BEGIN LATER SUN/MON. A WARM
FRONT WILL LIFT N ACROSS THE COASTAL WATERS SUN NIGHT INTO MON AM.
A STRONG FRONT WILL ARRIVE TUE NIGHT...WITH INCREASING POTENTIAL
OF SOUTHERLY GALES AT THAT TIME. REST OF WEEK WILL REMAIN BREEZY
AND UNSETTLED AS MORE FRONTS ARRIVES. PYLE/ROCKEY
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY UNTIL 6 AM PST SUNDAY FOR GREATER PORTLAND METRO
AREA.
WINTER WEATHER ADVISORY UNTIL 6 AM PST SUNDAY FOR CENTRAL
COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-WESTERN COLUMBIA
RIVER GORGE.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY
NIGHT FOR CENTRAL COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-
WESTERN COLUMBIA RIVER GORGE.
WA...WIND ADVISORY UNTIL 6 AM PST SUNDAY FOR GREATER VANCOUVER AREA.
WINTER WEATHER ADVISORY UNTIL 6 AM PST SUNDAY FOR CENTRAL
COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.
WINTER WEATHER ADVISORY UNTIL 6 AM PST SUNDAY FOR S WA CASCADES.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY
NIGHT FOR CENTRAL COLUMBIA RIVER GORGE-SOUTH WASHINGTON
CASCADES-WESTERN COLUMBIA RIVER GORGE.
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
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 GREENVILLE-SPARTANBURG SC
313 PM EST SAT MAR 1 2014
.SYNOPSIS...
DRY HIGH PRESSURE WILL LINGER OVER THE AREA THROUGH THE WEEKEND
BEFORE A MOIST COLD FRONT APPROACHES FROM THE WEST ON MONDAY.
ANOTHER AREA OF HIGH PRESSURE WILL BUILD DOWN THE EAST COAST TUESDAY
WITH A SOUTHEASTERN COASTAL LOW DEVELOPING ON THURSDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 230 PM...THERE WILL BE A FLAT UPR RIDGE ACRS THE SOUTHEAST
STATES THRU THE NEAR TERM...WHILE A POTENT SHORTWAVE TROF BEGINS TO
ENTER THE SRN PLAINS. SFC HIGH PRES WILL LINGER JUST OFF THE SOUTH
ATLANTIC COAST...ALLOWING FOR INCREASING SWLY LLVL RETURN FLOW ATOP
THE CWFA TONIGHT THRU SUNDAY. FCST SNDGS INDICATE DECENT RADIATIONAL
COOLING WITH INCREASING BL MOISTURE WITHIN THE SW FLOW. AS A
RESULT...THERE WILL BE SOME POTENTIAL FOR FOG DEVELOPMENT EARLY
SUNDAY MORNING. THE NAM IN PARTICULAR HINTS AT SOME FOG OR LOW
STRATUS DEVELOPMENT...PRIMARILY ACRS THE PIEDMONT. MOST OF THE OTHER
GUIDANCE DOES NOT SHOW THIS...EXCEPT PERHAPS THE RAP HINTING AS
WELL. WILL KEEP A MENTION OF PATCHY FOG TONIGHT...HIGHLIGHTING THE
AREA WHERE THE NAM AS NEAR ZERO SFC CONDENSATION PRES DEFICITS.
HOWEVER...CONFIDENCE ON DENSE FOG IS STILL LOW. TEMPS WILL BE KEPT
ABOVE NORMAL WITHIN THE RETURN FLOW REGIME OVERNIGHT.
SUNDAY...GUIDANCE IN GOOD AGREEMENT ON A COLD FRONT SAGGING SEWD
ACRS THE OH VLY...BUT PRECIP HOLDING OFF TO THE NORTH BEHIND THE SFC
BNDRY. SO WE WILL SEE AN INCREASE IN MAINLY THICKENING HIGH CLOUDS
DURING THE AFTN...BUT OTHERWISE IT SHUD BE A VERY NICE DAY WITH
HIGHS ABOUT 8-10 DEG ABOVE NORMAL.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 230 PM EST SAT...AN APPROACHING UPPER LEVEL SHORTWAVE WILL
DEAMPLIFY AS IT MOVES SWIFTLY EWD FROM THE PLAINS TO THE SRN
APPALACHIANS SUN NIGHT THROUGH MON MORNING. THE WAVE WILL INTERACT
WITH A LOW LEVEL FRONTAL ZONE DRAPED ALONG THE OH AND MID MS RIVER
VALLEYS AND GENERATE SFC WAVES ALONG THE BOUNDARY. MOST OF THE
MOISTURE WITH THE BOUNDARY WILL BE CONFINED TO THE IMMEDIATE FRONTAL
ZONE AND THE COLD SIDE...KEEPING OUR AREA IN THE WARM SECTOR THROUGH
SUN NIGHT...WITH ONLY SLOWLY BUILDING POPS AS THE FRONT BEGINS TO
GET SHUTTLED EWD. FORCING FEATURES COME TOGETHER BEST ACROSS THE
AREA MON MORNING IN THE FORM OF RIGHT ENTRANCE REGION UPPER JET
DIVERGENCE...PASSING DEEP LAYER Q VECTOR CONVERGENCE WITH THE
SHORTWAVE...LOW LEVEL CONVERGENCE AS THE SFC WAVE SWEEPS IN ALONG
THE FRONTAL ZONE...AND POSSIBLY WEAK DEFORMATION ZONE FORCING
THROUGH LATE DAY NW OF THE SFC WAVE AFTER THE BOUNDARY SLIPS THROUGH
THE AREA. THIS WILL WARRANT LIKELY TO CAT POPS THROUGHOUT MON
MORNING.
EVEN WITH THE SFC WAVE DEVELOPMENT...MUCAPES WILL BE LIKELY BE
LIMITED TO 100 J/KG OR LESS...WITH 850 TO 500 MB LAPSE RATES 5.5 TO
6 DEG C/KM...AND WITH WESTERLY SHEAR PROFILES. THIS WILL GREATLY
LIMIT THE TSTM POTENTIAL AND ONLY SHOWERS WILL BE MENTIONED IN THE
WARM SECTOR. COLD AIR WILL RAPIDLY SURGE INTO THE NRN TIER MON
AFTERNOON AS THE COLD FRONT MOVES THROUGH FROM THE W AND A BACKDOOR
FRONT WRAPS DOWN FROM THE N. THE RACE WILL THEN BE ON BETWEEN THE
MOISTURE EXITING SE AND COLDER PROFILES ARRIVING FROM THE N TO
SUPPORT A WINTRY MIX. STILL FEEL THAT ANY ACCUMULATING WINTRY PRECIP
WOULD BE CLIMATOLOGICALLY UNFAVORED IN THIS SETUP. IN ADDITION...
PROFILES APPEAR TO DRY OUT FROM THE TOP DOWN IN THE COLDER NRN
TIER...LIKELY ENDING THE POTENTIAL FOR ICE NUCLEATION AND ANY
ACCUMULATING FREEZING/FROZEN PRECIPITATION. BRIEF PATCHY FREEZING
DRIZZLE OR VERY LIGHT FREEZING RAIN COULD STILL OCCUR OVER THE NW NC
PIEDMONT LATE MON...WITH BRIEF FREEZING DRIZZLE OR LIGHT SNOW
SHOWERS LINGERING IN THE MTNS NEAR THE NC BORDER INTO EARLY EVENING.
NO HAZARD HEADLINES ARE EXPECTED AT THIS TIME.
H5 FLOW WILL QUICKLY BECOME ZONAL THROUGH TUE...WITH 1032 MB HIGH
PRES BUILDING OVER TO THE N FROM THE OH VALLEY TO THE MID ATLANTIC
REGION. THIS...ALONG WITH SOME PATCHY HIGH CLOUDS...MAY CAP TUE MAX
TEMPS AT 10 TO 15 DEGREES BELOW CLIMO.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 310 PM SATURDAY...TRICKY MEDIUM RANGE FCST CONTINUES AS
GENERAL OVERALL AGREEMENT EXISTS...BUT SIGNIFICANT DETAIL DIFFERENCES
REMAIN AS WELL. THE ECMWF HAS BEEN THE MOST CONSISTENT SHOWING A
STRONG SHORT WAVE DIVING TO THE WRN GULF COAST BY WED NITE THEN
CUTTING OFF AN UPPER LOW ON THU. THIS LOW THEN MOVES EAST ALONG THE
GULF COAST THU NITE AND UP THE EASTERN SEABOARD FRI AND SAT. THE
CANADIAN MODEL IS COMING AROUND TOWARD THIS SOLUTION WITH SOME MINOR
PLACEMENT AND TIMING DIFFERENCES. THE GFS REMAINS THE OUTLIER WITH A
MUCH FASTER AND OPEN WAVE. THE GFS HAS NOT BEEN AS CONSISTENT WITH
THE STRENGTH...POSITION OR TIMING OF THIS SYSTEM. THE GEFS ENSEMBLE
MEAN IS DEEPER AND SLOWER WITH THIS SYSTEM...BUT NOT AS DEEP OR SLOW
AS THE ECMWF OR CANADIAN. WPC IS TRENDING TOWARD THE DEEPER AND
SLOWER SCENARIO...SO HAVE GONE THIS DIRECTION AS WELL.
WED WILL BE A COOL DRY DAY WITH TEMPS 5 TO 10 DEGREES BELOW NORMAL
AS HIGH PRESSURE NOSES INTO THE AREA FROM THE NORTH IN A CLASSICAL
CAD PATTERN. THE GULF LOW SPINS UP ON THU AND MOVES EAST SPREADING
MOISTURE AND PRECIP INTO THE AREA OVER THE DEVELOPING CAD. THE GFS
WITH ITS WEAKER AND FASTER LOW...KEEPS THE BULK OF THE PRECIP
GENERALLY SOUTH OF I-85. HOWEVER...THE ECMWF AND CANADIAN ARE
WETTER. THEREFORE...SPREAD CHC POP IN ACROSS THE SRN CWFA WED NITE
AND THE ENTIRE CWFA THU. PARTIAL THICKNESSES...H85 TEMPS...AND SFC
TEMPS SUGGEST SNOW AND SLEET WOULD DEVELOP ALONG AND NORTH OF I-85
AS THE PRECIP MOVES IN WED NITE...WITH SOME FREEZING RAIN SOUTH. AS
TEMPS WARM THRU THE DAY THU...PRECIP CHANGES TO RAIN IN ALL BUT THE
DEEPEST PART OF THE CAD DOME...NEAR AND ALONG THE BLUE RIDGE. AS THE
LOW MOVES UP THE SERN COAST THU NITE AND FRI...PRECIP REMAINS ACROSS
THE CWFA. PARTIAL THICKNESSES AND TEMPS REMAIN COOL OVER THE MTNS
WITH SFC TEMPS FALLING ALONG THE I-40 CORRIDOR TOWARD DAYBREAK. A
STRONG WARM NOSE DEVELOPS WITH CONTINUING WWA. THIS CHANGES ANY
WINTRY PRECIP IN THOSE COLDER AREAS TO FREEZING RAIN. PRECIP TAPERS
OFF ACROSS THE WRN CWFA FRI AFTERNOON AND ALL AREAS FRI EVENING AS
THE LOW PULLS AWAY FROM THE AREA TAKING MOISTURE AND FORCING WITH
IT. PRECIP WILL CHANGE TO ALL RAIN FRI AS THE WWA CONTINUES AND
REMAINS RAIN UNTIL ENDING. RIGHT NOW...THERE IS MUCH UNCERTAINTY
REGARDING THE THICKNESS AND TEMP PATTERN...EVEN THOUGH THERE IS A
LITTLE BETTER CONFIDENCE THAT A PRECIP EVENT WITH A STRONG UPPER LOW
AND SFC GULF LOW WILL DEVELOP. FOR NOW...HAVE GONE FOR SNOW/SLEET
LESS THAN AN INCH ALONG AND NORTH OF I-85...WITH UP TO 2 INCHES OVER
THE NRN MTNS. ALSO HAVE TRACE ICE ACCRETION NORTH OF I-85 AND LESS
THAN A QUARTER INCH OVER THE MTNS...WITH HIGHEST AMOUNTS OVER THE
NRN MTNS. AGAIN...THIS IS VERY UNCERTAIN...SO STAY TUNED.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
AT KCLT...VFR CONDITIONS ARE EXPECTED THRU THE PERIOD. THE 18Z TAF
STARTING OUT WITH BKN-OVC MID CLOUDS...WHICH SHUD CLEAR OUT WITHIN
THE NEXT COUPLE HOURS...LEAVING MAINLY JUST FEW-SCT CIRRUS FOR THIS
EVENING THRU THE OVERNIGHT. HIGH PRES WILL SHIFT EAST OFF THE
COAST...ALLOWING FOR WINDS TO VEER FROM SE TO SW AND ADVECT HIGHER
DEWPTS INTO THE AREA. THE NAM AND RAP GUIDANCE HINT AT SOME FOG/LOW
STRATUS POTENTIAL AROUND DAYBREAK SUNDAY. HOWEVER...NONE OF THE
OTHER GUIDANCE IS EVEN PICKING UP ON THIS AT ALL. SO CONFIDENCE IS
TOO LOW TO MENTION IN THE TAF FOR NOW. SW WINDS WILL INCREASE TO THE
5-8 KT RANGE AROUND MIDDAY SUNDAY...WITH SOME INCREASING CIRRUS
STREAMING IN FROM THE WEST.
ELSEWHERE...VFR EXPECTED THRU THE PERIOD...EXCEPT FOR A SMALL
POTENTIAL FOR PATCHY FOG DEVELOPMENT AROUND DAYBREAK SUNDAY...ESP IN
THE MTN VLYS. MID CLOUDS WILL CLEAR OUT FOR THE MOST PART...AND HIGH
PRES WILL SHIFT EAST ALLOWING RETURN FLOW TO BRING INCREASING
MOISTURE FROM THE SOUTH. CONFIDENCE IS TOO LOW TO MENTION IN ANY OF
THE PIEDMONT TAFS FOR NOW. WINDS WILL BE LIGHT...GENERALLY OUT OF
THE S/SW.
OUTLOOK...QUIET SUNDAY. A FRONT WILL BRING WIDESPREAD SHOWERS AND
SOME RESTRICTIONS MONDAY. DRY HIGH PRESSURE TUESDAY AND WEDNESDAY.
CONFIDENCE TABLE...
20-02Z 02-08Z 08-14Z 14-20Z
KCLT HIGH 100% HIGH 100% HIGH 90% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 94% HIGH 100%
KAVL HIGH 100% HIGH 100% MED 77% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 94% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 97% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...SBK
NEAR TERM...ARK
SHORT TERM...HG
LONG TERM...RWH
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
409 PM CST SAT MAR 1 2014
.DISCUSSION...
REGARDING THE WINTER WEATHER ADVISORY ACROSS NORTH AND CENTRAL
TEXAS...WENT AHEAD AND EXPANDED THE ADVISORY SOUTH TO A CISCO TO
CLIFTON TO ATHENS LINE WITH THE AFTERNOON FORECAST PACKAGE. THE
BIGGEST IMPACTS FROM FREEZING RAIN AND/OR SLEET ACCUMULATIONS ARE
STILL EXPECTED TO OCCUR ALONG AND NORTH OF A LINE FROM GRAHAM TO
PLANO TO SULPHUR SPRINGS. POINTS SOUTH OF THIS LINE TO THE
SOUTHERN EDGE OF THE WINTER WEATHER ADVISORY ARE STILL EXPECTED
TO SEE IMPACTS FROM LIGHT ICE ACCUMULATIONS...BUT THESE IMPACTS
ARE EXPECTED TO BE FOCUSED ON ELEVATED SURFACES...IN PART DUE TO
THE VERY WARM TEMPERATURES ACROSS THE REGION TODAY. DETAILS
REGARDING THE FORECAST CONTINUE BELOW:
A 21Z SUBJECTIVE SURFACE ANALYSIS INDICATED A BOUNDARY LIFTING
SLOWLY NORTH TOWARDS THE RED RIVER WHERE MOST GUIDANCE INDICATES
IT WILL STALL OUT BY SUNSET. TEMPERATURES ACROSS NORTH TEXAS WERE
GENERALLY IN THE MID TO UPPER 70S FOR MOST LOCATIONS...WITH A
NOTABLE EXCEPTION SOUTHWEST OF THE DFW AREA...WHERE TEMPERATURES
SPIKED INTO THE MID TO UPPER 80S ALONG AN 850 MB THERMAL RIDGE.
WITH TEMPERATURES TOPPING OUT IN THE 70S TO 80S ON CONSECUTIVE
DAYS FOR MOST POINTS ACROSS NORTH AND CENTRAL TEXAS...SOIL
TEMPERATURES ARE WARM...AND THIS WILL PLAY AN IMPORTANT ROLE IN
OUR FORECAST OVER THE NEXT 24 HOURS.
TO OUR NORTH...21Z SURFACE OBSERVATIONS ACROSS SOUTHERN KANSAS AND
NORTHERN OKLAHOMA RANGED FROM THE LOWER TEENS TO THE MIDDLE 20S.
COMPARING THESE TEMPERATURES TO THE MORNING NAM 21Z FORECAST FOR
SURFACE TEMPERATURES INDICATED THAT THE NAM WAS RUNNING 8 TO 10
DEGREES TOO WARM WITH AIR ASSOCIATED WITH THE ARCTIC FRONT.
UNFORTUNATELY THE NAM IS THE COLDEST OF THE POPULAR OPERATIONAL
FORECAST MODELS...SO THERE ARE SOME SIGNIFICANT SHORT TERM SURFACE
TEMPERATURE ISSUES TO CONTEND WITH IN THE FORECAST MODELS MOVING
FORWARD. THE RAP IS DOING THE BEST JOB RESOLVING 21Z
TEMPERATURES...BUT THAT IS LARGELY DUE TO THE FACT THAT THE RAP
INGESTS NEW DATA EACH HOUR. AT ANY RATE...CONTINUED TO RELY UPON
THE NAM HEAVILY WITH THIS FORECAST PACKAGE...JUST LIKE THE
MIDNIGHT CREW...BECAUSE THE NAM IS THE COLDEST AND FASTEST WITH
THIS ARCTIC COLD FRONT OVER THE NEXT 24 HOURS.
DUE TO THE PRESENCE OF TWO BOUNDARIES IN THE AREA (THE NEARLY
STATIONARY FRONT NEAR THE RED RIVER...THEN THE ARCTIC FRONT TO THE
NORTH) IT WAS DIFFICULT TO TRACK THE SOUTHERN PROGRESS OF THE
ARCTIC FRONT EARLY THIS AFTERNOON. THIS IS PARTIALLY DUE TO MOSTLY
CLOUDY SKIES NORTH OF THE RED RIVER FRONT...AND PARTIALLY DUE TO
NORTHERLY WINDS EXTENDING FROM THE RED RIVER NORTH THROUGH KANSAS
MASKING THE WIND SHIFT ASSOCIATED WITH THE TRULY ARCTIC AIRMASS.
BASED ON HOURLY TEMPERATURE TRENDS...AT 21Z THE FRONT APPEARED TO
BE NEAR A LINE FROM CANADIAN TX TO WATONGA OK TO PONCA CITY OK.
TRACKING THIS FRONT WILL ALSO PLAY AN IMPORTANT ROLE IN THE
FORECAST FOR PRECIPITATION TYPE OVER THE NEXT 24 HOURS AS A FASTER
OR SLOWER FRONTAL PASSAGE COULD HAVE DRASTIC IMPACTS ON OUR
FORECAST AND IMPACTS.
TO THE FORECAST...THE COLD FRONT IS EXPECTED TO ARRIVE AT THE RED
RIVER JUST AFTER MIDNIGHT TONIGHT...PUSHING INTO THE DFW AREA
BETWEEN 3 AND 4 AM CST. THE FRONT IS EXPECTED TO PASS ACROSS WACO
AROUND 7 AM...AND THEN ACROSS PALESTINE AND TEMPLE/KILLEEN AN HOUR
LATER. THE FRONT IS EXPECTED TO BE SOUTHEAST OF THE FORT WORTH
CWA BEFORE NOON.
AHEAD OF THE FRONT...REGARDING THUNDERSTORM AND SEVERE WEATHER
CHANCES. PARAMETERS ARE THERE INDICATIVE OF A SEVERE THUNDERSTORM
THREAT WITH DEW POINTS IN THE LOWER TO MID 60S IN PLACE CURRENTLY
ACROSS MUCH OF CENTRAL TEXAS. MODELS INDICATE THAT THERE WILL BE
AROUND 1000 J/KG OF CAPE FOR STORMS AND KEEP LAYER BULK SHEAR OF
AROUND 50 KTS. TAKEN AT FACE VALUE THE INTERSECTION OF THIS
PARAMETER SPACE IS SUPPORTIVE OF ORGANIZED STORMS...PROBABLY
SUPERCELLS OR POSSIBLY MULTI-CELL CLUSTERS ASSUMING STRONG FORCING
ALONG THE COLD FRONT IS LARGELY RESPONSIBLE FOR RELEASING THE
POTENTIAL CONVECTIVE ENERGY INTO STORMS.
THE PROBLEM IS THAT THE CONSENSUS OF MODEL GUIDANCE SHOWS A LARGE
CAPPING INVERSION IN THE 850 TO 800 MB LAYER...WHICH IS QUITE
STOUT AT 300 TO 400 J/KG OF CONVECTIVE INHIBITION FOR SURFACE
BASED AIR PARCELS AHEAD OF THE FRONT. FORECAST SOUNDINGS DO
INDICATE THAT STRONG LIFT ASSOCIATED WITH THE ARCTIC FRONT WILL
LIFT AND COOL A LARGE CHUNK OF THIS CAPPING INVERSION...HOWEVER
THE CAP APPEARS TO BE CONSISTENTLY IN PLACE UNTIL 2-3 HOURS BEHIND
THE FRONT. THIS BEING THE CASE...THERE WOULD BE NEARLY A ZERO
CHANCE OF SURFACE BASED STORMS AND TORNADOES ACROSS THE CWA OUT
AHEAD OF THE FRONT TOMORROW MORNING. DAMAGING WIND MAY BE
POSSIBLE...HOWEVER STORMS ARE EXPECTED TO BECOME QUITE ELEVATED
BEHIND THE FRONT...SO ANY VERTICAL MOTIONS WITHIN THE FRONTAL
INVERSION ARE EXPECTED TO BE DAMPENED BY HIGH STABILITY. THAT
LEAVES A CHANCE FOR ELEVATED STORMS CAPABLE OF PRODUCING
HAIL...WHICH CANNOT BE RULED OUT AT THIS TIME. LEFT A MENTION OF
AN ELEVATED RISK FOR SEVERE STORMS ACROSS THE FAR SOUTHEASTERN CWA
FOR TOMORROW MORNING AS A RESULT IN OUR GRAPHICAL HAZARD IMAGES.
BEHIND THE FRONT...FORECAST SOUNDINGS ARE SUPPORTIVE OF SCATTERED
PRECIPITATION ASSOCIATED WITH PERSISTENT ISENTROPIC UPGLIDE AND
FRONTOGENETIC FORCING FOR ASCENT OVER ALL OF NORTH AND CENTRAL
TEXAS. WENT AHEAD AND BUMPED POPS UP TO 80 PERCENT FOR MOST
LOCATIONS SUNDAY MORNING AS CHANCES FOR ALL LOCATIONS TO RECEIVE
AT LEAST ONE HUNDREDTH OF AN INCH OF PRECIPITATION LOOKS VERY HIGH
AT THIS TIME. MOST PRECIPITATION SUNDAY MORNING IS EXPECTED TO BE
LIGHT...HOWEVER CANNOT RULE OUT SOME EMBEDDED THUNDERSTORMS AS AIR
PARCELS LIFTED FROM THE 900 TO 850 MB LAYER ARE CONSISTENTLY
FORECAST TO HAVE 3-500 J/KG OF POSITIVE CAPE. MORE WIDESPREAD
PRECIPITATION IS EXPECTED TO OCCUR SUNDAY AFTERNOON UNFORTUNATELY
AS A STRONG SHORTWAVE TROUGH CURRENTLY OVER SOUTHERN CALIFORNIA
SPREADS LARGE SCALE FORCING FOR ASCENT OVER THE CWA. THIS IS
UNFORTUNATE BECAUSE THE ARCTIC AIRMASS WILL BE THROUGH THE ENTIRE
CWA BY THIS TIME WITH SUB-FREEZING TEMPERATURES BUILDING QUICKLY
SOUTHEAST THROUGH THE AFTERNOON HOURS OF THE DAY.
DEPENDING ON HOW FAST TEMPERATURES FALL BEHIND THE FRONT...WE
SHOULD SEE A TRANSITION FROM RAIN SHOWERS TO FREEZING RAIN...TO
FREEZING RAIN MIXED WITH SLEET TO ALL SLEET THROUGHOUT THE DAY AS
THE ARCTIC AIRMASS CONTINUES TO BUILD INTO THE AREA FROM THE
NORTHWEST. AT THIS TIME HAVE THE BEST CHANCES FOR ACCUMULATING ICE
AND SLEET FOR LOCATIONS ALONG AND NORTH OF A LINE FROM GRAHAM TO
PLANO TO SULPHUR SPRINGS AS THESE LOCATIONS ARE MOST LIKELY TO
SPEND MOST OF THE DAY SUNDAY AT OR BELOW FREEZING. FROM THIS LINE
SOUTH TO A LINE FROM CISCO TO CLIFTON TO ATHENS (THIS INCLUDES THE
DFW METROPLEX)...EXPECT LESSER AMOUNTS OF ICE AND SLEET
ACCUMULATION SIMPLY BECAUSE THE SUB-FREEZING AIR IS SLOWER TO
BUILD IN...AND THESE AREAS SAW TEMPERATURES CLIMB ABOUT 10 DEGREES
HIGHER TODAY THAN LOCATIONS FURTHER NORTH.
ICE ACCUMULATIONS ARE VERY HARD TO PIN DOWN BECAUSE WE HAVE BEEN
SO WARM OVER THE PAST 48 HOURS. JUST LOOKING AT MODEL OUTPUT AND
FORECAST WATER EQUIVALENT PRECIPITATION AND CONVERTING THAT
DIRECTLY INTO ICE IS A VERY POOR ESTIMATE OF ICE ACCUMULATION FOR
THIS EVENT BECAUSE SOIL TEMPERATURES ARE IN THE MID TO UPPER 50S
ACROSS THE CWA. IT WILL TAKE QUITE A BIT OF TIME FOR SOIL
TEMPERATURES TO FALL...MEANING THAT A LARGE PORTION OF ANY LIQUID
PRECIPITATION THAT FALLS...EVEN WITH TEMPERATURES BELOW
FREEZING...WILL NOT STICK TO THE GROUND. ESTIMATING HOW MUCH
RAINFALL WILL RUN OFF VERSUS HOW MUCH WILL ACCUMULATE AS ICE IS
EXTREMELY DIFFICULT. AT THIS TIME FORECAST ACCUMULATION AMOUNTS
ARE APPROXIMATELY 25 PERCENT OF WHAT WE EXPECT TO FALL AS WATER
EQUIVALENT PRECIPITATION.
WHETHER THIS IS AGGRESSIVE OR CONSERVATIVE WILL DEPEND AT LEAST
PARTIALLY ON HOW FAST WE FALL BELOW FREEZING BEHIND THE ARCTIC
FRONT. FALLING BELOW FREEZING FASTER THAN EXPECTED WILL RESULT IN
GREATER IMPACTS ON AVERAGE. WE WILL MONITOR THE PROGRESS OF THE
FRONT THIS EVENING AND OVERNIGHT...AND IF IT LOOKS LIKE WE WILL
GET COLDER SIGNIFICANTLY FASTER...WE MAY HAVE TO UPGRADE SOME
PORTIONS OF THE ADVISORY INTO A WINTER STORM WARNING BEFORE SUNDAY
MORNING. AT THIS TIME THE MOST LIKELY SCENARIO IS ICE ACCUMULATION
AND IMPACTS MAINLY RELEGATED TO ELEVATED SURFACES...WHICH IS WHY A
WINTER WEATHER ADVISORY IS IN EFFECT AND NOT A WINTER STORM
WARNING AT THIS TIME. CURRENT THINKING IS THAT ONE TENTH TO ONE
QUARTER OF AN INCH OF SLEET IS POSSIBLE ACROSS THE ADVISORY
AREA...ALONG WITH LIGHT ICE ACCUMULATIONS OF LESS THAN ONE TENTH
OF AN INCH...MAINLY ON ELEVATED SURFACES.
WITH MOST ATTENTION FOCUSED ON SUNDAYS FRONT AND ASSOCIATED WINTER
WEATHER...HERE IS A QUICK SUMMARY OF THE REMAINDER OF THE FORECAST:
PRECIPITATION IS EXPECTED TO END FROM WEST TO EAST SUNDAY EVENING
ACROSS NORTH TEXAS. TEMPERATURES WILL REMAIN BELOW FREEZING ALL
NIGHT...MEANING ANY RESIDUAL WATER ON AREA ROADWAYS WILL FREEZE UP
CAUSING ADDITIONAL TRAVEL PROBLEMS.
MONDAY MORNING WIND CHILL VALUES WILL BE ZERO TO MINUS 5 DEGREES
FOR MUCH OF NORTH TEXAS...ASSUMING THIS DOES NOT CHANGE IN FUTURE
FORECASTS...WE WILL NEED A WIND CHILL ADVISORY FOR MUCH OF THE CWA
EARLY MONDAY MORNING TO ACCOUNT FOR THESE VERY COLD WIND CHILL
VALUES.
WITH COLD AIR IN PLACE...WE HAVE A CHANCE FOR LIGHT FREEZING RAIN
ACROSS CENTRAL TEXAS EARLY TUESDAY MORNING INTO THE LATE MORNING
HOURS OF THE DAY. WE WILL NEED TO WATCH THIS NEXT UPPER LEVEL
SYSTEM CLOSELY IN CASE IMPACTS ARE GREATER THAN CURRENTLY
FORECAST. CURRENTLY...ANY ICE ACCUMULATIONS ARE EXPECTED TO REMAIN
VERY LIGHT...ON THE ORDER OF ONE HUNDREDTH OF AN INCH.
WE WILL WARM UP FOR THE REMAINDER OF THE WEEK...BUT HAVE LOW RAIN
CHANCES IN THE FORECAST IN THE MIDDLE OF THE WEEK WITH YET ANOTHER
UPPER LEVEL STORM SYSTEM PASSING OVER THE REGION. THIS
PRECIPITATION IS EXPECTED TO REMAIN WARM ENOUGH FOR ALL RAIN AT
THIS TIME.
CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 36 39 16 36 24 / 60 80 10 0 10
WACO, TX 59 63 20 41 29 / 20 80 10 0 10
PARIS, TX 35 38 11 34 22 / 60 90 30 0 10
DENTON, TX 32 33 14 34 21 / 60 80 10 0 10
MCKINNEY, TX 33 35 13 34 19 / 60 80 20 0 10
DALLAS, TX 38 41 16 37 25 / 50 80 10 0 10
TERRELL, TX 44 52 15 36 23 / 50 80 20 0 10
CORSICANA, TX 59 62 18 38 26 / 30 80 20 0 10
TEMPLE, TX 66 67 21 42 30 / 10 80 10 0 20
MINERAL WELLS, TX 32 33 14 36 23 / 50 80 10 0 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 6 AM TO 9 PM CST SUNDAY FOR
TXZ091>095-100>107-115>123-129>135-144>146.
&&
$$
/
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
346 PM CST SAT MAR 1 2014
.SHORT TERM...
HARSH CHANGES AWAIT THE SOUTH PLAINS FOLLOWING OUR LATE SPRING-LIKE
WARMTH OF TODAY. ONE NEED ONLY LOOK AT THE 21Z STATE TEMPS THAT
RANGED FROM 91 IN BRADY TO JUST THE LOWER 20S IN PERRYTON...NOT FAR
FROM SNOW ALREADY OBSERVED IN THE OK PANHANDLE! STATIONARY FRONT AT
21Z STRETCHED FROM HAPPY SOUTHEAST TO FLOYDADA AND JAYTON. 88D
ALREADY SHOWS THIS FRONT EDGING SOUTHWESTWARD AND THIS TREND WILL
ONLY ACCELERATE IN THE COMING HOURS AS AN AXIS OF ARCTIC HIGH
PRESSURE BUILDS INTO THE ROLLING PLAINS. RUC HAS BEEN QUITE SOLID
TODAY WITH THIS BOUNDARY AND INDICATES COLD FROPA AT LUBBOCK NEAR
SUNSET. TEMPORARY DILUTION OF STRATUS NEAR CHILDRESS SHOULD RESUME
IN THE COMING HOURS AND GRADUALLY EXPAND SWWD TONIGHT.
BRUNT OF THE FORECAST CHALLENGE DOES NOT CONCERN THE FRONT...BUT
RATHER AN AXIS OF SUBTROPICAL MOISTURE CURRENTLY STREAMING ACROSS
SRN ARIZONA AND NEW MEXICO AHEAD OF A DECAYING UPPER LOW IN SRN
CALIFORNIA. LATEST MODELS ARE HANDLING THIS MOISTURE RATHER
WELL...BUT CONSIDERING THE PARENT LOW WILL BE DISSOLVING INTO AN
OPEN WAVE AS IT MOVES EAST TONIGHT...THE QUESTION BECOMES HOW MUCH
OF THIS RESIDUAL MOISTURE CAN TRANSLATE INTO PRECIP FOR OUR AREA? WE
ARE NOT OVERLY EXCITED ABOUT PRECIP AMOUNTS IN THE SETUP...BUT DO
ACKNOWLEDGE A WINDOW FROM 12Z TO 18Z WHEN BOTH LIFT AND DEEPENING
SATURATION LOOK SUFFICIENT FOR LIGHT PRECIP. AS THE MID-LEVEL VORT
MAX TRACKS ACROSS OUR WESTERN AND NWRN COUNTIES BY SUN AFTN...LIFT
SHOULD BE BOLSTERED AS IT ENCOUNTERS ELEVATED FN FORCING TRAILING
OUR SURFACE FRONT. GIVEN THE TRACK OF THE VORT MAX...OUR SERN
COUNTIES LOOK TO MISS OUT ON THE BEST PRECIP CHANCES...SO POPS HAVE
BEEN REDUCED HERE WHILE BUMPING UP TO LIKELY MENTION N-NW OF LUBBOCK.
PRECIP PHASE IS THE NEXT CHALLENGE...BUT MODEL SOUNDINGS AS A WHOLE
INSIST ON KEEPING SOME DEGREE OF A WARM NOSE PRESENT ALOFT WHICH
WILL ACT TO SUSTAIN A WINTRY MIX LONGER THAN WE/D CARE TO SEE. WE
DID SIDE A BIT COLDER THAN MODEL GUIDANCE WITH SURFACE WET BULB
TEMPS THROUGH SUNDAY GIVEN THE NATURE OF THE AIRMASS INVOLVED...SO
THIS RESULTS IN A BROADER COVERAGE OF LIGHT FREEZING RAIN/DRIZZLE
AND SLEET. ALL SNOW MAY BE HARD TO COME BY SO LONG AS WE RETAIN SOME
MELTING ALOFT. ALSO...THE WINDOW FOR FREEZING RAIN APPEARS TO BE
SMALL AS THE COLD AIR WILL ONLY DEEPEN WITH TIME AND TIP THE SCALES
IN FAVOR OF SLEET. GROUND TEMPS ARE NOT PARTICULARLY FAVORABLE FOR
ICING...BUT THE BEST CHANCE FOR LIGHT ACCUMS OF SLEET AND A THIN
GLAZE OF ICE ARE CURRENTLY FAVORED IN OUR NORTH AND NORTHWEST
COUNTIES WHERE WE HAVE HOISTED A WINTER WX ADVISORY FOR SUNDAY.
CLIMATOLOGY ALSO TENDS TO FAVOR THESE AREAS FOR WINTRY PRECIP IN
THESE SITUATIONS...BUT LATER SHIFTS WILL MONITOR TRENDS AND ADJUST
THE ADVISORY IF NEEDED. LASTLY...WE CONTINUED TO SCALE BACK MAX
TEMPS FOR SUNDAY IN LIGHT OF ABUNDANT STRATUS AND DEEPENING COLD
AIR ADVECTION.
&&
.LONG TERM...
AFTER A QUICK ROUND OF WINTRY WEATHER SUNDAY...THE REST OF THE
FORECAST PERIOD LOOKS RELATIVELY BENIGN...ALTHOUGH THERE REMAINS A
BIT OF UNCERTAINTY REGARDING THE DEVELOPMENT OF TWO SEPARATE STORM
SYSTEMS BY THE MIDDLE AND END OF NEXT WEEK.
BEGINNING TOMORROW EVENING...IT APPEARS THAT THE VAST MAJORITY OF
PRECIPITATION WILL HAVE ENDED...HOWEVER THE COLD AIR WILL
UNFORTUNATELY LINGER OVERNIGHT AND THROUGH THE DAY MONDAY. WHILE
SOUTHERLY SURFACE WINDS WILL MAKE AN ATTEMPT AT RECOVERY ACROSS
AT LEAST THE WESTERN SOUTH PLAINS MONDAY AFTERNOON... TEMPERATURES
WILL LIKELY REMAIN WELL ABOVE NORMAL THROUGHOUT THE
REGION...RANGING FROM THE UPPER 40S WEST...TO THE LOW 30S IN THE
NORTHERN ROLLING PLAINS.
SUBDUED...GRADUAL MODERATION WILL BEGIN TUESDAY UNDER A REGIME OF
WEAK ZONAL FLOW ALOFT AND A MOSTLY DRY AIRMASS...WITH THE
POSSIBLE EXCEPTION OF STUBBORN HIGH CIRRUS CLOUDS. FROM
HERE...MODEL SOLUTIONS DIVERGE SIGNIFICANTLY WITH ITS RESPECTIVE
SOLUTIONS. THE GFS MAINTAINS THE STATUS QUO...MORE OR LESS...BY
SENDING A SERIES OF PROGRESSIVE OPEN SHORTWAVES ACROSS THE CENTRAL
PLAINS. THIS PARTICULAR PATTERN WOULD LIKELY YIELD LITTLE MORE THAN
DRY...MILD COLD FRONTS ACROSS WEST TEXAS...AND AS OF NOW IS THE
PREFERRED SOLUTION GOING FORWARD. ON THE OTHER HAND... THE ECMWF
IS MUCH DEEPER AND SLOWER IN ITS DEPICTION OF UPPER WAVES ON
WEDNESDAY/THURSDAY AND AGAIN OVER THE WEEKEND. LIKEWISE...THIS
DEPICTION WOULD RESULT IN MUCH GREATER CHANCES FOR PRECIPITATION
IF IT WERE TO PAN OUT. FOR NOW THOUGH...THIS FORECAST WILL OPT TO
SIDE WITH THE DRIER GFS UNTIL A BETTER CONSENSUS IS REACHED AMONG
OPERATIONAL MODELS.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 33 33 16 48 26 / 30 60 0 0 0
TULIA 26 28 12 42 25 / 20 60 10 0 0
PLAINVIEW 27 30 12 43 25 / 10 60 0 0 0
LEVELLAND 34 34 18 45 26 / 10 60 0 0 0
LUBBOCK 29 31 15 43 25 / 10 50 0 0 0
DENVER CITY 38 46 19 48 27 / 10 40 0 0 0
BROWNFIELD 35 36 18 46 26 / 10 40 0 0 0
CHILDRESS 22 25 9 33 22 / 10 40 10 0 0
SPUR 27 29 11 38 23 / 10 30 0 0 0
ASPERMONT 29 29 10 38 23 / 20 20 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: TXZ021-022-027-028-033-034-039-040.
WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST SUNDAY FOR THE
FOLLOWING ZONES: TXZ021>025-027>030.
&&
$$
93/16
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
316 PM CST SAT MAR 1 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 315 PM CST SAT MAR 1 2014
FOR EARLY THIS EVENING...A SHORT WAVE TROUGH WILL MOVE QUICKLY
EAST THROUGH THE AREA. MUCH OF THE FRONTOGENESIS ASSOCIATED WITH
THIS SYSTEM IS LOCATED ACROSS NORTHEAST IOWA AND SOUTHWEST
WISCONSIN. AS A RESULT...HELD ONTO THE HIGHEST PRECIPITATION
PROBABILITIES IN THOSE AREAS THROUGH 02.02Z...AND THEN QUICKLY
LOWERED THE CHANCES AS SUBSIDENCE DEVELOPS ACROSS THE REGION.
ADDITIONAL SNOW TOTALS WILL BE UP TO AN INCH SOUTH OF A CHARLES
CITY IOWA TO LANCASTER WISCONSIN LINE.
FOR LATE TONIGHT AND SUNDAY...THE COMBINATION OF TEMPERATURES
IN THE 0 TO 20 BELOW RANGE AND NORTH WINDS UP TO 10 MPH WILL
PRODUCE WIND CHILLS IN THE 20 TO 35 BELOW RANGE TONIGHT AND
SUNDAY MORNING. DUE TO THIS...ISSUED A WIND CHILL ADVISORY.
WITH OUR NORTHERN AND WESTERN AREAS...REACHING CRITERIA THIS
EVENING...STARTED THEIR WIND CHILL ADVISORY AT 02.00Z. MEANWHILE
SOUTHWEST AND CENTRAL WISCONSIN WILL LIKELY NOT REACH CRITERIA
UNTIL AFTER MIDNIGHT...SO STARTED THESE AREAS AT 02.06Z.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 PM CST SAT MAR 1 2014
FROM SUNDAY NIGHT INTO MONDAY...WIND CHILLS WILL ONCE AGAIN FALL
INTO THE -20 TO -35 DEGREE RANGE. AS A RESULT...WE WILL SEE
ANOTHER WIND CHILL ADVISORY ISSUED FOR THIS TIME PERIOD ON SUNDAY
AFTERNOON.
FROM MONDAY NIGHT INTO TUESDAY MORNING...THE 01.12Z MODELS
CONTINUE TO SHOW THAT A SHORT WAVE TROUGH WILL MOVE SOUTHEAST
THROUGH THE REGION. THE NAM IS THE SLOWEST AT MOVING THIS SYSTEM
INTO THE AREA. MEANWHILE THE GFS...GEM...AND ECMWF HAS SNOW MOVING
IN THE REGION AS EARLY AS MONDAY EVENING. THE GFS HAS MODERATE TO
STRONG 265 TO 280K ISENTROPIC LIFT WHICH QUICKLY SATURATES THESE
SURFACES. WITH QPFS RUNNING UP TO 0.05" AND 20 TO 1 SNOW TO LIQUID
RATIOS...EXPECT SNOW TOTALS UP TO 1 INCH. EXPECT THE HIGHEST
TOTALS TO BE FOUND NORTH OF INTERSTATE 94 WHERE THERE IS THE
STRONGEST FRONTOGENESIS AND DEEPEST ISENTROPIC LIFT.
FROM THURSDAY INTO FRIDAY...THE DETERMINISTIC MODELS CONTINUE TO
SHOW THAT MODERATE WARM AIR ADVECTION WILL DEVELOP AHEAD OF AN
APPROACHING SHORT WAVE TROUGH. THE GFS WARMS THE 850 MB
TEMPERATURES INTO THE -2 TO 0C RANGE. MEANWHILE THE ECMWF WARM THE
850 MB TEMPERATURES INTO THE 2 TO 5C. EVEN THOUGH THE MODELS ARE
CONSISTENTLY WARMING UP THINGS DURING THIS TIME PERIOD...THERE IS
STILL A 3 STANDARD DEVIATION SHOWING UP IN THE MAXIMUM AND MINIMUM
TEMPERATURES FOR THIS TIME PERIOD IN THE MEN. THE CFS VERSION 2
HAS WARMED UP THIS PERIOD DURING ITS LAST 4 MODEL RUNS. HOWEVER IT
STILL HAS ITS MEAN IN THE UPPER 20S. AS A RESULT...STILL A BIT
CONCERNED THAT WE MAY BE GOING A BIT TOO HIGH WITH OUR
TEMPERATURES DURING THIS TIME PERIOD. HOWEVER MY CONFIDENCE WAS
NOT HIGH ENOUGH TO GO AWAY FROM THE MODEL CONSENSUS.
FROM FRIDAY NIGHT INTO SATURDAY...THE MODELS CONTINUE TO STRUGGLE
ON WHERE THE POLAR JET WILL BE LOCATED. THE ECMWF SUGGESTS THAT IT
WILL BE NORTH AND EAST OF THE FORECAST AREA. AS A RESULT...OUR
HIGH TEMPERATURES WOULD REMAIN IN THE 30S ON SATURDAY. MEANWHILE
THE GFS HAS ITS POLAR JET SOUTH AND WEST OF THE FORECAST AREA AND
THE HIGH TEMPERATURES WOULD ONLY BE IN THE TEENS FOR SATURDAY.
DUE TO THIS...JUST WENT WITH THE MODEL CONSENSUS WHICH HAS HIGH
TEMPERATURES IN THE MID AND UPPER 20S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1127 AM CST SAT MAR 1 2014
THE LIGHT SNOW HAS BEEN MOVING IN FASTER THAN PREVIOUSLY
ANTICIPATED...WHICH ALSO MEANS IT SHOULD MOVE OUT FASTER.
CONDITIONS HAVE ALREADY GONE DOWN TO IFR AT KRST AND BASED ON
RADAR TRENDS AND THE 01.15Z HRRR EXPECT THESE TO CONTINUE INTO THE
MIDDLE OF THE AFTERNOON AND THEN START TO IMPROVE WITH VFR
CONDITIONS EXPECTED BY LATE AFTERNOON. FOR KLSE...EXPECTING MVFR
TO IFR CONDITIONS IN THE LATE AFTERNOON BEFORE IMPROVE BEGINS WITH
VFR CONDITIONS BY EARLY AFTERNOON. ONCE THE SHORT WAVE TROUGH
MOVES PAST...SUBSIDENCE WILL DEVELOP THIS EVENING ALLOWING THE
CLOUDS TO SCATTER OUT OVERNIGHT WITH VFR CONDITIONS EXPECTED FOR
THE REMAINDER OF THE PERIOD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO NOON CST SUNDAY
FOR WIZ017-029-032>034.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST SUNDAY FOR
WIZ041>044-053>055-061.
MN...WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO NOON CST SUNDAY
FOR MNZ079-086>088-094-095.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST SUNDAY FOR
MNZ096.
IA...WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO NOON CST SUNDAY
FOR IAZ008>010-018-019-029.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST SUNDAY FOR
IAZ011-030.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 216 PM CST SAT MAR 1 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A STRONG ARCTIC
HIGH PRESSURE BUILDING SOUTHEAST TOWARDS THE WESTERN GREAT LAKES
THIS AFTERNOON. LOOKING ALOFT...MID-LEVEL CONFLUENCE IS OCCURRING
OVER THE NORTHERN PLAINS TO WESTERN GREAT LAKES. ASSOCIATED
MID-LEVEL FGEN IN THIS CONFLUENCE ZONE WITH HELP FROM SHORTWAVE
ENERGY OVER THE NE/SD IS GENERATING A BAND OF LIGHT SNOW FROM SOUTH
DAKOTA TO WESTERN MICHIGAN. ACROSS THE CWA...THIS SNOW IS GENERALLY
ALONG AND SOUTH OF ROUTE 29 AND MAY SEE A HALF INCH OF ACCUM FROM
WAUTOMA TO MANITOWOC THIS AFTERNOON. NORTHWEST WINDS BEHIND THE
SNOW BAND ARE COLD ADVECTING A BITTERLY COLD AIRMASS OUT OF THE
1045MB ARCTIC HIGH. TEMPS THIS AFTERNOON REMAIN BELOW ZERO OVER
CENTRAL AND NORTHERN MINNESOTA. CONCERNS INCLUDE TIMING THE END OF
THE SNOW...AND WIND CHILLS TONIGHT INTO SUNDAY MORNING.
TONIGHT...BROAD MID-LEVEL CONVERGENCE ZONE BETWEEN A NORTHERN STREAM
SHEAR AXIS AND SOUTHERN STREAM SHORTWAVE ENERGY WILL SLIDE TO THE
SOUTHEAST TO THE SOUTHERN GREAT LAKES AND NORTHERN OHIO VALLEY. THE BAND
OF LIGHT SNOW WITHIN THE FGEN OF THIS CONVERGENT ZONE WILL EXIT
EAST-CENTRAL WISCONSIN BY THE END OF THE AFTERNOON. NOT SURE IF THE
RETURNS OVER EASTERN SOUTH DAKOTA WILL MAKE IT THIS FAR EAST...BUT
WILL LEAVE A SMALL CHANCE OVER CENTRAL WISCONSIN EARLY IN THE
EVENING. FURTHERMORE...THE MESO-MODELS ARE PICKING UP A MID-LAKE
SNOW BAND OVER CENTRAL LAKE MICHIGAN THAT DEVELOPS THIS EVENING AND
DROPS SOUTH THROUGH THE NIGHT. ONE OF THE MESO MODELS INDICATES
THAT SOME OF THIS MID-LAKE SNOW WILL MOVE INLAND OVER THE LAKE SHORE
COUNTIES. GENERALLY DO NOT LIKE THIS IDEA...SINCE SYNOPTIC WINDS
WILL BE OFFSHORE AND ANY LAND BREEZE COMPONENT WILL WANT TO SHOVE
THE LAKE SNOW TO THE OTHER SIDE OF THE LAKE. WILL KEEP THE CHANCE OF
LIGHT SNOW ALONG THE LAKE SHORE THROUGH THE NIGHT...BUT KEEP ACCUMS
LIGHT.
THE OTHER PROBLEM AREA TONIGHT WILL BE WIND CHILLS ACROSS
NORTH-CENTRAL WISCONSIN. ARCTIC HIGH PRESSURE WILL BE BUILDING INTO
THE REGION TONIGHT...WITH MID AND HIGH CLOUDS THINNING OUT AFTER
MIDNIGHT. EXPECT THE SURFACE GRADIENT TO BE A LITTLE TOO TIGHT FOR
DECOUPLING THIS EVENING...BUT LOW LEVEL WINDS SUBSIDE OVERNIGHT SO
THINK SURFACE WINDS SHOULD TURN LIGHT AND VARIABLE. TEMPS FALLING
BELOW MINUS 20 SEEMS LIKELY...SO STUCK WITH THE PREVIOUS FORECASTERS
MIN TEMPS. WITH CLOUDS OVERHEAD IN THE EVENING...FOLLOWED BY THE
POTENTIAL FOR DECOUPLING AFTER MIDNIGHT...GENERALLY NOT EXCITED TO
ISSUE A WIND CHILL ADVISORY WITH SO MANY QUESTION MARKS...ESPECIALLY
AFTER SO MANY LOW WIND CHILL EVENTS ALREADY. BUT WITH OFFICES TO
THE WEST ISSUING HEADLINES...WILL FOLLOW SUIT TO BLEND.
SUNDAY...ANY LIGHT SNOW NEAR THE SHORELINE OF MANITOWOC AND KEWAUNEE
COUNTIES WILL BE EXITING DURING THE MORNING AS DRY ARCTIC AIR FLOWS
SOUTHEAST ACROSS THE REGION. SHOULD SEE A MOSTLY SUNNY SKY IN THE
AFTERNOON WITH HIGHS IN THE SINGLE DIGITS TO LOW TEENS.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
ISSUED AT 216 PM CST SAT MAR 1 2014
SPLIT FLOW PATTERN EARLY IN THIS PERIOD WILL CONSOLIDATE MONDAY
WITH SOME MODERATION OF COLD EXPECTED AS MORE ZONAL PATTERN SETS
UP. THEREAFTER...SERIES OF WEAK SYSTEMS MOVING THROUGH FLOW TO
BRING PCPN TO AREA FROM TIME TO TIME. ISSUES WILL BE TIMING THESE
SYSTEMS. MOISTURE WILL ALSO BE LIMITED SO AMOUNTS WILL ON LIGHT
SIDE. BY THU...850MB TEMPS RISE INTO SINGLE DIGITS BELOW
ZERO...WITH SURFACE TEMPS APPROACHING 30? PATTERN BEGINS TO
AMPLIFY ONCE AGAIN AS MOVE INTO THE WEEKEND WITH TROF OVER CENTER
OF U.S. COLDER TEMPERATURES RETURN...THOUGH MEDIUM RANGE MODELS
SUGGEST THIS COLDER TURN TO BE SHORT LIVED.
IN NEAR TERM....HIGH PRESSURE BUILDING IN OUT OF NORTHERN PLAINS
AND LIGHT WINDS TO LEAD TO CONTINUING VERY COLD PERIOD THROUGH
MONDAY. RECORD HIGH TEMP FOR MARCH 3RD MAY BE IN JEOPARDY.
QUESTION ON NEED FOR WIND CHILL ADVISORY SUN NIGHT AS WINDS
EXPECTED TO DROP OFF NORTH CENTRAL AND CENTRAL ESPECIALLY AFTER
6Z. WINDS ALOFT ONLY AROUND 10KTS THROUGH 850MB. WAA PATTERN...LFQ
OF JET MOVING THROUGH PLAINS TO LEAD TO NEXT CHANCE OF PCPN LATE
MON NIGHT INTO TUE. STAYED WITH CHANCE POPS GIVEN MOISTURE
CONCERNS WITH EXITING DRY SURFACE HIGH PRESSURE.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1113 AM CST SAT MAR 1 2014
ANOTHER ROUND OF LIGHT SNOW WILL SPREAD ACROSS SOUTHERN WISCONSIN
THIS AFTERNOON. THE NORTHERN EDGE WILL CLIP CENTRAL WISCONSIN BUT
SHOULD REACH INTO EAST-CENTRAL WISCONSIN BY MID TO LATE AFTERNOON.
THE FOX VALLEY AND LAKE SHORE TAF SITES SHOULD SEE VSBYS/CIGS FALL
TO MVFR CONDITIONS...AND POSSIBLY IFR AT MTW FOR A PERIOD. NOT
EXPECTING MORE THAN AN INCH OF ACCUMULATION THOUGH. THE MAIN AREA
OF SNOW WILL EXIT BY LATE IN THE EVENING...THEN MODELS ARE DEPICTING
A BAND OF SNOW DEVELOPING OVER LAKE MICHIGAN LATE TONIGHT. SOME
INDICATIONS THAT THIS BAND WILL BRUSH BY MTW INTO SUNDAY MORNING.
WILL KEEP MVFR CONDITIONS AT MTW THROUGH THEN.
OTHERWISE...CONDITIONS TO TURN VFR ELSEWHERE OVERNIGHT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO NOON CST SUNDAY
FOR WIZ005-010>013-018-019-021-030-035-036.
&&
$$
SHORT TERM.....MPC
LONG TERM......TE
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1127 AM CST SAT MAR 1 2014
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 230 AM CST SAT MAR 1 2014
BROAD UPPER LEVEL TROUGH IS PROGGED TO HOLD ACROSS SOUTHERN
CANADA...KEEPING THE BULK OF ITS ENERGY TO THE NORTH. HOWEVER...IT
DOES HELP ENHANCE TEMP GRADIENT/FRONTOGENETIC FORCING FARTHER
SOUTH...WHICH WILL PLAY A KEY ROLE IN SNOW CHANCES TODAY. NORTH-
SOUTH RUNNING X-SECTION POINTS TO A GOOD AMOUNT OF SLOPING
FRONTOGENETIC FORCING...MOSTLY IN THE 500-850 MB LAYER...STRONGEST
SOUTH OF I-90...AND FOCUSED FROM 21-06Z TONIGHT. SLOPING WARM AIR
ADVECTION ALSO...SOUTH TO NORTH. MEANWHILE...SOME HINTS THAT THERE
COULD BE SOME UPPER LEVEL SUPPORT VIA THE RIGHT ENTRANCE REGION OF
A 150 KT JET STREAK WORKING ACROSS THE GREAT LAKES. AMPLE FORCING
FOR PCPN PRODUCTION...BUT ACROSS THE SOUTH. MOISTURE DOESN/T APPEAR
TO BE AN ISSUE...WITH RH FIELDS AND SOUNDINGS POINTING TO AMPLE
SATURATION. SO...SNOW WILL FALL ACROSS IOWA/SOUTHERN WI...WITH MOST
ACCUMULATIONS STAYING SOUTH OF I-90. AMOUNTS FROM 1-3" LOOK
REASONABLE AT THIS TIME.
ANOTHER NIGHT OF BITTER COLD WITH TEMPERATURES EXPECTED TO TUMBLE
INTO THE TEENS TO SINGLE DIGITS BELOW NORMAL. SOUTHERN LOCATIONS
WILL STAY A BIT WARMER THANKS TO CLOUDS LINGERING IN THESE AREAS
LONGER. WINDS WON/T BE STRONG...BUT ENOUGH THAT WIND CHILLS FROM 20
TO 35 BELOW ARE EXPECTED...AND A WIND CHILL ADVISORY WILL BE NEEDED.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 230 AM CST SAT MAR 1 2014
BITTER COLD IS GOING TO STICK AROUND FOR A FEW MORE DAYS AS ECMWF
850 MB TEMPS HOVER CLOSE TO -2 THROUGH MONDAY. HIGH PRESSURE WORKS
OVERHEAD SUN-MON...RESULTING IN MOSTLY CLEAR SKIES AND GOOD
RADIATIONAL COOLING AT NIGHT. FRESH SNOWFALL FROM FRIDAY AND TODAY
WILL AID THE COOLING POTENTIAL. LOWS ARE EXPECTED TO DROP WELL INTO
THE MID TO UPPER TEENS BELOW NORMAL FOR MONDAY. ALTHOUGH WINDS WILL
BE LIGHT TO CALM AT TIMES...ANOTHER WIND CHILL ADVISORY WILL BE
NEEDED. EVEN A 4 MPH WIND WILL MAKE IT 7 TO 8 DEGREES COLDER.
THE GFS/ECMWF STILL HOLDING ON COURSE WITH A SHIFT TO A MORE ZONAL
FLOW A LOFT THIS WEEKEND...CONTINUING THROUGH MUCH OF NEXT WEEK. THE
BITTER COLD WILL SHUNT BACK TO THE NORTH...ALLOWING FOR MODERATING
TEMPERATURES. TRENDS ALSO FAVOR HITTING/EXCEEDING THE FREEZING MARK
FOR PARTS OF THE FORECAST AREA BY THU/FRI. EC A BIT MORE AGGRESSIVE
WITH ITS WARMING...BUT THE FLOW ALLOWS FOR SOME BIGGER SWING. WILL
STAY WITH THE WARMING - HOPING FOR TEMPS MORE NORMAL FOR EARLY
MARCH. ANYTHING MORE WOULD BE A BONUS.
THE ZONAL FLOW WILL ALSO ACT AS A HIGHWAY FOR VARIOUS UPPER LEVEL
PERTURBATIONS TO SPIN ACROSS...OR CLOSE TO...THE UPPER MISSISSIPPI
RIVER VALLEY. THERE WILL BE DIFFERENCES IN THE MODELS WITH THESE
SMALL SYSTEMS...POSITIONING AND TIMING...SO TRYING TO NAIL DOWN
WHERE/WHEN THE BEST SNOW CHANCES WILL BE IS PROBLEMATIC. WILL STICK
WITH THE CONSENSUS SOLUTION FOR NOW...WHICH BRINGS A LOT OF SMALL
CHANCES DAY TO DAY. THERE SHOULD BE MORE CLARITY TO THE VARIOUS
PRECIPITATION THREATS AS WE GET WITHIN 72 HOURS.
SUFFICE TO SAY...TRENDS ARE FAVORING SOME WARMING TOWARD THE END OF
NEXT WEEK...WITH A MORE ACTIVE UPPER LEVEL FLOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1127 AM CST SAT MAR 1 2014
THE LIGHT SNOW HAS BEEN MOVING IN FASTER THAN PREVIOUSLY
ANTICIPATED...WHICH ALSO MEANS IT SHOULD MOVE OUT FASTER.
CONDITIONS HAVE ALREADY GONE DOWN TO IFR AT KRST AND BASED ON
RADAR TRENDS AND THE 01.15Z HRRR EXPECT THESE TO CONTINUE INTO THE
MIDDLE OF THE AFTERNOON AND THEN START TO IMPROVE WITH VFR
CONDITIONS EXPECTED BY LATE AFTERNOON. FOR KLSE...EXPECTING MVFR
TO IFR CONDITIONS IN THE LATE AFTERNOON BEFORE IMPROVE BEGINS WITH
VFR CONDITIONS BY EARLY AFTERNOON. ONCE THE SHORT WAVE TROUGH
MOVES PAST...SUBSIDENCE WILL DEVELOP THIS EVENING ALLOWING THE
CLOUDS TO SCATTER OUT OVERNIGHT WITH VFR CONDITIONS EXPECTED FOR
THE REMAINDER OF THE PERIOD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04