Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/12/15
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1026 AM MST THU DEC 10 2015
.UPDATE...
ISSUED AT 1025 AM MST THU DEC 10 2015
A "DIRTY" UPPER LEVEL HIGH PRESSURE RIDGE WILL PASS OVER NORTH
CENTRAL AND NORTHEAST COLORADO TODAY...CAUSING TEMPERATURES ALOFT
TO WARM SLIGHTLY AND THE MODERATELY STRONG WESTERLY MTN TOP FLOW
TO BECOME SOUTHWESTERLY WITH THE RIDGE AXIS PASSES OVER THE FRONT
RANGE AROUND MIDDAY. MEANWHILE BNDRY LAYER WINDS HAVE GONE SELY
OVER THE PALMER DIVIDE AND ALONG THE FRONT RANGE BEHIND A WEAK
COLD FRONT THAT RACED SEWRD ACRS NERN COLORADO EARLIER THIS
MORNING.LATEST MESOSCALE MODEL OUTPUT SHOWS A CLOCKWISE SHIFT TO
SOUTH-SOUTHEASTERLY WIND COMPONENT OVER THE NEXT FEW HOURS.
HOWEVER MANY OF THESE SAME MODELS SHOW GUSTY WEST-SOUTHWEST WINDS
DEVELOPING OVER AND NEAR THE FOOTHILLS NOT LONG AFTER 19Z
APPARENTLY IN RESPONSE TO FALLING PRESSURE AT THE BASE OF THE
FOOTHILLS. HRRR AND WRF SFC WIND FIELDS INDICATE A SURGE IN
DOWNSLOPE WINDS IN THE FOOTHILLS THRU THE AFTERNOON WITH GUSTS IN
THE 20-30KT RANGE AT THE BASE OF THE FOOTHILLS AROUND 21Z TODAY.
RAP EVEN SHOWS A BURST OF WESTERLY WINDS REACHING DIA AND AURORA
AROUND MID-AFTERNOON WHICH COULD CAUSE A SUDDEN JUMP IN
TEMPERATURE. AT PRESENT TIME...TEMPS OVER SOUTHEASTERN AND EASTERN
SECTIONS OF THE CWA ARE GENERALLY RUNNING 4 TO 10 DEGS F BEHIND
THOSE OBSERVED YESTERDAY AT THIS TIME...BUT AS MUCH AS 10 DEGS F
WARMER OVER NORTHERN SECTIONS. OTHERWISE EXPECT HIGH CLOUDS TO
GRADUALLY INCREASE AND THICKEN THROUGH THE DAY AND DAYTIME TEMPS
TO REMAIN WELL ABOVE AVERAGE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 323 AM MST THU DEC 10 2015
WINDS HAVE DECREASED CONSIDERABLY OVER THE MOUNTAINS AS THE WAVE
AMPLIFICATION WENT AWAY AND THE FLOW ALOFT HAS BEGUN TO DIMINISH.
SURGE OF WIND AT LOWER ELEVATIONS IS MOVING ACROSS THE NORTHEAST
CORNER NOW...BUT WINDS ARE ALSO STARTING TO DECREASE THERE. WE
NEVER HAD A REALLY GOOD AMPLIFIED WAVE...THE TROUGH STRUCTURE WAS
NOT VERY SHARP SO THERE WAS NOT A STRONGLY SUBSIDENT AREA AS THE
JET WENT BY...BUT THERE WERE A COUPLE OF LITTLE BURSTS OF WIND
NEAR HIGH WIND CRITERIA.
IT WILL REMAIN WINDY OVER THE MOUNTAINS THOUGH SPEEDS SHOULD
DECREASE A BIT TODAY...AND MORE SO TONIGHT. TEMPERATURES ARE SEE-
SAWING WITH SOME COOLING ON THE PLAINS AS THE WINDS LET UP THIS
MORNING...WHILE WARMING ALOFT WILL ALLOW FOR TEMPERATURES TO RISE
TO NEAR YESTERDAYS NEAR RECORD NUMBERS THIS AFTERNOON. RAISED
HIGHS TODAY JUST A LITTLE...THEN WITH LIGHTER WINDS TONIGHT THE
LOWS WILL BE COOLER. CLOUD COVER STILL COMING AND GOING...BUT I
DID LOWER THE LOWS TONIGHT A LITTLE EXPECTING MORE COOLING THAN WE
HAVE HAD THE LAST SEVERAL NIGHTS. MID LEVEL MOISTURE AHEAD OF THE
APPROACHING TROUGH STARTS TO EASE INTO THE MOUNTAINS LATE TONIGHT.
LEFT SOME POPS...BUT OVERNIGHT SNOW WILL BE LIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 323 AM MST THU DEC 10 2015
THE MODELS ARE IN DECENT AGREEMENT WITH THE TIMING OF THE NEXT
STORM SYSTEM. A STRONG SOUTHWESTERLY FLOW ALOFT WILL BE OVER THE
STATE ON FRIDAY WITH MOISTURE INCREASING IN THE MOUNTAINS OF
NORTHERN COLORADO IN THE AFTN. ZONE 31 WILL HAVE THE BEST CHC OF
SNOW ON FRIDAY...BUT SNOW WILL START TO DEVELOP IN THE FRONT RANGE
MOUNTAINS BY LATE AFTN. BY LATE IN THE DAY THE MDLS SHOW A 150 KT
JET OVER NORTHWESTERN CO. AS THE TROUGH MOVES INTO THE GREAT BASIN
THIS UPPER LEVEL JET SHIFTS INTO SRN AND ERN CO BY 00Z SATURDAY.
THE MOUNTAINS COULD RECEIVE SOME ENHANCED BANDED SNOWFALL FRIDAY
NIGHT...IN PARTICULAR ZONES 31 AND 33. ALONG THE URBAN
CORRIDOR...NAM12 SPATIAL CROSS SECTIONS SHOW LOW LEVEL NELY
UPSLOPE DEVELOPING FRIDAY EVENING...WITH DEEPENING
MOISTURE/UPSLOPE TO 675 MB 03-06Z. NOT MUCH ACCUMULATION EXPECTED
IN THE EVENING WITH THE WARMER SFC TEMPERATURES...BUT COULD SEE
SOME IN THE GRASSY AREAS BY LATE EVENING. THE FOCUS FOR THE
HEAVIEST SNOWFALL APPEARS TO BE JACKSON AND LARIMER COUNTIES AND
MAYBE WELD AS WELL...WHERE THE BEST COMBINATION OF JET DYNAMICS
AND LOW LEVEL UPSLOPE WILL BE. QG ASCENT GENERATED BY THE MDLS
STRONGEST 06-12Z SATURDAY...WITH DECREASING ASCENT IN THE AFTN AS
THE TROUGH AXIS MOVES INTO EASTERN COLORADO. OVERALL SNOW AMOUNTS
APPEAR TO BE ADVISORY CRITERIA IN THE MOUNTAINS AND FRONT RANGE
FOOTHILLS...MAYBE 6-12 INCHES PRIMARILY FRIDAY NIGHT AND SATURDAY
MORNING. SINCE THIS IS MORE THIRD/FOURTH PERIOD WILL LET THE DAY
SHIFT HOIST IF NEED BE. ALONG THE URBAN CORRIDOR...AREAS NORTH OF
A FT COLLINS TO GREELEY LINE APPEAR TO HAVE THE BEST CHC OF
ACCUMULATING SNOWFALL. COULD SEE 2 TO 6 INCHES FROM SOUTH TO NORTH
ACROSS THE URBAN CORRIDOR FRIDAY NIGHT AND SATURDAY. A STRONG
NORTHWESTERLY FLOW WITH INCREASING MID LEVEL SUBSIDENCE SATURDAY
NIGHT AND SUNDAY. NO SNOW BUT THE WIND COULD AGAIN INCREASE IN THE
MOUNTAINS AND FOOTHILLS. THE NEXT SYSTEM STILL LOOKS LIKE IT WILL
BRING ANOTHER ROUND OF WIND/SNOW TO NORTH CENTRAL AND NORTHEAST
COLORADO MONDAY INTO TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1025 AM MST THU DEC 10 2015
SOUTH-SOUTHEAST WINDS OF 7-14KT AT KDEN AND KAPA WILL GRADUALLY
BECOME TURN SOUTHWESTERLY THROUGH THE AFTERNOON AT SPEEDS
GENERALLY UNDER 15KTS. THERE IS A POSSIBILITY THAT WINDS AT BOTH
AIRPORTS COULD GO WESTERLY AT 15-22KTS AROUND MID-AFTERNOON WITH
A WIND SURGE OFF THE FOOTHILLS. THEN BACK TO A MORE TYPICAL
SOUTHERLY WIND WITH DARKNESS. AT KBJC NEAR THE FOOTHILLS...LIGHT
SOUTHERLY WINDS AT THE PRESENT TIME SHOULD TRANSITION TO A
WESTERLY COMPONENT AROUND MIDDAY WITH GUSTS POTENTIALLY IN THE
25-35KT RANGE THROUGH 00Z/FRI. SHOULD THEN SEE A DROP OFF IN
SPEEDS AND A SHIFT TO A SOUTHWEST WIND IN THE EVENING. OTHERWISE
VFR CONDITIONS NEXT 24 HOURS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BAKER
SHORT TERM...GIMMESTAD
LONG TERM...COOPER
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1251 AM EST THU DEC 10 2015
.SYNOPSIS...
A TROUGH OF LOW PRESSURE APPROACHES FROM THE WEST LIFTS TO THE
NORTHEAST LATE OVERNIGHT AND THURSDAY MORNING. HIGH PRESSURE
BUILDS BACK INTO THE REGION ON THURSDAY WITH A WARM FRONT
APPROACHING FROM THE WEST THURSDAY NIGHT. WEAK LOW PRESSURE WILL
PASS TO THE SOUTH AND EAST ON FRIDAY WITH HIGH PRESSURE AND
POTENTIALLY RECORD BREAKING WARMTH THIS WEEKEND. A FRONTAL SYSTEM
WILL IMPACT THE AREA MONDAY AND MONDAY NIGHT WITH HIGH PRESSURE
BUILDING IN FOR THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
CLOUD COVER EASTERN LONG ISLAND IS VARIABLE...SO TEMPERATURES ARE
BOUNCING UP AND DOWN WITH IT. REGARDLESS...LOWS GENERALLY HAVE
EITHER ALREADY OCCURRED OR SHOULD OCCUR BY MIDNIGHT...THEN EXPECT
STEADY OR SLOWLY RISING TEMPERATURES WITH MORE PERSISTENT AND
THICKENING CLOUD COVER THEN.
LOWS OUTSIDE OF TWIN FORKS REMAIN A BLEND OF MAV/MET GUIDANCE.
A WELL DEFINED MIDDLE AND UPPER LEVEL SHORTWAVE SWINGS ACROSS THE
REGION OVERNIGHT. LOW AND MID LEVEL MOISTURE BRIEFLY INCREASES AS
THE SHORTWAVE ENERGY MOVES BY...BUT THE OVERALL ATMOSPHERIC
PROFILE IS QUITE DRY. BUFKIT PROFILES AND HIGH RESOLUTION MODELS
HAVE BEEN CONSISTENT WITH ADVECTING AN AREA OF STRATUS OVER THE
AREA FROM THE CENTRAL APPALACHIANS AFTER MIDNIGHT. STILL CANNOT
COMPLETELY RULE OUT A BRIEF SHOWER SO HAVE KEPT SLIGHT CHANCE POPS
IN THE FORECAST...BUT NOW HAVE AFTER 6Z BASED ON LATEST TRENDS IN
HI-RES MODELS - NOTE DO NOT BUY BLOOM HRRR AND NAM HAVE AHEAD OF
MAIN AREA OF SHOWERS IMMEDIATELY AHEAD OF SURFACE TROUGH. SEE NO
EVIDENCE OF THIS ON RADAR...AND THIS IS AN OBSERVED BIAS OF BOTH
MODELS IN SIMILAR SITUATIONS IN THE PAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
HIGH PRESSURE BUILDS INTO THE AREA ON THURSDAY AS RIDGING BRIEFLY
MOVES OVERHEAD BEHIND DEPARTING SHORTWAVE. THERE WILL STILL BE A
SLIGHT CHANCE OF A SHOWER ACROSS EASTERN LONG ISLAND AND SOUTHEAST
CONNECTICUT DURING THE EARLY MORNING HOURS. OTHERWISE...CLOUD WILL
SLOWLY ERODE DURING THE MORNING LEADING TO A PARTLY TO MOSTLY SUNNY
AFTERNOON.
WITH MORE SUNSHINE THEN ON WEDNESDAY IN COMBINATION WITH
WARMER AIR BEING TRANSPORTED NORTH VIA SOUTHERLY FLOW...UNSEASONABLE
WARM TEMPERATURES ARE FORECAST. HIGHS WILL REACH THE MIDDLE AND
UPPER 50S. RECORD HIGH TEMPERATURES AT JFK AND ISP COULD BE TIED OR
BROKEN IF THE TEMPERATURES WARM A DEGREE OR SO MORE THAN
CURRENTLY FORECAST.
CLOUDS INCREASE AGAIN THURSDAY NIGHT AS A WARM FRONT APPROACHES FROM
THE WEST. WEAK SURFACE TROUGHING ALONG THE COAST MAY INTERACT WITH A
SHORTWAVE PASSING TO THE NORTH TO CREATE JUST ENOUGH LIFT FOR A
SLIGHT CHANCE POP ACROSS THE SOUTH FORK OF LONG ISLAND AND FAR
SOUTHEAST CONNECTICUT. UNSEASONABLY MILD TEMPERATURES...GENERALLY IN
THE 40S...EXPECTED THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
OVERALL H5 PATTERN IS IN GOOD AGREEMENT INTO NEXT WEEK WITH JUST
SOME TIMING AND AMPLITUDE DIFFERENCES DURING THE LATTER HALF OF
THE FORECAST PERIOD. THESE DIFFERENCES ARE IMPACTING THE STRENGTH
OF A LOW PRESSURE SYSTEM FORECAST TO TRACK FROM THE DEEP SOUTH ON
SUN THROUGH THE GREAT LAKES MON AND INTO THE CANADIAN MARITIMES ON
TUE. THIS SYSTEM WILL NEED TO BEAR WATCHING AS IT IS A FAIRLY
DYNAMIC SYSTEM AND THERE IS THE POTENTIAL FOR STRONG WINDS MONDAY
NIGHT AND TUESDAY. THE STRONGEST WINDS WILL LIKELY BE BEHIND THE
SYSTEM ON TUE WITH DEEP MIXING...BUT HAVE LOW CONFIDENCE IN THE
VELOCITY AS THERE ARE SIGNIFICANT DIFFERENCES IN THE STRENGTH OF
THE SYSTEM. ITS A FAST MOVER SO JUST A QUICK SHOT OF RAIN WHICH
SHOULD NOT POSE ANY HYDRO ISSUES.
PRIOR TO THIS...A SHORTWAVE TROUGH WILL PASS THROUGH THE NORTHEAST
ON FRI...WITH A WEAK AREA OF LOW PRESSURE AT THE SURFACE TRACKING
NEAR THE 40N 70W BENCHMARK. THE BIGGER STORY IS THE BROAD RIDGE
THAT WILL DEVELOP AHEAD OF THE AFOREMENTIONED STORM SYSTEM WITH
THE POTENTIAL FOR RECORD BREAKING WARMTH THIS WEEKEND. HIGH TEMPS
ARE FORECASTED TO REACH 60-65 ON SUNDAY WITH THE POTENTIAL FOR
UPPER 60S IN THE METRO AREA. HOWEVER...THIS WILL BE DEPENDENT ON
CLOUD COVER. MODELS ARE FORECASTING MAINLY HIGH CLOUDS...BUT WOULD
NOT BE SURPRISED IF THERE WAS STRATUS AROUND WHICH WOULD KEEP
THESE HIGHER TEMPS FROM OCCURRING.
ONCE THE COLD/OCCLUDED FRONT MOVES THROUGH MON NIGHT TEMPS WILL
DROP CONSIDERABLY...BUT SHOULD STILL REMAIN 5 TO 10 DEGREES ABOVE
NORMAL TUE AND WED.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
A WARM FRONT WILL APPROACH OVERNIGHT AND PASS THROUGH ABOUND
DAYBREAK THU.
MVFR CIGS NW OF THE NYC METRO TERMINALS COULD LIFT TO VFR FOR A TIME
LATER THIS EVENING AT KHPN...THEN RETURN OVERNIGHT. SHOWERS AND FOG
WITH IFR VSBY STILL EXPECTED FOR A PERIOD LATE TONIGHT INTO EARLY
THU MORNING AT KSWF.
THE LOWER HUDSON VALLEY AND CT TERMINALS SHOULD REMAIN MVFR UNTIL
ABOUT 16Z. NYC METRO AND LONG ISLAND TERMINALS NOW LOOK LESS LIKELY
TO SEE BRIEF MVFR CONDS FOR AN HR OR TWO AROUND SUNRISE...BUT HELD
ONTO TEMPO MVFR CIGS AT KEWR/KTEB.
SE-S WINDS 5-10 KT SHOULD SHIFT SW OR WNW AFTER DAYBREAK
THU...THEN DIMINISH AND BECOME MORE SOUTHERLY DAY THU.
.OUTLOOK FOR 06Z FRI THROUGH MON...
.LATE THU NIGHT...MVFR CONDS LIKELY. IFR CONDS POSSIBLE AT KSWF.
.FRI...BECOMING VFR.
.SAT-SUNDAY...VFR.
.SUNDAY NIGHT...POSSIBLE MVFR OR LOWER CONDITIONS LATE.
.MON...MVFR OR LOWER CONDS IN RAIN.
&&
.MARINE...
MINOR CHANGES WERE MADE WITH THIS UPDATE TO REFLECT THE LATEST
TRENDS IN OBSERVATIONS AND GUIDANCE. THE FORECAST APPEARS ON
TRACK.
A RELAXED PRESSURE GRADIENT OVER THE WATERS SHOULD KEEP SUB SCA
CONDITIONS THROUGH THURSDAY NIGHT. ON THE OCEAN...WINDS SHOULD
GENERALLY BE NO GREATER THAN 15 KT WITH SEAS BETWEEN 2 AND 4 FT.
SUB-ADVISORY CONDITIONS WILL PERSIST THROUGH THE WEEKEND. WINDS
AND SEAS WILL INCREASE AS THE PRES GRADIENT TIGHTENS DUE TO A
STRENGTHENING LOW PASSING TO THE WEST AND DEPARTING HIGH PRES TO
THE SE. SCA CONDITIONS LIKELY MON...WITH THE POTENTIAL FOR GALES
AND EVEN A CHANCE OF STORM FORCE WINDS ON THE OCEAN WATERS LATE
MON NIGHT AND TUE. HAVE HIGHLIGHTED THIS IN THE HWO.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH THE WEEKEND.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...24/MALOIT/DS
NEAR TERM...MALOIT/DS
SHORT TERM...DS
LONG TERM...24
AVIATION...GOODMAN
MARINE...24/MALOIT/DS
HYDROLOGY...24/DS
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
345 AM EST THU DEC 10 2015
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL AFFECT THE AREA THIS MORNING. HIGH
PRESSURE FROM THE SOUTHEAST WILL RIDGE UP ACROSS THE AREA LATER
TODAY AND REMAIN THROUGH THE WEEKEND. A WARM FRONT WILL CROSS THE
AREA SATURDAY. LOW PRESSURE WILL MOVE ACROSS ACROSS THE GREAT LAKES
AND SOUTHERN CANADA SUNDAY THROUGH TUESDAY. ITS ASSOCIATED COLD
FRONT WILL CROSS THE MIDDLE ATLANTIC REGION MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SFC HIGH PRES AND UPR RIDGE WILL REMAIN THE DOMINANT WX FEATURES
ONCE AGAIN AS THE UNSEASONABLY WARM DECEMBER WX CONTINUES.
A WK UPR LEVEL DISTURBANCE WAS MOVG ACRS THE AREA THIS AM AND HAS
TOUCHED OFF SOME SHWRS. THE OVERALL AREAL COVERAGE HAS DECREASED,
BUT ONE PORTION OF THE SHWRS WILL MOVE ACRS THE WRN SUBURBS OF
PHILLY AND THE LEHIGH VLY BEFORE MOVG INTO CNTRL NJ, IF IT HOLDS
TOGETHER LONG ENOUGH.
THE HRRR DOES NOT KEEP THE PRECIP TOGETHER WHILE OTHER SHORT TERM
GUID DOES.
ONCE THIS FEATURE MOVES THRU, EXPECT A GENLY PARTLY CLOUDY DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
QUIET AND MILD WX IS EXPECTED TONIGHT WITH HIGH PRES
S OF THE AREA AND LIGHT SWLY FLOW. THERE CUD BE SOME PATCHY FOG
ONCE AGAIN BUT LOW TEMPS WILL BE AROUND WHAT NRML HIGHS SHOULD BE.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NO SIGN OF ANY WINTER-LIKE WEATHER DURING THE EXTENDED PERIOD.
THE ENTIRE PERIOD IS EXPECTED TO HAVE TEMPERATURES ABOVE NORMAL.
THE WARMEST PART WILL BE THE FIRST SEVERAL DAYS WHEN HIGH TEMPERATURES
WILL BE IN THE LOW/MID 60S IN MANY AREAS. LITTLE OR NO RAIN IS EXPECTED
FRIDAY THRU SUNDAY AS HIGH PRESSURE REMAIN IN CONTROL.
A STRONG LOW WILL MOVE ACROSS MICHIGAN AND THEN INTO SOUTHERN CANADA
BETWEEN SUNDAY AND TUESDAY. THE LOW WILL DEEPEN TO AROUND 982
MBS...SO A DECENT PRESSURE GRADIENT WILL BE ACROSS MUCH OF OUR AREA.
WE WILL CONTINUE ON THE WARM SIDE OF THE SYSTEM MONDAY WITH HIGHS
AGAIN IN THE 60S. FREQUENT SHOWERS CAN BE EXPECTED AS A COLD FRONT
CROSSES THE REGION.
TEMPERATURES WILL FALL BEHIND THE FRONT...BUT HIGHS TUE AND WED WILL
STILL BE IN THE 50S...SO READINGS ABOUT 10 DEGREES ABOVE NORMAL.
LITTLE RAIN IS EXPECTED TUE INTO WED AS HIGH PRESSURE REMAIN IN
CONTROL OF THE WEATHER.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
AN UPR LEVEL DISTURBANCE WAS MOVG THRU ERLY THIS MRNG AND HAS
BROUGHT SOME MVFR CIGS, MAINLY N AND W. SOME BRIEF SHRA IS ALSO
PSBL ERLY THIS MRNG MAINLY N AND W OF KPHL. THERE IS THE POTENTIAL
FOR IFR, THOUGH THESE CONDS HAVE NOT MATERIALIZED YET. FURTHER SE
ALG THE I-95 CORRIDOR, THERE IS ALSO THE POTENTIAL FOR MVFR/IFR,
THRU MID-MRNG, BUT CONFIDENCE REMAINS LOW AND THESE SITES REMAIN
VFR. WILL TAKE A LOOK AT ADDITIONAL DATA AND MAKE AMENDMENTS AS
NEEDED.
AFTER MID MRNG, VFR CONDS ARE EXPECTED FOR THE BALANCE OF THE DAY
AND INTO THE EVE HOURS. THEN, THERE CUD BE SOME ADDITIONAL MVFR
CIGS/VSBYS FRI MRNG.
WIND IS EXPECTED TO GENLY BE W TO SW AT 5 KT OR LESS THRU THE PD.
OUTLOOK...
FRI THRU SUN NIGHT...GENERALLY VFR. THERE COULD BE SOME LOW CLOUDS
AND FOG DURING THE PRE-DAWN HOURS.
MONDAY...WIDESPREAD MVFR AND IFR POSSIBLE WITH SHOWERS. GUSTY
WINDS AND LLWS POSSIBLE.
&&
.MARINE...
NO MARINE FLAGS ARE ANTICIPATED THRU THE NR AND SHORT TERM PDS
WITH LIGHT S TO SW FLOW. SEAS ARE CURRENTLY AROUND 4 FT AND SHOULD
DECREASE TO AROUND 3 FT LATER TODAY. WIND WILL GENLY BE IN THE 10
TO 15 KT RANGE.
OUTLOOK...
SUB-SCA CONDITIONS FRI AND THROUGH THE WEEKEND. FAIR WEATHER.
WINDS AND SEAS BUILD SUN NIGHT AND PERSIST INTO MONDAY. GALE GUSTS
POSSIBLE. SHOWERS AND GUSTY WINDS MONDAY.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS FOR FRIDAY, SATURDAY, SUNDAY AND MONDAY
/DECEMBER 11-14/ ARE LISTED BELOW FOR REFERENCE. THE WARMEST DAY OF
THESE LISTED SHOULD BE SUNDAY AHEAD OF A COLD FRONT, HOWEVER EVEN
MONDAY COULD BE CLOSE FOR SOME AREAS IF THE SHOWERS HOLD OFF LONGER.
LOCATION DEC 11 DEC 12 DEC 13 DEC 14
-------- ------ ------ ------ ------
KACY 66 IN 1971 67 IN 1931 69 IN 1991 65 IN 1929
KPHL 65 IN 1971* 65 IN 1931 65 IN 1923 69 IN 1881
KILG 66 IN 1971 64 IN 1983* 64 IN 1923 63 IN 2001
KABE 61 IN 1979* 63 IN 1931 62 IN 1923 60 IN 2001
KTTN 65 IN 1911 67 IN 1931 65 IN 1990 67 IN 1901
KGED 66 IN 2008 68 IN 1971 67 IN 1985 67 IN 2001*
KRDG 66 IN 1911 66 IN 1911 61 IN 1946 66 IN 1920*
KMPO 60 IN 1979 63 IN 1979 58 IN 1979 58 IN 1901
* INDICATES LATEST OF MULTIPLE YEARS.
&&
.EQUIPMENT...
HOWELL NJ AND ALLENTOWN PA NWR TRANSMITTERS HAD ISSUES LAST NIGHT...BUT
SEEM OKAY AS OF 330 AM.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...NIERENBERG
SHORT TERM...NIERENBERG
LONG TERM...O`HARA
AVIATION...NIERENBERG/O`HARA
MARINE...NIERENBERG/O`HARA
CLIMATE...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
234 PM EST THU DEC 10 2015
.DISCUSSION...
TONIGHT AND FRIDAY...HIGHER CLOUDINESS WILL BE ABOUT THE ONLY SKY
COVER REMAINING ONCE LOSS OF SFC HEATING OCCURS AT DUSK. VERY
LIGHT TO CALM WINDS AND SOME RESIDUAL LL MOISTURE WL LEAD TO SOME
DEVELOPMENT OF GROUND FOG GENERALLY OVER THE SOUTH HALF OF THE
FORECAST AREA SOUTH OF METRO ORLANDO DURING THE EARLY MORNING
HOURS FRIDAY. OTHERWISE A PLEASANT EVENING CAN BE EXPECTED LOWS IN
THE U50S TO LWR 60S.
SLOW MOVING SHOWERS OVER THE GULF STREAM ASCD WITH A HIGHER LL
ENVIRONMENTAL LAPSE RATE ALONG WITH SOME PROXIMITY TO A WEAK SFC
TROUGH ARE EXPECTED TO CONTINUE OVER THE MARINE AREA TO SOME
DEGREE INTO THE OVERNIGHT HOURS. LCL ARW3 ALONG WITH HRRR GUIDANCE
WANTS TO SQUEEZE OUT SOME COASTAL SHOWERS AND WL KEEP A SMALL
MENTION FOR MARTIN AND ST LUCIE COS TONIGHT.
FRIDAY WILL FEATURE MOSTLY SUNNY SKIES AFTER BREAKUP OF PATCHY
MORNING FOG. RELATIVELY LIGHT SURFACE WINDS AND AMPLE SUN WL PUSH
HIGHS TO AROUND 80 WITH NO MENTION OF PRECIP.
SAT-SUN...
WEEKEND WEATHER LOOKS QUIET AS THE SRN BRANCH OF THE JET STREAM
LIFTS NE AND MERGES WITH THE NRN STREAM OVER THE W ATLC. AS IT
DOES...IT WILL DRAG A BROAD HI PRES RIDGE FROM THE GOMEX ACRS FL AND
INTO THE MID ATLC COASTAL WATERS. THE PASSAGE OF THE RIDGE WILL
MAINTAIN A TIGHT H85-H50 SUBSIDENCE INVERSION OVER CENTRAL FL THAT
WILL EFFECTIVELY LIMIT VERTICAL MOTION TO 10KFT OR LESS.
WINDS THRU THE H100-H70 LYR WILL RESPOND BY VEERING TO THE E...BCMG
RATHER BRISK SAT NIGHT THRU SUN AS THE RIDGE INTERACTS WITH A WEAK
AREA OF LOW PRES NE OF THE BAHAMAS. AS SUCH FLOW REGIMES TAP AN
OCEAN MODIFIED AIRMASS... THEY USUALLY GENERATE LOW END PRECIP
CHANCES AS THEY PUSH LCL POCKETS OF ENHANCED MOISTURE ONSHORE...
WHERE THE COASTAL CONVERGENCE ZONE SQUEEZES THE MOISTURE OUT IN THE
FORM OF LOW TOPPED SHRAS. SUCH SHRAS RARELY HAVE ANY SIG IMPACT AS
THEIR LIMITED DEPTH PREVENTS ANY SIG MOISTURE LOADING...QPF AMNTS
USUALLY BLO 0.10".
MOS GUIDANCE KEEPS THE FCST ESSENTIALLY DRY THRU THE DAY ON SUN WITH
POPS IN THE SINGLE DIGITS...THEN MINIMAL POPS (AOB 20PCT) SUN NIGHT
AS WINDS VEER TO THE S/SE AHEAD OF A NEW FRONTAL BNDRY AND FORCES
THE BASE OF THE SUBSIDENCE INVERSION TO LIFT FROM THE H85 LVL TO
ARND H70. HARD TO ARGUE AS RUC ANALYSIS SHOWS AND AIRMASS QUITE
HOSTILE TO SHRA FORMATION: THERMAL CAPPING THRU THE H85-H70 LYR IS
QUITE STRONG WITH LAPSE RATES RUNNING BLO 5.0C/KM AND AS LOW AS
2.5C/KM ACRS THE I-4 CORRIDOR...LIMITED LCL AND UPSTREAM MOISTURE
AVAILABLE WITH MEAN RH VALUES BTWN 80-90PCT THRU THE H100-H85
LYR...DECREASING TO BLO 35PCT THRU THE H85-H50 LYR.
A SUBSIDING AIRMASS WILL COMBINE WITH DEEP ONSHORE FLOW TO KEEP
TEMPS A SOLID 10-15F ABV CLIMO AVG. AFTN MAXES IN THE U70S/L80S ALNG
THE COAST...L/M80S INTERIOR. MRNG MINS IN THE M60S/L70S ALNG THE
COAST...L/M60S INTERIOR.
EXTENDED...(PREV DISC)
THE 00Z MODELS SHOW WEAKENING FRONTAL BOUNDARY REACHING THE AREA
MON. A SQUALL LINE MAY PRECEDE THE FRONT OVER THE GULF OF MEXICO SUN
NIGHT...BUT PRE FRONTAL CONVERGENCE IS FORECAST TO RAPIDLY WEAKEN
AND MID LEVEL TEMPS WILL BE QUITE WARM FOR MID DECEMBER...SO WILL
NOT INCLUDE MENTION OF THUNDER. CONSENSUS POPS CONTINUE LOW WITH
THIS FRONT...AROUND 20 PERCENT. THE FRONT IS STILL FORECAST TO STALL
OUT AND LIFT BACK NORTH THROUGH MID WEEK...SO A PERIOD OF STRUNG OUT
LOW POPS MAY OCCUR AGAIN. ALSO...WITH LITTLE AIR MASS CHANGE
INDICATED...WE WILL CONTINUE HAVING WELL ABOVE NORMAL TEMPERATURES.
&&
.AVIATION...
NO OBSTRUCTIONS TO CIG AND VSBY EXPECTED THROUGH 11/07Z. LCL
GROUND FOG DEVELOPING FM MLB-FPR-SUA AND INLAND TO ISM/MCO WL
BRING LCL VSBYS NR 3-5SM AND SCT006-010 FM 11/08Z-11/13Z. VFR
CONDS AREA WIDE AFT 11/13Z.
&&
.MARINE...
TONIGHT AND FRIDAY...HIGH PRESSURE IN PROXIMITY TO THE WATERS WL
ALLOW FOR CONTINUED DECREASE IN WV HGHTS WITH FAVORABLE CONDS
EXPECTED OVER THE WATERS DURING FRIDAY. SEAS 2-3 FT NEAR THE COAST
AND 3 TO 4 FT OFFSHORE. WINDS AROUND 10 KTS OR LESS.
SAT-SUN...
GENTLE TO MODERATE ERLY BREEZE ON SAT BCMG MODERATE TO FRESH BREEZE
ON SUN AS A BROAD HI PRES RIDGE LIFTS FROM THE GOMEX TO THE MID ATLC
COAST INTERACTS WITH A WEAK INVERTED TROF NE OF THE BAHAMAS. WIND
VEERING TO SE BY LATE SUN AFTN...THEN DIMINISHING TO A GENTLE TO
MODERATE SRLY BREEZE OVERNIGHT AS A NEW COLD FRONT WORKS ITS WAY
INTO THE PANHANDLE/ERN GOMEX. SEAS 3-5FT SAT BUILDING TO 5-7FT
SAT NIGHT...THEN UP TO 6-8FT OFFSHORE BY DAYBREAK SUN MRNG.
MON-MON NIGHT...
FRONTAL TROF WILL PUSH INTO CENTRAL FL...REACHING THE VCNTY OF CAPE
CANAVERAL/TAMPA BAY AFT MIDNIGHT TUE MRNG. WINDS VEERING TO W/SW
THRU THE DAY WHILE DIMINISHING TO A LIGHT TO GENTLE BREEZE...BCMG
N/NW AFT SUNSET. SEAS 4-6FT DIMINISHING TO 3-5FT.
TUE-TUE NIGHT...
HIGH PRES OFF THE MID ATLC COAST WILL BUILD E AND FORCE WINDS TO
VEER FROM A LIGHT NRLY BREEZE TO A LIGHT ERLY BREEZE THRU THE
DAY...THEN A LIGHT TO GENTLE SE OVERNIGHT. FRONTAL BNDRY WILL STALL
IN THE VCNTY OF LAKE OKEECHOBEE BY DAYBREAK TUE BEFORE RETREATING
BACK TO THE N AS A WEAK WARM FRONT. SEAS 2-4FT SUBSIDING TO 2-3FT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 57 78 63 78 / 0 0 10 10
MCO 58 82 62 83 / 0 0 10 0
MLB 64 79 67 81 / 10 0 10 0
VRB 62 80 66 81 / 10 0 10 0
LEE 57 81 61 82 / 0 0 10 0
SFB 58 82 62 82 / 0 0 10 0
ORL 60 81 63 82 / 0 0 10 0
FPR 62 80 66 81 / 10 0 10 0
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...PENDERGRAST
LONG TERM....BRAGAW
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
911 PM EST FRI DEC 11 2015
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE FAIR AND WARM WEATHER INTO SUNDAY.
A WEAK FRONT WILL PROVIDE A CHANCE OF SHOWERS LATE SUNDAY NIGHT
AND MONDAY. ANOTHER FRONT TO PROVIDE A CHANCE OF SHOWERS WEDNESDAY
AND THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE SURFACE PRESSURE RIDGE AXIS WILL REMAIN JUST SOUTH OF THE
FORECAST AREA THROUGH TONIGHT. FLAT UPPER RIDGING WILL CONTINUE
AND SATELLITE TRENDS INDICATE THIN CIRRUS WILL CONTINUE SPILLING
OVER THE RIDGE AND INTO THE FORECAST AREA. SHALLOW LOW-LEVEL
MOISTURE AND NOCTURNAL COOLING WILL HELP CAUSE AREAS OF FOG DURING
THE EARLY MORNING HOURS. THE LAMP GUIDANCE SUGGESTED WIDESPREAD
FOG BUT OTHER MODELS WERE LESS AGGRESSIVE. THE HRRR INDICATED FOG
MAINLY TO THE WEST OF THE FORECAST AREA BUT THE TREND IN THE HRRR
HAS BEEN MORE FOG COVERAGE. WE HAVE INCLUDED FOG IN THE FORECAST
THROUGH THE EARLY MORNING. A DENSE FOG ADVISORY MAY BE NEEDED.
LOWS NEAR OR JUST ABOVE 50 DEGREES ARE EXPECTED.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
DRY WEATHER AND ABOVE NORMAL TEMPERATURES WILL PERSIST SATURDAY
THROUGH SATURDAY NIGHT. UPPER RIDGE WILL REMAIN OVER THE
SOUTHEASTERN STATES...AS UPPER TROUGH/CLOSED LOW CROSSES THE
WESTERN CONUS. THIS WILL LEAD TO A CONTINUED WARMING TREND FOR
OUR REGION. SURFACE HIGH PRESSURE CENTERED OVER NORTHERN FLORIDA
WILL LIFT NORTH TOWARDS THE CAROLINAS SATURDAY. FAVORED WARMER
TEMPERATURES INDICATED BY THE MAV MOS WITH HIGHS IN THE MID TO
UPPER 70S AND LOWS IN THE UPPER 40S TO LOWER 50S.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
THE UPPER-LEVEL RIDGE AND SURFACE HIGH PRESSURE WILL MOVE OFF THE
COAST SUNDAY AS AN UPPER LOW LIFTS NORTHEAST FROM THE GREAT PLAINS
INTO THE GREAT LAKES REGION SUNDAY INTO MONDAY. THIS WILL DRAG A
FRONTAL BOUNDARY THROUGH THE FORECAST AREA MONDAY. PRECIPITATION
TO OUR WEST ALONG THE FRONT EXPECTED TO WEAKEN AS IT APPROACHES
OUR REGION AS BEST UPPER DYNAMICS SHIFT TO THE NORTH. INCREASING
LOW-LEVEL SOUTHERLY FLOW/ISENTROPIC LIFT TO DEVELOP OVER OUR
REGION LATE SUNDAY NIGHT AHEAD OF THE APPROACHING WEAK FRONT.
SURFACE AND ELEVATED INSTABILITIES PROGGED TO BE QUITE WEAK ACROSS
THE MIDLANDS AND CSRA...THUS NO MENTION OF THUNDER.
HIGH CHANCE TO LOW LIKELY POPS CONTINUE WITH THE FRONTAL PASSAGE
MONDAY. DRY HIGH PRESSURE WILL BUILD INTO THE REGION MONDAY NIGHT
INTO TUESDAY. ABOVE NORMAL TEMPS WILL CONTINUE TUESDAY GIVEN
SOUTHWEST FLOW ALOFT WITH WEAK UPPER RIDGING OVER THE SOUTHEASTERN
STATES.
GFS/ECMWF IN AGREEMENT WITH UPPER TROUGH MOVING EAST INTO THE
CENTRAL CONUS...WITH UPPER RIDGE SHIFTING TO OUR EAST WEDNESDAY.
SURFACE FRONT PROGGED TO CROSS THE AREA THURSDAY. STILL SOME
TIMING DIFFERENCES WITH THE GFS INDICATING THE FROPA THURSDAY AND
THE ECMWF SLOWER...INDICATING THE FRONT MOVING EAST OF THE AREA
FRIDAY. INCREASING MOISTURE/ISENTROPIC LIFT AHEAD OF THE FRONT MAY
LEAD TO SOME LIGHT PRECIP WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT.
GIVEN MODEL DIFFERENCES WILL KEEP CHANCE OF SHOWERS THURSDAY INTO
FRIDAY. ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH
THURSDAY...COOLING TO THE 50S FOR FRIDAY.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
WEAK HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH TONIGHT.
SHALLOW LOW-LEVEL MOISTURE AND NOCTURNAL COOLING SHOULD HELP CAUSE
AREAS OF FOG DURING THE EARLY MORNING HOURS. THE LAMP GUIDANCE
SUGGESTED WIDESPREAD IFR FOG BUT OTHER MODELS WERE LESS
AGGRESSIVE. THE HRRR INDICATED FOG MAINLY TO THE WEST OF THE
FORECAST AREA. USED AN AVERAGE OF THE GUIDANCE AND FORECASTED MVFR
FOG EXCEPT THE ADDED MOISTURE AND COOLING IN THE RIVER VALLEY
SUPPORT IFR FOG AT AGS. HEATING AND MIXING SHOULD RESULT IN A
RETURN TO VFR CONDITIONS BEGINNING AROUND 14Z.
EXTENDED AVIATION OUTLOOK...A WEAK FRONT MOVING INTO THE AREA
EARLY NEXT WEEK MAY BRING RESTRICTIONS.
&&
.CLIMATE...
FORECAST MAX TEMPS SAT/SUN
CAE...77/79
AGS...78/79
NORMAL MAX TEMPS SAT/SUN
CAE...59/59
AGS...61/60
RECORD MAX TEMPS SAT/SUN
CAE...81/80
AGS...82/81
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
CLIMATE...
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
900 PM CST FRI DEC 11 2015
.UPDATE...
ISSUED AT 859 PM CST FRI DEC 11 2015
A warm frontal feature is poised just north of I-64 approaching
central IL this evening with widespread low cloud cover and a few
reports of drizzle ahead of it through central IL. Behind the
front...some clearing at low levels is noted in the
observations...especially southwest of Springfield, and may need
to adjust forecasts to account for this. However...any clearing of
skies may lead to increased fog density. Otherwise...very warm
temperatures mainly in the 50s expected overnight...potentially
leading to a few record warm minimum temperatures.
&&
.SHORT TERM...(Tonight)
ISSUED AT 239 PM CST FRI DEC 11 2015
Overcast low clouds below 2k ft and patchy fog and drizzle lifting
northward from southern into central IL and reaching north of
Lincoln by mid afternoon. These low clouds and will overspread rest
of northern CWA next few hours. HRRR model has been handling this
quicker timing of arrival of IFR clouds well and even have a few
sites with vsbys below 1 mile with Paris the lowest at 1/2 mile in
fog. South to southeast winds advecting low level moisture northward
into central IL this afternoon and this to continue tonight with
patchy drizzle as well. Continue slight chances of light rain
showers over central and eastern IL tonight though mostly a trace
event tonight.
A 1000 mb surface low pressure over southeast Nebraska will weaken
to 1010 mb as it moves into south central IA by dawn Sat. One warm
front near I-74 to lift into northern IL tonight while another warm
front near I-70 will slowly lift northward across central IL
tonight. Weak lift along with boundary to develop very light
precipitation along with areas of fog and patchy drizzle especially
east of the IL river with very moist low levels from surface up to
850 mb. SSE winds 5-10 mph and low clouds will not allow temps to
drop too much tonight. Unseasonably mild lows range from around 50F
nw of the IL river to the upper 50s in southeast IL from I-70
southeast.
.LONG TERM...(Saturday through Friday)
ISSUED AT 239 PM CST FRI DEC 11 2015
Models finally in better agreement with timing of the approaching
system for this weekend. However, all models still have trended a
little slower with the system as it moves into and through the CWA.
Before the main system gets here, light, warm advection type pcpn
will move across the state during the day on Sat. This will include
cloudy skies and much warmer temps...with some sites reaching or
exceeding record temps. Then the main punch of the pcpn will begin
late Sat night and continue through Sunday and Sun night. Models
have also trended with less pcpn through the period, but still
showing around an inch in the east and over 1.5 inches west of I-55.
The heaviest pcpn looks to be Sun afternoon and Sun evening. The
pcpn will diminish on Monday, with just chance pops for mainly Mon
morning. By afternoon, things should push to the east and northeast.
Besides the record warmth on Sat, Sunday highs will also be quite
warm...well above normal for middle of Dec. Once the system moves
through, temps will decrease but still be above normal.
The main focus for next week, Mon night through Friday, will be the
slightly cooler temps and then the decreasing temps back to normal
for later in the week. With the upper level flow remaining
southwesterly in the extended, another wave or two will move
northeast through the flow. However, with the gulf being blocked,
there should be limited moisture in the area for any weak system to
work with. So, only slight chc pops expected for when the weak wave
moves through, which will be Tue night through Wed night. Besides
this, dry weather is expected most of the area through most of the
week.
Temps will stay above normal through about Wed and then fall to
around normal for the end of the week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
ISSUED AT 552 PM CST FRI DEC 11 2015
Overcast conditions with ceiling heights mostly in IFR to lower
MVFR ranges this evening, although though local LIFR/VLIFR
ceilings exist as well. Visibilities primarily MVFR with locally
lower visibilities. With a warm frontal feature lifting north of
the area tonight...should see a continued very moist lower
atmosphere with low ceilings and some decrease in visibility
continuing overnight...along with some drizzle. Some possibility
for improved ceilings/visibility developing afternoon
Saturday...but ceilings unlikely to rise much over lower-end MVFR.
Winds primarily ESE 6-10 kts turning southerly overnight after
warm frontal passage.
&&
.CLIMATE...
ISSUED AT 300 AM CST FRI DEC 10 2015
Record highs for the weekend:
Location Today Saturday Sunday
DEC 11 DEC 12 DEC 13
---------- --------- --------- ---------
Bloomington 65 (1949) 65 (1896) 63 (1975)
Champaign 64 (1949) 62 (1991) 64 (1975)
Charleston 66 (1931) 67 (1949) 64 (1991)
Decatur 65 (1949) 65 (1929) 66 (1975)
Effingham 60 (1979) 67 (1929) 65 (1991)
Lincoln 66 (1949) 64 (1929) 64 (1975)
Peoria 64 (1949) 62 (1991) 63 (1975)
Springfield 67 (1949) 64 (1929) 67 (1948)
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Onton
SHORT TERM...07
LONG TERM...Auten
AVIATION...Onton
CLIMATE...Geelhart
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
552 PM CST FRI DEC 11 2015
.SHORT TERM...(Tonight)
ISSUED AT 239 PM CST FRI DEC 11 2015
Overcast low clouds below 2k ft and patchy fog and drizzle lifting
northward from southern into central IL and reaching north of
Lincoln by mid afternoon. These low clouds and will overspread rest
of northern CWA next few hours. HRRR model has been handling this
quicker timing of arrival of IFR clouds well and even have a few
sites with vsbys below 1 mile with Paris the lowest at 1/2 mile in
fog. South to southeast winds advecting low level moisture northward
into central IL this afternoon and this to continue tonight with
patchy drizzle as well. Continue slight chances of light rain
showers over central and eastern IL tonight though mostly a trace
event tonight.
A 1000 mb surface low pressure over southeast Nebraska will weaken
to 1010 mb as it moves into south central IA by dawn Sat. One warm
front near I-74 to lift into northern IL tonight while another warm
front near I-70 will slowly lift northward across central IL
tonight. Weak lift along with boundary to develop very light
precipitation along with areas of fog and patchy drizzle especially
east of the IL river with very moist low levels from surface up to
850 mb. SSE winds 5-10 mph and low clouds will not allow temps to
drop too much tonight. Unseasonably mild lows range from around 50F
nw of the IL river to the upper 50s in southeast IL from I-70
southeast.
.LONG TERM...(Saturday through Friday)
ISSUED AT 239 PM CST FRI DEC 11 2015
Models finally in better agreement with timing of the approaching
system for this weekend. However, all models still have trended a
little slower with the system as it moves into and through the CWA.
Before the main system gets here, light, warm advection type pcpn
will move across the state during the day on Sat. This will include
cloudy skies and much warmer temps...with some sites reaching or
exceeding record temps. Then the main punch of the pcpn will begin
late Sat night and continue through Sunday and Sun night. Models
have also trended with less pcpn through the period, but still
showing around an inch in the east and over 1.5 inches west of I-55.
The heaviest pcpn looks to be Sun afternoon and Sun evening. The
pcpn will diminish on Monday, with just chance pops for mainly Mon
morning. By afternoon, things should push to the east and northeast.
Besides the record warmth on Sat, Sunday highs will also be quite
warm...well above normal for middle of Dec. Once the system moves
through, temps will decrease but still be above normal.
The main focus for next week, Mon night through Friday, will be the
slightly cooler temps and then the decreasing temps back to normal
for later in the week. With the upper level flow remaining
southwesterly in the extended, another wave or two will move
northeast through the flow. However, with the gulf being blocked,
there should be limited moisture in the area for any weak system to
work with. So, only slight chc pops expected for when the weak wave
moves through, which will be Tue night through Wed night. Besides
this, dry weather is expected most of the area through most of the
week.
Temps will stay above normal through about Wed and then fall to
around normal for the end of the week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
ISSUED AT 552 PM CST FRI DEC 11 2015
Overcast conditions with ceiling heights mostly in IFR to lower
MVFR ranges this evening, although though local LIFR/VLIFR
ceilings exist as well. Visibilities primarily MVFR with locally
lower visibilities. With a warm frontal feature lifting north of
the area tonight...should see a continued very moist lower
atmosphere with low ceilings and some decrease in visibility
continuing overnight...along with some drizzle. Some possibility
for improved ceilings/visibility developing afternoon
Saturday...but ceilings unlikely to rise much over lower-end MVFR.
Winds primarily ESE 6-10 kts turning southerly overnight after
warm frontal passage.
&&
.CLIMATE...
ISSUED AT 300 AM CST FRI DEC 10 2015
Record highs for the weekend:
Location Today Saturday Sunday
DEC 11 DEC 12 DEC 13
---------- --------- --------- ---------
Bloomington 65 (1949) 65 (1896) 63 (1975)
Champaign 64 (1949) 62 (1991) 64 (1975)
Charleston 66 (1931) 67 (1949) 64 (1991)
Decatur 65 (1949) 65 (1929) 66 (1975)
Effingham 60 (1979) 67 (1929) 65 (1991)
Lincoln 66 (1949) 64 (1929) 64 (1975)
Peoria 64 (1949) 62 (1991) 63 (1975)
Springfield 67 (1949) 64 (1929) 67 (1948)
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...Auten
AVIATION...Onton
CLIMATE...Geelhart
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1200 PM CST THU DEC 10 2015
.UPDATE...
ISSUED AT 1045 AM CST THU DEC 10 2015
Will update the forecast today for more cloud cover especially
into early afternoon. Also nudged up high temperatures a bit with
most areas reaching low to mid 60s and mildest in Jacksonville
which currently is up to 61F. Strong SSW winds of 15-25 mph and
gusts of 25-35 mph to diminish to 10-15 mph and gusts to around
20 mph toward sunset. Strong 990 mb low pressure over nw WI with a
cold front over central IA into NW MO late this morning. Front to
push into central IL during mid/late afternoon with ssw winds
veering more WSW and front to come through dry. Low clouds over
central and northern IA into MN to pass mostly north of central IL
later this afternoon and evening.
&&
.SHORT TERM...(Today)
ISSUED AT 255 AM CST THU DEC 10 2015
Southerly winds and occasional cloud cover keeping temperatures on
the mild side this morning with most areas still in the 40s. A storm
system over the Northern Plains this morning is forecast to pass
well north of our area, resulting in windy and mild weather today
with temperatures some 20 to 25 degrees above normal for this time
of year. A rather tight pressure gradient across the Midwest today
as the intense storm system passes to our north, resulting in gusty
south to southwest winds with RAP and hi-res NAM forecast soundings
suggesting a few of the more favored locations across the north
possibly gusting up to 35 to 40 mph at times later this morning into
the afternoon hours. Still some uncertainty with respect to how much
of the stronger winds will be able to mix down to the surface later
this morning, especially with most of the soundings indicating a low
level inversion in place, which would keep the stronger winds from
reaching the surface. At this time, it appears the sustained wind
speeds will remain just below wind advisory criteria.
Soundings also showing quite a bit of dry air in place this afternoon
just ahead of the weak surface trof/wind shift line with the better
mid level forcing remaining to our north. So will continue with a
dry forecast with forecast highs trending towards the warmer MAV
guidance this afternoon, resulting in highs in the upper 50s far
north to the middle 60s west. Record high for Peoria today is 67
degrees which was set back in 1918, and 69 degrees in Springfield
which was also set back in 1918.
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 255 AM CST THU DEC 10 2015
Not a lot of change in thinking in regards to our unseasonably mild
weather the next several days. Upper low west of Washington state
early this morning will help dig a broad scale upper trough along
the West coast beginning later today, with the trough sharpening as
it digs south toward the 4-corners region Friday night. Nice surge
of anomalously warm and moist air will be transported into our
region as this trough digs. A few parts of the CWA could be flirting
with 70 degrees Saturday afternoon with widespread record highs
likely (see Climate section further down). Even at night,
temperatures this weekend likely to be 15-20 degrees above what
the normal highs would be. A bit of a slowdown in this system will
result in lower 60s for highs lingering into Sunday.
Initial hints at the upcoming rainfall will begin later tonight, as
the upper low currently tracking across southern Saskatchewan passes
across the northern Great Lakes. While this system itself will miss
us, it will help draw some moisture northward with a steady flow off
the Gulf of Mexico. Have maintained some 30% rain chances across the
southeast third of the forecast area for Friday as this moisture
feed gets amplified, as dew points start to surge into the 50s. Rain
threat starts to shift toward the warm frontal boundary to our north
Friday night, before the main show begins as a surface low forms
near the Texas Panhandle as the upper trough arrives. A couple
surface lows will impact our area, one passing near or just
northwest of us Sunday, then a secondary one going over us Sunday
night just ahead of a strong upper low. The ECMWF has been most
consistent with the idea of the upper low, while the the GFS
maintains a sharp upper trough passing overhead Sunday night. The
Canadian model follows the ECMWF but is a bit slower in this regard.
With the system slowing a bit, have extended the categorical PoP`s
over the entire CWA through Sunday night. Precipitable water still
progged to be in record territory near 1.4 inches Saturday night and
Sunday. Current indications are that 2-3 inches of rain are likely
from about I-57 westward, with a bit lower totals east as the rain
will be a bit slower to arrive Saturday night. With the system
rather strong as it moves away, have increased rain chances Monday
morning, but most sites should be dry by afternoon.
Looking later in time, another broad trough will form over the
western CONUS early next week, with an upper low forming near the
South Dakota/Nebraska area. This system will track northeast and may
draw some moisture northward with it, and have some low chance PoP`s
over the southeast CWA Tuesday night.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 1159 AM CST THU DEC 10 2015
Strong 990 mb low pressure over northern WI with cold front over
eastern IA into NW MO to give strong SSW winds of 15-25 kts with
gusts of 25-35 kts into mid afternoon. Winds to veer sw during the
afternoon and diminish to 10-15 kts late this afternoon with gusts
15-20 kts as weakening front moves into central IL. Winds weaken
further to 5-10 kts between 00-03Z early this evening. Winds then
veer SSE 7-11 kts Friday morning as tight pressure gradient today
relaxes tonight and Friday morning. Broken high clouds 20-25k ft
along with few-sct lower clouds to occur into early evening and
then return Friday morning.
&&
.CLIMATE...
ISSUED AT 255 AM CST THU DEC 10 2015
Record highs for the weekend:
Location Today Friday Saturday Sunday
Dec 10 Dec 11 Dec 12 Dec 13
-------- -------- -------- -------- --------
Bloomington 65 (1918) 65 (1949) 65 (1896) 63 (1975)
Champaign 65 (1889) 64 (1949) 62 (1991) 64 (1975)
Charleston 65 (1918) 66 (1931) 67 (1949) 64 (1991)
Decatur 66 (1918) 65 (1949) 65 (1929) 66 (1975)
Effingham 69 (1971) 60 (1979) 67 (1929) 65 (1991)
Lincoln 65 (1918) 66 (1949) 64 (1929) 64 (1975)
Peoria 64 (1889) 64 (1949) 62 (1991) 63 (1975)
Springfield 67 (1889) 67 (1949) 64 (1929) 67 (1948)
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...07
SHORT TERM...Smith
LONG TERM...Geelhart
AVIATION...07
CLIMATE...Geelhart
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1045 AM CST THU DEC 10 2015
.UPDATE...
ISSUED AT 1045 AM CST THU DEC 10 2015
Will update the forecast today for more cloud cover especially
into early afternoon. Also nudged up high temperatures a bit with
most areas reaching low to mid 60s and mildest in Jacksonville
which currently is up to 61F. Strong SSW winds of 15-25 mph and
gusts of 25-35 mph to diminish to 10-15 mph and gusts to around
20 mph toward sunset. Strong 990 mb low pressure over nw WI with a
cold front over central IA into NW MO late this morning. Front to
push into central IL during mid/late afternoon with ssw winds
veering more WSW and front to come through dry. Low clouds over
central and northern IA into MN to pass mostly north of central IL
later this afternoon and evening.
&&
.SHORT TERM...(Today)
ISSUED AT 255 AM CST THU DEC 10 2015
Southerly winds and occasional cloud cover keeping temperatures on
the mild side this morning with most areas still in the 40s. A storm
system over the Northern Plains this morning is forecast to pass
well north of our area, resulting in windy and mild weather today
with temperatures some 20 to 25 degrees above normal for this time
of year. A rather tight pressure gradient across the Midwest today
as the intense storm system passes to our north, resulting in gusty
south to southwest winds with RAP and hi-res NAM forecast soundings
suggesting a few of the more favored locations across the north
possibly gusting up to 35 to 40 mph at times later this morning into
the afternoon hours. Still some uncertainty with respect to how much
of the stronger winds will be able to mix down to the surface later
this morning, especially with most of the soundings indicating a low
level inversion in place, which would keep the stronger winds from
reaching the surface. At this time, it appears the sustained wind
speeds will remain just below wind advisory criteria.
Soundings also showing quite a bit of dry air in place this afternoon
just ahead of the weak surface trof/wind shift line with the better
mid level forcing remaining to our north. So will continue with a
dry forecast with forecast highs trending towards the warmer MAV
guidance this afternoon, resulting in highs in the upper 50s far
north to the middle 60s west. Record high for Peoria today is 67
degrees which was set back in 1918, and 69 degrees in Springfield
which was also set back in 1918.
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 255 AM CST THU DEC 10 2015
Not a lot of change in thinking in regards to our unseasonably mild
weather the next several days. Upper low west of Washington state
early this morning will help dig a broad scale upper trough along
the West coast beginning later today, with the trough sharpening as
it digs south toward the 4-corners region Friday night. Nice surge
of anomalously warm and moist air will be transported into our
region as this trough digs. A few parts of the CWA could be flirting
with 70 degrees Saturday afternoon with widespread record highs
likely (see Climate section further down). Even at night,
temperatures this weekend likely to be 15-20 degrees above what
the normal highs would be. A bit of a slowdown in this system will
result in lower 60s for highs lingering into Sunday.
Initial hints at the upcoming rainfall will begin later tonight, as
the upper low currently tracking across southern Saskatchewan passes
across the northern Great Lakes. While this system itself will miss
us, it will help draw some moisture northward with a steady flow off
the Gulf of Mexico. Have maintained some 30% rain chances across the
southeast third of the forecast area for Friday as this moisture
feed gets amplified, as dew points start to surge into the 50s. Rain
threat starts to shift toward the warm frontal boundary to our north
Friday night, before the main show begins as a surface low forms
near the Texas Panhandle as the upper trough arrives. A couple
surface lows will impact our area, one passing near or just
northwest of us Sunday, then a secondary one going over us Sunday
night just ahead of a strong upper low. The ECMWF has been most
consistent with the idea of the upper low, while the the GFS
maintains a sharp upper trough passing overhead Sunday night. The
Canadian model follows the ECMWF but is a bit slower in this regard.
With the system slowing a bit, have extended the categorical PoP`s
over the entire CWA through Sunday night. Precipitable water still
progged to be in record territory near 1.4 inches Saturday night and
Sunday. Current indications are that 2-3 inches of rain are likely
from about I-57 westward, with a bit lower totals east as the rain
will be a bit slower to arrive Saturday night. With the system
rather strong as it moves away, have increased rain chances Monday
morning, but most sites should be dry by afternoon.
Looking later in time, another broad trough will form over the
western CONUS early next week, with an upper low forming near the
South Dakota/Nebraska area. This system will track northeast and may
draw some moisture northward with it, and have some low chance PoP`s
over the southeast CWA Tuesday night.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
ISSUED AT 530 AM CST THU DEC 10 2015
The main forecast concern this period will be with gusty southwest
winds today. Latest ILX sounding data indicates southwest winds
of up to around 40 kts at 1500 feet and expect some of those
stronger winds to mix down to the surface late this morning into
the afternoon hours. Sustained winds of 20 to 25 kts are expected
today with gusts approaching 35 kts in a few of the more favored
sites (BMI and CMI) thru 21z before we see winds rapidly decrease
towards 00z. VFR conditions are expected with occasional cigs of
around 20000 feet thru the morning with some decrease in the
cirrus this afternoon. Winds should continue out of a southwesterly
direction tonight with speeds in the 7 to 12 kt range at all
locations after 02z.
&&
.CLIMATE...
ISSUED AT 255 AM CST THU DEC 10 2015
Record highs for the weekend:
Location Friday Saturday Sunday
-------- ------ -------- ------
Bloomington 65 (1949) 65 (1896) 63 (1975)
Champaign 64 (1949) 62 (1991) 64 (1975)
Charleston 66 (1931) 67 (1949) 64 (1991)
Decatur 65 (1949) 65 (1929) 66 (1975)
Effingham 60 (1979) 67 (1929) 65 (1991)
Lincoln 66 (1949) 64 (1929) 64 (1975)
Peoria 64 (1949) 62 (1991) 63 (1975)
Springfield 67 (1949) 64 (1929) 67 (1948)
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...07
SHORT TERM...Smith
LONG TERM...Geelhart
AVIATION...Smith
CLIMATE...Geelhart
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
536 AM CST THU DEC 10 2015
.SHORT TERM...(Today)
ISSUED AT 255 AM CST THU DEC 10 2015
Southerly winds and occasional cloud cover keeping temperatures on
the mild side this morning with most areas still in the 40s. A storm
system over the Northern Plains this morning is forecast to pass
well north of our area, resulting in windy and mild weather today
with temperatures some 20 to 25 degrees above normal for this time
of year. A rather tight pressure gradient across the Midwest today
as the intense storm system passes to our north, resulting in gusty
south to southwest winds with RAP and hi-res NAM forecast soundings
suggesting a few of the more favored locations across the north
possibly gusting up to 35 to 40 mph at times later this morning into
the afternoon hours. Still some uncertainty with respect to how much
of the stronger winds will be able to mix down to the surface later
this morning, especially with most of the soundings indicating a low
level inversion in place, which would keep the stronger winds from
reaching the surface. At this time, it appears the sustained wind
speeds will remain just below wind advisory criteria.
Soundings also showing quite a bit of dry air in place this afternoon
just ahead of the weak surface trof/wind shift line with the better
mid level forcing remaining to our north. So will continue with a
dry forecast with forecast highs trending towards the warmer MAV
guidance this afternoon, resulting in highs in the upper 50s far
north to the middle 60s west. Record high for Peoria today is 67
degrees which was set back in 1918, and 69 degrees in Springfield
which was also set back in 1918.
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 255 AM CST THU DEC 10 2015
Not a lot of change in thinking in regards to our unseasonably mild
weather the next several days. Upper low west of Washington state
early this morning will help dig a broad scale upper trough along
the West coast beginning later today, with the trough sharpening as
it digs south toward the 4-corners region Friday night. Nice surge
of anomalously warm and moist air will be transported into our
region as this trough digs. A few parts of the CWA could be flirting
with 70 degrees Saturday afternoon with widespread record highs
likely (see Climate section further down). Even at night,
temperatures this weekend likely to be 15-20 degrees above what
the normal highs would be. A bit of a slowdown in this system will
result in lower 60s for highs lingering into Sunday.
Initial hints at the upcoming rainfall will begin later tonight, as
the upper low currently tracking across southern Saskatchewan passes
across the northern Great Lakes. While this system itself will miss
us, it will help draw some moisture northward with a steady flow off
the Gulf of Mexico. Have maintained some 30% rain chances across the
southeast third of the forecast area for Friday as this moisture
feed gets amplified, as dew points start to surge into the 50s. Rain
threat starts to shift toward the warm frontal boundary to our north
Friday night, before the main show begins as a surface low forms
near the Texas Panhandle as the upper trough arrives. A couple
surface lows will impact our area, one passing near or just
northwest of us Sunday, then a secondary one going over us Sunday
night just ahead of a strong upper low. The ECMWF has been most
consistent with the idea of the upper low, while the the GFS
maintains a sharp upper trough passing overhead Sunday night. The
Canadian model follows the ECMWF but is a bit slower in this regard.
With the system slowing a bit, have extended the categorical PoP`s
over the entire CWA through Sunday night. Precipitable water still
progged to be in record territory near 1.4 inches Saturday night and
Sunday. Current indications are that 2-3 inches of rain are likely
from about I-57 westward, with a bit lower totals east as the rain
will be a bit slower to arrive Saturday night. With the system
rather strong as it moves away, have increased rain chances Monday
morning, but most sites should be dry by afternoon.
Looking later in time, another broad trough will form over the
western CONUS early next week, with an upper low forming near the
South Dakota/Nebraska area. This system will track northeast and may
draw some moisture northward with it, and have some low chance PoP`s
over the southeast CWA Tuesday night.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
ISSUED AT 530 AM CST THU DEC 10 2015
The main forecast concern this period will be with gusty southwest
winds today. Latest ILX sounding data indicates southwest winds
of up to around 40 kts at 1500 feet and expect some of those
stronger winds to mix down to the surface late this morning into
the afternoon hours. Sustained winds of 20 to 25 kts are expected
today with gusts approaching 35 kts in a few of the more favored
sites (BMI and CMI) thru 21z before we see winds rapidly decrease
towards 00z. VFR conditions are expected with occasional cigs of
around 20000 feet thru the morning with some decrease in the
cirrus this afternoon. Winds should continue out of a southwesterly
direction tonight with speeds in the 7 to 12 kt range at all
locations after 02z.
&&
.CLIMATE...
ISSUED AT 255 AM CST THU DEC 10 2015
Record highs for the weekend:
Location Friday Saturday Sunday
-------- ------ -------- ------
Bloomington 65 (1949) 65 (1896) 63 (1975)
Champaign 64 (1949) 62 (1991) 64 (1975)
Charleston 66 (1931) 67 (1949) 64 (1991)
Decatur 65 (1949) 65 (1929) 66 (1975)
Effingham 60 (1979) 67 (1929) 65 (1991)
Lincoln 66 (1949) 64 (1929) 64 (1975)
Peoria 64 (1949) 62 (1991) 63 (1975)
Springfield 67 (1949) 64 (1929) 67 (1948)
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Smith
LONG TERM...Geelhart
AVIATION...Smith
CLIMATE...Geelhart
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
257 AM CST THU DEC 10 2015
.SHORT TERM...(Today)
ISSUED AT 255 AM CST THU DEC 10 2015
Southerly winds and occasional cloud cover keeping temperatures on
the mild side this morning with most areas still in the 40s. A storm
system over the Northern Plains this morning is forecast to pass
well north of our area, resulting in windy and mild weather today
with temperatures some 20 to 25 degrees above normal for this time
of year. A rather tight pressure gradient across the Midwest today
as the intense storm system passes to our north, resulting in gusty
south to southwest winds with RAP and hi-res NAM forecast soundings
suggesting a few of the more favored locations across the north
possibly gusting up to 35 to 40 mph at times later this morning into
the afternoon hours. Still some uncertainty with respect to how much
of the stronger winds will be able to mix down to the surface later
this morning, especially with most of the soundings indicating a low
level inversion in place, which would keep the stronger winds from
reaching the surface. At this time, it appears the sustained wind
speeds will remain just below wind advisory criteria.
Soundings also showing quite a bit of dry air in place this afternoon
just ahead of the weak surface trof/wind shift line with the better
mid level forcing remaining to our north. So will continue with a
dry forecast with forecast highs trending towards the warmer MAV
guidance this afternoon, resulting in highs in the upper 50s far
north to the middle 60s west. Record high for Peoria today is 67
degrees which was set back in 1918, and 69 degrees in Springfield
which was also set back in 1918.
&&
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 255 AM CST THU DEC 10 2015
Not a lot of change in thinking in regards to our unseasonably mild
weather the next several days. Upper low west of Washington state
early this morning will help dig a broad scale upper trough along
the West coast beginning later today, with the trough sharpening as
it digs south toward the 4-corners region Friday night. Nice surge
of anomalously warm and moist air will be transported into our
region as this trough digs. A few parts of the CWA could be flirting
with 70 degrees Saturday afternoon with widespread record highs
likely (see Climate section further down). Even at night,
temperatures this weekend likely to be 15-20 degrees above what
the normal highs would be. A bit of a slowdown in this system will
result in lower 60s for highs lingering into Sunday.
Initial hints at the upcoming rainfall will begin later tonight, as
the upper low currently tracking across southern Saskatchewan passes
across the northern Great Lakes. While this system itself will miss
us, it will help draw some moisture northward with a steady flow off
the Gulf of Mexico. Have maintained some 30% rain chances across the
southeast third of the forecast area for Friday as this moisture
feed gets amplified, as dew points start to surge into the 50s. Rain
threat starts to shift toward the warm frontal boundary to our north
Friday night, before the main show begins as a surface low forms
near the Texas Panhandle as the upper trough arrives. A couple
surface lows will impact our area, one passing near or just
northwest of us Sunday, then a secondary one going over us Sunday
night just ahead of a strong upper low. The ECMWF has been most
consistent with the idea of the upper low, while the the GFS
maintains a sharp upper trough passing overhead Sunday night. The
Canadian model follows the ECMWF but is a bit slower in this regard.
With the system slowing a bit, have extended the categorical PoP`s
over the entire CWA through Sunday night. Precipitable water still
progged to be in record territory near 1.4 inches Saturday night and
Sunday. Current indications are that 2-3 inches of rain are likely
from about I-57 westward, with a bit lower totals east as the rain
will be a bit slower to arrive Saturday night. With the system
rather strong as it moves away, have increased rain chances Monday
morning, but most sites should be dry by afternoon.
Looking later in time, another broad trough will form over the
western CONUS early next week, with an upper low forming near the
South Dakota/Nebraska area. This system will track northeast and may
draw some moisture northward with it, and have some low chance PoP`s
over the southeast CWA Tuesday night.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1120 PM CST WED DEC 9 2015
Low Level Wind Shear /LLWS/ is the initial concern for the first 6
hours of this TAF period. A surface trough extending south of a
low in southern Manitoba will approach IL late tonight. A low
level jet of 50-55kt at 925mb will crank up across Missouri and
into western Illinois before sunrise, setting the stage for LLWS.
The western TAF sites will have the best chances of seeing LLWS
through mid-morning. CMI and DEC may see surface winds increase
enough to preclude LLWS by the time the low level jet reaches into
eastern Illinois. We did continue to include LLWS for all TAF
sites from roughly 10z-15z as a precaution for now.
Wind direction will be south-southwest over the next 24 hours,
with the strongest winds developing toward 18z tomorrow. Sustained
winds could reach 20-25kt, with gusts to near 35kt at times.
Cloud cover will remain VFR through this TAF period, under mainly
cirrus cloud cover. Mid clouds associated with the low should
remain north of our TAF sites.
&&
.CLIMATE...
ISSUED AT 255 AM CST THU DEC 10 2015
Record highs for the weekend:
Location Friday Saturday Sunday
-------- ------ -------- ------
Bloomington 65 (1949) 65 (1896) 63 (1975)
Champaign 64 (1949) 62 (1991) 64 (1975)
Charleston 66 (1931) 67 (1949) 64 (1991)
Decatur 65 (1949) 65 (1929) 66 (1975)
Effingham 60 (1979) 67 (1929) 65 (1991)
Lincoln 66 (1949) 64 (1929) 64 (1975)
Peoria 64 (1949) 62 (1991) 63 (1975)
Springfield 67 (1949) 64 (1929) 67 (1948)
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Smith
LONG TERM...Geelhart
AVIATION...Shimon
CLIMATE...Geelhart
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1054 PM EST FRI DEC 11 2015
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL CROSS THE REGION TONIGHT. HIGH
PRESSURE WILL BEGIN TO BUILD TOWARD THE AREA SATURDAY THROUGH
SUNDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
1040 PM UPDATE: LATEST RADAR SHOWED A LINE OF HEAVY RAIN SHOWERS
W/GUSTY WINDS MOVING THROUGH FAR NORTHERN MAINE. BASE VELOCITY OFF
THE RADAR INDICATED POTENTIAL FOR WIND GUSTS UP TO 35 MPH W/THIS
LINE. LAPS AND RAP SOUNDINGS SHOWED ELEVATED CAPE OF 140+ JOULES
ABOVE THE INVERSION. NOTHING ON THE LIGHTNING DETECTION. CANNOT
RULE OUT A RUMBLE OF THUNDER W/THIS LINE AS IT MOVES THROUGH. FOG
HAS BRIEFLY SETTLED BACK IN AHEAD OF THE FRONT BUT VSBYS SHOULD
IMPROVE W/THE PASSAGE OF THIS LINE. MOST DENSE FOG ATTM IS ACROSS
THE ST. JOHN VALLEY. KEPT AREAS OF FOG IN THROUGH ABOUT MIDNIGHT.
THE LATEST RAP AND NAM12 SHOWED SHOWER ACTIVITY WINDING DOWN AFTER
2 AM W/A WEST WIND KICKING IN. THIS SHOULD HELP TO SCOUR OUT LLVL
MOISTURE W/FOG AND CLOUD DECK LIFTING.
LOWS TONIGHT WILL ONCE AGAIN BE WELL ABOVE NORMAL FOR THIS TIME
OF YEAR. EXPECT THE MID TO UPPER 30S NORTH AND UPPER 30S TO NEAR
40 DOWN EAST.
THE UPPER DISTURBANCE THAT WILL BRING SOME SHOWERS WILL CONTINUE
TO MOVE EAST ON SATURDAY AS HIGH PRESSURE BEGINS TO BUILD IN. THE
DEGREE OF CLEARING IS NOT ALL THAT CERTAIN AS THERE WILL STILL BE
QUITE BIT OF LOWER LEVEL MOISTURE IN THE 1000-850MB LAYER ACROSS
THE REGION ON SATURDAY. HIGHS ON SATURDAY WILL CONTINUE ABOVE
NORMAL. EXPECT THE LOWER 40S NORTH AND MID TO UPPER 40S CENTRAL
AND DOWN EAST.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
SATURDAY NIGHT INTO SUNDAY A BACKDOOR COLD FRONT WILL BRING COOLER
WEATHER INTO THE REGION. BY SUNDAY MORNING A 500MB RIDGE BEGINS TO
BUILD OVER THE REGION AS THE FLOW AMPLIFIES OVER THE NORTHEAST
QUADRANT OF THE COUNTRY. SURFACE RIDGING WILL REMAIN OVER THE
REGION THROUGH THE DAY...WHICH COULD BRING THE BEST CHANCE FOR A
FEW BREAKS IN THE CLOUDS DURING THE MORNING HOURS. HIGH CLOUDS
WILL BE ON THE INCREASE IN THE LATE AFTERNOON THROUGH. SUNDAY
NIGHT A SURFACE WARM FRONT BEGINS TO PUSH INTO THE REGION...WITH
ISENTROPIC LIFT INCREASING THE CHANCE FOR LIGHT SNOW TOWARDS
DAYBREAK MONDAY MORNING.
DURING THE DAY ON MONDAY THE SURFACE WARM FRONT WILL CONTINUE TO
PUSH NORTH MOVING THE CHANCE FOR PRECIPITATION ALL THE WAY TO
EXTREME NORTHERN MAINE. THERE STILL REMAINS QUITE A BIT OF SPREAD
IN CRITICAL THICKNESS LEVELS AT THIS TIME...BUT MIXED
PRECIPITATION SHOULD QUICKLY CHANGEOVER TO RAIN DOWNEAST AND
ACROSS THE PENOBSCOT/BANGER REGION DURING THE DAY. VERY LIGHT
SNOWFALL ACCUMULATIONS ARE POSSIBLE WITH THE WARM FRONT ON MONDAY
FURTHER INLAND.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
PERIOD WILL BEGIN ON THE MESSY SIDE AS A COMPLEX WEATHER SYSTEM
PUSHES INTO CENTRAL AND NORTHERN MAINE MONDAY NIGHT THROUGH
TUESDAY. FORECAST CONFIDENCE CONTINUES TO INCREASE FOR THE
POSSIBILITY OF A MIXED PRECIPITATION EVENT MONDAY NIGHT INTO
TUESDAY AS A SECONDARY SURFACE LOW IS PROGGED TO DEVELOP OVER
SOUTHERN MAINE FROM THE PRIMARY LOW IN THE SAINT LAWRENCE VALLEY.
THE DEVELOPMENT OF THIS LOW WILL DRIVE HOW FAR NORTH OR SOUTH THE
MIXED PRECIPITATION LINE IS IN THE STATE. THERE IS STILL
CONSIDERABLE SPREAD BETWEEN THE COLDER ECWMF FAMILY AND THE WARMER
GEFS CAMP TO PIN-DOWN THESE DETAILS AT THIS POINT. WITH THAT BEING
SAID THE LASTEST 12Z GUIDANCE DID TREND SLIGHTLY COLDER. ON THE
COAST IT WILL BE ALL RAIN...WITH A POSSIBLE GALE ON THE WATERS ON
STRONG SE WINDS.
TUESDAY THE SURFACE LOW PULLS OFF INTO THE CANADIAN MARITIMES WITH
RAIN/ICY MIX CHANGING BACK OVER TO SNOW. THE STORM IS EXPECTED TO
PULL AWAY TUESDAY NIGHT ENDING ALL PRECIP. COULD BE A SMALL BREAK
IN THE WEATHER ON WEDNESDAY...BEFORE A WARMING TREND AND CHANCE OF
RAIN RETURNS AGAIN BY THE END OF WEEK.
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: WIDESPREAD IFR CONDITIONS CAN BE EXPECTED THIS EVENING
WITH CONDITIONS IMPROVING TO MVFR AFTER MIDNIGHT AND EVENTUALLY
TO VFR BY SATURDAY MORNING.
SHORT TERM:
CHANCE OF MIXED PRECIPITATION ON MONDAY AS A WARM FRONT PUSHES
INTO THE REGION. MVFR CONDITIONS WILL PUSH FROM CENTRAL MAINE
INTO NORTHERN MAINE BY THE AFTERNOON HOURS.
&&
.MARINE...
NEAR TERM: WINDS/SEAS SHOULD REMAIN JUST BELOW SMALL CRAFT
ADVISORY LEVELS TONIGHT. THERE MAY BE A FEW GUSTS TO AROUND 25 KT
SATURDAY.
SHORT TERM:
A SURFACE LOW WILL DEVELOP MONDAY NIGHT OFF THE SOUTHERN MAINE
WATERS. WINDS AND SEAS WILL INCREASE THROUGH OUT THE NIGHT WITH
GALE CONDITIONS POSSIBLE. SEAS WILL QUICKLY SUBSIDE DURING THE DAY
ON TUES.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
116 PM EST THU DEC 10 2015
LATEST UPDATE...
HYDRO
.SYNOPSIS...
ISSUED AT 314 AM EST THU DEC 10 2015
MILD WEATHER WILL CONTINUE THROUGH THE REST OF THE WEEK. DAYTIME
TEMPERATURES WILL MAINLY BE 50 TO 55...HOWEVER AREAS NEAR I-94 MAY
APPROACH 60 ON SATURDAY. THERE COULD BE SOME LIGHT RAIN SHOWERS
THIS EVENING NORTH OF I-96...THEN A FEW MORE LIGHT RAIN SHOWERS WILL
BE POSSIBLE FRIDAY NIGHT INTO EARLY SATURDAY.
SUNDAY LOOKS TO BE ANOTHER WARM DAY...BUT A BETTER CHANCE FOR A
STEADY RAIN. IT WILL COOL OFF BEHIND THIS RAIN FOR THE FIRST HALF
OF NEXT WEEK...WITH DAYTIME HIGHS MAINLY AROUND 40.
&&
.UPDATE...
ISSUED AT 1038 AM EST THU DEC 10 2015
BASED ON LATEST RUC GUIDANCE HAVE NUDGED UP MAX TEMPS A FEW
DEGREES TODAY TO HAVE HIGHS NEAR 60 IN SEVERAL AREAS INLAND FROM
LK MI. RECORDS FOR TODAY INCLUDE 61 AT MKG... 62 AT GRR... AND 63
AT LAN. THESE WERE ALL SET IN 1971.
ALSO INCREASED THE WIND GUSTS A TAD TO HAVE SOME GUSTS AROUND 40
MPH. THE STRONGEST GUSTS ARE EXPECTED TO BE NEAR AND WEST OF HWY
131 PER RUC 925 MB WIND SPEED PROGS... WHERE THERE IS EVEN A
SUGGESTION OF THE POSSIBILITY OF A FEW GUSTS NEAR ADVISORY
CRITERIA OF 45 MPH GIVEN ENOUGH MIXING. NOT CONFIDENT ENOUGH TO
ISSUE A WIND ADVISORY THOUGH.
LATEST RADAR MOSAIC AND HRRR REFLECTIVITY PROGS IMPLY A FEW LIGHT
SHOWERS OR SPRINKLES POSSIBLY REACHING THE GROUND THIS AFTERNOON.
BASED ON CLOUD BASES MAINLY ABOVE 12,000 FT THIS WILL PROBABLY
JUST BE VIRGA.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 314 AM EST THU DEC 10 2015
MILD WEATHER WILL CONTINUE THROUGH THE SHORT TERM. A FRONT WILL
PASS THROUGH THIS EVENING AND COULD BRING WIDELY SCATTERED LIGHT
SHOWERS. THEN A WARM FRONT WILL LIFT NORTH THROUGH THE REGION FRIDAY
NIGHT/EARLY SATURDAY WHICH MAY ALSO BRING A FEW SHOWERS.
MOISTURE DEPTH WITH THE FRONT THIS EVENING IS LACKING AND IT APPEARS
ANY SHOWERS WILL BE VERY LIGHT OR JUST SPRINKLES NORTH OF I-96. WE
WILL SEE A SOUTH SOUTHWEST WIND GUSTING TO AROUND 30 MPH IN MANY
AREAS THIS AFTERNOON INTO EARLY EVENING.
IT WILL BE ABOUT 5 DEGREES COOLER FRIDAY BEHIND THE FRONT WITH A MIX
OF CLOUDS AND SUN. A WARM FRONT WILL TAKE SHAPE OVER THE OHIO
VALLEY FRIDAY AND LIFT NORTH INTO SW MI FRIDAY NIGHT. ONCE AGAIN
MOISTURE LOOKS TO BE SHALLOW WITH THE FRONT...LEADING TO JUST CHANCE
POPS FOR SOME LIGHT SHOWERS.
THE MODELS HAVE TRENDED FURTHER NORTH WITH THE FRONT BY SATURDAY
AND WE MAY STAY FAIRLY DRY. AREAS NORTH OF I-96 WILL PROBABLY SEE
LIGHT SHOWERS INTO THE MORNING...BUT I ADJUSTED POPS DOWN FOR THE
AFTERNOON AS WE MAY VERY WELL GET INTO THE DRY WARM SECTOR MUCH OF
THE DAY. THIS SHOULD LEAD TO TEMPS APPROACHING 60 ALONG I-94. NOT
BAD FOR MID DEC.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 314 AM EST THU DEC 10 2015
LOOKS LIKE A MILD AND WET START TO THE PERIOD FOLLOWED BY A COOLING
TREND INTO THE MIDDLE OF THE WEEK.
ANOMALOUS WARM AND MOIST AIRMASS SPREADS INTO THE REGION SATURDAY
NIGHT INTO SUNDAY. LIFT ALONG A WARM FRONT WILL SUPPORT RAIN
SHOWERS SATURDAY NIGHT. SOME WEAKNESS IN THE STABILITY SHOWS
UP...SO THE RISK FOR THUNDER IS NOT ZERO. THE HIGH RES EURO
ACTUALLY SHOWS 850 MB LIFTED INDEX VALUES OF -2 DEG C 12Z SUN HERE
IN SOUTHWEST MI. WITH A LOW LEVEL JET CROSSING THIS FRONTAL
ZONE...THE RAIN WILL LIKELY BE HEAVY AT TIMES ACCOMPANYING THE
FRONTAL PASSAGE.
ON SUNDAY WE ARE FORECASTED TO BE BETWEEN FRONTS WITH THE WARM FRONT
LIFTING NORTH OF THE REGION AND THE COLD FRONT APPROACHING FROM THE
SOUTHWEST. WILL KEEP THE HIGH POPS GOING...ESPECIALLY WESTERN
ZONES. THE COMBINATION OF STEADY MID LEVEL HEIGHT FALLS AND
INCREASING LOW LEVEL CONVERGENCE IN AN UNSEASONABLY MOIST AIRMASS
SHOULD SUPPORT ON AND OFF SHOWERS.
POTENT MID LEVEL LOW ARRIVES FROM THE SOUTHWEST SUNDAY NIGHT. MODELS
DO VARY ON THE TIMING OF THIS FEATURE SO SOME UNCERTAINTY AS TO HOW
THIS WILL EVOLVE. THE GFS WOULD SUPPORT A MAINLY DRY DAY FOR MONDAY
AS IT IS QUICKER WITH THE MID LEVEL WAVE. WILL HOLD ONTO RELATIVELY
HIGH POPS SUNDAY NIGHT THROUGH MONDAY...BUT THAT COULD CHANGE IF THE
GFS ENDS UP VERIFYING.
ANOTHER WAVE APPROACHES FROM THE WEST GOING INTO THE MIDDLE PART OF
NEXT WEEK. THE MODELS SHOW IT WEAKENING AS IT MOVES IN. STILL...THIS
FEATURE WILL LIMIT HOW MUCH COLD AIR ARRIVES ON THE BACKSIDE OF THE
DEPARTING WAVE MONDAY. SO...OVERALL THIS FORECAST REFLECTS NOT AS
COLD TEMPERATURES TUESDAY INTO WEDNESDAY...AND LESS IN THE WAY OF
SNOW SHOWER POTENTIAL.
MODELS ARE IN DECENT AGREEMENT IN SPREADING IN A COLDER AIRMASS
BEHIND THE THE DEPARTING WAVE FOR THE END OF NEXT WEEK. FORECAST
SOUNDINGS FROM THE HIGH RES EURO AND GFS SUPPORT TEMPERATURES
TRENDING TOWARD MORE SEASONABLE VALUES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1147 AM EST THU DEC 10 2015
WINDY CONDITIONS WILL DEVELOP THIS AFTERNOON. SOUTH WINDS WILL
GUST TO AROUND 30 KTS AT TIMES WITH A FEW HIGHER GUSTS POSSIBLE
MAINLY AT KMKG. WIND SPEEDS/GUSTS WILL DIMINISH SOMEWHAT AFTER
SUNSET. VFR CONDITIONS ARE ANTICIPATED AT ALL THE TERMINALS
THROUGH 18Z FRIDAY. BREEZY CONDITIONS OVERNIGHT INTO FRIDAY MORNING
WILL INHIBIT FOG FROM FORMING.
&&
.MARINE...
ISSUED AT 314 AM EST THU DEC 10 2015
WAVES WILL CONTINUE TO BUILD EARLY THIS MORNING WITH SOUTH SOUTHWEST
WINDS INCREASING. SOUTHWEST WINDS WILL REMAIN BRISK INTO TONIGHT...
BEFORE FINALLY DROPPING OFF TOWARD MID DAY FRIDAY.
&&
.HYDROLOGY...
ISSUED AT 116 PM EST THU DEC 10 2015
RAINFALL THROUGH THE UPCOMING WEEKEND CONTINUES TO BE THE MAIN
CONCERN. WHILE HEAVY RAIN IS POSSIBLE...ESPECIALLY GOING INTO
SUNDAY...SOME QUESTIONS LINGER ON FLOODING POTENTIAL.
GUIDANCE IS CONSISTENT IN PLACING A STRENGTHENING STORM SYSTEM
SOMEWHERE OVER THE MIDWEST BY THIS COMING WEEKEND. MOISTURE
VALUES...THAT ARE WELL ABOVE NORMAL FOR DECEMBER...SURGE NORTHWARD
AHEAD OF THE SYSTEM BY LATE SATURDAY. IN RESPONSE...THE BEST
RAINFALL CHANCES AND HIGHER PRECIPITATION TOTALS MAY FALL IN THE
PERIOD FROM EARLY SUNDAY THROUGH MONDAY MORNING.
CURRENT SUGGESTIONS ARE THAT THE AREA AVERAGES WILL BE SOMEWHERE
IN THE REALM OF 1-2 INCHES BY MONDAY. HOWEVER...THE MAIN QUESTION
IS THE EASTWARD EXTENT OF THE STORM TRACK. THE NATURE OF THE
WISCONSIN TRACKS HAVE THE POTENTIAL TO DRY SLOT...AT LEAST SOME
PORTION OF THE CWA. ALSO...GIVEN THE THAWED SOIL...RECENT DRY
PERIOD AND...A LONGER DURATION RAIN (24+ HOURS) MAY NOT BE MUCH
MORE THAN A WEEKEND HINDERANCE. RIVER RESPONSES WITH THIS NATURE
OF RAIN MAY BE SLOW...GRADUAL AND WITHIN BANKS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR LMZ844>849.
&&
$$
UPDATE...MEADE
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...MJS
AVIATION...LAURENS
HYDROLOGY...JAM
MARINE...JK
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1155 AM EST THU DEC 10 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 314 AM EST THU DEC 10 2015
MILD WEATHER WILL CONTINUE THROUGH THE REST OF THE WEEK. DAYTIME
TEMPERATURES WILL MAINLY BE 50 TO 55...HOWEVER AREAS NEAR I-94 MAY
APPROACH 60 ON SATURDAY. THERE COULD BE SOME LIGHT RAIN SHOWERS
THIS EVENING NORTH OF I-96...THEN A FEW MORE LIGHT RAIN SHOWERS WILL
BE POSSIBLE FRIDAY NIGHT INTO EARLY SATURDAY.
SUNDAY LOOKS TO BE ANOTHER WARM DAY...BUT A BETTER CHANCE FOR A
STEADY RAIN. IT WILL COOL OFF BEHIND THIS RAIN FOR THE FIRST HALF
OF NEXT WEEK...WITH DAYTIME HIGHS MAINLY AROUND 40.
&&
.UPDATE...
ISSUED AT 1038 AM EST THU DEC 10 2015
BASED ON LATEST RUC GUIDANCE HAVE NUDGED UP MAX TEMPS A FEW
DEGREES TODAY TO HAVE HIGHS NEAR 60 IN SEVERAL AREAS INLAND FROM
LK MI. RECORDS FOR TODAY INCLUDE 61 AT MKG... 62 AT GRR... AND 63
AT LAN. THESE WERE ALL SET IN 1971.
ALSO INCREASED THE WIND GUSTS A TAD TO HAVE SOME GUSTS AROUND 40
MPH. THE STRONGEST GUSTS ARE EXPECTED TO BE NEAR AND WEST OF HWY
131 PER RUC 925 MB WIND SPEED PROGS... WHERE THERE IS EVEN A
SUGGESTION OF THE POSSIBILITY OF A FEW GUSTS NEAR ADVISORY
CRITERIA OF 45 MPH GIVEN ENOUGH MIXING. NOT CONFIDENT ENOUGH TO
ISSUE A WIND ADVISORY THOUGH.
LATEST RADAR MOSAIC AND HRRR REFLECTIVITY PROGS IMPLY A FEW LIGHT
SHOWERS OR SPRINKLES POSSIBLY REACHING THE GROUND THIS AFTERNOON.
BASED ON CLOUD BASES MAINLY ABOVE 12,000 FT THIS WILL PROBABLY
JUST BE VIRGA.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 314 AM EST THU DEC 10 2015
MILD WEATHER WILL CONTINUE THROUGH THE SHORT TERM. A FRONT WILL
PASS THROUGH THIS EVENING AND COULD BRING WIDELY SCATTERED LIGHT
SHOWERS. THEN A WARM FRONT WILL LIFT NORTH THROUGH THE REGION FRIDAY
NIGHT/EARLY SATURDAY WHICH MAY ALSO BRING A FEW SHOWERS.
MOISTURE DEPTH WITH THE FRONT THIS EVENING IS LACKING AND IT APPEARS
ANY SHOWERS WILL BE VERY LIGHT OR JUST SPRINKLES NORTH OF I-96. WE
WILL SEE A SOUTH SOUTHWEST WIND GUSTING TO AROUND 30 MPH IN MANY
AREAS THIS AFTERNOON INTO EARLY EVENING.
IT WILL BE ABOUT 5 DEGREES COOLER FRIDAY BEHIND THE FRONT WITH A MIX
OF CLOUDS AND SUN. A WARM FRONT WILL TAKE SHAPE OVER THE OHIO
VALLEY FRIDAY AND LIFT NORTH INTO SW MI FRIDAY NIGHT. ONCE AGAIN
MOISTURE LOOKS TO BE SHALLOW WITH THE FRONT...LEADING TO JUST CHANCE
POPS FOR SOME LIGHT SHOWERS.
THE MODELS HAVE TRENDED FURTHER NORTH WITH THE FRONT BY SATURDAY
AND WE MAY STAY FAIRLY DRY. AREAS NORTH OF I-96 WILL PROBABLY SEE
LIGHT SHOWERS INTO THE MORNING...BUT I ADJUSTED POPS DOWN FOR THE
AFTERNOON AS WE MAY VERY WELL GET INTO THE DRY WARM SECTOR MUCH OF
THE DAY. THIS SHOULD LEAD TO TEMPS APPROACHING 60 ALONG I-94. NOT
BAD FOR MID DEC.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 314 AM EST THU DEC 10 2015
LOOKS LIKE A MILD AND WET START TO THE PERIOD FOLLOWED BY A COOLING
TREND INTO THE MIDDLE OF THE WEEK.
ANOMALOUS WARM AND MOIST AIRMASS SPREADS INTO THE REGION SATURDAY
NIGHT INTO SUNDAY. LIFT ALONG A WARM FRONT WILL SUPPORT RAIN
SHOWERS SATURDAY NIGHT. SOME WEAKNESS IN THE STABILITY SHOWS
UP...SO THE RISK FOR THUNDER IS NOT ZERO. THE HIGH RES EURO
ACTUALLY SHOWS 850 MB LIFTED INDEX VALUES OF -2 DEG C 12Z SUN HERE
IN SOUTHWEST MI. WITH A LOW LEVEL JET CROSSING THIS FRONTAL
ZONE...THE RAIN WILL LIKELY BE HEAVY AT TIMES ACCOMPANYING THE
FRONTAL PASSAGE.
ON SUNDAY WE ARE FORECASTED TO BE BETWEEN FRONTS WITH THE WARM FRONT
LIFTING NORTH OF THE REGION AND THE COLD FRONT APPROACHING FROM THE
SOUTHWEST. WILL KEEP THE HIGH POPS GOING...ESPECIALLY WESTERN
ZONES. THE COMBINATION OF STEADY MID LEVEL HEIGHT FALLS AND
INCREASING LOW LEVEL CONVERGENCE IN AN UNSEASONABLY MOIST AIRMASS
SHOULD SUPPORT ON AND OFF SHOWERS.
POTENT MID LEVEL LOW ARRIVES FROM THE SOUTHWEST SUNDAY NIGHT. MODELS
DO VARY ON THE TIMING OF THIS FEATURE SO SOME UNCERTAINTY AS TO HOW
THIS WILL EVOLVE. THE GFS WOULD SUPPORT A MAINLY DRY DAY FOR MONDAY
AS IT IS QUICKER WITH THE MID LEVEL WAVE. WILL HOLD ONTO RELATIVELY
HIGH POPS SUNDAY NIGHT THROUGH MONDAY...BUT THAT COULD CHANGE IF THE
GFS ENDS UP VERIFYING.
ANOTHER WAVE APPROACHES FROM THE WEST GOING INTO THE MIDDLE PART OF
NEXT WEEK. THE MODELS SHOW IT WEAKENING AS IT MOVES IN. STILL...THIS
FEATURE WILL LIMIT HOW MUCH COLD AIR ARRIVES ON THE BACKSIDE OF THE
DEPARTING WAVE MONDAY. SO...OVERALL THIS FORECAST REFLECTS NOT AS
COLD TEMPERATURES TUESDAY INTO WEDNESDAY...AND LESS IN THE WAY OF
SNOW SHOWER POTENTIAL.
MODELS ARE IN DECENT AGREEMENT IN SPREADING IN A COLDER AIRMASS
BEHIND THE THE DEPARTING WAVE FOR THE END OF NEXT WEEK. FORECAST
SOUNDINGS FROM THE HIGH RES EURO AND GFS SUPPORT TEMPERATURES
TRENDING TOWARD MORE SEASONABLE VALUES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1147 AM EST THU DEC 10 2015
WINDY CONDITIONS WILL DEVELOP THIS AFTERNOON. SOUTH WINDS WILL
GUST TO AROUND 30 KTS AT TIMES WITH A FEW HIGHER GUSTS POSSIBLE
MAINLY AT KMKG. WIND SPEEDS/GUSTS WILL DIMINISH SOMEWHAT AFTER
SUNSET. VFR CONDITIONS ARE ANTICIPATED AT ALL THE TERMINALS
THROUGH 18Z FRIDAY. BREEZY CONDITIONS OVERNIGHT INTO FRIDAY MORNING
WILL INHIBIT FOG FROM FORMING.
&&
.MARINE...
ISSUED AT 314 AM EST THU DEC 10 2015
WAVES WILL CONTINUE TO BUILD EARLY THIS MORNING WITH SOUTH SOUTHWEST
WINDS INCREASING. SOUTHWEST WINDS WILL REMAIN BRISK INTO TONIGHT...
BEFORE FINALLY DROPPING OFF TOWARD MID DAY FRIDAY.
&&
.HYDROLOGY...
ISSUED AT 1216 AM EST WED DEC 9 2015
THE THREAT FOR PRECIPITATION REMAINS LOW THROUGH THE REMAINDER OF
THE WORK WEEK. SCATTERED SHOWERS LATE THURSDAY MAY EVEN BE HARD TO
COME BY. THERE ARE NO CONCERNS FOR FLOODING IN THE NEAR TERM.
A STRENGTHENING STORM SYSTEM CONTINUES TO BE FORECAST TO PASS JUST
WEST OF LAKE MICHIGAN SUNDAY. THIS WILL INCREASE RAIN CHANCES AS
WE HEAD DEEPER INTO THE WEEKEND. MOISTURE FEED FROM THE GULF IS
PLENTIFUL AND COULD LEAD TO HEAVY RAINFALL...PARTICULARLY SUNDAY.
THE WESTERN HALF OF LOWER MICHIGAN LOOKS TO HAVE THE BETTER ODDS
FOR HEAVY RAINFALL WITH GRADUALLY INCREASING TOTALS FROM EAST TO
WEST. 1-2 INCH TOTALS MAY BE COMMON BY MONDAY.
ONE THING TO CONSIDER...FROST DEPTHS ARE NON-EXISTENT AT
THIS POINT. IN ADDITION...RIVERS ARE RUNNING WELL BELOW ACTION
STAGE. WHILE SOME CONCERNS FOR HEAVY RAIN EXIST...TOLERANCE FOR
HIGHER TOTALS MAY BE ABOVE WHAT IS TYPICAL FOR DECEMBER...WHEN WE
ARE OFTEN CONSIDERING A HARD SURFACE DUE TO SUB-FREEZING TERRAIN.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR LMZ844>849.
&&
$$
UPDATE...MEADE
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...MJS
AVIATION...LAURENS
HYDROLOGY...JAM
MARINE...JK
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1038 AM EST THU DEC 10 2015
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 314 AM EST THU DEC 10 2015
MILD WEATHER WILL CONTINUE THROUGH THE REST OF THE WEEK. DAYTIME
TEMPERATURES WILL MAINLY BE 50 TO 55...HOWEVER AREAS NEAR I-94 MAY
APPROACH 60 ON SATURDAY. THERE COULD BE SOME LIGHT RAIN SHOWERS
THIS EVENING NORTH OF I-96...THEN A FEW MORE LIGHT RAIN SHOWERS WILL
BE POSSIBLE FRIDAY NIGHT INTO EARLY SATURDAY.
SUNDAY LOOKS TO BE ANOTHER WARM DAY...BUT A BETTER CHANCE FOR A
STEADY RAIN. IT WILL COOL OFF BEHIND THIS RAIN FOR THE FIRST HALF
OF NEXT WEEK...WITH DAYTIME HIGHS MAINLY AROUND 40.
&&
.UPDATE...
ISSUED AT 1038 AM EST THU DEC 10 2015
BASED ON LATEST RUC GUIDANCE HAVE NUDGED UP MAX TEMPS A FEW
DEGREES TODAY TO HAVE HIGHS NEAR 60 IN SEVERAL AREAS INLAND FROM
LK MI. RECORDS FOR TODAY INCLUDE 61 AT MKG... 62 AT GRR... AND 63
AT LAN. THESE WERE ALL SET IN 1971.
ALSO INCREASED THE WIND GUSTS A TAD TO HAVE SOME GUSTS AROUND 40
MPH. THE STRONGEST GUSTS ARE EXPECTED TO BE NEAR AND WEST OF HWY
131 PER RUC 925 MB WIND SPEED PROGS... WHERE THERE IS EVEN A
SUGGESTION OF THE POSSIBILITY OF A FEW GUSTS NEAR ADVISORY
CRITERIA OF 45 MPH GIVEN ENOUGH MIXING. NOT CONFIDENT ENOUGH TO
ISSUE A WIND ADVISORY THOUGH.
LATEST RADAR MOSAIC AND HRRR REFLECTIVITY PROGS IMPLY A FEW LIGHT
SHOWERS OR SPRINKLES POSSIBLY REACHING THE GROUND THIS AFTERNOON.
BASED ON CLOUD BASES MAINLY ABOVE 12,000 FT THIS WILL PROBABLY
JUST BE VIRGA.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 314 AM EST THU DEC 10 2015
MILD WEATHER WILL CONTINUE THROUGH THE SHORT TERM. A FRONT WILL
PASS THROUGH THIS EVENING AND COULD BRING WIDELY SCATTERED LIGHT
SHOWERS. THEN A WARM FRONT WILL LIFT NORTH THROUGH THE REGION FRIDAY
NIGHT/EARLY SATURDAY WHICH MAY ALSO BRING A FEW SHOWERS.
MOISTURE DEPTH WITH THE FRONT THIS EVENING IS LACKING AND IT APPEARS
ANY SHOWERS WILL BE VERY LIGHT OR JUST SPRINKLES NORTH OF I-96. WE
WILL SEE A SOUTH SOUTHWEST WIND GUSTING TO AROUND 30 MPH IN MANY
AREAS THIS AFTERNOON INTO EARLY EVENING.
IT WILL BE ABOUT 5 DEGREES COOLER FRIDAY BEHIND THE FRONT WITH A MIX
OF CLOUDS AND SUN. A WARM FRONT WILL TAKE SHAPE OVER THE OHIO
VALLEY FRIDAY AND LIFT NORTH INTO SW MI FRIDAY NIGHT. ONCE AGAIN
MOISTURE LOOKS TO BE SHALLOW WITH THE FRONT...LEADING TO JUST CHANCE
POPS FOR SOME LIGHT SHOWERS.
THE MODELS HAVE TRENDED FURTHER NORTH WITH THE FRONT BY SATURDAY
AND WE MAY STAY FAIRLY DRY. AREAS NORTH OF I-96 WILL PROBABLY SEE
LIGHT SHOWERS INTO THE MORNING...BUT I ADJUSTED POPS DOWN FOR THE
AFTERNOON AS WE MAY VERY WELL GET INTO THE DRY WARM SECTOR MUCH OF
THE DAY. THIS SHOULD LEAD TO TEMPS APPROACHING 60 ALONG I-94. NOT
BAD FOR MID DEC.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 314 AM EST THU DEC 10 2015
LOOKS LIKE A MILD AND WET START TO THE PERIOD FOLLOWED BY A COOLING
TREND INTO THE MIDDLE OF THE WEEK.
ANOMALOUS WARM AND MOIST AIRMASS SPREADS INTO THE REGION SATURDAY
NIGHT INTO SUNDAY. LIFT ALONG A WARM FRONT WILL SUPPORT RAIN
SHOWERS SATURDAY NIGHT. SOME WEAKNESS IN THE STABILITY SHOWS
UP...SO THE RISK FOR THUNDER IS NOT ZERO. THE HIGH RES EURO
ACTUALLY SHOWS 850 MB LIFTED INDEX VALUES OF -2 DEG C 12Z SUN HERE
IN SOUTHWEST MI. WITH A LOW LEVEL JET CROSSING THIS FRONTAL
ZONE...THE RAIN WILL LIKELY BE HEAVY AT TIMES ACCOMPANYING THE
FRONTAL PASSAGE.
ON SUNDAY WE ARE FORECASTED TO BE BETWEEN FRONTS WITH THE WARM FRONT
LIFTING NORTH OF THE REGION AND THE COLD FRONT APPROACHING FROM THE
SOUTHWEST. WILL KEEP THE HIGH POPS GOING...ESPECIALLY WESTERN
ZONES. THE COMBINATION OF STEADY MID LEVEL HEIGHT FALLS AND
INCREASING LOW LEVEL CONVERGENCE IN AN UNSEASONABLY MOIST AIRMASS
SHOULD SUPPORT ON AND OFF SHOWERS.
POTENT MID LEVEL LOW ARRIVES FROM THE SOUTHWEST SUNDAY NIGHT. MODELS
DO VARY ON THE TIMING OF THIS FEATURE SO SOME UNCERTAINTY AS TO HOW
THIS WILL EVOLVE. THE GFS WOULD SUPPORT A MAINLY DRY DAY FOR MONDAY
AS IT IS QUICKER WITH THE MID LEVEL WAVE. WILL HOLD ONTO RELATIVELY
HIGH POPS SUNDAY NIGHT THROUGH MONDAY...BUT THAT COULD CHANGE IF THE
GFS ENDS UP VERIFYING.
ANOTHER WAVE APPROACHES FROM THE WEST GOING INTO THE MIDDLE PART OF
NEXT WEEK. THE MODELS SHOW IT WEAKENING AS IT MOVES IN. STILL...THIS
FEATURE WILL LIMIT HOW MUCH COLD AIR ARRIVES ON THE BACKSIDE OF THE
DEPARTING WAVE MONDAY. SO...OVERALL THIS FORECAST REFLECTS NOT AS
COLD TEMPERATURES TUESDAY INTO WEDNESDAY...AND LESS IN THE WAY OF
SNOW SHOWER POTENTIAL.
MODELS ARE IN DECENT AGREEMENT IN SPREADING IN A COLDER AIRMASS
BEHIND THE THE DEPARTING WAVE FOR THE END OF NEXT WEEK. FORECAST
SOUNDINGS FROM THE HIGH RES EURO AND GFS SUPPORT TEMPERATURES
TRENDING TOWARD MORE SEASONABLE VALUES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 657 AM EST THU DEC 10 2015
A TIGHT PRESSURE GRADIENT WILL SET UP ACROSS THE TAF SITES TODAY.
THIS WILL RESULT IN SOUTHWESTERLY WIND GUSTS THAT WILL TOP 25
KNOTS AT THE TAF SITES. THESE WINDS WILL ACT TO PUSH THE LOW LEVEL
MOISTURE NORTH OF THE TAF SITES TODAY. THIS EVENING A PERIOD OF
LOWER CLOUDS WILL BE POSSIBLE AS COLD FRONT PUSHES THROUGH.
CEILINGS WILL INCREASE LATER AT NIGHT AS THE LOW LEVELS DRY OUT
BEHIND THE FRONT.
&&
.MARINE...
ISSUED AT 314 AM EST THU DEC 10 2015
WAVES WILL CONTINUE TO BUILD EARLY THIS MORNING WITH SOUTH SOUTHWEST
WINDS INCREASING. SOUTHWEST WINDS WILL REMAIN BRISK INTO TONIGHT...
BEFORE FINALLY DROPPING OFF TOWARD MID DAY FRIDAY.
&&
.HYDROLOGY...
ISSUED AT 1216 AM EST WED DEC 9 2015
THE THREAT FOR PRECIPITATION REMAINS LOW THROUGH THE REMAINDER OF
THE WORK WEEK. SCATTERED SHOWERS LATE THURSDAY MAY EVEN BE HARD TO
COME BY. THERE ARE NO CONCERNS FOR FLOODING IN THE NEAR TERM.
A STRENGTHENING STORM SYSTEM CONTINUES TO BE FORECAST TO PASS JUST
WEST OF LAKE MICHIGAN SUNDAY. THIS WILL INCREASE RAIN CHANCES AS
WE HEAD DEEPER INTO THE WEEKEND. MOISTURE FEED FROM THE GULF IS
PLENTIFUL AND COULD LEAD TO HEAVY RAINFALL...PARTICULARLY SUNDAY.
THE WESTERN HALF OF LOWER MICHIGAN LOOKS TO HAVE THE BETTER ODDS
FOR HEAVY RAINFALL WITH GRADUALLY INCREASING TOTALS FROM EAST TO
WEST. 1-2 INCH TOTALS MAY BE COMMON BY MONDAY.
ONE THING TO CONSIDER...FROST DEPTHS ARE NON-EXISTENT AT
THIS POINT. IN ADDITION...RIVERS ARE RUNNING WELL BELOW ACTION
STAGE. WHILE SOME CONCERNS FOR HEAVY RAIN EXIST...TOLERANCE FOR
HIGHER TOTALS MAY BE ABOVE WHAT IS TYPICAL FOR DECEMBER...WHEN WE
ARE OFTEN CONSIDERING A HARD SURFACE DUE TO SUB-FREEZING TERRAIN.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR LMZ844>849.
&&
$$
UPDATE...MEADE
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...MJS
AVIATION...MJS
HYDROLOGY...JAM
MARINE...JK
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
637 PM CST FRI DEC 11 2015
.UPDATE...
ISSUED AT 617 PM CST FRI DEC 11 2015
UPDATED TO INCLUDE 00Z AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 340 PM CST FRI DEC 11 2015
THE SHORT TERM IS DEFINITELY THE CALM BEFORE THE STORM WITH THE
BIG CHANGE MADE THROUGH THE DAY SATURDAY BEING TO REDUCE POPS
THROUGHOUT THE PERIOD.
THIS AFTERNOON...THE SFC RIDGE THAT WORKED ACROSS MN THIS MORNING
IS NOW WORKING ACROSS WI...WITH EASTERLY LOW LEVEL WINDS SETTING
UP AS LEE CYCLOGENESIS SLOWLY EVOLVES ACROSS COLORADO. LEAD
SHORTWAVE EMANATING FROM THE MAIN WRN THROUGH IS WORKING ACROSS
CENTRAL NODAK THIS AFTERNOON AND IS ON ITS WAY FOR SOUTHERN
MANITOBA. PRECIP ASSOCIATED WITH THIS WAVE HAS BEEN TIED TO
MOISTURE AND ISENTROPIC LIFT ON THE 295K SFC...AND THE RAP SHOWS
THIS AREA OF FORCING/MOISTURE HEADING FOR NW MN...SO REMOVED WHAT
LITTLE POPS WE HAD FOR TODAY AND THIS EVENING ACROSS WESTERN AND
CENTRAL MN.
LATER TONIGHT...WE WILL SEE ANOTHER AREA OF PRECIP PUSH NORTH ON
THE LEADING EDGE OF THE FIRST MOISTURE SURGE. THERE WILL LIKELY
BE AN AREA OF DRIZZLE/LIGHT RAIN ASSOCIATED WITH IT...BUT PRIMARY
MOISTURE TRANSPORT AT 925MB WILL BE GOING FROM EASTERN IOWA TOWARD
THE MICH/WI BORDER. AS A RESULT...KEPT THE FORECAST DRY FOR
TONIGHT ACROSS THE ENTIRE MPX CWA...AS ANY DZ/RA PRODUCTION LOOKS
TO OCCUR SOUTHEAST OF OUR FORECAST AREA.
FOR SATURDAY...CONTINUED THE TREND OF DRYING THE FORECAST AS
WELL...AS GUIDANCE IS IN GOOD AGREEMENT ON THE BULK OF THE PRECIP
WITH THIS WEEKENDS SYSTEM COMING AFTER 00Z SUNDAY /SATURDAY
EVENING/. THE ONE EXCEPTION IS THE DEVELOPMENT OF A BAND OF
ELEVATED FGEN IN THE H7-H6 LAYER SATURDAY AFTERNOON. MOST
GUIDANCE...CAM AND NON-CAM ALIKE...SHOW A BAND OF PRECIP
DEVELOPING IN WRN MN AND WORKING UP TO CENTRAL MN DURING THE
AFTERNOON...SO THIS WAS WHERE PRECIP MENTION WAS MAINTAINED...
EVERYWHERE ELSE WE KEPT DRY UNTIL WE GET INTO SATURDAY EVENING...
WHEN THINGS LOOK TO GO DOWNHILL PRETTY QUICK. LOOKS PLENTY WARM
ENOUGH SATURDAY AFTERNOON TO KEEP THE VAST MAJORITY OF THE PRECIP
WE SEE AS RAIN...THOUGH WE MAY SEE A SNOWFLAKE OR TWO MIX IN OUT
TOWARD ALEXANDRIA. WITH RAIN EXPECTED TO DOMINATE...REMOVED ANY
SNOW ACCUMULATIONS FROM SATURDAY AS WELL.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 340 PM CST FRI DEC 11 2015
WIDESPREAD RAIN IS STILL ON TRACK FOR THE WEEKEND INTO MONDAY WITH
1-3 INCHES OF RAIN IN THE EASTERN FORECAST AREA...TAPERING TO
ABOUT A HALF INCH OF LIQUID IN WESTERN MN. AT THIS POINT...WESTERN
MN IS THE MOST SUSCEPTIBLE TO A FEW INCHES OF SNOW GIVEN THE
COOLER TEMPERATURE PROFILE IN THIS AREA.
THE NAM AND ECMWF HAVE BEEN DIALED IN WITH ONLY SMALL WOBBLES IN
THE SURFACE LOW TRACK OVER THE PAST 3 RUNS GOING BACK TO LAST
NIGHT. THE GFS HAS SHOWN A LITTLE MORE RUN-TO-RUN VARIABILITY OVER
THE PAST 3-4 RUNS. AS PREVIOUS DISCUSSIONS HAVE MENTIONED...THE
FORECAST LOW TRACK HAS THE LOOK OF A MAJOR WINTER STORM...ITS
SIMPLY TOO WARM. BOTH THE 60HR CIPS ANALOG FROM THE NAM AND THE
72HR ANALOG FROM THE GFS SUGGEST WE SHOULD BE GETTING READY TO
ISSUE WINTER STORM WATCH HEADLINES ACROSS MOST OF OUR MINNESOTA
COUNTIES...AGAIN NOT EVEN CLOSE WITH THESE TEMPERATURES. WHAT WE
ARE CONFIDENT IN...IS WIDESPREAD 1"+ RAIN TOTALS ACROSS EASTERN
MN AND WESTERN WI. WE NOW HAVE 100% RAIN IN THE FORECAST FOR
SEVERAL PERIODS SAT-MON. SOUTHEAST MN AND WESTERN WI COULD GET A
FEW RUMBLES OF THUNDER AS WELL.
THE MODEL CONSENSUS IS FOR A LOW TRACK OUT OF THE SOUTHERN PLAINS
ACROSS NORTHEAST IA AND INTO NORTHERN WI FROM SATURDAY NIGHT INTO
MONDAY MORNING. THERE WILL BE TWO MAIN BURSTS OF PRECIP...THE
FIRST IS WITH THE MOISTURE SURGE AND ISENTROPIC LIFT SATURDAY
NIGHT...FOLLOWED BY A RELATIVE LULL...AND THE SECOND SURGE SUNDAY
MORNING/AFTERNOON WITH THE CLASSIC FLUID DEFORMATION - THIS LINGERS
INTO MONDAY. THE ONE AREA OF CONCERN IS IN WESTERN MN...WHERE SOME
OF THE MODEL GUIDANCE HAS TRENDED A BIT COOLER. AS IT STANDS
NOW...WE ARE FORECASTING 1-3" OF SNOW NEAR AND WEST OF A LINE FROM
GRANITE FALLS...TO SAUK CENTRE...TO STAPLES - WITH A WINTRY MIX OF
PRECIP. THE COLD SIDE OF THIS SYSTEM ISN/T AS COLD AS WE MIGHT
EXPECT...WHICH IS WHY WE AREN`T GOING WITH HIGHER SNOW TOTALS AT
THIS POINT. HOWEVER...STRONG SYSTEMS LIKE THIS THAT DEEPEN AS
THEY LIFT OUT OF THE PLAINS CAN DYNAMICALLY LOWER THE FREEZING
LEVEL AND GIVE YOU A QUICKER CHANGEOVER TO SNOW. IF THAT WERE TO
HAPPEN...LOCATIONS SUCH AS ALEXANDRIA...GRANITE FALLS AND BENSON
COULD END UP WITH SEVERAL INCHES OF SNOW - MAYBE AS MUCH AS 6".
WE`LL CONTINUE TO WATCH OUR WESTERN MN AREA CLOSELY. THE
FORECAST SOUNDINGS DEFINITELY SHOW MORE SLEET IN THESE AREAS AS
WELL BECAUSE THEY HAVE COOLED BUT CONTINUE TO SHOW A WARM LAYER
ALOFT.
THE TRAILING SYSTEM TUESDAY NIGHT AND WEDNESDAY STILL LOOKS
COOLER WITH A BETTER CHANCE FOR SNOW. IT HAS A VERY SIMILAR TRACK
TO THE WEEKEND STORM...HOWEVER...IT IS ALSO DRIER AND FASTER. WE
WILL LEAVE IT THERE AND TAKE THIS ONE SYSTEM AT A TIME.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 617 PM CST FRI DEC 11 2015
HIGH CONFIDENCE ON ALL SITES EXPERIENCING IFR CEILINGS BY DAYBREAK
SAT MORNING DUE TO A STRONG SOUTHERLY SURGE OF DEEP MOISTURE INTO
THE REGION ALONG WITH LLVL EASTERLY WINDS WHICH WILL BE CONDUCIVE
TO MAINTAINING LOW STRATUS ACRS THE AREA. ANY SITES THAT HAVE
STARTED OUT AS MVFR WILL GRADUALLY DROP TO IFR OVERNIGHT THRU TMRW
MRNG. IN ADDITION...SHOULD WINDS DROP OFF BELOW 5 KT...THEN A
DECREASE IN VSBY WILL ALSO BE COMMONPLACE. AM NOT THINKING VSBY
DROPS TO LESS THAN 2-3SM SINCE THE PIECES DO NOT ADD UP TO A DENSE
FOG EVENT...BUT GOING TO 1SM CANNOT BE RULED OUT AROUND DAYBREAK
TMRW MRNG. CONDS GRADUALLY IMPROVE THRU THE DAY...SUCH THAT VSBY
GREATER THAN 6SM MAY WELL BE ACHIEVED BY LATE DAY. PRECIPITATION
LOOKS TO GENERALLY HOLD OFF UNTIL AFTER 00Z TMRW EVE...BUT KAXN
MAY WELL BE SUSCEPTIBLE TO SOME LATE AFTN -RA.
KMSP...HAVE GENERALLY MAINTAINED CONTINUITY WITH THE INHERITED
11/18Z TAF IN STARTING OUT WITH SUB-1700 FT CEILINGS AND ALTHOUGH
THE CLEARING LINE IS AWFULLY CLOSE TO THE S OF KMSP...AM NOT
THINKING IT WILL MAKE IT FAR ENOUGH N TO MAKE A SIGNIFICANT BREAK
IN THE DEGRADED CONDS. AM OPTING TO KEEP THE LOW CEILINGS IN PLACE
THROUGHOUT THIS TAF PERIOD...INCLUDING IFR CEILINGS STARTING
AROUND DAYBREAK TMRW AND LASTING THRU TMRW NIGHT.
/OUTLOOK FOR KMSP/
SUN...IFR WITH PERIODS OF RA. WINDS NE TO N 10-15 KTS.
MON...MVFR/IFR. -RA/-SN POSSIBLE EARLY. WINDS NW 15-20 KTS.
TUE...VFR EARLY. MVFR/IFR WITH CHC -SN LATE. WINDS E 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
UPDATE...JPC
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...JPC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1201 PM CST THU DEC 10 2015
.UPDATE...
ISSUED AT 1149 AM CST THU DEC 10 2015
UPDATED FOR THE 18Z AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
SHORT TERM CONCERNS ARE TIMING OF THE RAIN THREAT TODAY AND
TEMPERATURES.
MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE THOUGHT OF A BAND OF
RAIN MOVING FROM WEST TO EAST OVER THE CWA DURING THE MORNING/EARLY
AFTERNOON. THIS MATCHES WELL WITH THE CURRENT HRRR AS WELL. WILL
MOVE A LIKELY POP BAND ACROSS THE AREA...GENERALLY 15Z-18Z OVER
EASTERN MN AND THEN INTO WEST CENTRAL WI AFTER THAT. DOESNT LOOK
LIKE MUCH RAIN...GENERALLY LESS THAN ONE TENTH OF AN INCH. PTYPE
DOES NOT APPEAR TO BE AN ISSUE WITH WARM BOUNDARY LAYER IN PLACE.
SOME GUSTY WINDS DEVELOPING WITH PASSAGE OF FRONT. BETTER PRESSURE
RISES DROP SOUTHEAST OVER SOUTHWEST MN INTO IOWA DURING THE
MORNING...SO STRONGER WINDS WILL BE FELT THERE. THE GFS IS
STRONGER WITH THE SURGE WITH THE SECONDARY COLD FRONT/TROUGH LATER
IN THE AFTERNOON. THIS COULD INCREASE WINDS AGAIN OVER THE WEST LATE
AS CAA DEVELOPS.
VERY MILD START OVER THE AREA AHEAD OF THE SURFACE FRONT. WILL
LIKELY SEE SOME LOWER 50S IN THE SOUTH WHERE SUNSHINE PEAKS THROUGH
FROM TIME TO TIME. NOT QUITE RECORD TERRITORY BUT CLOSE. COLDER AIR
LAGS WITH SECONDARY COLD FRONT DROPPING IN TONIGHT...POSSIBLY WITH
LOWER STRATOCUMULUS. WILL HAVE TO SEE HOW FAR THAT MOVES SOUTH AND
EAST WITH TIME.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 415 AM CST THU DEC 10 2015
THE LONG TERM FORECAST PERIOD INCLUDES PRECIPITATION CHANCES
PRETTY MUCH EVERY OTHER DAY...AS A ZONAL FLOW REGIME DEVELOPS AND
ALSO ALSO FOSTERS THE CONTINUANCE OF MILD TEMPERATURES.
EYES THIS MORNING ARE ON THE PACIFIC NORTHWEST...WHERE A TIGHTLY
WOUND LOW IS OBSERVED ENTERING WASHINGTON STATE ON WATER VAPOR
IMAGERY. LEESIDE SURFACE CYCLONGENESIS IS INDUCED AHEAD OF THIS
FEATURE OVER THE CENTRAL PLAINS OVER THE NEXT 24 HOURS.
FRIDAY...PRECIPITATION IS EXPECTED TO DEVELOP ON THE NORTHERN
FRINGES OF THE SURFACE TROUGH AS IT LIFTS ACROSS IOWA. EXPECT TO
SEE A BAND OF SNOW /POSSIBLY MIXED WITH RAIN/ DEVELOPING EASTWARD
ACROSS CENTRAL MN. ASSOCIATED ACCUMULATIONS WOULD BE LIGHT...A
DUSTING AT MOST.
THE NEXT WAVE AND SURGE OF PV ADVECTION ARRIVE ON
FRIDAY...ALTHOUGH MODELS ARE TRENDING FARTHER NORTH WITH TIME
WHICH COULD KEEP THE MAJORITY THE MPX AREA DRY. HAVE INCLUDED
20-30 POPS NORTH OF THE I-94 CORRIDOR.
SATURDAY INTO SUNDAY THE NEXT TROUGH OF LOW PRESSURE NOSES FROM
THE TX PANHANDLE INTO MO/IA/MN. AS EXPECTED...THE 12.00Z ECMWF
CONTINUES TO FEATURE A MAINLY WARM/LIQUID SYSTEM...KEEPING NEARLY
ALL OF THE FORECAST AREA SNOW-FREE. MEANWHILE...THE 12.06Z GFS
PAINTED WARNING-CRITERIA FROM SOUTHWEST INTO WEST/NORTH CENTRAL
MN BY DAYBREAK MONDAY. FEEL A LEAN TOWARD THE ECMWF IS A BETTER
ROUTE TO GO...GIVEN RECENT SYSTEMS AND MODEL TRENDS. DO INCLUDE
0.5-2.0 INCH SNOWFALL AMOUNTS IN THE NORTHWEST FORECAST
AREA...BUT HAVE INCREASING CONFIDENCE THE TWIN CITIES WILL ESCAPE
A MEASURABLE SNOWFALL WITH THE WEEKEND SYSTEM.
AND LAST BUT NOT LEAST...A STRONG SURFACE SYSTEM IS PROGGED BY THE
MEDIUM RANGE CONSENSUS ON MONDAY NIGHT INTO WEDNESDAY. THIS TIME
AROUND WE LOOK A LITTLE COLDER AND THE LOW A BIT DEEPER...SO A
SLIGHTLY HIGHER CONFIDENCE IN SNOW ARRIVES FOR EARLY NEXT WEEK.
AFTER A PROLONGED STRETCH OF WARM WEATHER...TEMPS LOOK TO RETREAT
BACK TOWARD CLIMATOLOGICAL NORMALS BY WEDNESDAY OF THE UPCOMING
WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1149 AM CST THU DEC 10 2015
NORTH TO SOUTH ORIENTED BAND OF RAIN MOVING THROUGH EASTERN MN
CURRENTLY...ACCOMPANIED BY MVFR CIGS AND VIS. THIS AREA WILL
CONTINUE EAST AND MOVE THROUGH WESTERN WI LATE THIS AFTERNOON. VFR
CONDITIONS WILL FOLLOW THE BACK SIDE OF THE RAIN BAND...BUT THERE
IS AN AREA OF MVFR STRATUS IN NORTH DAKOTA THAT IS PRIME TO DIVE
SOUTHEAST THIS AFTERNOON AND NIGHT AND OVERSPREAD MOST OF THE FA
TONIGHT. THE STRATUS WILL LAST THROUGH THE REMAINDER OF THE PERIOD
UNDER THE CYCLONIC CIRCULATION OF THE MAIN LOW TO OUR EAST.
KMSP...RAIN SHOULD BE ENDING AROUND 1930-2000Z. RECENTLY...CIGS
HAVE LIFTED ABOVE 017 AND MAY INDEED STAY ABOVE THIS NEXT HOUR OR
TWO UNTIL VFR CIGS COME BACK ON THE BACK SIDE OF THE RAIN BAND.
/OUTLOOK FOR KMSP/
FRI NITE...VFR. WINDS E 5-10 KTS.
SAT...VFR WITH MVFR -RA POSSIBLE. WINDS NNW 5-10 KTS.
SUN...VFR WITH MVFR -RA/-SN POSSIBLE. WINDS NE 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
UPDATE...SPD
SHORT TERM...DWE
LONG TERM...LS
AVIATION...SPD
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
529 AM CST THU DEC 10 2015
.UPDATED FOR 12Z AVIATION DISCUSSION BELOW...
.SHORT TERM...(TODAY AND TONIGHT)
SHORT TERM CONCERNS ARE TIMING OF THE RAIN THREAT TODAY AND
TEMPERATURES.
MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE THOUGHT OF A BAND OF
RAIN MOVING FROM WEST TO EAST OVER THE CWA DURING THE MORNING/EARLY
AFTERNOON. THIS MATCHES WELL WITH THE CURRENT HRRR AS WELL. WILL
MOVE A LIKELY POP BAND ACROSS THE AREA...GENERALLY 15Z-18Z OVER
EASTERN MN AND THEN INTO WEST CENTRAL WI AFTER THAT. DOESNT LOOK
LIKE MUCH RAIN...GENERALLY LESS THAN ONE TENTH OF AN INCH. PTYPE
DOES NOT APPEAR TO BE AN ISSUE WITH WARM BOUNDARY LAYER IN PLACE.
SOME GUSTY WINDS DEVELOPING WITH PASSAGE OF FRONT. BETTER PRESSURE
RISES DROP SOUTHEAST OVER SOUTHWEST MN INTO IOWA DURING THE
MORNING...SO STRONGER WINDS WILL BE FELT THERE. THE GFS IS
STRONGER WITH THE SURGE WITH THE SECONDARY COLD FRONT/TROUGH LATER
IN THE AFTERNOON. THIS COULD INCREASE WINDS AGAIN OVER THE WEST LATE
AS CAA DEVELOPS.
VERY MILD START OVER THE AREA AHEAD OF THE SURFACE FRONT. WILL
LIKELY SEE SOME LOWER 50S IN THE SOUTH WHERE SUNSHINE PEAKS THROUGH
FROM TIME TO TIME. NOT QUITE RECORD TERRITORY BUT CLOSE. COLDER AIR
LAGS WITH SECONDARY COLD FRONT DROPPING IN TONIGHT...POSSIBLY WITH
LOWER STRATOCUMULUS. WILL HAVE TO SEE HOW FAR THAT MOVES SOUTH AND
EAST WITH TIME.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 415 AM CST THU DEC 10 2015
THE LONG TERM FORECAST PERIOD INCLUDES PRECIPITATION CHANCES
PRETTY MUCH EVERY OTHER DAY...AS A ZONAL FLOW REGIME DEVELOPS AND
ALSO ALSO FOSTERS THE CONTINUANCE OF MILD TEMPERATURES.
EYES THIS MORNING ARE ON THE PACIFIC NORTHWEST...WHERE A TIGHTLY
WOUND LOW IS OBSERVED ENTERING WASHINGTON STATE ON WATER VAPOR
IMAGERY. LEESIDE SURFACE CYCLONGENESIS IS INDUCED AHEAD OF THIS
FEATURE OVER THE CENTRAL PLAINS OVER THE NEXT 24 HOURS.
FRIDAY...PRECIPITATION IS EXPECTED TO DEVELOP ON THE NORTHERN
FRINGES OF THE SURFACE TROUGH AS IT LIFTS ACROSS IOWA. EXPECT TO
SEE A BAND OF SNOW /POSSIBLY MIXED WITH RAIN/ DEVELOPING EASTWARD
ACROSS CENTRAL MN. ASSOCIATED ACCUMULATIONS WOULD BE LIGHT...A
DUSTING AT MOST.
THE NEXT WAVE AND SURGE OF PV ADVECTION ARRIVE ON
FRIDAY...ALTHOUGH MODELS ARE TRENDING FARTHER NORTH WITH TIME
WHICH COULD KEEP THE MAJORITY THE MPX AREA DRY. HAVE INCLUDED
20-30 POPS NORTH OF THE I-94 CORRIDOR.
SATURDAY INTO SUNDAY THE NEXT TROUGH OF LOW PRESSURE NOSES FROM
THE TX PANHANDLE INTO MO/IA/MN. AS EXPECTED...THE 12.00Z ECMWF
CONTINUES TO FEATURE A MAINLY WARM/LIQUID SYSTEM...KEEPING NEARLY
ALL OF THE FORECAST AREA SNOW-FREE. MEANWHILE...THE 12.06Z GFS
PAINTED WARNING-CRITERIA FROM SOUTHWEST INTO WEST/NORTH CENTRAL
MN BY DAYBREAK MONDAY. FEEL A LEAN TOWARD THE ECMWF IS A BETTER
ROUTE TO GO...GIVEN RECENT SYSTEMS AND MODEL TRENDS. DO INCLUDE
0.5-2.0 INCH SNOWFALL AMOUNTS IN THE NORTHWEST FORECAST
AREA...BUT HAVE INCREASING CONFIDENCE THE TWIN CITIES WILL ESCAPE
A MEASURABLE SNOWFALL WITH THE WEEKEND SYSTEM.
AND LAST BUT NOT LEAST...A STRONG SURFACE SYSTEM IS PROGGED BY THE
MEDIUM RANGE CONSENSUS ON MONDAY NIGHT INTO WEDNESDAY. THIS TIME
AROUND WE LOOK A LITTLE COLDER AND THE LOW A BIT DEEPER...SO A
SLIGHTLY HIGHER CONFIDENCE IN SNOW ARRIVES FOR EARLY NEXT WEEK.
AFTER A PROLONGED STRETCH OF WARM WEATHER...TEMPS LOOK TO RETREAT
BACK TOWARD CLIMATOLOGICAL NORMALS BY WEDNESDAY OF THE UPCOMING
WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 530 AM CST THU DEC 10 2015
TIMING OF THE BAND OF RAIN IS THE MAIN FOCUS EARLY. THEN POSSIBLE
MVFR CIGS DROPPING IN LATER TONIGHT. STILL LOOKS LIKE THE RAIN
BAND MOVING OVER WESTERN AREAS 13Z-16Z AND OVER EASTERN MN 16Z-19Z
AND LATER INTO WESTERN WI. SHOULD BE 2-3 HOUR DURATION....MAINLY
EAST. MAY GO BRIEFLY MVFR IN THE BAND BUT MAIN SHOT OF MVFR CIGS
COMING IN FROM NW TO SE AFTER 00Z FRI. THIS MAY AFFECT THE
NORTHEAST HALF OF THE CWA OVERNIGHT. SURFACE WINDS SOUTHEAST TO
SOUTH BECOMING WEST/NORTHWEST WITH SURFACE FRONTAL PASSAGE AND
GUSTY AROUND 25KTS POSSIBLE OUT WEST. SHOULD DIMINISH LATER
TONIGHT.
KMSP...
EXPECT RAIN BAND 16Z-1830Z LOCALLY. BRIEF VIS/CIG REDUCTIONS TO
MVFR LEVELS CANNOT BE RULED OUT WITH PASSAGE. MAY SEE MVFR CIGS
MOVE INTO THE AREA AFTER 06Z FRI AS COLDER AIR ARRIVES. SOUTHEAST
TO SOUTH WIND EARLY BECOMING MORE WEST THIS AFTERNOON AND TONIGHT
AND GUSTY AT TIMES. SHOULD DIMINISH LATER TONIGHT.
/OUTLOOK FOR KMSP/
FRI NITE...VFR. WINDS E 5-10 KTS.
SAT...VFR WITH MVFR -RA POSSIBLE. WINDS NNW 5-10 KTS.
SUN...VFR WITH MVFR -RA/-SN POSSIBLE. WINDS NE 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
415 AM CST THU DEC 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
SHORT TERM CONCERNS ARE TIMING OF THE RAIN THREAT TODAY AND
TEMPERATURES.
MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE THOUGHT OF A BAND OF
RAIN MOVING FROM WEST TO EAST OVER THE CWA DURING THE MORNING/EARLY
AFTERNOON. THIS MATCHES WELL WITH THE CURRENT HRRR AS WELL. WILL
MOVE A LIKELY POP BAND ACROSS THE AREA...GENERALLY 15Z-18Z OVER
EASTERN MN AND THEN INTO WEST CENTRAL WI AFTER THAT. DOESNT LOOK
LIKE MUCH RAIN...GENERALLY LESS THAN ONE TENTH OF AN INCH. PTYPE
DOES NOT APPEAR TO BE AN ISSUE WITH WARM BOUNDARY LAYER IN PLACE.
SOME GUSTY WINDS DEVELOPING WITH PASSAGE OF FRONT. BETTER PRESSURE
RISES DROP SOUTHEAST OVER SOUTHWEST MN INTO IOWA DURING THE
MORNING...SO STRONGER WINDS WILL BE FELT THERE. THE GFS IS
STRONGER WITH THE SURGE WITH THE SECONDARY COLD FRONT/TROUGH LATER
IN THE AFTERNOON. THIS COULD INCREASE WINDS AGAIN OVER THE WEST LATE
AS CAA DEVELOPS.
VERY MILD START OVER THE AREA AHEAD OF THE SURFACE FRONT. WILL
LIKELY SEE SOME LOWER 50S IN THE SOUTH WHERE SUNSHINE PEAKS THROUGH
FROM TIME TO TIME. NOT QUITE RECORD TERRITORY BUT CLOSE. COLDER AIR
LAGS WITH SECONDARY COLD FRONT DROPPING IN TONIGHT...POSSIBLY WITH
LOWER STRATOCUMULUS. WILL HAVE TO SEE HOW FAR THAT MOVES SOUTH AND
EAST WITH TIME.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 415 AM CST THU DEC 10 2015
THE LONG TERM FORECAST PERIOD INCLUDES PRECIPITATION CHANCES
PRETTY MUCH EVERY OTHER DAY...AS A ZONAL FLOW REGIME DEVELOPS AND
ALSO ALSO FOSTERS THE CONTINUANCE OF MILD TEMPERATURES.
EYES THIS MORNING ARE ON THE PACIFIC NORTHWEST...WHERE A TIGHTLY
WOUND LOW IS OBSERVED ENTERING WASHINGTON STATE ON WATER VAPOR
IMAGERY. LEESIDE SURFACE CYCLONGENESIS IS INDUCED AHEAD OF THIS
FEATURE OVER THE CENTRAL PLAINS OVER THE NEXT 24 HOURS.
FRIDAY...PRECIPITATION IS EXPECTED TO DEVELOP ON THE NORTHERN
FRINGES OF THE SURFACE TROUGH AS IT LIFTS ACROSS IOWA. EXPECT TO
SEE A BAND OF SNOW /POSSIBLY MIXED WITH RAIN/ DEVELOPING EASTWARD
ACROSS CENTRAL MN. ASSOCIATED ACCUMULATIONS WOULD BE LIGHT...A
DUSTING AT MOST.
THE NEXT WAVE AND SURGE OF PV ADVECTION ARRIVE ON
FRIDAY...ALTHOUGH MODELS ARE TRENDING FARTHER NORTH WITH TIME
WHICH COULD KEEP THE MAJORITY THE MPX AREA DRY. HAVE INCLUDED
20-30 POPS NORTH OF THE I-94 CORRIDOR.
SATURDAY INTO SUNDAY THE NEXT TROUGH OF LOW PRESSURE NOSES FROM
THE TX PANHANDLE INTO MO/IA/MN. AS EXPECTED...THE 12.00Z ECMWF
CONTINUES TO FEATURE A MAINLY WARM/LIQUID SYSTEM...KEEPING NEARLY
ALL OF THE FORECAST AREA SNOW-FREE. MEANWHILE...THE 12.06Z GFS
PAINTED WARNING-CRITERIA FROM SOUTHWEST INTO WEST/NORTH CENTRAL
MN BY DAYBREAK MONDAY. FEEL A LEAN TOWARD THE ECMWF IS A BETTER
ROUTE TO GO...GIVEN RECENT SYSTEMS AND MODEL TRENDS. DO INCLUDE
0.5-2.0 INCH SNOWFALL AMOUNTS IN THE NORTHWEST FORECAST
AREA...BUT HAVE INCREASING CONFIDENCE THE TWIN CITIES WILL ESCAPE
A MEASURABLE SNOWFALL WITH THE WEEKEND SYSTEM.
AND LAST BUT NOT LEAST...A STRONG SURFACE SYSTEM IS PROGGED BY THE
MEDIUM RANGE CONSENSUS ON MONDAY NIGHT INTO WEDNESDAY. THIS TIME
AROUND WE LOOK A LITTLE COLDER AND THE LOW A BIT DEEPER...SO A
SLIGHTLY HIGHER CONFIDENCE IN SNOW ARRIVES FOR EARLY NEXT WEEK.
AFTER A PROLONGED STRETCH OF WARM WEATHER...TEMPS LOOK TO RETREAT
BACK TOWARD CLIMATOLOGICAL NORMALS BY WEDNESDAY OF THE UPCOMING
WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1005 PM CST WED DEC 9 2015
THE MAIN FOCUS FOR THIS PERIOD WILL BE A LINE OF SHOWERS ALONG A
FRONT EXPECTED TO MOVE THROUGH OUR AREA FROM THURSDAY MORNING
THROUGH THE EARLY AFTERNOON. SHOWERS ARE EXPECTED TO MOVE INTO
WESTERN MN BY 12Z...REACH EASTERN MN BETWEEN 15Z-18Z...AND IMPACT
OUR WESTERN WI LOCATIONS AROUND 17Z-20Z. BRIEF VIS/CIG REDUCTIONS
TO MVFR LEVELS CANNOT BE RULED OUT...BUT VFR CONDITIONS WILL
PREVAIL FOR THE REMAINDER OF THE PERIOD. WINDS COULD GUST UP TO
20-25 KTS DURING THE AFTERNOON AS THEY BECOME WESTERLY BEHIND THE
FRONT.
KMSP...SHOWERS ARE EXPECTED TO MOVE THROUGH BETWEEN 14-18Z...AND
BRIEF VIS/CIG REDUCTIONS TO MVFR LEVELS CANNOT BE RULED OUT.
OTHERWISE...VFR CONDITIONS WILL PREVAIL. SOUTHERLY WINDS OVERNIGHT
WILL BECOME WESTERLY AND INCREASE BY THURSDAY AFTERNOON...POTENTIALLY
GUSTING ABOVE 20 KTS THROUGH SUNSET.
/OUTLOOK FOR KMSP/
FRI...VFR. WINDS E 5-10 KTS.
SAT...VFR WITH MVFR POSSIBLE. WINDS NNW 5-10 KTS.
SUN...VFR WITH MVFR POSSIBLE. WINDS NE 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...ADL
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
940 PM CST FRI DEC 11 2015
.UPDATE:
Issued at 937 PM CST Fri Dec 11 2015
Updated forecast to include areas of fog across the northern CWA
where visibility ranges from 1/4SM at IRK to 4SM at UIN. Have also
updated for latest temperature and dewpoint trends. Walked outside
a few minutes ago and everything is soaked as low level moisture
continues to increase and condense on the cooler ground.
CVKING
&&
.SHORT TERM: (Through Late Tonight)
Issued at 336 PM CST Fri Dec 11 2015
Forecast problem for tonight is sky cover and possibility of fog.
Low clouds have mostly cleared out of central Missouri, but are
hanging tough across eastern Missouri and much of southern and
central Illinois. Model guidance has been less than helpful so far
in forecasting these low clouds...though the HRRR has been the best
so far. HRRR has the low clouds continuing to push northeast this
evening, but high clouds will likely persist over the area. The net
effect for the public forecast will still be a mostly cloudy to
cloudy sky regardless of what the low clouds ultimately decide to
do. While there could be some fog tonight, boundary layer winds
look too strong to support truly dense fog...except possibly over
the eastern Ozarks. However, it`s more likely that low visibility
will be caused by low clouds which are forecast to redevelop over
the higher terrain. South-southwest flow combined with clouds will
keep lows well above normal tonight. MOS guidance in the low to mid
50s looks very reasonable.
Carney
.LONG TERM: (Saturday through Next Friday)
Issued at 336 PM CST Fri Dec 11 2015
(Saturday through Monday)
Operational models are showing a slightly slower motion of the upper
low toward the area over the weekend which will result in a slower
onset of the steadier showers on Saturday night and Sunday. Before
then, still expect chances of light rain to increase during the day
on Saturday as transport of moisture from the Gulf increases via
40kt low level jet. Then showers and scattered thunderstorms will
spread across the area on Saturday night and Sunday as strong
moisture convergence moves from west to east across the area
under enhanced ascent caused by negatively tilting mid level
trough. The rain will continue into Sunday night before ending
during the day Monday as the trough lifts out of the area.
While temperatures will cool off slightly over the weekend because
of the rain, they will remain above normal because of the warm
sector. There will not be much of diurnal swing because of the
clouds and rain.
(Tuesday through Friday)
The GFS and ECMWF are depicting similar solutions to yesterday with
an upper low moving from the southern Rockies into the Great Lakes
at midweek. Most of the dynamics look to be staying to the
northwest of our area with this system, and the most of the moisture
will be staying to the south, so precipitation will be limited. The
system will still pull a cold front through the area on Wednesday
with 850mb temperatures falling to around -10C on the ECMWF by
Friday behind it. This still confirms that temperatures will go
from well above normal on Tuesday to near mid December normals by
Friday.
Britt
&&
.AVIATION: (For the 00z TAFs through 00z Saturday Evening)
Issued at 522 PM CST Fri Dec 11 2015
Another complex forecast for this TAF set. CI streaming over low
clouds makes seeing and tracking MVFR/IFR cigs difficult. Believe
COU will remain VFR thru much of the eve, with either FG
developing or ST building into the region overnight. A similar
situation is expected, but with visbys currently at 7SM, FG
potential may be higher. Will continue to monitor for trends. For
SUS/CPS, low level flow is NNE, which shud advect more MVFR cigs
into the area this evening with cigs lowering late in the eve
before becoming IFR overnight.
A lot of uncertainty remains with timing as well as FG
development.
Specifics for KSTL: Expect conditions to improve for a short
period early this eve before lower cigs advect back into the
region becoming IFR overnight. Conditions are expected to improve
during the morning hours.
Tilly
&&
.CLIMATE:
Record max temps through the weekend...
FRI 12/11 SAT 12/12 SUN 12/13
STL 70/1979 70/1991 73/1948
COU 73/1949 74/1889 75/1948
UIN 69/1949 67/1991 67/1948
Record hi lows through the weekend...
FRI 12/11 SAT 12/12 SUN 12/13
STL 53/1965 55/1929 56/1889
COU 55/1965 46/1929 55/1889
UIN 55/1965 42/1991 50/1927
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
538 PM CST FRI DEC 11 2015
.SHORT TERM: (Through Late Tonight)
Issued at 336 PM CST Fri Dec 11 2015
Forecast problem for tonight is sky cover and possibility of fog.
Low clouds have mostly cleared out of central Missouri, but are
hanging tough across eastern Missouri and much of southern and
central Illinois. Model guidance has been less than helpful so far
in forecasting these low clouds...though the HRRR has been the best
so far. HRRR has the low clouds continuing to push northeast this
evening, but high clouds will likely persist over the area. The net
effect for the public forecast will still be a mostly cloudy to
cloudy sky regardless of what the low clouds ultimately decide to
do. While there could be some fog tonight, boundary layer winds
look too strong to support truly dense fog...except possibly over
the eastern Ozarks. However, it`s more likely that low visibility
will be caused by low clouds which are forecast to redevelop over
the higher terrain. South-southwest flow combined with clouds will
keep lows well above normal tonight. MOS guidance in the low to mid
50s looks very reasonable.
Carney
.LONG TERM: (Saturday through Next Friday)
Issued at 336 PM CST Fri Dec 11 2015
(Saturday through Monday)
Operational models are showing a slightly slower motion of the upper
low toward the area over the weekend which will result in a slower
onset of the steadier showers on Saturday night and Sunday. Before
then, still expect chances of light rain to increase during the day
on Saturday as transport of moisture from the Gulf increases via
40kt low level jet. Then showers and scattered thunderstorms will
spread across the area on Saturday night and Sunday as strong
moisture convergence moves from west to east across the area
under enhanced ascent caused by negatively tilting mid level
trough. The rain will continue into Sunday night before ending
during the day Monday as the trough lifts out of the area.
While temperatures will cool off slightly over the weekend because
of the rain, they will remain above normal because of the warm
sector. There will not be much of diurnal swing because of the
clouds and rain.
(Tuesday through Friday)
The GFS and ECMWF are depicting similar solutions to yesterday with
an upper low moving from the southern Rockies into the Great Lakes
at midweek. Most of the dynamics look to be staying to the
northwest of our area with this system, and the most of the moisture
will be staying to the south, so precipitation will be limited. The
system will still pull a cold front through the area on Wednesday
with 850mb temperatures falling to around -10C on the ECMWF by
Friday behind it. This still confirms that temperatures will go
from well above normal on Tuesday to near mid December normals by
Friday.
Britt
&&
.AVIATION: (For the 00z TAFs through 00z Saturday Evening)
Issued at 522 PM CST Fri Dec 11 2015
Another complex forecast for this TAF set. CI streaming over low
clouds makes seeing and tracking MVFR/IFR cigs difficult. Believe
COU will remain VFR thru much of the eve, with either FG
developing or ST building into the region overnight. A similar
situation is expected, but with visbys currently at 7SM, FG
potential may be higher. Will continue to monitor for trends. For
SUS/CPS, low level flow is NNE, which shud advect more MVFR cigs
into the area this evening with cigs lowering late in the eve
before becoming IFR overnight.
A lot of uncertainty remains with timing as well as FG
development.
Specifics for KSTL: Expect conditions to improve for a short
period early this eve before lower cigs advect back into the
region becoming IFR overnight. Conditions are expected to improve
during the morning hours.
Tilly
&&
.CLIMATE:
Record max temps through the weekend...
FRI 12/11 SAT 12/12 SUN 12/13
STL 70/1979 70/1991 73/1948
COU 73/1949 74/1889 75/1948
UIN 69/1949 67/1991 67/1948
Record hi lows through the weekend...
FRI 12/11 SAT 12/12 SUN 12/13
STL 53/1965 55/1929 56/1889
COU 55/1965 46/1929 55/1889
UIN 55/1965 42/1991 50/1927
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ELKO NV
318 PM PST FRI DEC 11 2015
.SYNOPSIS...IN THE WAKE OF THE RECENT FRONTAL PASSAGE EXPECTING ISOLATED
SNOW FLURRIES TONIGHT AND TOMORROW. ALL THE WHILE...ANOTHER
PACIFIC STORM IS LOOMING UPSTREAM. EXPECT ANOTHER SHOT OF WINTRY
WEATHER ON SUNDAY. THIS WILL BE THE SECOND SNOW STORM FOR
NORTHEAST NEVADA FOR THE MONTH OF DECEMBER.
&&
.SHORT TERM...TODAY THROUGH MONDAY. MORE UNSETTLED WEATHER WILL BE
ON TAP FOR THIS FORECAST PERIOD. THE HRRR CONTINUES TO PLACE
ISOLATED SNOW SHOWERS OVER THE LKN CWA THIS EVENING...ALTHOUGH
SIGNIFICANT ACCUMULATIONS ARE NOT EXPECTED. THE NEXT SURFACE LOW
WILL ARRIVE IN HUMBOLDT COUNTY 18Z SUNDAY...WITH A LOW OF 1000 MB
OVER DENIO...THAT WILL RAPIDLY PUSH INTO THE LKN CWA. THE
POTENTIAL VORTICITY ADVECTION IS PRETTY IMPRESSIVE WITH THIS
STORM. THE GFS IS STILL HOLDING ONTO A MIXED P-TYPE EVENT...THAT
TRANSITIONS ENTIRELY TO SNOW BY 6Z MONDAY. MOST OF THE QPF WITH
THIS SYSTEM...WILL BE POST FRONTAL AND WILL CONTINUE THROUGH THE
FORECAST PERIOD. THE MOISTURE FROM THIS STORM WILL EASILY REACH
TONOPAH AND LUND. GIVEN THE VAGARIES OF THE MODELS...HELD OFF ON
ISSUING A HEADLINE WITH THIS PACKAGE.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY. THE PERIOD BEGINS WITH
UPPER TROUGH EXITING THE REGION TO THE EAST WITH LINGERING SNOW
SHOWERS ACROSS EASTERN NV MONDAY NIGHT AND TUESDAY. UPPER RIDGE
BUILDING IN FROM THE WEST WILL BRING GENERALLY DRY CONDITIONS
TUESDAY NIGHT THROUGH FRIDAY,EXCEPT FOR A FEW SHOWERS FAR NORTH
MAINLY ON THURSDAY AS MOISTURE MOVING OVER THE RIDGE BRUSHES THAT
AREA.
&&
.AVIATION...ISOLATED TO SCATTERED SNOW SHOWERS NEXT 24 HOURS, MAINLY
IMPACTING THE KWMC AND KEKO TERMINALS. GENERALLY VFR CONDITIONS
EXCEPT UNDER ANY SNOW SHOWERS WHERE CONDITIONS COULD DETERIORATE TO
MVFR OR IFR CONDITIONS.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
97/90/90
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
357 AM EST THU DEC 10 2015
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE REGION TODAY THROUGH THE
WEEKEND ACCOMPANIED BY A WARMING TREND. THE NEXT CHANCE OF RAIN
WILL DEVELOP AHEAD OF A COLD FRONT SUNDAY NIGHT AND MONDAY. HIGH
PRESSURE WILL BUILD IN BEHIND COLD FRONT TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM THURSDAY...THE TAIL END OF A 500 MB TROUGH MOVED ACROSS
THE AREA A FEW HOURS AGO...SUPPORTING A WEAK WAVE OF SURFACE LOW
PRESSURE THAT IS NOW ACCELERATING NE AWAY FROM THE NC COAST. A VERY
WEAK SURFACE COLD FRONT ALSO ACCOMPANIED THIS FEATURE. THE PRESSURE
GRADIENT IS WEAK ENOUGH THAT THE SURFACE LAYER HAS DECOUPLED FROM
THE REMAINDER OF THE TROPOSPHERE...TRAPPING A VERY SHALLOW LAYER OF
MOISTURE WITH FOG AND LOW CLOUDS THE RESULT. FORECAST SOUNDINGS FROM
THE GFS AND NAM BOTH INDICATE VERY DRY AIR IS ADVECTING IN RIGHT
DOWN TO THE TOP OF THE DECOUPLED LAYER...LEAVING ONLY A 200-300 FOOT
VERTICAL DEPTH OF MOISTURE TO SUPPORT FOG. THE APPROACH OF SCATTERED
CIRRUS CLOUDS OVER THE FEW HOURS REMAINING BEFORE SUNRISE SHOULD
HELP THIS INCOMING DRY AIR TEMPER THE SEVERITY OF FOG...AND NO DENSE
FOG ADVISORIES ARE PLANNED.
AFTER SUNRISE ATTENTION WILL SHIFT WESTWARD TO SURFACE HIGH PRESSURE
CENTERED OVER GEORGIA WHICH SHOULD SHIFT EAST TO THE COAST THIS
AFTERNOON. PLENTY OF SUNSHINE AND 850 MB TEMPS OF 7C TO 8C SHOULD
SUPPORT HIGHS IN THE UPPER 60S TO NEAR 70...AROUND 10 DEGREES ABOVE
NORMAL.
THE HIGH SHOULD DRIFT OFFSHORE TONIGHT...BUT A WEAK PRESSURE
GRADIENT SHOULD REMAIN ACROSS THE AREA. WITH GOOD RADIATIONAL
COOLING LOOK FOR LOWS TO REACH 45-50...WARMEST ALONG THE BEACHES.
FOG POTENTIAL APPEARS LESS THAN WE`VE SEEN OVER THE PAST THREE
NIGHTS DUE TO MARGINAL MOISTURE WITHIN THE BOUNDARY LAYER.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM THURSDAY...HIGH PRESSURE WILL EXTEND BACK OVER THE
SOUTHEAST WITH A FAIRLY WEAK RETURN FLOW AS A DEEP RIDGE BUILDS
ALOFT. THIS WILL PRODUCE PLENTY OF DRY AIR AND SUBSIDENCE AS H5
HEIGHTS RISE CLOSE TO 590 DEM BY SAT NIGHT. PLENTY OF SUNSHINE
ALONG WITH RISING HEIGHTS AND A WESTERLY COMPONENT TO THE
FLOW...WILL PRODUCE TEMPS WELL ABOVE NORMAL...UP TO 15 DEGREES
BOTH FRI AND SATURDAY. EXPECT TEMPS TO REACH INTO THE MID 70S MOST
PLACES LEAVING TEMPS SHY OF RECORD MAXES BUT STILL QUITE WARM FOR
THIS TIME OF YEAR.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...CONTINUED WARMTH FOR EARLY NEXT WEEK AS
RIDGE SLIPS SLOWLY EAST. GRADIENT WILL TIGHTEN LATE SUN INTO MON AS
COLD FRONT MAKES ITS WAY INTO AND ACROSS THE CAROLINAS. THIS WILL
AID IN WAA WITH A DEEP SOUTHERLY FLOW OF WARM AIR. TEMPS SHOULD
REACH UP INTO THE MID TO UPPER 70S ON SUNDAY...BUT INCREASING
CLOUDS AND CHC OF PCP WILL KEEP TEMPS DOWN A BIT ON MONDAY...BUT
STILL WELL INTO THE 70S. OVERNIGHT LOWS SUN NIGHT SHOULD BE RIGHT
AROUND THE NORMAL HIGH FOR THIS TIME OF YEAR...NEAR 60. OVERALL
EXPECT WARM AND RELATIVELY MOIST AIR MASS THROUGH MONDAY WITH BEST
CHC OF SHWRS ON MON. TEMPS WILL CONTINUE WARM THROUGH MID WEEK AS
HIGH PRESSURE BUILDS IN BEHIND COLD FRONT MON NIGHT THROUGH WED.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...A SHORTWAVE TROUGH WILL MOVE OFF THE COAST SHORTLY AND
ALLOW FOR SOME CLEARING OF SKIES. HOWEVER...LOW LEVEL FLOW HAS
DROPPED TO ABOUT NOTHING SO FOG IS EXPECTED TO CONTINUE TO
DEVELOP. IFR CONDITIONS SHOULD PERSIST AT FLO THROUGH 12 Z. IFR
CONDITIONS MAY DEVELOP AT LBT AS WELL...WITH THE HRRR MODEL
SUGGESTING CRE/MYR MAY GET IFR CONDITIONS JUST BEFORE SUNRISE.
MOISTURE IS VERY SHALLOW SO AFTER SUNRISE VFR CONDITIONS ARE
EXPECTED WITH LIGHT W TO NW WINDS THAT SHOULD BECOME W TO SW
AROUND SUNSET.
EXTENDED OUTLOOK...MORNING FOG POSSIBLE FRIDAY THROUGH SUNDAY.
POTENTIAL FOR RESTRICTIONS TO DEVELOP ON MONDAY DUE TO LOW CIGS AND
SHOWERS. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM THURSDAY...A WEAK FRONT MOVED OFFSHORE A FEW HOURS
AGO...AND HIGH PRESSURE OVER GEORGIA WILL BUILD EAST TO THE COAST
THIS AFTERNOON. THE HIGH WILL SLIP OFFSHORE TONIGHT BUT THE PRESSURE
GRADIENT SHOULD REMAIN RATHER WEAK WITH WINDS REMAINING 10 KT OR
LESS. SEAS ARE CURRENTLY HIGHEST NEAR CAPE FEAR...UP TO 4 FEET...DUE
TO THE STRONG SOUTH WINDS THAT WERE PRESENT JUST OFFSHORE OVER THE
PAST 3-6 HOURS. THIS LINGERING EFFECT SHOULD DIMINISH QUICKLY THIS
MORNING WITH SEAS DIMINISHING TO ONLY 2 FEET THIS AFTERNOON THROUGH
TONIGHT.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM THURSDAY...HIGH PRESSURE WILL EXTEND BACK OVER THE
SOUTHEAST AS IT SHIFTS SLOWLY EASTWARD OVER THE WEEKEND. THE
GRADIENT REMAINS FAIRLY SLACK...KEEPING WINDS LESS THAN 10 KTS FRI
THROUGH SATURDAY. SEAS WILL REMAIN LESS THAN 3 FT.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 330 AM THURSDAY...AN INCREASING RETURN FLOW AHEAD OF
APPROACHING COLD FRONT LATE SUN INTO MONDAY WILL PRODUCE A RISE IN
SEAS THROUGH SUN AFTN INTO MONDAY. EXPECT SEAS LESS THAN 3 FT
EARLY SUNDAY TO INCREASE ABOVE SCA THRESHOLDS BY MIDNIGHT. VERY
WARM TEMPS ON SUN AND MONDAY WILL ALSO HELP TO PRODUCE AN ENHANCED
SEA BREEZE CIRCULATION. OVERALL EXPECT S-SW WINDS INCREASING UP TO
20 TO 25 KTS AHEAD OF FRONT SUN NIGHT INTO MONDAY.
WINDS AND SEAS WILL DROP STEADILY BEHIND COLD FRONT LATE MONDAY
INTO MID WEEK. SEAS WILL BE BACK DOWN BELOW 3 FT BY TUES
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...TRA/RAN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1203 AM EST THU DEC 10 2015
.SYNOPSIS...
A WEAK COLD FRONT WILL CROSS THE COAST TONIGHT. HIGH PRESSURE
WILL BUILD ACROSS THE REGION THROUGH THE WEEKEND ACCOMPANIED BY A
WARMING TREND. THE NEXT CHANCE OF RAIN WILL DEVELOP AHEAD OF A
COLD FRONT SUNDAY NIGHT AND MONDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 1230 AM THURSDAY...BIGGEST CHANGE WITH THIS MIDNIGHT UPDATE
WAS TO INCREASE THE PREVALENCE OF FOG ACROSS EASTERN SOUTH
CAROLINA AND INTERIOR SE NORTH CAROLINA. SHALLOW LOW-LEVEL
MOISTURE HAS BEEN LEFT BEHIND WITHIN A DECOUPLED BOUNDARY LAYER
WHILE DRY AIR IS BUILDING IN ALOFT. RADIATIONAL COOLING HAS PUSHED
HUMIDITY TO 100 PERCENT AT THE SURFACE AND FOG IS THE RESULT.
LATEST HRRR RUNS SHOW FOG EXPANDING AS THE NIGHT PROGRESSES...
ALTHOUGH NOT ALL THE WAY TO WILMINGTON. WE MAY END UP WITH DENSE
FOG ADVISORIES BEFORE THE NIGHT IF THROUGH. DISCUSSION FROM
EARLIER FOLLOWS...
A COASTAL TROUGH WILL BRIEFLY GRAZE THE CAPE FEAR REGION LATE
THIS EVENING BEFORE EXITING TO THE NNE. KLTX PICKING UP RETURNS
ALONG THE TROUGH AXIS MOVING INTO COASTAL BRUNSWICK WHICH IS
EXPECTED TO LIFT ACROSS THE NORTH COAST AND A PORTION OF THE
INTERIOR. SHOWERS MAY DROP A COUPLE HUNDREDTHS THROUGH LATE
EVENING AND A SLIGHT CHANCE OF MEASURABLE RAIN WAS INSERTED FOR
THIS ACTIVITY. PATCHY FOG WAS ALSO NEEDED IN AREAS WHERE CLEARING
HAS OCCURRED FARTHER INLAND. THE CLEARING TREND LATE AREA-WIDE MAY
RESULT IN ADDITIONAL FOG AND WINDS MAY NOT BE STRONG ENOUGH TO
PREVENT PATCHY OCCURRENCES OVERNIGHT...THOUGH WIDESPREAD COVERAGE
IS NOT EXPECTED AS WINDS TURN OFFSHORE AND A DRYING TREND ENSUES.
LOWS IN THE MIDDLE 40S INLAND TO AROUND 50 AT THE COAST STILL
LOOKS GOOD AT DAYBREAK THURSDAY.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...AN EXITING SHORTWAVE WILL BE MOVING AWAY
FROM THE REGION JUST AS THE FORECAST PERIOD STARTS. AT THE SURFACE
HIGH PRESSURE WILL BE IN CONTROL WITH WESTERLY TO SOUTHWESTERLY
FLOW ALOFT DURING THE PERIOD. A WEAK IMPULSE IN THE MID-LEVELS
WILL PASS ACROSS THE AREA OVERNIGHT THURSDAY BUT WILL BRING LITTLE
IN THE WAY OF MOISTURE WITH PW WATERS INCREASING ONLY TO .75
INCHES AND NO CHANCES OF PRECIPITATION IS EXPECTED.
THE TEMPERATURES WILL BE THE BIGGEST STORY AS THE WARM AIR MOVING
INTO THE REGION WILL PUSH THE HIGH TEMPERATURES TO ABOUT 5 DEGREES
ABOVE NORMAL ON THURSDAY AND 10 DEGREES ABOVE NORMAL ON FRIDAY.
LOW TEMPERATURES WILL RUN AROUND 10 DEGREES ABOVE NORMAL.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM...THE MAIN STORY FOR THE WEEKEND INTO NEXT WEEK WILL BE
THE UNUSUALLY WARM TEMPERATURES AND A COLD FRONT MOVING ACROSS LATER
MONDAY. AT THE MID LEVELS A DEEP CYCLONE DEVELOPS OUT WEST WITH AN
UNUSUALLY STRONG RIDGE ACROSS THE SOUTHEAST...MUCH DIFFERENT THAN
THE AMPLITUDE WE HAVE SEEN RECENTLY. THIS FLOW ALLOWS 850MB
TEMPERATURES OF WELL OVER TEN DEGREES C TO ADVECT/DEVELOP ACROSS THE
AREA SATURDAY THROUGH MONDAY. SEEMS A GOOD BET HIGHS WILL BE WELL
INTO THE 70S ALL THREE DAYS BUT SOME SEA FOG MAY DEVELOP WHICH WOULD
COMPLICATE THE MATTER ALONG THE COAST. AS FOR THE FRONT...CONTINUED
TO ADVERTISE CHANCE POPS AS THE MID LEVEL FORCING IS WEAKENING AS IT
MOVES ACROSS MONDAY. NOT ENOUGH INSTABILITY AS OF YET TO INCLUDE ANY
MENTION OF THUNDER BUT CONSIDERING STRONG WIND FIELDS THE TYPICAL
GUSTY SHOWERS...WHEN THE TIME COMES MAY SUFFICE.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...A SHORTWAVE TROUGH WILL MOVE OFF THE COAST SHORTLY AND
ALLOW FOR SOME CLEARING OF SKIES. HOWEVER...LOW LEVEL FLOW HAS
DROPPED TO ABOUT NOTHING SO FOG IS EXPECTED TO CONTINUE TO
DEVELOP. IFR CONDITIONS SHOULD PERSIST AT FLO THROUGH 12 Z. IFR
CONDITIONS MAY DEVELOP AT LBT AS WELL...WITH THE HRRR MODEL
SUGGESTING CRE/MYR MAY GET IFR CONDITIONS JUST BEFORE SUNRISE.
MOISTURE IS VERY SHALLOW SO AFTER SUNRISE VFR CONDITIONS ARE
EXPECTED WITH LIGHT W TO NW WINDS THAT SHOULD BECOME W TO SW
AROUND SUNSET.
EXTENDED OUTLOOK...MORNING FOG POSSIBLE FRIDAY THROUGH SUNDAY.
POTENTIAL FOR RESTRICTIONS TO DEVELOP ON MONDAY DUE TO LOW CIGS AND
SHOWERS. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 AM THURSDAY...MULTIPLE BUOYS INDICATE WINDS ARE
CURRENTLY ABOUT 5-8 KT STRONGER THAN EXPECTED EAST OF THE COASTAL
TROUGH OVER THE CAPE FEAR-SURF CITY WATERS...BUT THE TROUGH WILL
KICK EAST OF THIS AREA SHORTLY TAKING THOSE STRONGER SOUTH WINDS
OFFSHORE. A LIGHTER W/NW WIND IS EXPECTED OVERNIGHT. DISCUSSION
FROM EARLIER THIS EVENING FOLLOWS...
THE COASTAL TROUGH HAS ADVANCED WESTWARD TOWARDS THE COAST. THE
TROUGH WILL CONTINUE TO MOVE NNE THIS EVENING. MODERATE SE WINDS
WILL SEE A SHIFT TO THE WEST AND NORTHWEST OVERNIGHT. SEAS
GENERALLY 2-3 FEET EXPECTED WITH ISOLATED SHOWERS FROM CAPE FEAR
NORTHWARD FOR THE REST OF TONIGHT...CLEARING INTO EARLY THURSDAY.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM...WINDS WILL BACK FROM THE NORTHWEST TO THE SOUTHWEST
THROUGH THE PERIOD AS HIGH PRESSURE BUILD OVER THE WATERS. MODELS
ARE SHOWING WIND SPEEDS RUNNING LESS THAN 15 KNOTS THROUGH THE
PERIOD. SEAS WILL BE A RATHER TRANQUIL 2 FEET.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 PM...WEAK HIGH PRESSURE WILL PREVAIL ACROSS THE
WATERS SATURDAY AND MOST OF SUNDAY WITH A SOUTHERLY FLOW OF TEN
KNOTS OR LESS. WITH WARMER TEMPERATURES EXPECTED INLAND SOME SEA
BREEZE ACCELERATION NEAR THE COAST CAN BE EXPECTED. LATER SUNDAY
INTO MONDAY SPEEDS PICK UP DRAMATICALLY AS A FRONT APPROACHES FROM
THE WEST. THE BOUNDARY MAY JUST PASS THE WATERS BY THE END OF THE
PERIOD. SPEEDS INCREASE TO 20-25 KNOTS WITH DIRECTION VEERING TO THE
SOUTHWEST. SIGNIFICANT SEAS WILL INCREASE FROM TEPID VALUES SATURDAY
AND SUNDAY TO WELL INTO SMALL CRAFT CRITERIA MONDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...TRA/MJC
SHORT TERM...DRH
LONG TERM...SHK
AVIATION...TRA/RAN
AREA FORECAST DISCUSSION
NWS BISMARCK ND
942 PM CST FRI DEC 11 2015
.UPDATE...
ISSUED AT 933 PM CST FRI DEC 11 2015
MAIN CHANGE FOR LATE EVENING UPDATE WAS TO ADJUST BACK EDGE OF
SNOW A BIT OVER THE NORTH. OTHERWISE...REMAINDER OF FORECAST
REMAINS GOOD WITH THE POSSIBILITY OF FOG AND FREEZING
DRIZZLE...WITH SOME VERY LIGHT FREEZING DRIZZLE CURRENTLY BEING
OBSERVED AT NWS BISMARCK.
UPDATE ISSUED AT 757 PM CST FRI DEC 11 2015
HAVE SENT OUT A QUICK UPDATE TO ADD PATCHY FREEZING DRIZZLE TO THE
FORECAST OVER MUCH OF THE AREA. SOME LIGHT DRIZZLE STARTED AT THE
OFFICE WITHIN THE PAST HOUR. THIS IS SUPPORTED IN LATEST MODEL
RUN FORECAST SOUNDINGS SHOWING LACK OF ICE CRYSTALS IN SHALLOWER
CLOUD LAYER AS AREA OF SNOW EXITS TO THE NORTHEAST. UPDATES HAVE
BEEN SENT.
UPDATE ISSUED AT 618 PM CST FRI DEC 11 2015
SNOW CONTINUES TO GRADUALLY DIMINISH OVER THE AREA WITH THE BACK
EDGE RUNNING ALONG AND NEAR HIGHWAY 52. THIS TREND WILL CONTINUE
THROUGH THIS EVENING AS UPPER LOW/TROUGH CONTINUES TO LIFT TO THE
NORTH-NORTHEAST. WITH THE FRESH SNOW AND PLENTY OF LOW LEVEL
MOISTURE IN PLACE HAVE BROADENED OUT THE POSSIBILITY OF FOG THIS
EVENING AND OVERNIGHT. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 241 PM CST FRI DEC 11 2015
LATEST RADAR LOOPS HAVE THE BACK EDGE OF THE PRECIPITATION
APPROACHING A NEW SALEM TO BEULAH LINE. EXPECT THE SNOW TO END
WEST OF THE MISSOURI RIVER BY 4 PM. RADAR LOOPS ALSO SHOW THE
SYSTEM MAY BE LIFTING NORTH A BIT FASTER NOW SO THE SNOW WILL
PROGRESSIVELY END THIS EVENING NORTH. EXPECT STORM TOTALS 2 TO 3
INCHES ACROSS CENTRAL NORTH DAKOTA AND 1 TO 2 INCHES NORTH.
ISOLATED 4 INCH AMOUNTS ARE POSSIBLE SOUTH CENTRAL SUCH AS
BISMARCK.
TONIGHT WITH LOW LEVEL MOISTURE IN PLACE WILL SEE CLOUDS ALL BUT
THE FAR SOUTHWEST WHERE A SOUTHWEST WIND COMPONENT AT H925-850 MAY
ERODE CLOUD DECK A BIT. OTHERWISE CLOUDY. BASED ON THE HRRR KEPT
SOME FOG IN AFTER MIDNIGHT THROUGH SATURDAY MORNING WEST CENTRAL
AND SOUTH.
ON SATURDAY WILL DONT SEE ANYTHING THAT WILL CLEAR CLOUDS SO
CLOUDY EXCEPT FOR THE FAR SOUTHWEST. HIGHS WILL BE LIMITED TO THE
LOWER 30S EXCEPT MID TO UPPER 30S SOUTHWEST.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 241 PM CST FRI DEC 11 2015
SATURDAY NIGHT A LONGWAVE TROUGH IS WELL ESTABLISHED OVER THE
ROCKIES TO 4-CORNERS AREA. SHORTWAVE ENERGY MOVING NORTHEASTWARD
UPSTREAM OF THE TROUGH GLANCES THE JAMES RIVER VALLEY SATURDAY NIGHT
INTO SUNDAY MORNING. AREAS SOUTH OF JAMESTOWN COULD RECEIVE 1/2 INCH
TO AN INCH OF SNOW.
ATTENTION THEN TURNS TO THE NEXT STORM SYSTEM MOVING EAST ACROSS THE
ROCKIES. ON SUNDAY ANOTHER LONGWAVE TROUGH MOVES INTO THE WEST COAST
AND DIGS SOUTH TOWARDS CALIFORNIA. THE SYSTEM CONTINUES TO DEEPEN AS
IT MOVES ACROSS THE ROCKIES SUNDAY NIGHT AND MONDAY. UNCERTAINTIES
CONTINUE REGARDING PLACEMENT/TIMING OF THIS SYSTEM...BUT MODEL
CONSENSUS WOULD SUGGEST THE LEADING EDGE OF SHORTWAVE ENERGY AND
MOISTURE REACHING THE WESTERN DAKOTAS MONDAY AFTERNOON/EVENING. THE
MODELS DEVELOP THE STORM SYSTEM SUCH THAT THE TRACK OF THE MID-LEVEL
LOW MOVES FROM COLORADO ACROSS THE CENTRAL PLAINS TO EASTERN SOUTH
DAKOTA BY TUESDAY AFTERNOON AND INTO MINNESOTA TUESDAY NIGHT. THIS
LATEST RUN OF THE MODELS SUGGESTS SOUTHERN NORTH DAKOTA COULD
RECEIVE MODERATE SNOW AMOUNTS WITH LIGHT AMOUNTS IN THE NORTHWEST
AND NORTH CENTRAL...AND THIS OCCURRING OVER A PERIOD FROM MONDAY
AFTERNOON THROUGH TUESDAY NIGHT/WEDNESDAY MORNING. THIS TRACK WOULD
SUGGEST THAT AREAS SOUTH AND EAST OF OUR AREA WOULD RECEIVE THE BULK
OF PRECIPITATION WITH THIS SYSTEM.
ANOTHER SHORTWAVE DIVES SOUTHEAST OUT OF ALBERTA/SASKATCHEWAN
WEDNESDAY/THURSDAY...BUT WITH MUCH LESS MOISTURE AND ONLY SLIGHT
CHANCES OF LIGHT SNOW/FLURRIES.
A COOLING TREND THROUGH THE LONG TERM...WITH SEASONABLE TEMPERATURES
EXPECTED BY THE MIDDLE AND END OF NEXT WEEK...WITH HIGHS IN THE 20S
AND LOWS IN THE SINGLE DIGITS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 618 PM CST FRI DEC 11 2015
IFR CIGS WILL CONTINUE OVER THE AREA TONIGHT...WITH THE
POSSIBILITY OF MANY LOCATIONS DROPPING TO LIFR LATER TONIGHT INTO
SATURDAY MORNING AS AREAS OF FOG DEVELOP. CONDITIONS WILL IMPROVE
LATE MORNING OVER PARTS OF THE AREA TO MVFR AS CIGS/VIS IMPROVE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...WAA
LONG TERM...JV
AVIATION...JJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
801 PM CST FRI DEC 11 2015
.UPDATE...
ISSUED AT 757 PM CST FRI DEC 11 2015
HAVE SENT OUT A QUICK UPDATE TO ADD PATCHY FREEZING DRIZZLE TO THE
FORECAST OVER MUCH OF THE AREA. SOME LIGHT DRIZZLE STARTED AT THE
OFFICE WITHIN THE PAST HOUR. THIS IS SUPPORTED IN LATEST MODEL
RUN FORECAST SOUNDINGS SHOWING LACK OF ICE CRYSTALS IN SHALLOWER
CLOUD LAYER AS AREA OF SNOW EXITS TO THE NORTHEAST. UPDATES HAVE
BEEN SENT.
UPDATE ISSUED AT 618 PM CST FRI DEC 11 2015
SNOW CONTINUES TO GRADUALLY DIMINISH OVER THE AREA WITH THE BACK
EDGE RUNNING ALONG AND NEAR HIGHWAY 52. THIS TREND WILL CONTINUE
THROUGH THIS EVENING AS UPPER LOW/TROUGH CONTINUES TO LIFT TO THE
NORTH-NORTHEAST. WITH THE FRESH SNOW AND PLENTY OF LOW LEVEL
MOISTURE IN PLACE HAVE BROADENED OUT THE POSSIBILITY OF FOG THIS
EVENING AND OVERNIGHT. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 241 PM CST FRI DEC 11 2015
LATEST RADAR LOOPS HAVE THE BACK EDGE OF THE PRECIPITATION
APPROACHING A NEW SALEM TO BEULAH LINE. EXPECT THE SNOW TO END
WEST OF THE MISSOURI RIVER BY 4 PM. RADAR LOOPS ALSO SHOW THE
SYSTEM MAY BE LIFTING NORTH A BIT FASTER NOW SO THE SNOW WILL
PROGRESSIVELY END THIS EVENING NORTH. EXPECT STORM TOTALS 2 TO 3
INCHES ACROSS CENTRAL NORTH DAKOTA AND 1 TO 2 INCHES NORTH.
ISOLATED 4 INCH AMOUNTS ARE POSSIBLE SOUTH CENTRAL SUCH AS
BISMARCK.
TONIGHT WITH LOW LEVEL MOISTURE IN PLACE WILL SEE CLOUDS ALL BUT
THE FAR SOUTHWEST WHERE A SOUTHWEST WIND COMPONENT AT H925-850 MAY
ERODE CLOUD DECK A BIT. OTHERWISE CLOUDY. BASED ON THE HRRR KEPT
SOME FOG IN AFTER MIDNIGHT THROUGH SATURDAY MORNING WEST CENTRAL
AND SOUTH.
ON SATURDAY WILL DONT SEE ANYTHING THAT WILL CLEAR CLOUDS SO
CLOUDY EXCEPT FOR THE FAR SOUTHWEST. HIGHS WILL BE LIMITED TO THE
LOWER 30S EXCEPT MID TO UPPER 30S SOUTHWEST.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 241 PM CST FRI DEC 11 2015
SATURDAY NIGHT A LONGWAVE TROUGH IS WELL ESTABLISHED OVER THE
ROCKIES TO 4-CORNERS AREA. SHORTWAVE ENERGY MOVING NORTHEASTWARD
UPSTREAM OF THE TROUGH GLANCES THE JAMES RIVER VALLEY SATURDAY NIGHT
INTO SUNDAY MORNING. AREAS SOUTH OF JAMESTOWN COULD RECEIVE 1/2 INCH
TO AN INCH OF SNOW.
ATTENTION THEN TURNS TO THE NEXT STORM SYSTEM MOVING EAST ACROSS THE
ROCKIES. ON SUNDAY ANOTHER LONGWAVE TROUGH MOVES INTO THE WEST COAST
AND DIGS SOUTH TOWARDS CALIFORNIA. THE SYSTEM CONTINUES TO DEEPEN AS
IT MOVES ACROSS THE ROCKIES SUNDAY NIGHT AND MONDAY. UNCERTAINTIES
CONTINUE REGARDING PLACEMENT/TIMING OF THIS SYSTEM...BUT MODEL
CONSENSUS WOULD SUGGEST THE LEADING EDGE OF SHORTWAVE ENERGY AND
MOISTURE REACHING THE WESTERN DAKOTAS MONDAY AFTERNOON/EVENING. THE
MODELS DEVELOP THE STORM SYSTEM SUCH THAT THE TRACK OF THE MID-LEVEL
LOW MOVES FROM COLORADO ACROSS THE CENTRAL PLAINS TO EASTERN SOUTH
DAKOTA BY TUESDAY AFTERNOON AND INTO MINNESOTA TUESDAY NIGHT. THIS
LATEST RUN OF THE MODELS SUGGESTS SOUTHERN NORTH DAKOTA COULD
RECEIVE MODERATE SNOW AMOUNTS WITH LIGHT AMOUNTS IN THE NORTHWEST
AND NORTH CENTRAL...AND THIS OCCURRING OVER A PERIOD FROM MONDAY
AFTERNOON THROUGH TUESDAY NIGHT/WEDNESDAY MORNING. THIS TRACK WOULD
SUGGEST THAT AREAS SOUTH AND EAST OF OUR AREA WOULD RECEIVE THE BULK
OF PRECIPITATION WITH THIS SYSTEM.
ANOTHER SHORTWAVE DIVES SOUTHEAST OUT OF ALBERTA/SASKATCHEWAN
WEDNESDAY/THURSDAY...BUT WITH MUCH LESS MOISTURE AND ONLY SLIGHT
CHANCES OF LIGHT SNOW/FLURRIES.
A COOLING TREND THROUGH THE LONG TERM...WITH SEASONABLE TEMPERATURES
EXPECTED BY THE MIDDLE AND END OF NEXT WEEK...WITH HIGHS IN THE 20S
AND LOWS IN THE SINGLE DIGITS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 618 PM CST FRI DEC 11 2015
IFR CIGS WILL CONTINUE OVER THE AREA TONIGHT...WITH THE
POSSIBILITY OF MANY LOCATIONS DROPPING TO LIFR LATER TONIGHT INTO
SATURDAY MORNING AS AREAS OF FOG DEVELOP. CONDITIONS WILL IMPROVE
LATE MORNING OVER PARTS OF THE AREA TO MVFR AS CIGS/VIS IMPROVE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...WAA
LONG TERM...JV
AVIATION...JJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
630 PM CST FRI DEC 11 2015
.UPDATE...
ISSUED AT 618 PM CST FRI DEC 11 2015
SNOW CONTINUES TO GRADUALLY DIMINISH OVER THE AREA WITH THE BACK
EDGE RUNNING ALONG AND NEAR HIGHWAY 52. THIS TREND WILL CONTINUE
THROUGH THIS EVENING AS UPPER LOW/TROUGH CONTINUES TO LIFT TO THE
NORTH-NORTHEAST. WITH THE FRESH SNOW AND PLENTY OF LOW LEVEL
MOISTURE IN PLACE HAVE BROADENED OUT THE POSSIBILITY OF FOG THIS
EVENING AND OVERNIGHT. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 241 PM CST FRI DEC 11 2015
LATEST RADAR LOOPS HAVE THE BACK EDGE OF THE PRECIPITATION
APPROACHING A NEW SALEM TO BEULAH LINE. EXPECT THE SNOW TO END
WEST OF THE MISSOURI RIVER BY 4 PM. RADAR LOOPS ALSO SHOW THE
SYSTEM MAY BE LIFTING NORTH A BIT FASTER NOW SO THE SNOW WILL
PROGRESSIVELY END THIS EVENING NORTH. EXPECT STORM TOTALS 2 TO 3
INCHES ACROSS CENTRAL NORTH DAKOTA AND 1 TO 2 INCHES NORTH.
ISOLATED 4 INCH AMOUNTS ARE POSSIBLE SOUTH CENTRAL SUCH AS
BISMARCK.
TONIGHT WITH LOW LEVEL MOISTURE IN PLACE WILL SEE CLOUDS ALL BUT
THE FAR SOUTHWEST WHERE A SOUTHWEST WIND COMPONENT AT H925-850 MAY
ERODE CLOUD DECK A BIT. OTHERWISE CLOUDY. BASED ON THE HRRR KEPT
SOME FOG IN AFTER MIDNIGHT THROUGH SATURDAY MORNING WEST CENTRAL
AND SOUTH.
ON SATURDAY WILL DONT SEE ANYTHING THAT WILL CLEAR CLOUDS SO
CLOUDY EXCEPT FOR THE FAR SOUTHWEST. HIGHS WILL BE LIMITED TO THE
LOWER 30S EXCEPT MID TO UPPER 30S SOUTHWEST.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 241 PM CST FRI DEC 11 2015
SATURDAY NIGHT A LONGWAVE TROUGH IS WELL ESTABLISHED OVER THE
ROCKIES TO 4-CORNERS AREA. SHORTWAVE ENERGY MOVING NORTHEASTWARD
UPSTREAM OF THE TROUGH GLANCES THE JAMES RIVER VALLEY SATURDAY NIGHT
INTO SUNDAY MORNING. AREAS SOUTH OF JAMESTOWN COULD RECEIVE 1/2 INCH
TO AN INCH OF SNOW.
ATTENTION THEN TURNS TO THE NEXT STORM SYSTEM MOVING EAST ACROSS THE
ROCKIES. ON SUNDAY ANOTHER LONGWAVE TROUGH MOVES INTO THE WEST COAST
AND DIGS SOUTH TOWARDS CALIFORNIA. THE SYSTEM CONTINUES TO DEEPEN AS
IT MOVES ACROSS THE ROCKIES SUNDAY NIGHT AND MONDAY. UNCERTAINTIES
CONTINUE REGARDING PLACEMENT/TIMING OF THIS SYSTEM...BUT MODEL
CONSENSUS WOULD SUGGEST THE LEADING EDGE OF SHORTWAVE ENERGY AND
MOISTURE REACHING THE WESTERN DAKOTAS MONDAY AFTERNOON/EVENING. THE
MODELS DEVELOP THE STORM SYSTEM SUCH THAT THE TRACK OF THE MID-LEVEL
LOW MOVES FROM COLORADO ACROSS THE CENTRAL PLAINS TO EASTERN SOUTH
DAKOTA BY TUESDAY AFTERNOON AND INTO MINNESOTA TUESDAY NIGHT. THIS
LATEST RUN OF THE MODELS SUGGESTS SOUTHERN NORTH DAKOTA COULD
RECEIVE MODERATE SNOW AMOUNTS WITH LIGHT AMOUNTS IN THE NORTHWEST
AND NORTH CENTRAL...AND THIS OCCURRING OVER A PERIOD FROM MONDAY
AFTERNOON THROUGH TUESDAY NIGHT/WEDNESDAY MORNING. THIS TRACK WOULD
SUGGEST THAT AREAS SOUTH AND EAST OF OUR AREA WOULD RECEIVE THE BULK
OF PRECIPITATION WITH THIS SYSTEM.
ANOTHER SHORTWAVE DIVES SOUTHEAST OUT OF ALBERTA/SASKATCHEWAN
WEDNESDAY/THURSDAY...BUT WITH MUCH LESS MOISTURE AND ONLY SLIGHT
CHANCES OF LIGHT SNOW/FLURRIES.
A COOLING TREND THROUGH THE LONG TERM...WITH SEASONABLE TEMPERATURES
EXPECTED BY THE MIDDLE AND END OF NEXT WEEK...WITH HIGHS IN THE 20S
AND LOWS IN THE SINGLE DIGITS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 618 PM CST FRI DEC 11 2015
IFR CIGS WILL CONTINUE OVER THE AREA TONIGHT...WITH THE
POSSIBILITY OF MANY LOCATIONS DROPPING TO LIFR LATER TONIGHT INTO
SATURDAY MORNING AS AREAS OF FOG DEVELOP. CONDITIONS WILL IMPROVE
LATE MORNING OVER PARTS OF THE AREA TO MVFR AS CIGS/VIS IMPROVE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...WAA
LONG TERM...JV
AVIATION...JJS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1132 PM CST WED DEC 9 2015
.UPDATE...
ISSUED AT 1132 PM CST WED DEC 9 2015
LARGE PRECIP SHIELD MOVING ACROSS CENTRAL AND EASTERN ND WILL
CONTINUE FOR MUCH OF THE NIGHT. HAVE THE HIGHEST POPS MOVING FROM
THE WESTERN CWA INTO THE EAST TOWARDS MORNING. A FEW SPOTS RIGHT
ON THE CANADIAN BORDER HAVE DROPPED TO 32...BUT THE REST OF THE
CWA STILL IS WELL ABOVE FREEZING. WILL CONTINUE THE TREND OF SOME
MIXED PRECIP COMING IN FOR THE FAR NORTH LATER TONIGHT.
UPDATE ISSUED AT 944 PM CST WED DEC 9 2015
RADAR LOOP AND OBS SHOW THAT PRECIP IS COMING IN A BIT FURTHER
SOUTH THAN ORIGINALLY EXPECTED...WITH RAIN ALREADY REPORTED AT
VALLEY CITY AND DEVILS LAKE. THE RAP AND HRRR HAVE BEEN TRENDING
FURTHER SOUTH WITH THE PRECIP ALSO...SO INCREASED POPS BETWEEN THE
HIGHWAY 2 AND I-94 CORRIDORS. HOWEVER...CANADIAN RADAR SHOWS
PLENTY OF ACTIVITY FURTHER NORTH...SO THINK THAT THE RAIN WILL
EVENTUALLY TRANSITION TOWARDS THE NORTHERN CWA LATE TONIGHT. RAIN
CONTINUES TO BE LIQUID AS TEMPS ARE STILL IN THE UPPER 30S TO LOW
40S...BUT WITH SOME COLDER AIR COMING INTO THE NORTH TOWARDS
MORNING WILL KEEP THE WINTERY MIX MENTION IN THE NORTH AFTER
MIDNIGHT. BEST COLD AIR LOOKS LIKE IT WILL HOLD OFF ARRIVING UNTIL
THURSDAY.
UPDATE ISSUED AT 636 PM CST WED DEC 9 2015
ADJUSTED CLOUD COVER A BIT...BUT NO CHANGES YET TO THE REST OF THE
FORECAST. RADAR HAS SHOWN INCREASING RETURNS OVER THE WESTERN AND
CENTRAL PORTIONS OF THE STATE...BUT NOT MUCH REACHING THE GROUND
YET AS IT IS TAKING A WHILE TO SATURATE. GOING FORECAST HAS SOME
POPS MOVING INTO THE NORTHWEST COUNTIES LATER THIS EVENING AND
THIS STILL SEEM REASONABLE AT THIS POINT. WILL MONITOR CLOSELY FOR
THE NEXT FEW HOURS AS PRECIP STARTS MOVING IN.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 311 PM CST WED DEC 9 2015
MAIN FORECAST CHALLENGE WILL BE TEMPS/PCPN TYPE AS THE NEXT
WEATHER SYSTEM MOVES IN LATER TONIGHT AND CONTINUES INTO THU/THU
NIGHT. AS FOR THIS AFTERNOON...IT IS ANOTHER DAY WITH NEAR RECORD
TEMPS FOR AREAS TO THE WEST OF THE RED RIVER VALLEY. TEMPS FROM
KGFK TO KFAR TO KBWP REMAIN COOLEST WITH WINDS FROM THE SOUTH.
LOOKING INTO TONIGHT...EXPECT THINNER SPOTS TO FILL BACK IN WITH
CLOUDS. WINDS WILL ALSO STAY UP WITH VERY MILD AIR HANGING TOUGH.
TEMPS SHOULD STAY IN THE MID TO UPPER 30S FOR MOST AREAS WITH THE
EXCEPTION OF LOCATIONS ALONG THE CANADIAN BORDER. UP IN THAT AREA
TEMPS MAY COME DOWN TO AROUND THE 32F MARK...MAKING PCPN PHASE THE
MAIN QUESTION THERE. HAVE GONE WITH THE IDEA OF MIXED PCPN
POSSIBLE ALONG THE CANADIAN BORDER...BUT IF THE COOLER TEMPS ARE
DELAYED IT MAY ALSO STAY AS JUST RAIN TOO. FOR AREAS SOUTH OF THE
CANADIAN BORDER...EXPECTING JUST RAIN TONIGHT. AMOUNTS A TOUGH
CALL TOO. SEEMS LIKE MODELS TRACK THE CLIPPER ALONG THE CANADIAN
BORDER. MOST MODELS SEEM TO SHOW PCPN AMOUNTS IN THE 0.15 TO 0.25
INCH RANGE ALONG AND NORTH OF HIGHWAY 200...WITH MUCH LESS TO THE
SOUTH. FORECASTING RAIN AT NIGHT IN DECEMBER IS DEFINITELY A RARE
THING. SOMETIMES MODELS ARE TOO WET WITH PCPN AMOUNTS FOR THESE
QUICK MOVING CLIPPERS...SO WOULD NOT BE SURPRISED TO SEE AMOUNTS
TREND TO THE LOWER SIDE OF THE TOTALS LISTED ABOVE.
PCPN TYPE QUESTIONS CONTINUE INTO THU AS WELL. 925 MB TEMPS BEGIN
TO FALL ACROSS THE AREA DURING THE DAY...BUT NOT SIGNIFICANTLY.
THEREFORE SFC TEMPS SHOULD RISE DURING THE LATE MORNING/EARLY
AFTERNOON. THEREFORE MAY SEE A MIX ON THU ACROSS THE NORTH AND
MORE LIQUID PCPN ACROSS THE SOUTH. HAVE TRIED TO INDICATE DRYING
WORKING INTO THE SYSTEM OVER SOUTHEAST ND BY THU AFTERNOON...BUT
SOME LIGHTER PCPN MAY LINGER ACROSS THE NORTH OR EAST INTO THU
NIGHT. MODELS HAVE BEEN BACKING OFF ON PCPN AMOUNTS AND SHIFTING
THEM FURTHER NORTH DURING THIS TIME FRAME...AS THE COLDER AIR
WORKS INTO THE SYSTEM. THERE IS STILL A POTENTIAL FOR AN INCH OR
TWO OF SNOW ALONG THE CANADIAN BORDER INTO THE LAKE OF THE WOODS
REGION. WINDS LOOK GUSTY THU INTO THU NIGHT AS WELL.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 311 PM CST WED DEC 9 2015
WILL NOT BE MUCH OF A BREAK BETWEEN SYSTEMS BEFORE ANOTHER SHOT OF
LIGHT PCPN MOVES BACK IN FRI. MODELS START TO DIFFER QUITE A BIT
BY THIS TIME. SOME MOVE THE PCPN OFF QUICKLY AND OTHERS LINGER IT
INTO SAT. THE TREND AT LEAST FOR THE FRI SYSTEM IS FURTHER NORTH
THAN THEY SHOWED YESTERDAY. SO NOT A LOT OF CONFIDENCE IN THE
FRI/SAT TIME FRAME. AT LEAST BY THEN...PCPN TYPE LOOKS TO BE
MAINLY SNOW.
FOR SATURDAY NIGHT THROUGH TUESDAY... MODELS INITIALIZED WELL THIS
RUN AND ARE IN GENERAL AGREEMENT. OVERALL PATTERN IN TRANSITION AND
EXPECT AN UNSETTLED PERIOD AS IT SWITCHES TO MORE OF A SW FLOW ALOFT
BY THE END OF THE PERIOD. SPLIT JET PATTERN REMAINS IN PLACE TO
START THE PERIOD WITH THE NRN STREAM OVER THE REGION. A SYSTEM WILL
CROSS THE NRN PART OF THE AREA BY SUNDAY...WITH A CHANCE FOR SOME
-RA/-SN OVER THE CENTRAL PORTION OF MN...AND -SN OVER THE REST OF
THE AREA. OTHERWISE...THE UPPER TROF DIGS INTO THE FOUR CORNERS
REGION BY TUESDAY...AND ANOTHER WAVE IS FORECAST TO MOVE NE INTO THE
DAKOTAS AND MINNESOTA BRINGING A CHC OF SNOW TO THE ENTIRE AREA.
LITTLE CHANGE IS EXPECTED TO THE TEMPERATURE FORECAST ATTM AND WILL
REMAIN GENERALLY ABOVE NORMAL...WITH HIGHS IN THE MID TO UPPER
20S...TO LOW 30S IN THE SOUTH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1132 PM CST WED DEC 9 2015
VFR CONDITIONS CONTINUE WITH CIGS IN THE 5000-10000 FT RANGE EVEN
AS RAIN MOVES INTO THE AREA. LIGHT RAIN WILL CONTINUE THROUGH THE
EARLY MORNING HOURS BEFORE TAPERING OFF FROM WEST TO EAST. WINDS
WILL SHIFT TO THE SOUTHWEST...THEN NORTHWEST LATER THIS AFTERNOON
AS A COLD FRONT COMES THROUGH. WINDS WILL BECOME BLUSTERY BEHIND
THE FRONT...WITH GUSTS ABOVE 25 KTS. MVFR CIGS WILL MOVE DOWN INTO
THE REGION ALONG WITH THE FRONT...AND SOME SNOW IS NOT OUT OF THE
QUESTION ALTHOUGH WILL LEAVE IT OUT FOR NOW. WINDS WILL SETTLE
DOWN LATE IN THE PERIOD TOMORROW EVENING BUT CIGS WILL STAY MVFR.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...GODON
LONG TERM...GODON/HOPKINS
AVIATION...JR
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
910 AM EST THU DEC 10 2015
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE ACROSS THE AREA THURSDAY NIGHT. HIGH
PRESSURE WILL BRIEFLY RESIDE OVER THE AREA ON FRIDAY. A STRONGER
SYSTEM FROM THE SOUTHERN PLAINS WILL MOVE TO THE WESTERN GREAT
LAKES SUNDAY NIGHT. THIS SYSTEM WILL BRING A PUSH OF WARMER AIR
FOR THE WEEKEND AND A COLD FRONT AND SHOWERS EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NOT A HALF BAD DECEMBER DAY. TEMPERATURES RUNNING WELL ABOVE
NORMAL TODAY...BUT A FAIRLY STIFF BREEZE WILL NOT MAKE IT FEEL AS
WARM. OTHER THAN ANY LINGERING FOG BURNING OFF...THE DAY WILL
FEATURE INCREASING CLOUDS. THERE WILL BE A FAIR AMOUNT OF HIGH
CLOUDS...BUT SOME STRATUS WILL BE SPREADING NORTH FROM CENTRAL OH
AND FILLING IN OVER AT LEAST THE EASTERN HALF OF THE AREA. A GOOD
WEDGE OF WARMER TEMPERATURES WILL SURGE NORTHWARD AHEAD OF A WEAK
COLD FRONT TIMED TO MOVE THROUGH LATE TONIGHT. WITH THE ADDITIONAL
CLOUD COVER...TEMPS WILL NOT BE TOO FAR OFF FROM YESTERDAY.
GENERALLY LOWER AND MID 50S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
THE WEAK FRONT APPROACHES FOR TONIGHT. THERE COULD BE A SPRINKLE
ACROSS THE EAST HALF BUT LIKELY NOTHING MEASURABLE. MOISTURE IS
LACKING THROUGH THE COLUMN BUT A LITTLE LIFT MIGHT GIVE US SOME
VIRGA/SPRINKLES. THIS WILL BE THE LAST IN A SHORT SERIES OF
PACIFIC ORIGIN SYSTEMS WITH LITTLE MOISTURE TO TAP INTO. WINDS
WILL STAY UP TONIGHT AND IT WILL BE MILD...SLIGHTLY WARMER THAN
OUR TYPICAL HIGHS...LOWER/MID 40S.
A DEEP UPPER TROUGH WILL DIG INTO THE DESERT SOUTHWEST/FOUR
CORNERS SATURDAY AFTERNOON...AMPLIFYING THE DOWNSTREAM RIDGE
ACROSS THE EASTERN U.S. THE GULF WILL OPEN UP AND MOISTURE WILL BE
DRAWN NORTHWARD. ONE SURGE OF WARMER AIR WITH A WARM FRONT ARRIVES
FRIDAY NIGHT WITH LOWS ONLY UPPER 40S/AROUND 50. FRIDAY NIGHT INTO
SATURDAY EVENING STARTS THE PERIOD OF PRECIP CHANCES. MOISTURE
STILL NOT OVERLY HIGH...BUT INCREASING. THE LIFT WITH THE WARM
FRONT AND GENERAL UPGLIDE INTO SATURDAY MAY YIELD A FEW LIGHT
SHOWERS. BY LATER SATURDAY HEIGHTS WILL BE RISING SIGNIFICANTLY
AND WE WILL BE PLANTED WELL IN THE WARM SECTOR...AND OUR PRECIP
CHANCES DECREASE. BY SATURDAY H8 TEMPS WILL BE UP AROUND 8C WITH
ANOTHER PUSH OF WARM AIR ON OUR DOORSTEP. HIGHS SATURDAY WILL BE
FLIRTING WITH MID 60S. LOWER 50S SATURDAY NIGHT. BUT THE CLOUD
COVER WILL BE PLENTIFUL.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
NEAR RECORD WARMTH STILL ON TRACK TO START THE EXTENDED. MODELS ARE
STARTING TO COME INTO BETTER AGREEMENT WITH THE HANDLING OF THE
SUNDAY/MONDAY SYSTEM AS A DEEP UPPER LEVEL TROUGH OVER THE PLAINS
CURLS NORTHEAST AND MOVES THROUGH THE GREAT LAKES REGION. 00Z MODELS
HAVE HELD ONTO THE SLOWER TIMING THAT HAS BEEN THE TREND OVER THE
LAST 48 HOURS WHICH PLACES THE FORECAST AREA IN THE WARM SECTOR ON
SUNDAY. MOST OF THE AREA WILL LIKELY ALSO BE DRY WITH JUST A CHANCE
OF SHOWERS IN NW OHIO. A DRY LAYER OF AIR IN THE 850-700MB LAYER IS
FORECAST TO MOVE ACROSS NORTH CENTRAL OHIO INTO PENNSYLVANIA. CIRRUS
AND SCATTERED MID-LEVEL CLOUDS ARE EXPECTED...BUT IT LOOKS AS THOUGH
SOME FILTERED SUN IS POSSIBLE. GIVEN THE STRONG SOUTHERLY FLOW HIGH
TEMPERATURES ARE FORECAST TO REACH THE MID 60S TO NEAR 70 DEGREES.
RECORD HIGHS FOR SUNDAY ALL RANGE FROM 60-65 AT THE CLIMATE SITES.
RAIN WILL SPREAD EAST ACROSS THE AREA AHEAD OF THE COLD FRONT FROM
SUNDAY NIGHT INTO MONDAY. MODELS STILL EXHIBIT SOME SPREAD WITH
REGARD TO TRACK AND TIMING WITH THE GFS STILL ON THE FASTER END OF
THE MODEL GUIDANCE WITH THE DEEPEST LOW. SOUTHEASTERLY WINDS WILL BE
STRONG IN ERIE PA ON SUNDAY NIGHT FOLLOWED BY GUSTY SOUTHWESTERLY
WINDS ON MONDAY AND HEADLINES MAY BE NEEDED. THIS SYSTEM IS FORECAST
TO DEPART QUICKLY TO THE NE ON MONDAY NIGHT WITH A SHORTWAVE RIDGE
AND SOUTHERLY FLOW ON TUESDAY. ALTHOUGH POST FRONTAL HIGHS ON
TUESDAY WILL DROP BY 20+ DEGREES...THEY WILL LIKELY REMAIN SLIGHTLY
ABOVE NORMAL. ANOTHER LOW WILL MOVE THROUGH THE UPPER GREAT LAKES ON
TUESDAY NIGHT AND WEDNESDAY WITH ANOTHER COLD FRONT THAT WILL
FINALLY DROP TEMPERATURES BACK TO NEAR NORMAL BY MID-WEEK.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
MAJOR CHANGES MADE TO TAFS IN CENTRAL AND NORTHEAST OHIO WITH THIS
PACKAGE. A LARGE AREA OF FOG/STRATUS CAN BE SEEN ON SATELLITE
IMAGERY EXPANDING NORTHEAST ACROSS SOUTHERN AND CENTRAL OHIO.
CEILINGS ARE GENERALLY IN THE 300-600 FOOT RANGE WITH IFR
VISIBILITIES AND SOME AREAS OF FOG. BOTH THE RAP AND HRRR INDICATE
THE LOW CLOUDS WILL REACH MFD/CAK/YNG AND CLE BETWEEN 12-15Z. CLE IS
EXPECTED TO BE NEAR THE WESTERN EDGE OF THE LOW CLOUDS AND THERE IS
A SLIM CHANCE THE IFR CONDITIONS WILL NOT MAKE IT. KEPT THE IFR OUT
OF TOL/FDY BUT THERE IS ALSO A LOW CHANCE IT WILL REACH THESE SITES.
THE DEPTH OF MOISTURE IS EXPECTED TO BE SHALLOW AND CLOUDS WILL
ATTEMPT TO SCATTER OUT THIS AFTERNOON. SOUTHERLY WINDS WILL BE
BREEZY AT MANY SITES AS WELL WHICH SHOULD TO BREAK APART THE
CLOUD DECK.
THE CLOUD FORECAST WILL REMAIN A CHALLENGE INTO TONIGHT AS WITH THE
POTENTIAL FOR STRATUS TO EITHER FILL BACK IN QUICKLY AFTER SUNSET OR
WAIT FOR THE ARRIVAL OF A WEAK COLD FRONT THAT WILL SWEEP EAST
ACROSS THE AREA IN THE 3-9Z WINDOW.
OUTLOOK...NON VFR LIKELY INTO FRI FOR NE OH/NW PA. NON VFR
POSSIBLE FRIDAY NIGHT THROUGH THE FIRST HALF OF THE
WEEKEND...THEN RETURNING SUNDAY NIGHT AND MONDAY.
&&
.MARINE...
SOUTHERLY FLOW WILL INCREASE ON LAKE ERIE TODAY AS A LOW PRESSURE
SYSTEM MOVES EAST ACROSS LAKE SUPERIOR. WINDS WILL PEAK IN THE 20-25
KNOT RANGE THIS EVENING. THERE IS A CHANCE OF NEEDING A SMALL CRAFT
ADVISORY...MAINLY EAST END OF THE LAKE THIS EVENING BUT ONLY FOR A
FAIRLY SHORT WINDOW SO WILL HOLD OFF FOR NOW AND LET DAY SHIFT RE-
EVALUATE. THIS SYSTEM WILL PULL AWAY TO THE NORTHEAST ON FRIDAY WITH
A RIDGE BUILDING OVER THE OHIO VALLEY.
A WARM FRONT WILL LIFT NORTH ACROSS LAKE ERIE SATURDAY. A STRONG LOW
PRESSURE SYSTEM WILL TRACK OUT OF THE PLAINS ON SUNDAY AND PULL A
STRONG COLD FRONT EAST ACROSS LAKE ERIE ON MONDAY AS IT MOVES
THROUGH THE CENTRAL GREAT LAKES. WINDS INCREASE TO NEAR 30 KNOTS AND
MAY REACH GALES ON A PORTION OF THE LAKE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...OUDEMAN/ADAMS
SHORT TERM...OUDEMAN
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
715 AM EST THU DEC 10 2015
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE ACROSS THE AREA THURSDAY NIGHT. HIGH
PRESSURE WILL BRIEFLY RESIDE OVER THE AREA ON FRIDAY. A STRONGER
SYSTEM FROM THE SOUTHERN PLAINS WILL MOVE TO THE WESTERN GREAT
LAKES SUNDAY NIGHT. THIS SYSTEM WILL BRING A PUSH OF WARMER AIR
FOR THE WEEKEND AND A COLD FRONT AND SHOWERS EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NOT A HALF BAD DECEMBER DAY. TEMPERATURES RUNNING WELL ABOVE
NORMAL TODAY...BUT A FAIRLY STIFF BREEZE WILL NOT MAKE IT FEEL AS
WARM. THERE ARE SOME AREAS OF LIGHT FOG HERE AND THERE...NOTHING
LIKE WE HAVE SEEN RECENTLY. OTHER THAN THE FOG BURNING OFF THE DAY
WILL FEATURE INCREASING CLOUDS. THERE WILL BE A FAIR AMOUNT OF
HIGH CLOUDS...BUT SOME STRATUS WILL BE WORKING NORTHWARD FROM
CENTRAL OH AND FILLING IN OVER AT LEAST THE EASTERN PART OF THE
AREA. A GOOD WEDGE OF WARMER TEMPERATURES WILL SURGE NORTHWARD
AHEAD OF A WEAK COLD FRONT TIMED TO MOVE THROUGH TONIGHT. WITH THE
ADDITIONAL CLOUD COVER...TEMPS WILL NOT BE TOO FAR OFF FROM
YESTERDAY. GENERALLY LOWER AND MID 50S. ONLY SKY COVERAGE AND
HOURLY TEMPS TWEAKED WITH THIS EARLY MORNING UPDATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
THE WEAK FRONT APPROACHES FOR TONIGHT. THERE COULD BE A SPRINKLE
ACROSS THE EAST HALF BUT LIKELY NOTHING MEASURABLE. MOISTURE IS
LACKING THROUGH THE COLUMN BUT A LITTLE LIFT MIGHT GIVE US SOME
VIRGA/SPRINKLES. THIS WILL BE THE LAST IN A SHORT SERIES OF
PACIFIC ORIGIN SYSTEMS WITH LITTLE MOISTURE TO TAP INTO. WINDS
WILL STAY UP TONIGHT AND IT WILL BE MILD...SLIGHTLY WARMER THAN
OUR TYPICAL HIGHS...LOWER/MID 40S.
A DEEP UPPER TROUGH WILL DIG INTO THE DESERT SOUTHWEST/FOUR
CORNERS SATURDAY AFTERNOON...AMPLIFYING THE DOWNSTREAM RIDGE
ACROSS THE EASTERN U.S. THE GULF WILL OPEN UP AND MOISTURE WILL BE
DRAWN NORTHWARD. ONE SURGE OF WARMER AIR WITH A WARM FRONT ARRIVES
FRIDAY NIGHT WITH LOWS ONLY UPPER 40S/AROUND 50. FRIDAY NIGHT INTO
SATURDAY EVENING STARTS THE PERIOD OF PRECIP CHANCES. MOISTURE
STILL NOT OVERLY HIGH...BUT INCREASING. THE LIFT WITH THE WARM
FRONT AND GENERAL UPGLIDE INTO SATURDAY MAY YIELD A FEW LIGHT
SHOWERS. BY LATER SATURDAY HEIGHTS WILL BE RISING SIGNIFICANTLY
AND WE WILL BE PLANTED WELL IN THE WARM SECTOR...AND OUR PRECIP
CHANCES DECREASE. BY SATURDAY H8 TEMPS WILL BE UP AROUND 8C WITH
ANOTHER PUSH OF WARM AIR ON OUR DOORSTEP. HIGHS SATURDAY WILL BE
FLIRTING WITH MID 60S. LOWER 50S SATURDAY NIGHT. BUT THE CLOUD
COVER WILL BE PLENTIFUL.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
NEAR RECORD WARMTH STILL ON TRACK TO START THE EXTENDED. MODELS ARE
STARTING TO COME INTO BETTER AGREEMENT WITH THE HANDLING OF THE
SUNDAY/MONDAY SYSTEM AS A DEEP UPPER LEVEL TROUGH OVER THE PLAINS
CURLS NORTHEAST AND MOVES THROUGH THE GREAT LAKES REGION. 00Z MODELS
HAVE HELD ONTO THE SLOWER TIMING THAT HAS BEEN THE TREND OVER THE
LAST 48 HOURS WHICH PLACES THE FORECAST AREA IN THE WARM SECTOR ON
SUNDAY. MOST OF THE AREA WILL LIKELY ALSO BE DRY WITH JUST A CHANCE
OF SHOWERS IN NW OHIO. A DRY LAYER OF AIR IN THE 850-700MB LAYER IS
FORECAST TO MOVE ACROSS NORTH CENTRAL OHIO INTO PENNSYLVANIA. CIRRUS
AND SCATTERED MID-LEVEL CLOUDS ARE EXPECTED...BUT IT LOOKS AS THOUGH
SOME FILTERED SUN IS POSSIBLE. GIVEN THE STRONG SOUTHERLY FLOW HIGH
TEMPERATURES ARE FORECAST TO REACH THE MID 60S TO NEAR 70 DEGREES.
RECORD HIGHS FOR SUNDAY ALL RANGE FROM 60-65 AT THE CLIMATE SITES.
RAIN WILL SPREAD EAST ACROSS THE AREA AHEAD OF THE COLD FRONT FROM
SUNDAY NIGHT INTO MONDAY. MODELS STILL EXHIBIT SOME SPREAD WITH
REGARD TO TRACK AND TIMING WITH THE GFS STILL ON THE FASTER END OF
THE MODEL GUIDANCE WITH THE DEEPEST LOW. SOUTHEASTERLY WINDS WILL BE
STRONG IN ERIE PA ON SUNDAY NIGHT FOLLOWED BY GUSTY SOUTHWESTERLY
WINDS ON MONDAY AND HEADLINES MAY BE NEEDED. THIS SYSTEM IS FORECAST
TO DEPART QUICKLY TO THE NE ON MONDAY NIGHT WITH A SHORTWAVE RIDGE
AND SOUTHERLY FLOW ON TUESDAY. ALTHOUGH POST FRONTAL HIGHS ON
TUESDAY WILL DROP BY 20+ DEGREES...THEY WILL LIKELY REMAIN SLIGHTLY
ABOVE NORMAL. ANOTHER LOW WILL MOVE THROUGH THE UPPER GREAT LAKES ON
TUESDAY NIGHT AND WEDNESDAY WITH ANOTHER COLD FRONT THAT WILL
FINALLY DROP TEMPERATURES BACK TO NEAR NORMAL BY MID-WEEK.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
MAJOR CHANGES MADE TO TAFS IN CENTRAL AND NORTHEAST OHIO WITH THIS
PACKAGE. A LARGE AREA OF FOG/STRATUS CAN BE SEEN ON SATELLITE
IMAGERY EXPANDING NORTHEAST ACROSS SOUTHERN AND CENTRAL OHIO.
CEILINGS ARE GENERALLY IN THE 300-600 FOOT RANGE WITH IFR
VISIBILITIES AND SOME AREAS OF FOG. BOTH THE RAP AND HRRR INDICATE
THE LOW CLOUDS WILL REACH MFD/CAK/YNG AND CLE BETWEEN 12-15Z. CLE IS
EXPECTED TO BE NEAR THE WESTERN EDGE OF THE LOW CLOUDS AND THERE IS
A SLIM CHANCE THE IFR CONDITIONS WILL NOT MAKE IT. KEPT THE IFR OUT
OF TOL/FDY BUT THERE IS ALSO A LOW CHANCE IT WILL REACH THESE SITES.
THE DEPTH OF MOISTURE IS EXPECTED TO BE SHALLOW AND CLOUDS WILL
ATTEMPT TO SCATTER OUT THIS AFTERNOON. SOUTHERLY WINDS WILL BE
BREEZY AT MANY SITES AS WELL WHICH SHOULD TO BREAK APART THE
CLOUD DECK.
THE CLOUD FORECAST WILL REMAIN A CHALLENGE INTO TONIGHT AS WITH THE
POTENTIAL FOR STRATUS TO EITHER FILL BACK IN QUICKLY AFTER SUNSET OR
WAIT FOR THE ARRIVAL OF A WEAK COLD FRONT THAT WILL SWEEP EAST
ACROSS THE AREA IN THE 3-9Z WINDOW.
OUTLOOK...NON VFR LIKELY INTO FRI FOR NE OH/NW PA. NON VFR
POSSIBLE FRIDAY NIGHT THROUGH THE FIRST HALF OF THE
WEEKEND...THEN RETURNING SUNDAY NIGHT AND MONDAY.
&&
.MARINE...
SOUTHERLY FLOW WILL INCREASE ON LAKE ERIE TODAY AS A LOW PRESSURE
SYSTEM MOVES EAST ACROSS LAKE SUPERIOR. WINDS WILL PEAK IN THE 20-25
KNOT RANGE THIS EVENING. THERE IS A CHANCE OF NEEDING A SMALL CRAFT
ADVISORY...MAINLY EAST END OF THE LAKE THIS EVENING BUT ONLY FOR A
FAIRLY SHORT WINDOW SO WILL HOLD OFF FOR NOW AND LET DAY SHIFT RE-
EVALUATE. THIS SYSTEM WILL PULL AWAY TO THE NORTHEAST ON FRIDAY WITH
A RIDGE BUILDING OVER THE OHIO VALLEY.
A WARM FRONT WILL LIFT NORTH ACROSS LAKE ERIE SATURDAY. A STRONG LOW
PRESSURE SYSTEM WILL TRACK OUT OF THE PLAINS ON SUNDAY AND PULL A
STRONG COLD FRONT EAST ACROSS LAKE ERIE ON MONDAY AS IT MOVES
THROUGH THE CENTRAL GREAT LAKES. WINDS INCREASE TO NEAR 30 KNOTS AND
MAY REACH GALES ON A PORTION OF THE LAKE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...OUDEMAN
SHORT TERM...OUDEMAN
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS NORMAN OK
347 PM CST THU DEC 10 2015
.DISCUSSION...
THERE ARE SEVERAL WEATHER CONCERNS INCLUDING FOG POTENTIAL LATE
TONIGHT INTO FRIDAY MORNING...RECORD WARMTH AND WILDFIRE
DANGER ON FRIDAY...THEN STRONG TO SEVERE STORMS SATURDAY AND
SATURDAY NIGHT.
LATE TONIGHT INTO FRIDAY MORNING...WILL MONITOR FOR FOG
POTENTIAL...MAINLY EAST OF A MARIETTA TO ARDMORE TO SHAWNEE
LINE...WHERE LOW LEVEL MOISTURE WILL POOL NEAR A WEAK SURFACE
TROUGH. SOME OF THIS FOG COULD BE DENSE WITH VISIBILITIES UNDER
1/4 MILE. THE LATEST HRRR RUNS HAVE BEEN HINTING AT THIS FOG
DEVELOPMENT...SO ADDED MENTION. NOT SURE HOW FAR WEST THE FOG
DEVELOPMENT WILL OCCUR/EXPAND. THERE IS AN OUTSIDE CHANCE THE
OKLAHOMA CITY METRO...STILLWATER...AND PONCA CITY AREAS COULD BE
AFFECTED BY THE FOG AS WELL...THOUGH CONFIDENCE IS RATHER LOW.
WENT WITH THE COLDER SIDE OF GUIDANCE LOWS TONIGHT ACROSS MUCH OF
THE AREA DUE TO LIGHT WINDS....LOW SURFACE DEWPOINTS IN MOST
LOCATIONS...AND ONLY HIGH CLOUDS OVERHEAD WHICH WILL ALLOW FOR
RAPID RADIATIONAL COOLING.
FRIDAY WILL BE PARTLY TO MOSTLY SUNNY AND UNSEASONABLY WARM WITH A
SOUTH TO SOUTHWEST BREEZE. WENT TOWARDS THE WARMER SIDE OF
GUIDANCE EXCEPT EAST OF I-35 WHERE MORNING FOG/CLOUDS MAY HAMPER
HEATING A BIT. THE 80 DEGREE MARK WILL LIKELY BE EXCEEDED IN PARTS
OF WESTERN NORTH TEXAS AND SOUTHWESTERN OKLAHOMA. HIGH LEVEL CLOUD
COVER REMAINS A BIT UNCERTAIN AND COULD KEEP TEMPERATURES DOWN IF
IT IS THICKER THAN CURRENTLY FORECAST.
FRIDAY NIGHT...LOW LEVEL MOISTURE AND CLOUDS WILL INCREASE ACROSS
THE AREA. KEPT MENTION OF FOG AND DRIZZLE NEAR ATOKA AND DURANT
WHERE LOW LEVEL MOISTURE WILL BE DEEPEST. FOG MAY FORM ACROSS MUCH
OF THE AREA...THOUGH NOT CONFIDENT IT WILL BE DENSE AS LOW LEVEL
WINDS MAY KEEP THE AIR SLIGHTLY MIXED NEAR THE GROUND.
SATURDAY MORNING INTO EARLY AFTERNOON...CLOUDY SKIES...FOG...AND
PERHAPS DRIZZLE WILL OCCUR ACROSS MUCH OF THE AREA. THERE IS A
CHANCE FOR SOME SHOWER AND THUNDERSTORM ACTIVITY...THOUGH MOST OF
THE DAY COULD BE RAINFREE DUE TO STRONG CAPPING. IF STORMS
FORM...THEY WOULD LIKELY BE ELEVATED IN NATURE AND COULD PRODUCE
LOCALLY HEAVY DOWNPOURS AND MARGINALLY SEVERE HAIL UP TO QUARTERS
AS MID LEVEL LAPSE RATES WILL BE RATHER STEEP 7 TO 8 C/KM. APPEARS
THE GREATER CHANCES FOR STORMS WILL BE OVER SOUTHERN OR
SOUTHEASTERN OKLAHOMA DURING THIS TIME FRAME. THINK CLOUD COVER
WILL LIMIT HEATING...SO WENT COOLER THAN GUIDANCE HIGHS.
LATE SATURDAY AFTERNOON INTO SATURDAY NIGHT...STORM CHANCES WILL
INCREASE ACROSS THE ENTIRE AREA AS THE MID/UPPER LOW APPROACH.
FIRST STORMS MAY FORM NEAR THE DRYLINE TOWARDS SUNSET SATURDAY IN
FAR WESTERN OKLAHOMA AND FAR WESTERN TEXAS...THEN ORGANIZE INTO A
SQUALL LINE...PUSHING EASTWARD THROUGH THE NIGHT. FIRST STORMS
WOULD HAVE A CHANCE OF BEING DISCRETE AND SUPERCELLULAR DUE TO THE
VERY STRONG SHEAR WHICH WOULD SUPPORT LARGE HAIL AS THE MAIN
HAZARD...ESPECIALLY IF PARTIAL CLEARING AND SURFACE HEATING OCCUR.
POCKETS OF DAMAGING WINDS WITH MESOVORTICES ALONG THE SQUALL LINE
COULD OCCUR. THE AMOUNT OF INSTABILITY REMAINS VERY QUESTIONABLE
AS CLOUD COVER MAY LIMIT LOW LEVEL DESTABILIZATION. TORNADO
POTENTIAL APPEARS TO BE RATHER LOW DUE TO WEAK LOW LEVEL
INSTABILITY. SOME LOCATIONS MAY GET AN INCH OR TWO OF RAINFALL IN
AN HOUR OR TWO WHICH COULD PRODUCE MINOR FLOODING IN A FEW
LOCATIONS.
SUNDAY INTO SUNDAY NIGHT...THE MID/UPPER LOW WILL BRING ADDITIONAL
CHANCES FOR PRECIPITATION OVER MAINLY THE NORTHERN HALF OF
OKLAHOMA...WHILE THE MID/UPPER LEVEL DRY SLOT BRINGS DRY
CONDITIONS TO SOUTHERN OKLAHOMA AND NORTH TEXAS. KEPT A RAIN/SNOW
MIX OVER FAR NORTHERN OKLAHOMA DURING THIS TIME FRAME...THOUGH
LATEST MODEL SOLUTIONS HAVE BEEN TRENDING WARMER AND FARTHER NORTH
WITH THE MID/UPPER LOW WHICH WOULD PUSH THE CHANCES FOR SNOW INTO
KANSAS. ACCUMULATING SNOW SEEMS UNLIKELY EVEN IN NORTHERN OKLAHOMA
BASED ON LATEST MODEL GUIDANCE AS LOW LEVEL TEMPERATURES APPEAR TO
BE TOO WARM.
MONDAY THROUGH NEXT THURSDAY...A DRY AND COLDER WEATHER PATTERN IS
FORECAST...THOUGH CONFIDENCE IS LOW. TEMPERATURES MAY BE BELOW
AVERAGE BY TUESDAY NIGHT THEN CONTINUE THROUGH THE END OF THE
WEEK.
MBS
&&
.FIRE WEATHER...
UNSEASONABLY WARM TEMPERATURES...DRY CONDITIONS...LOW HUMIDITY...
ABUNDANT FUELS TO BURN....AND BREEZY CONDITIONS WILL LIKELY
ELEVATE FIRE WEATHER CONCERNS ON FRIDAY...ESPECIALLY OVER WESTERN
OKLAHOMA AND WESTERN NORTH TEXAS. WINDS APPEAR TO BE BELOW 20 MPH
TO KEEP RED FLAG CONDITIONS FROM OCCURRING.
&&
.CLIMATE...
RECORD HIGHS ARE POSSIBLE...IF NOT LIKELY...ACROSS THE AREA ON
FRIDAY. HERE ARE THE RECORDS.
OKLAHOMA CITY...75 DEGREES SET IN 1939
WICHITA FALLS...79 DEGREES SET IN 1929
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 38 72 53 67 / 0 0 10 30
HOBART OK 38 77 48 67 / 0 0 10 20
WICHITA FALLS TX 39 79 55 69 / 0 0 10 30
GAGE OK 38 77 39 65 / 0 0 0 10
PONCA CITY OK 38 72 51 66 / 0 0 10 40
DURANT OK 48 71 62 68 / 0 0 20 70
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
06/17
AREA FORECAST DISCUSSION
NWS MEDFORD OR
915 AM PST THU DEC 10 2015
.DISCUSSION...LAST NIGHT FEATURED HIGH WINDS...HEAVY RAIN...AND
SOME THUNDERSTORMS. 53 LIGHTNING STRIKES OCCURRED IN CURRY COUNTY...23
IN COOS COUNTY...AND 12 IN DOUGLAS COUNTY. THIS INSTABILITY WILL
CONTINUE TODAY AS A BROAD FETCH OF CONVECTIVE CLOUDS ARE NOTED ON
THE THE SATELLITE IMAGERY THIS MORNING...PUSHING TOWARDS THE
OREGON COAST. THE HRRR REFLECTIVITY PRODUCT HAS BEEN CAPTURING THE
THUNDERSTORM POTENTIAL...AND IT SUGGESTS THIS WILL CONTINUE
THROUGH THE DAY...GENERALLY FROM INTERSTATE 5 WEST TO THE COAST.
HIGHEST WIND GUSTS REGISTERED AT 70 MPH IN THE HIGHER TERRAIN OF
SOUTHWESTERN OREGON...AND 40 TO 60 MPH AT THE IMMEDIATE
COASTLINE. EAST SIDE GUSTED TO 60 MPH. WINDS WILL DIMINISH SOME
TODAY...GENERALLY BELOW ADVISORY OR WARNING CRITERIA FROM THE
CASCADES WEST...BUT WILL REMAIN GUSTY. EAST SIDE WINDS WILL TAKE
MORE TIME TO DIMINISH BELOW CRITERIA.
RAINFALL RANGED FROM A HALF INCH TO 2 INCHES ACROSS MOST OF THE
FORECAST AREA...WITH HEAVIEST AMOUNTS IN THE COAST RANGE AND INTO
SISKIYOU COUNTY. RAINFALL WILL BE MORE SHOWERY TODAY BUT HEAVY
RAIN IS POSSIBLE WITHIN ANY OF THE SHOWERS. AN AREAL FLOOD WATCH
CONTINUES IN SISKIYOU...COOS...AND CURRY COUNTIES FOR MAINLY URBAN
AND SMALL STREAM FLOODING POTENTIAL...AS WELL AS TO HIGHLIGHT THE
COQUILLE RIVER AT COQUILLE REACHING ACTION STAGE. RIVER LEVELS
SHOULD GENERALLY STEADY SOME OR FALL TODAY WITH SNOW LEVELS
FALLING AND PRECIPITATION BECOMING MORE SHOWERY.
SNOW LEVELS HAVE DROPPED SHARPLY THIS MORNING AND SNOW IS FALLING
OVER THE CASCADES AND EAST OF THE CASCADES. SNOW SHOWERS WILL
CONTINUE THROUGH THE NIGHT MOSTLY ABOVE 4000 FEET...AND A WINTER
WEATHER ADVISORY AT WSWMFR HIGHLIGHTS THIS IMPACT. OF NOTE IS THE
LATEST SREF PLUME GUIDANCE...AN INDICATOR OF CONFIDENCE FOR SNOW
AMOUNTS ON EXPOSED AREAS OF HIGH TERRAIN. THE LATEST AVERAGE 3-DAY
SNOWFALL FORECAST AMONGST THE ENSEMBLE MEMBERS SHOWS 50 INCHES OF
SNOW AT CRATER LAKE. THESE ARE SNOWFALL AMOUNTS THAT HAVEN`T BEEN
OBSERVED SINCE 2010...AND IF THIS OCCURS IT WILL BE VERY BENEFICIAL
FOR SNOWPACK BUT WILL CERTAINLY HAVE SIGNIFICANT TRAVEL IMPACTS OVER
THE PASSES.
PLEASE SEE THE PREVIOUS DISCUSSION BELOW FOR DETAILS ON THE
CONTINUED ACTIVE WEATHER PATTERN THROUGH THE WEEKEND.
&&
.AVIATION...FOR THE 10/12Z TAF CYCLE...GUSTY SOUTHWEST
WINDS WITH WIDESPREAD SHOWERS AND SNOW SHOWERS WILL CONTINUE ACROSS
THE AREA THIS MORNING THROUGH TONIGHT. THERE WILL ALSO BE SCATTERED
THUNDERSTORMS WEST OF THE CASCADES. THESE THUNDERSTORMS MAY PRODUCE
SMALL HAIL AND STRONG DOWNDRAFTS. THERE WILL BE BROKEN TO OVERCAST
CEILINGS THROUGH TONIGHT. CONDITIONS WILL BE MAINLY VFR WITH
OCCASIONAL MVFR NEAR SHOWERS...EXCEPT A MIX OF IFR AND MVFR
CONDITIONS WILL DEVELOP IN WEST SIDE VALLEYS TONIGHT. -DW
&&
.MARINE...UPDATED 845 AM PST THURSDAY 9 DEC 2015...A DEEP LOW
CENTERED OFFSHORE FROM WASHINGTON WILL CONTINUE TO PRODUCE SOUTHWEST
WINDS TODAY...BUT THESE WILL REMAIN BELOW GALE STRENGTH.
HOWEVER...GALE FORCE GUSTS MAY ACCOMPANY THUNDERSTORMS THROUGH THIS
EVENING. WEST SWELL WILL BUILD TO A PEAK LATE THIS AFTERNOON OF 25
TO 32 FEET...THEN HEAVY SEAS WILL CONTINUE THROUGH FRIDAY NIGHT.
GALES ARE LIKELY TO RETURN WITH A FRONT ON SATURDAY THEN A SERIES OF
DISTURBANCES WILL CONTINUE INTO EARLY NEXT WEEK WITH SEAS REMAINING
HIGH AND VERY STEEP. -BPN/DW
&&
.PREV DISCUSSION... /ISSUED 441 AM PST THU DEC 10 2015/
DISCUSSION...ALTHOUGH THE SYSTEM ON SATELLITE APPEARS TO HAVE
MOVED THROUGH MUCH OF THE AREA THIS MORNING THERE ARE ARE SEVERAL
LINES OF CONVECTION OFFSHORE THAT ARE PUTTING DOWN LIGHTNING AT
THIS TIME. THIS LINES WILL MOVE THROUGH THE REGION EARLY THIS
MORNING WITH BRIEF VERY HEAVY PRECIP EXPECTED. INSTABILITY IS
INDICATED ALMOST UP TO THE CASCADES...AND IN THE STRONGEST
CONVECTION THIS MAY LOWER SNOW DOWN TO THE WEST SIDE I-5 PASSES
BEYOND WHAT IS EXPECTE AT SISKIYOU SUMMIT. A SHORT WAVE MOVES
THROUGH THE REGION AS IT SITS BENEATH THE LEFT EXIT REGION OF A
145 KT JET FRIDAY. THIS WILL BRING ANOTHER ROUND OF MODERATE SNOW
TO THE CASCADES...BUT WITH THE CURRENT ADVISORIES IN EFFECT WILL
WAIT UNTIL THIS ROUND PASSES BEFORE ISSUING THE NEXT ADVISORY.
THE NEXT ROUND OF HEAVY PRECIPITATION CONTINUES ON TRACK SATURDAY
AS THE JET CONTINUES TO FOCUS ON THE REGION. THIS SYSTEM WILL
HAVE A LONGER DURATION WITH THE SAME PATTERN OF BROAD UPPER
DIVERGENCE...LOW LEVEL CONVERGENCE AND OROGRAPHIC LIFT BRING
STRONG VERTICAL MOTION OVER THE AREA. WITH A SUB-TROPICAL MOISTURE
TAP THIS WILL RESULT IN VERY HEAVY PRECIP RATES..ESPECIALLY IN THE
SOUTH COASTAL RANGES...THE CASCADES AND SISKIYOUS. SNOW LEVELS ARE
EXPECTED TO START LOW ON SATURDAY...BUT RISE ABOVE PASS LEVELS
SATURDAY AFTERNOON INTO SUNDAY. THIS WILL COMPLICATE RUNOFFCONDITIONS
AT THE LOWER LEVEL OF SNOW COVER THAT MAY SEE A SNOW MELT
CONTRIBUTION TO THE HEAVY PRECIP RUNOFF IN WELL SATURATED SOIL
CONDITIONS. THIS MAY CAUSE SLIDES ACROSS THE REGION ESPECIALLY ON
RECENT FIRE AREAS...AND SLUMPS ALONG HIGHWAY 101. SVEN
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING UNTIL 2 PM PST THIS AFTERNOON FOR ORZ029>031.
WINTER WEATHER ADVISORY UNTIL 4 AM PST FRIDAY ABOVE 4500 FEET
FOR FOR ORZ029>031.
FLOOD WATCH THROUGH FRIDAY MORNING FOR ORZ021-022-024.
HIGH SURF WARNING UNTIL 2 AM PST SATURDAY FOR ORZ021-022.
FLASH FLOOD WATCH UNTIL 10 AM PST THIS MORNING FOR ORZ023.
WINTER WEATHER ADVISORY UNTIL 4 AM PST FRIDAY ABOVE 4500 FEET
FOR FOR ORZ025-027-028.
CA...HIGH WIND WARNING UNTIL 2 PM PST THIS AFTERNOON FOR CAZ083>085.
FLASH FLOOD WATCH UNTIL 10 AM PST THIS MORNING FOR CAZ080.
FLOOD WATCH THROUGH FRIDAY MORNING FOR CAZ080.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM PST
FRIDAY ABOVE 4000 FEET FOR FOR CAZ080>083.
PACIFIC COASTAL WATERS...GALE WARNING UNTIL 10 AM PST THIS MORNING FOR PZZ350-356-376.
HAZARDOUS SEAS WARNING UNTIL 7 AM PST SATURDAY FOR
PZZ350-356-376.
GALE WARNING UNTIL 2 PM PST THIS AFTERNOON FOR PZZ370.
HAZARDOUS SEAS WARNING UNTIL 7 AM PST SATURDAY FOR PZZ370.
$$
NSK/SBN/DW
AREA FORECAST DISCUSSION
NWS MEDFORD OR
906 AM PST THU DEC 10 2015
.DISCUSSION...LAST NIGHT FEATURED HIGH WINDS...HEAVY RAIN...AND
SOME THUNDERSTORMS. 53 LIGHTNING STRIKES OCCURRED IN CURRY COUNTY...23
IN COOS COUNTY...AND 12 IN DOUGLAS COUNTY. THIS INSTABILITY WILL
CONTINUE TODAY AS A BROAD FETCH OF CONVECTIVE CLOUDS ARE NOTED ON
THE THE SATELLITE IMAGERY THIS MORNING...PUSHING TOWARDS THE
OREGON COAST. THE HRRR REFLECTIVITY PRODUCT HAS BEEN CAPTURING THE
THUNDERSTORM POTENTIAL...AND IT SUGGESTS THIS WILL CONTINUE
THROUGH THE DAY...GENERALLY FROM INTERSTATE 5 WEST TO THE COAST.
HIGHEST WIND GUSTS REGISTERED AT 70 MPH IN THE HIGHER TERRAIN OF
SOUTHWESTERN OREGON...AND 40 TO 60 MPH AT THE IMMEDIATE
COASTLINE. EAST SIDE GUSTED TO 60 MPH. WINDS WILL DIMINISH SOME
TODAY...GENERALLY BELOW ADVISORY OR WARNING CRITERIA FROM THE
CASCADES WEST...BUT WILL REMAIN GUSTY. EAST SIDE WINDS WILL TAKE
MORE TIME TO DIMINISH BELOW CRITERIA.
RAINFALL RANGED FROM A HALF INCH TO 2 INCHES ACROSS MOST OF THE
FORECAST AREA...WITH HEAVIEST AMOUNTS IN THE COAST RANGE AND INTO
SISKIYOU COUNTY. RAINFALL WILL BE MORE SHOWERY TODAY BUT HEAVY
RAIN IS POSSIBLE WITHIN ANY OF THE SHOWERS. AN AREAL FLOOD WATCH
CONTINUES IN SISKIYOU...COOS...AND CURRY COUNTIES FOR MAINLY URBAN
AND SMALL STREAM FLOODING POTENTIAL...AS WELL AS TO HIGHLIGHT THE
COQUILLE RIVER AT COQUILLE REACHING ACTION STAGE. RIVER LEVELS
SHOULD GENERALLY STEADY SOME OR FALL TODAY WITH SNOW LEVELS
FALLING AND PRECIPITATION BECOMING MORE SHOWERY.
SNOW LEVELS HAVE DROPPED SHARPLY THIS MORNING AND SNOW IS FALLING
OVER THE CASCADES AND EAST OF THE CASCADES. SNOW SHOWERS WILL
CONTINUE THROUGH THE NIGHT MOSTLY ABOVE 4000 FEET...AND A WINTER
WEATHER ADVISORY AT WSWMFR HIGHLIGHTS THIS IMPACT.
PLEASE SEE THE PREVIOUS DISCUSSION BELOW FOR DETAILS ON THE
CONTINUED ACTIVE WEATHER PATTERN THROUGH THE WEEKEND.
&&
.AVIATION...FOR THE 10/12Z TAF CYCLE...GUSTY SOUTHWEST
WINDS WITH WIDESPREAD SHOWERS AND SNOW SHOWERS WILL CONTINUE ACROSS
THE AREA THIS MORNING THROUGH TONIGHT. THERE WILL ALSO BE SCATTERED
THUNDERSTORMS WEST OF THE CASCADES. THESE THUNDERSTORMS MAY PRODUCE
SMALL HAIL AND STRONG DOWNDRAFTS. THERE WILL BE BROKEN TO OVERCAST
CEILINGS THROUGH TONIGHT. CONDITIONS WILL BE MAINLY VFR WITH
OCCASIONAL MVFR NEAR SHOWERS...EXCEPT A MIX OF IFR AND MVFR
CONDITIONS WILL DEVELOP IN WEST SIDE VALLEYS TONIGHT. -DW
&&
.MARINE...UPDATED 845 AM PST THURSDAY 9 DEC 2015...A DEEP LOW
CENTERED OFFSHORE FROM WASHINGTON WILL CONTINUE TO PRODUCE SOUTHWEST
WINDS TODAY...BUT THESE WILL REMAIN BELOW GALE STRENGTH.
HOWEVER...GALE FORCE GUSTS MAY ACCOMPANY THUNDERSTORMS THROUGH THIS
EVENING. WEST SWELL WILL BUILD TO A PEAK LATE THIS AFTERNOON OF 25
TO 32 FEET...THEN HEAVY SEAS WILL CONTINUE THROUGH FRIDAY NIGHT.
GALES ARE LIKELY TO RETURN WITH A FRONT ON SATURDAY THEN A SERIES OF
DISTURBANCES WILL CONTINUE INTO EARLY NEXT WEEK WITH SEAS REMAINING
HIGH AND VERY STEEP. -BPN/DW
&&
.PREV DISCUSSION... /ISSUED 441 AM PST THU DEC 10 2015/
DISCUSSION...ALTHOUGH THE SYSTEM ON SATELLITE APPEARS TO HAVE
MOVED THROUGH MUCH OF THE AREA THIS MORNING THERE ARE ARE SEVERAL
LINES OF CONVECTION OFFSHORE THAT ARE PUTTING DOWN LIGHTNING AT
THIS TIME. THIS LINES WILL MOVE THROUGH THE REGION EARLY THIS
MORNING WITH BRIEF VERY HEAVY PRECIP EXPECTED. INSTABILITY IS
INDICATED ALMOST UP TO THE CASCADES...AND IN THE STRONGEST
CONVECTION THIS MAY LOWER SNOW DOWN TO THE WEST SIDE I-5 PASSES
BEYOND WHAT IS EXPECTE AT SISKIYOU SUMMIT. A SHORT WAVE MOVES
THROUGH THE REGION AS IT SITS BENEATH THE LEFT EXIT REGION OF A
145 KT JET FRIDAY. THIS WILL BRING ANOTHER ROUND OF MODERATE SNOW
TO THE CASCADES...BUT WITH THE CURRENT ADVISORIES IN EFFECT WILL
WAIT UNTIL THIS ROUND PASSES BEFORE ISSUING THE NEXT ADVISORY.
THE NEXT ROUND OF HEAVY PRECIPITATION CONTINUES ON TRACK SATURDAY
AS THE JET CONTINUES TO FOCUS ON THE REGION. THIS SYSTEM WILL
HAVE A LONGER DURATION WITH THE SAME PATTERN OF BROAD UPPER
DIVERGENCE...LOW LEVEL CONVERGENCE AND OROGRAPHIC LIFT BRING
STRONG VERTICAL MOTION OVER THE AREA. WITH A SUB-TROPICAL MOISTURE
TAP THIS WILL RESULT IN VERY HEAVY PRECIP RATES..ESPECIALLY IN THE
SOUTH COASTAL RANGES...THE CASCADES AND SISKIYOUS. SNOW LEVELS ARE
EXPECTED TO START LOW ON SATURDAY...BUT RISE ABOVE PASS LEVELS
SATURDAY AFTERNOON INTO SUNDAY. THIS WILL COMPLICATE RUNOFFCONDITIONS
AT THE LOWER LEVEL OF SNOW COVER THAT MAY SEE A SNOW MELT
CONTRIBUTION TO THE HEAVY PRECIP RUNOFF IN WELL SATURATED SOIL
CONDITIONS. THIS MAY CAUSE SLIDES ACROSS THE REGION ESPECIALLY ON
RECENT FIRE AREAS...AND SLUMPS ALONG HIGHWAY 101. SVEN
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING UNTIL 2 PM PST THIS AFTERNOON FOR ORZ029>031.
WINTER WEATHER ADVISORY UNTIL 4 AM PST FRIDAY ABOVE 4500 FEET
FOR FOR ORZ029>031.
FLOOD WATCH THROUGH FRIDAY MORNING FOR ORZ021-022-024.
HIGH SURF WARNING UNTIL 2 AM PST SATURDAY FOR ORZ021-022.
FLASH FLOOD WATCH UNTIL 10 AM PST THIS MORNING FOR ORZ023.
WINTER WEATHER ADVISORY UNTIL 4 AM PST FRIDAY ABOVE 4500 FEET
FOR FOR ORZ025-027-028.
CA...HIGH WIND WARNING UNTIL 2 PM PST THIS AFTERNOON FOR CAZ083>085.
FLASH FLOOD WATCH UNTIL 10 AM PST THIS MORNING FOR CAZ080.
FLOOD WATCH THROUGH FRIDAY MORNING FOR CAZ080.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM PST
FRIDAY ABOVE 4000 FEET FOR FOR CAZ080>083.
PACIFIC COASTAL WATERS...GALE WARNING UNTIL 10 AM PST THIS MORNING FOR PZZ350-356-376.
HAZARDOUS SEAS WARNING UNTIL 7 AM PST SATURDAY FOR
PZZ350-356-376.
GALE WARNING UNTIL 2 PM PST THIS AFTERNOON FOR PZZ370.
HAZARDOUS SEAS WARNING UNTIL 7 AM PST SATURDAY FOR PZZ370.
$$
NSK/SBN/DW
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
343 PM EST THU DEC 10 2015
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD OVER THE REGION TODAY...FOLLOWED BY
A WEAKENING TROUGH OF LOW PRESSURE THAT WILL SLIDE NORTH OF THE
AREA FRIDAY. MILDER AIR IS EXPECTED TO MOVE IN FOR THE WEEKEND AS
HIGH PRESSURE SETS UP OFF THE MID ATLANTIC COAST. THE NEXT CHANCE
FOR WIDESPREAD SHOWERS WILL BE LIKELY MONDAY AS A COLD FRONT MOVES
INTO THE STATE.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
HAVE ALLOWED THE DENSE FOG ADVISORY TO EXPIRE AS SATELLITE SHOWS
THE LOW CLOUDS AND FOG BURNING OFF MUCH MORE EFFICIENTLY THAN ON
PREVIOUS DAYS.
SOME MID AND HIGH CLOUDS WILL DRIFT ACROSS MAINLY NORTHERN AREAS
FOR THE REMAINDER OF THE DAY WHICH WILL BE LARGELY UNEVENTFUL.
TEMPS LOOK ON TRACK TO TOP OUT IN THE LOW TO MID 509S IN MOST
LOCATIONS.
ANOTHER SHEARING TROUGH IS FORECAST TO SLIDE OFF TO OUR NORTH
OVERNIGHT. CHANCES FOR RAIN SHOULD REMAIN QUITE LOW AS THE ENTIRE
NORTHEAST IS BASICALLY UNDER AN AREA OF RISING HEIGHTS ALOFT.
EXPERIMENTAL HRRR AND MOS GUIDANCE SUGGEST AREAS OF FOG WILL ONCE
AGAIN BECOME AN ISSUE LATER TONIGHT....BUT CENTERED MOST ON MY
SERN ZONES MORE THAN THE WIDESPREAD FOG WE HAVE SEEN THE LAST
SEVERAL DAYS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
EARLY FOG AND LOW CLOUDS WILL ONCE AGAIN BURN OFF TO A DAY OF
MIXED SUN AND CLOUDS WITH TEMPERATURES WELL ABOVE NORMAL. SERN
ZONES COULD TOUCH 60 WHILE THE REMAINDER OF THE REGION LOOKS TO
MAKE IT INTO THE MID TO UPPER 50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
ABOVE NORMAL TO NEAR-RECORD WARMTH WILL BE THE MAIN STORY THIS
PERIOD...WITH DAYTIME HIGHS FCST +20 TO +30 DEGREES ABOVE CLIMO
BY LATE IN THE WEEKEND. POSSIBLE LOW CLOUDS...LIGHT PRECIP...AND
FOG MAY COMPLICATE THINGS AT FIRST AND WILL ASSESS THIS RISK IN
THE SHORT RANGE.
THE NEXT WEATHER SYSTEM MOVES THROUGH PENNSYLVANIA ON
MONDAY...WITH ABOVE AVERAGE CONFIDENCE IN THE PCPN PATTERN THIS
FAR OUT GIVEN VERY GOOD MODEL AND ENSEMBLE AGREEMENT. SW WINDS
SHOULD AID IN THE CONTINUED WARM UP ON MONDAY UNTIL A COLD FRONT
MOVES THROUGH LATER IN THE DAY. HOWEVER...THERE IS STILL A GOOD
DEAL OF MODEL SPREAD REGARDING MONDAY/S MAX TEMPS AND A LOT WILL
DEPEND ON EXACT TIMING OF THE SYSTEM AND ASSOCIATED CLOUD
SHIELD/PRECIP.
TEMPERATURES ARE FCST TO STAY RELATIVELY MILD FOR DECEMBER
THROUGH MUCH OF NEXT WEEK WITH A COOLDOWN TO "NEAR NORMAL"
POSSIBLE AROUND THE 18-19TH...ACCOMPANIED BY THE NEXT CHANCE FOR
SOME LIGHT PCPN.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
1PM/18Z UPDATE...
LOW CLOUD AND FOG POCKETS HAVE BECOME VERY LOCALIZED
OVER THE CENTRAL RIDGE-VALLEY AREA...AND WILL CONTINUE TO MELT
AWAY. THE BULK OF THE SUB VFR CONDITIONS REMAIN OVER THE MID AND
LOWER SUSQ VALLEY..BUT EVEN THERE I EXPECT CONDITIONS TO IMPROVE
TO VFR OVER THE NEXT COUPLE OF HOURS.
LOCALIZED FOG AND LOW CLOUDS ARE EXPECTED TO REDEVELOP ONCE AGAIN
LATER TONIGHT...ESPECIALLY OVER MY EASTERN AND SOUTHERN TERMINALS.
THESE WILL LIFT AND BURN OFF FRIDAY MORNING LEAVING ALL TERMINALS
VFR BY MID DAY.
OUTLOOK...
SAT...MVFR WITH CHC SHRA NW HALF. MAINLY VFR SE.
SUN...MAINLY VFR.
MON...FROPA WITH WIDESPREAD SHOWERS AND MVFR/IFR.
TUE...MVFR WEST EARLY...MAINLY VFR BY AFTERNOON.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/HAGNER
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
111 PM EST THU DEC 10 2015
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD OVER THE REGION TODAY...FOLLOWED BY
A WEAKENING TROUGH OF LOW PRESSURE THAT WILL SLIDE NORTH OF THE
AREA FRIDAY. MILDER AIR IS EXPECTED TO MOVE IN FOR THE WEEKEND AS
HIGH PRESSURE SETS UP OFF THE MID ATLANTIC COAST. THE NEXT CHANCE
FOR WIDESPREAD SHOWERS WILL BE LIKELY MONDAY AS A COLD FRONT MOVES
INTO THE STATE.
&&
.NEAR TERM /THROUGH TONIGHT/...
HAVE ALLOWED THE DENSE FOG ADVISORY TO EXPIRE AS SATELLITE SHOWS
THE LOW CLOUDS AND FOG BURNING OFF MUCH MORE EFFICIENTLY THAN ON
PREVIOUS DAYS.
SOME MID AND HIGH CLOUDS WILL DRIFT ACROSS MAINLY NORTHERN AREAS
FOR THE REMAINDER OF THE DAY WHICH WILL BE LARGELY UNEVENTFUL.
TEMPS LOOK ON TRACK TO TOP OUT IN THE LOW TO MID 509S IN MOST
LOCATIONS.
ANOTHER SHEARING TROUGH IS FORECAST TO SLIDE OFF TO OUR NORTH
OVERNIGHT. CHANCES FOR RAIN SHOULD REMAIN QUITE LOW AS THE ENTIRE
NORTHEAST IS BASICALLY UNDER AN AREA OF RISING HEIGHTS ALOFT.
EXPERIMENTAL HRRR AND MOS GUIDANCE SUGGEST AREAS OF FOG WILL ONCE
AGAIN BECOME AN ISSUE LATER TONIGHT....BUT CENTERED MOST ON MY
SERN ZONES MORE THAN THE WIDESPREAD FOG WE HAVE SEEN THE LAST
SEVERAL DAYS.
&&
.SHORT TERM /FRIDAY/...
EARLY FOG AND LOW CLOUDS WILL ONCE AGAIN BURN OFF TO A DAY OF
MIXED SUN AND CLOUDS WITH TEMPERATURES WELL ABOVE NORMAL. SERN
ZONES COULD TOUCH 60 WHILE THE REMAINDER OF THE REGION LOOKS TO
MAKE IT INTO THE MID TO UPPER 50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
ABOVE NORMAL TO NEAR-RECORD WARMTH WILL BE THE MAIN STORY THIS
PERIOD...WITH DAYTIME HIGHS FCST +20 TO +30 DEGREES ABOVE CLIMO
BY LATE IN THE WEEKEND. POSSIBLE LOW CLOUDS AND FOG MAY COMPLICATE
THINGS AT FIRST AND WILL ASSESS THIS RISK IN THE SHORT RANGE.
THE GREATEST RISK FOR RAIN WILL LIKELY BE ON MONDAY WITH ABOVE
AVERAGE CONFIDENCE IN THE PCPN PATTERN THIS FAR OUT GIVEN VERY
GOOD MODEL AND ENSEMBLE AGREEMENT. TEMPERATURES ARE FCST TO STAY
RELATIVELY MILD FOR DECEMBER THROUGH MUCH OF NEXT WEEK WITH A COOL
DOWN TO "NEAR NORMAL" POSSIBLE AROUND THE 18-19TH.
&&
.AVIATION /17Z THURSDAY THROUGH TUESDAY/...
1PM/18Z UPDATE...
LOW CLOUD AND FOG POCKETS HAVE BECOME VERY LOCALIZED
OVER THE CENTRAL RIDGE-VALLEY AREA...AND WILL CONTINUE TO MELT
AWAY. THE BULK OF THE SUB VFR CONDITIONS REMAIN OVER THE MID AND
LOWER SUSQ VALLEY..BUT EVEN THERE I EXPECT CONDITIONS TO IMPROVE
TO VFR OVER THE NEXT COUPLE OF HOURS.
LOCALIZED FOG AND LOW CLOUDS ARE EXPECTED TO REDEVELOP ONCE AGAIN
LATER TONIGHT...ESPECIALLY OVER MY EASTERN AND SOUTHERN TERMINALS.
THESE WILL LIFT AND BURN OFF FRIDAY MORNING LEAVING ALL TERMINALS
VFR BY MID DAY.
OUTLOOK...
SAT...MVFR WITH CHC SHRA NW HALF. MAINLY VFR SE.
SUN...MAINLY VFR.
MON...FROPA WITH WIDESPREAD SHOWERS AND MVFR/IFR.
TUE...MVFR WEST EARLY...MAINLY VFR BY AFTERNOON.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/STEINBUGL
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
753 AM EST THU DEC 10 2015
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL MOVE EAST OF THE SUSQUEHANNA
VALLEY EARLY TODAY. ANOTHER...SIMILARLY WEAK FRONT WILL CROSS THE
REGION FRIDAY...FOLLOWED BY AN ANOMALOUSLY STRONG RIDGE OF HIGH
PRESSURE THAT WILL BRING MUCH WARMER THAN NORMAL CONDITIONS FOR
THE UPCOMING WEEKEND. MORE WIDESPREAD SHOWERS WILL BE LIKELY ALONG
AND AHEAD OF A STRONGER COLD FRONT THAT WILL CROSS THE REGION ON
MONDAY.
&&
.NEAR TERM /UNTIL 10 AM THIS MORNING/...
HAVE EXPANDED THE FOG ADVISORY AS THE CLOUDS CLEARED OUT JUST IN
TIME TO ALLOW ENOUGH RADIATIONAL COOLING TO OCCUR THAT FOG HAS
BECOME MORE WIDESPREAD THAN EARLIER EXPECTED.
FOR CLOUD COVER THIS MORNING...EMPLOYED A BLEND OF THE LATEST
OPTIMISTIC RAP AND HRRRX DATA WITH THE MORE CLOUDY LOOKING NAM.
TEMPS WILL RISE GRADUALLY FROM THEIR DAYBREAK START IN THE UPPER
30S THROUGHOUT THE CENTRAL VALLEY AND NRN MTNS...AND MILDER
READINGS IN THE LOWER TO MID 40S ACROSS THE LOWER SUSQ
VALLEY...AND LAUREL HIGHLANDS.
&&
.SHORT TERM /10 AM THIS MORNING THROUGH 6 PM FRIDAY/...
A WEAK FRONT WILL SHEAR OUT TO OUR NE TODAY...WITH HIGH PRESSURE
ESTABLISHING ITSELF OFF TO OUR SOUTHWEST. THE NET EFFECT WILL BE
FOR A SOUTHWEST FLOW TO SET UP WHICH SHOULD HELP SCOUR OUT THE
PERSISTENT LOW CLOUDS /AND AREAS OF FOG ACROSS MAINLY THE SOUTH
AND EAST/ DURING THE LATE MORNING HOURS.
WITH A GRADUAL INCREASE IN SUNSHINE...AND A MILDER /ALBEIT LIGHT/
SOUTHWEST FLOW EXPECTED TO DEVELOP...HIGHS THIS AFTERNOON WILL
AVERAGE IN THE LOW TO MID 50S...STILL SOME 10-15 DEG WARMER THAN
NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
ABOVE NORMAL TO NEAR-RECORD WARMTH WILL BE THE MAIN STORY THIS
PERIOD...WITH DAYTIME HIGHS FCST +20 TO +30 DEGREES ABOVE CLIMO
BY LATE IN THE WEEKEND. POSSIBLE LOW CLOUDS AND FOG MAY COMPLICATE
THINGS AT FIRST AND WILL ASSESS THIS RISK IN THE SHORT RANGE.
THE GREATEST RISK FOR RAIN WILL LIKELY BE ON MONDAY WITH ABOVE
AVERAGE CONFIDENCE IN THE PCPN PATTERN THIS FAR OUT GIVEN VERY
GOOD MODEL AND ENSEMBLE AGREEMENT. TEMPERATURES ARE FCST TO STAY
RELATIVELY MILD FOR DECEMBER THROUGH MUCH OF NEXT WEEK WITH A COOL
DOWN TO "NEAR NORMAL" POSSIBLE AROUND THE 18-19TH.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
PATCHY DENSE FOG CONTINUES ACROSS CENTRAL AND SOUTHERN TAF SITES
THIS MORNING EXPECT VSBYS OF 1/4SM OR LESS AT TIMES AT UNV...AOO
AND LNS. MDT WILL BE IFR THROUGH THIS TIMEFRAME. THESE
CONDITIONS WILL CONTINUE THROUGH THE MORNING HOURS BEFORE
IMPROVING LATE THIS MORNING. THE FOG IS RATHER SHALLOW SO ONCE THE
SFC DECOUPLES IT SHOULD LIFT/DISSIPATE. ELSEWHERE BFD AND IPT ARE
MVFR AND WILL IMPROVE BY 14Z. THE WIDESPREAD IFR/MVFR CEILINGS
AND PATCHY FOG OVER EASTERN AREAS WILL IMPROVE TO VFR BY EARLY
AFTERNOON AS THE WEST- SOUTHWEST FLOW BEGINS TO DOMINATE THE
REGION.
OUTLOOK...
FRI...AREAS OF MORNING FOG. THEN MAINLY VFR.
SAT...MVFR WITH CHC SHRA NW HALF. MAINLY VFR SE.
SUN...MAINLY VFR.
MON...FROPA WITH WIDESPREAD SHOWERS AND MVFR/IFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ005-006-
010>012-017>019-025>028-034>037-041-042-045-046-049>053-056-
057-059-063>066.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/STEINBUGL
AVIATION...LA CORTE/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
749 AM EST THU DEC 10 2015
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL MOVE EAST OF THE SUSQUEHANNA
VALLEY EARLY TODAY. ANOTHER...SIMILARLY WEAK FRONT WILL CROSS THE
REGION FRIDAY...FOLLOWED BY AN ANOMALOUSLY STRONG RIDGE OF HIGH
PRESSURE THAT WILL BRING MUCH WARMER THAN NORMAL CONDITIONS FOR
THE UPCOMING WEEKEND. MORE WIDESPREAD SHOWERS WILL BE LIKELY ALONG
AND AHEAD OF A STRONGER COLD FRONT THAT WILL CROSS THE REGION ON
MONDAY.
&&
.NEAR TERM /UNTIL 10 AM THIS MORNING/...
HAVE EXPANDED THE FOG ADVISORY AS THE CLOUDS CLEARED OUT JUST IN
TIME TO ALLOW ENOUGH RADIATIONAL COOLING TO OCCUR THAT FOG HAS
BECOME MORE WIDESPREAD THAN EARLIER EXPECTED.
FOR CLOUD COVER THIS MORNING...EMPLOYED A BLEND OF THE LATEST
OPTIMISTIC RAP AND HRRRX DATA WITH THE MORE CLOUDY LOOKING NAM.
TEMPS WILL RISE GRADUALLY FROM THEIR DAYBREAK START IN THE UPPER
30S THROUGHOUT THE CENTRAL VALLEY AND NRN MTNS...AND MILDER
READINGS IN THE LOWER TO MID 40S ACROSS THE LOWER SUSQ
VALLEY...AND LAUREL HIGHLANDS.
&&
.SHORT TERM /10 AM THIS MORNING THROUGH 6 PM FRIDAY/...
A WEAK FRONT WILL SHEAR OUT TO OUR NE TODAY...WITH HIGH PRESSURE
ESTABLISHING ITSELF OFF TO OUR SOUTHWEST. THE NET EFFECT WILL BE
FOR A SOUTHWEST FLOW TO SET UP WHICH SHOULD HELP SCOUR OUT THE
PERSISTENT LOW CLOUDS /AND AREAS OF FOG ACROSS MAINLY THE SOUTH
AND EAST/ DURING THE LATE MORNING HOURS.
WITH A GRADUAL INCREASE IN SUNSHINE...AND A MILDER /ALBEIT LIGHT/
SOUTHWEST FLOW EXPECTED TO DEVELOP...HIGHS THIS AFTERNOON WILL
AVERAGE IN THE LOW TO MID 50S...STILL SOME 10-15 DEG WARMER THAN
NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
ABOVE NORMAL TO NEAR-RECORD WARMTH WILL BE THE MAIN STORY THIS
PERIOD...WITH DAYTIME HIGHS FCST +20 TO +30 DEGREES ABOVE CLIMO
BY LATE IN THE WEEKEND. POSSIBLE LOW CLOUDS AND FOG MAY COMPLICATE
THINGS AT FIRST AND WILL ASSESS THIS RISK IN THE SHORT RANGE.
THE GREATEST RISK FOR RAIN WILL LIKELY BE ON MONDAY WITH ABOVE
AVERAGE CONFIDENCE IN THE PCPN PATTERN THIS FAR OUT GIVEN VERY
GOOD MODEL AND ENSEMBLE AGREEMENT. TEMPERATURES ARE FCST TO STAY
RELATIVELY MILD FOR DECEMBER THROUGH MUCH OF NEXT WEEK WITH A COOL
DOWN TO "NEAR NORMAL" POSSIBLE AROUND THE 18-19TH.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
SHOWERS CONTINUE TO MOVE EASTWARD AS THE COLD FRONT SUPPORTED BY
MODEST LOOKING UPPER CONTINUES TO CROSS THE AIRSPACE OVERNIGHT.
HOWEVER THE SFC HAS DECOUPLED ONCE AGAIN ALLOWING FOR CALMING
WINDS...REDUCED CIGS AND LOW STRATOCU. EXPECT THESE TO ALLOW FOR
RESTRICTIONS OVERNIGHT AT ALL TAF SITES. EXPECT PERIODS OF IFR AT
ALL TAF SITES THROUGH 12Z...THOUGH WITH THE SOUTH WESTERN TAF
SITES IT WILL BE INTERMITTENT. AS THE FRONT PASSES THURSDAY IT SHOULD
FINALLY HELP SCOUR OUT STABLE AMS/LOW LEVEL CLOUDS AND FOG THAT
HAS BEEN IN PLACE OVER PARTS OF CENTRAL PA FOR THE LAST FEW DAYS.
THE WIDESPREAD IFR/MVFR CEILINGS AND PATCHY FOG OVER EASTERN
AREAS WILL CONTINUE THROUGH THE MORNING BUT CONDITIONS TO IMPROVE
TO VFR BY LATE MORNING TO EARLY AFTERNOON AS THE WEST- SOUTHWEST
FLOW BEGINS TO DOMINATE THE REGION.
OUTLOOK...
FRI...AREAS OF MORNING FOG. THEN MAINLY VFR.
SAT...MVFR WITH CHC SHRA NW HALF. MAINLY VFR SE.
SUN...MAINLY VFR.
MON...FROPA WITH WIDESPREAD SHOWERS AND MVFR/IFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ005-006-
010>012-017>019-025>028-034>037-041-042-045-046-049>053-056-
057-059-063>066.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/STEINBUGL
AVIATION...LA CORTE/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
554 AM EST THU DEC 10 2015
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL MOVE EAST OF THE SUSQUEHANNA
VALLEY EARLY TODAY. ANOTHER...SIMILARLY WEAK FRONT WILL CROSS THE
REGION FRIDAY...FOLLOWED BY AN ANOMALOUSLY STRONG UPPER RIDGE THAT
WILL BRING MUCH WARMER THAN NORMAL CONDITIONS FOR THE UPCOMING
WEEKEND. MORE WIDESPREAD SHOWERS WILL BE LIKELY ALONG AND AHEAD OF
A STRONGER COLD FRONT THAT WILL CROSS THE REGION ON MONDAY.
&&
.NEAR TERM /UNTIL 10 AM THIS MORNING/...
A LARGE AREA OF STRATO CU CLOUDS /OCCUPYING A FEW LAYERS/ WILL
BREAK UP DURING THE MID MORNING HOURS. THE AREAS OF CLEARING AND
TIGHT TEMP/DWPT SPREADS OF LESS THAN 2 DEG F ACROSS THE CENTRAL
AND EASTERN PARTS OF THE CWA WILL COMBINE WITH LIGHT WIND /AND
DECREASING WIND ALOFT THIS MORNING/ TO CREATE AREAS OF 1/2SM TO
1SM VALLEY FOG. THE FOG WILL BE LOCALLY DENSE...AND EVEN QUITE
WIDESPREAD ACROSS THE LOWER SUSQ VALLEY WHERE A BRIEF...BUT SOLID
AREA OF SHOWERS MOVED THROUGH SHORTLY AFTER MIDNIGHT FOLLOWED BY A
PERIOD OF CLEARING.
ISSUED A DENSE FOG ADVISORY THROUGH 15Z FOR 5 OF OUR FAR SE
COUNTIES...WHERE SEVERAL LOCATIONS ARE REPORTING CONDITIONS BELOW
1/4SM.
FOR CLOUD COVER THIS MORNING...EMPLOYED A BLEND OF THE
LATEST OPTIMISTIC RAP AND HRRRX DATA WITH THE MORE CLOUDY LOOKING
NAM.
TEMPS WILL RISE GRADUALLY FROM THEIR DAYBREAK START IN THE UPPER
30S THROUGHOUT THE CENTRAL VALLEY AND NRN MTNS...AND MILDER
READINGS IN THE LOWER TO MID 40S ACROSS THE LOWER SUSQ
VALLEY...AND LAUREL HIGHLANDS.
&&
.SHORT TERM /10 AM THIS MORNING THROUGH 6 PM FRIDAY/...
A WEAK FRONT WILL SHEAR OUT TO OUR NE TODAY...WITH HIGH PRESSURE
ESTABLISHING ITSELF OFF TO OUR SOUTHWEST. THE NET EFFECT WILL BE
FOR A SOUTHWEST FLOW TO SET UP WHICH SHOULD HELP SCOUR OUT THE
PERSISTENT LOW CLOUDS /AND AREAS OF FOG ACROSS MAINLY THE SOUTH
AND EAST/ DURING THE LATE MORNING HOURS.
WITH A GRADUAL INCREASE IN SUNSHINE...AND A MILDER /ALBEIT LIGHT/
SOUTHWEST FLOW EXPECTED TO DEVELOP...HIGHS THIS AFTERNOON WILL
AVERAGE IN THE LOW TO MID 50S...STILL SOME 10-15 DEG WARMER THAN
NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
ABOVE NORMAL TO NEAR-RECORD WARMTH WILL BE THE MAIN STORY THIS
PERIOD...WITH DAYTIME HIGHS FCST +20 TO +30 DEGREES ABOVE CLIMO
BY LATE IN THE WEEKEND. POSSIBLE LOW CLOUDS AND FOG MAY COMPLICATE
THINGS AT FIRST AND WILL ASSESS THIS RISK IN THE SHORT RANGE.
THE GREATEST RISK FOR RAIN WILL LIKELY BE ON MONDAY WITH ABOVE
AVERAGE CONFIDENCE IN THE PCPN PATTERN THIS FAR OUT GIVEN VERY
GOOD MODEL AND ENSEMBLE AGREEMENT. TEMPERATURES ARE FCST TO STAY
RELATIVELY MILD FOR DECEMBER THROUGH MUCH OF NEXT WEEK WITH A COOL
DOWN TO "NEAR NORMAL" POSSIBLE AROUND THE 18-19TH.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
SHOWERS CONTINUE TO MOVE EASTWARD AS THE COLD FRONT SUPPORTED BY
MODEST LOOKING UPPER CONTINUES TO CROSS THE AIRSPACE OVERNIGHT.
HOWEVER THE SFC HAS DECOUPLED ONCE AGAIN ALLOWING FOR CALMING
WINDS...REDUCED CIGS AND LOW STRATOCU. EXPECT THESE TO ALLOW FOR
RESTRICTIONS OVERNIGHT AT ALL TAF SITES. EXPECT PERIODS OF IFR AT
ALL TAF SITES THROUGH 12Z...THOUGH WITH THE SOUTH WESTERN TAF
SITES IT WILL BE INTERMITTENT. AS THE FRONT PASSES THURSDAY IT SHOULD
FINALLY HELP SCOUR OUT STABLE AMS/LOW LEVEL CLOUDS AND FOG THAT
HAS BEEN IN PLACE OVER PARTS OF CENTRAL PA FOR THE LAST FEW DAYS.
THE WIDESPREAD IFR/MVFR CEILINGS AND PATCHY FOG OVER EASTERN
AREAS WILL CONTINUE THROUGH THE MORNING BUT CONDITIONS TO IMPROVE
TO VFR BY LATE MORNING TO EARLY AFTERNOON AS THE WEST- SOUTHWEST
FLOW BEGINS TO DOMINATE THE REGION.
OUTLOOK...
FRI...AREAS OF MORNING FOG. THEN MAINLY VFR.
SAT...MVFR WITH CHC SHRA NW HALF. MAINLY VFR SE.
SUN...MAINLY VFR.
MON...FROPA WITH WIDESPREAD SHOWERS AND MVFR/IFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ057-059-
064>066.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/STEINBUGL
AVIATION...LA CORTE/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
310 AM EST THU DEC 10 2015
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL MOVE EAST OF THE SUSQUEHANNA
VALLEY EARLY TODAY. ANOTHER...SIMILARLY WEAK FRONT WILL CROSS THE
REGION FRIDAY...FOLLOWED BY AN ANOMALOUSLY STRONG UPPER RIDGE THAT
WILL BRING MUCH WARMER THAN NORMAL CONDITIONS FOR THE UPCOMING
WEEKEND. MORE WIDESPREAD SHOWERS WILL BE LIKELY ALONG AND AHEAD OF
A STRONGER COLD FRONT THAT WILL CROSS THE REGION ON MONDAY.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
A FEW AREAS OF SHOWERS /ALONG AND AHEAD OF A WEAK SFC/UPPER LEVEL
TROUGH/ WILL EXIT TO THE EAST OF THE SUSQ VALLEY OVER THE NEXT FEW
HOURS.
FOR THE REST OF THE EARLY TO MID MORNING HOURS...A LARGE AREA OF
STRATO CU CLOUDS /OCCUPYING A FEW LAYERS/ WILL BLANKET THE REGION
WITH A BIT OF DRIZZLE POSSIBLE ACROSS RIDGES...AND PERHAPS JUST
ANOTHER BRIEF SHOWER OVER THE CENTRAL AND NRN MTNS.
LATEST RAP AND HRRRX APPEAR TO BE ON THE VERY OPTIMISTIC SIDE
CLEARING OUT THIS CLOUD AREA/ADVECTING IT EAST OF THE REGION IN
THE 10-12Z TIMEFRAME...WHILE THE NAM FCST SOUNDINGS HOLD ONTO
AREAS OF LOW CIGS FOR THE REST OF THE MORNING AS WINDS LIGHTEN UP
IN THE LOWEST KFT AGL.
A FEW LOCATIONS WILL SEE VSBYS DIP TO UNDER 1SM EARLY TODAY /SUCH
AS KFIG/...BUT VSBYS IN THE 2-4SM RANGE SHOULD PREVAIL IN MOST
PLACES.
TEMPS WILL BE NEARLY STEADY IN THE UPPER 30S THROUGHOUT THE
CENTRAL VALLEY AND NRN MTNS...WHILE MILDER READINGS IN THE LOWER
TO MID 40S WILL BE FOUND ACROSS THE LOWER SUSQ VALLEY...AND
LAUREL HIGHLANDS.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM FRIDAY/...
A WEAK FRONT WILL SHEAR OUT TO OUR NE TODAY...WITH HIGH PRESSURE
ESTABLISHING ITSELF OFF TO OUR SOUTHWEST. THE NET EFFECT WILL BE
FOR A SOUTHWEST FLOW TO SET UP WHICH SHOULD HELP SCOUR OUT THE
PERSISTENT LOW CLOUDS /AND SOME AREAS OF GENERALLY LIGHT FOG/
DURING THE LATE MORNING HOURS.
WITH A GRADUAL INCREASE IN SUNSHINE...AND A MILDER /ALBEIT LIGHT/
SOUTHWEST FLOW EXPECTED TO DEVELOP...HIGHS THIS AFTERNOON WILL
AVERAGE IN THE LOW TO MID 50S...STILL SOME 10-15 DEG WARMER THAN
NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
ABOVE NORMAL TO NEAR-RECORD WARMTH WILL BE THE MAIN STORY THIS
PERIOD...WITH DAYTIME HIGHS FCST +20 TO +30 DEGREES ABOVE CLIMO
BY LATE IN THE WEEKEND. POSSIBLE LOW CLOUDS AND FOG MAY COMPLICATE
THINGS AT FIRST AND WILL ASSESS THIS RISK IN THE SHORT RANGE.
THE GREATEST RISK FOR RAIN WILL LIKELY BE ON MONDAY WITH ABOVE
AVERAGE CONFIDENCE IN THE PCPN PATTERN THIS FAR OUT GIVEN VERY
GOOD MODEL AND ENSEMBLE AGREEMENT. TEMPERATURES ARE FCST TO STAY
RELATIVELY MILD FOR DECEMBER THROUGH MUCH OF NEXT WEEK WITH A COOL
DOWN TO "NEAR NORMAL" POSSIBLE AROUND THE 18-19TH.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
SHOWERS CONTINUE TO MOVE EASTWARD AS THE COLD FRONT SUPPORTED BY
MODEST LOOKING UPPER CONTINUES TO CROSS THE AIRSPACE OVERNIGHT.
HOWEVER THE SFC HAS DECOUPLED ONCE AGAIN ALLOWING FOR CALMING
WINDS...REDUCED CIGS AND LOW STRATOCU. EXPECT THESE TO ALLOW FOR
RESTRICTIONS OVERNIGHT AT ALL TAF SITES. EXPECT PERIODS OF IFR AT
ALL TAF SITES THROUGH 12Z...THOUGH WITH THE SOUTH WESTERN TAF
SITES IT WILL BE INTERMITTENT. AS THE FRONT PASSES THURSDAY IT SHOULD
FINALLY HELP SCOUR OUT STABLE AMS/LOW LEVEL CLOUDS AND FOG THAT
HAS BEEN IN PLACE OVER PARTS OF CENTRAL PA FOR THE LAST FEW DAYS.
THE WIDESPREAD IFR/MVFR CEILINGS AND PATCHY FOG OVER EASTERN
AREAS WILL CONTINUE THROUGH THE MORNING BUT CONDITIONS TO IMPROVE
TO VFR BY LATE MORNING TO EARLY AFTERNOON AS THE WEST- SOUTHWEST
FLOW BEGINS TO DOMINATE THE REGION.
OUTLOOK...
FRI...AREAS OF MORNING FOG. THEN MAINLY VFR.
SAT...MVFR WITH CHC SHRA NW HALF. MAINLY VFR SE.
SUN...MAINLY VFR.
MON...FROPA WITH WIDESPREAD SHOWERS AND MVFR/IFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT/MARTIN
SHORT TERM...LA CORTE/MARTIN
LONG TERM...STEINBUGL
AVIATION...LA CORTE/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
303 AM EST THU DEC 10 2015
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL MOVE EAST OF THE SUSQUEHANNA
VALLEY EARLY TODAY. ANOTHER...SIMILARLY WEAK FRONT WILL CROSS THE
REGION FRIDAY...FOLLOWED BY AN ANOMALOUSLY STRONG UPPER RIDGE THAT
WILL BRING MUCH WARMER THAN NORMAL CONDITIONS FOR THE UPCOMING
WEEKEND. MORE WIDESPREAD SHOWERS WILL BE LIKELY ALONG AND AHEAD OF
A STRONGER COLD FRONT THAT WILL CROSS THE REGION ON MONDAY.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
A FEW AREAS OF SHOWERS /ALONG AND AHEAD OF A WEAK SFC/UPPER LEVEL
TROUGH/ WILL EXIT TO THE EAST OF THE SUSQ VALLEY OVER THE NEXT FEW
HOURS.
FOR THE REST OF THE EARLY TO MID MORNING HOURS...A LARGE AREA OF
STRATO CU CLOUDS /OCCUPYING A FEW LAYERS/ WILL BLANKET THE REGION
WITH A BIT OF DRIZZLE POSSIBLE ACROSS RIDGES...AND PERHAPS JUST
ANOTHER BRIEF SHOWER OVER THE CENTRAL AND NRN MTNS.
LATEST RAP AND HRRRX APPEAR TO BE ON THE VERY OPTIMISTIC SIDE
CLEARING OUT THIS CLOUD AREA/ADVECTING IT EAST OF THE REGION IN
THE 10-12Z TIMEFRAME...WHILE THE NAM FCST SOUNDINGS HOLD ONTO
AREAS OF LOW CIGS FOR THE REST OF THE MORNING AS WINDS LIGHTEN UP
IN THE LOWEST KFT AGL.
A FEW LOCATIONS WILL SEE VSBYS DIP TO UNDER 1SM EARLY TODAY /SUCH
AS KFIG/...BUT VSBYS IN THE 2-4SM RANGE SHOULD PREVAIL IN MOST
PLACES.
TEMPS WILL BE NEARLY STEADY IN THE UPPER 30S THROUGHOUT THE
CENTRAL VALLEY AND NRN MTNS...WHILE MILDER READINGS IN THE LOWER
TO MID 40S WILL BE FOUND ACROSS THE LOWER SUSQ VALLEY...AND
LAUREL HIGHLANDS.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM FRIDAY/...
A WEAK FRONT WILL SHEAR OUT TO OUR NE TODAY...WITH HIGH PRESSURE
ESTABLISHING ITSELF OFF TO OUR SOUTHWEST. THE NET EFFECT WILL BE
FOR A SOUTHWEST FLOW TO SET UP WHICH SHOULD HELP SCOUR OUT THE
PERSISTENT LOW CLOUDS /AND SOME AREAS OF GENERALLY LIGHT FOG/
DURING THE LATE MORNING HOURS.
WITH A GRADUAL INCREASE IN SUNSHINE...AND A MILDER /ALBEIT LIGHT/
SOUTHWEST FLOW EXPECTED TO DEVELOP...HIGHS THIS AFTERNOON WILL
AVERAGE IN THE LOW TO MID 50S...STILL SOME 10-15 DEG WARMER THAN
NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
ABOVE NORMAL TO NEAR-RECORD WARMTH WILL BE THE MAIN STORY THIS
PERIOD...WITH DAYTIME HIGHS FCST +20 TO +30 DEGREES ABOVE CLIMO
BY LATE IN THE WEEKEND. POSSIBLE LOW CLOUDS AND FOG MAY COMPLICATE
THINGS AT FIRST AND WILL ASSESS THIS RISK IN THE SHORT RANGE.
THE GREATEST RISK FOR RAIN WILL LIKELY BE ON MONDAY WITH ABOVE
AVERAGE CONFIDENCE IN THE PCPN PATTERN THIS FAR OUT GIVEN VERY
GOOD MODEL AND ENSEMBLE AGREEMENT. TEMPERATURES ARE FCST TO STAY
RELATIVELY MILD FOR DECEMBER THROUGH MUCH OF NEXT WEEK WITH A COOL
DOWN TO "NEAR NORMAL" POSSIBLE AROUND THE 18-19TH.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
COLD FRONT SUPPORTED BY MODEST LOOKING UPPER TROF WILL CROSS THE
AIRSPACE OVERNIGHT. AREA OF LIGHT RAIN SHOWERS AHEAD OF THE FRONT
NOW CROSSING WEST TO EAST ACROSS CENTRAL PA. PASSAGE OF THE FRONT
SHOULD FINALLY HELP SCOUR OUT STABLE AMS/LOW LEVEL CLOUDS AND FOG
THAT HAS BEEN IN PLACE OVER PARTS OF CENTRAL PA FOR THE LAST FEW
DAYS. OVERNIGHT AND THE DAY THURSDAY SHOULD START WITH FAIRLY
WIDESPREAD IFR/MVFR CEILINGS AND EVEN SOME FOG OVER EASTERN
AREAS...BUT CONDITIONS WILL IMPROVE TO VFR BY LATE MORNING OR
EARLY AFTERNOON AS THE WEST-SOUTHWEST FLOW DOMINATES THE REGION.
OUTLOOK...
FRI...AREAS OF MORNING FOG. THEN MAINLY VFR.
SAT...MVFR WITH CHC SHRA NW HALF. MAINLY VFR SE.
SUN...MAINLY VFR.
MON...FROPA WITH WIDESPREAD SHOWERS AND MVFR/IFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...STEINBUGL
AVIATION...LA CORTE/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1109 PM EST WED DEC 9 2015
.SYNOPSIS...
A WEAKENING COLD FRONT WILL TRACK THROUGH THE REGION LATER
TONIGHT AND EARLY THURSDAY...FOLLOWED AN ANOMALOUSLY STRONG UPPER
RIDGE THAT WILL BRING WARMER THAN NORMAL CONDITIONS FROM THE END
OF THE WEEK INTO NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
ABOUT 20 KNOTS OF WIND...SEE VAD WINDS AT 3000 FEET...HAVE
ALLOWED MIXING OF THE DENSE FOG...AND HELP KEEP TEMPS
ABOVE FREEZING THIS EVENING.
ADJUSTED MIN TEMPS SOME TONIGHT.
A FEW SHOWERS TO THE WEST. FREEZING LEVEL ABOUT 6000 FT.
EARLIER DISCUSSION BELOW...LATE AFT.
NE WIND HAS RESULTED IN MORE DENSE FOG AT AOO. MOST AREAS
SE TO NW WINDS NOW.
OTHER SITES NOT BAD...WILL CONTINUE TO MONITOR THE NEED FOR
A DENSE FOG OR FREEZING FOG ADVISORY.
STILL A STRONG INVERSION IN PLACE...BUT BINOVC ALLOWED
TEMPERATURES TO CLIMB ABOVE HIGHS YESTERDAY BY ABOUT
5 TO 10 DEGREES.
ALSO WINDS PICKING UP FROM THE SOUTH...VAD WINDS ABOUT 20 KNOTS
AT 3000 FEET.
LINE OF VERY LIGHT SHOWERS TO THE WEST. WILL HAVE TO MONITOR
THE TEMPERATURES. STILL 32 DEGREES AT THE RDA.
EARLIER DISCUSSION BELOW...EARLY AFT.
SATELLITE SHOWS THE LOW CLOUDS MELTING AWAY VERY...VERY SLOWLY AT
THE EDGES. OTHERWISE BANDS OF FRONTAL CLOUDS ASSOCIATED WITH A
WEAKENING COLD FRONT ARE ENTERING EASTERN OHIO AND WILL OVERSPREAD
THE REGION TONIGHT.
HAVE BEEN USING THE HRRR TRYING TO GET A HANDLE ON THE VERY NEAR
TERM CLOUDS AND TEMPERATURE TRENDS. IT HAS BEEN TOO FAST ERODING
THE LOW CLOUDS BUT 2M TEMPS AND PBL PROGS SUGGEST KEEPING THE
IMPROVEMENT SLOW FOR CENTRAL AREAS.
NEAR TERM MODELS ARE IN GOOD AGREEMENT IN SHEARING THE PARENT
UPPER TROUGH OUT AND TRACKING IT NORTH OF THE REGION. RAIN SHOWERS
WILL APPROACH MY FAR NWRN ZONES BY NIGHTFALL BEFORE TRACKING
ACROSS THE FCST AREA OVERNIGHT AND WEAKENING. THE BEST CHANCE FOR
RAIN WILL BE OVER THE NORTHWEST AND DURING THE HOURS BEFORE
MIDNIGHT...WITH POPS DWINDLING OVER CENTRAL AND EASTERN AREAS FOR
THE SECOND HALF OF THE OVERNIGHT.
OVERNIGHT LOWS IN THE MID TO UPPER 30S WILL ACTUALLY AVERAGE SOME
10-15 DEG WARMER THAN NORMAL IN MOST SPOTS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
DID EDGE MAX TEMPS UP SOME FOR THU.
EARLIER DISCUSSION BELOW.
ANOTHER WEAKENING FRONT IS EXPECTED TO SHEAR OUT TO
OUR NW...WITH HIGH PRESSURE ESTABLISHING ITSELF OFF TO OUR
SOUTHWEST. THE NET EFFECT WILL BE FOR A SOUTHWEST FLOW TO SET UP
WHICH SHOULD HELP SCOUR OUT THE PERSISTENT LOW CLOUDS AND FOG THAT
HAVE PLAGUED THE REGION FOR THE LAST SEVERAL DAYS.
WITH AN INCREASE IN SUNSHINE AND A MILDER SOUTHWEST FLOW EXPECTED
TO DEVELOP...HIGHS TUESDAY WILL AVERAGE IN THE LOW TO MID
50S...STILL SOME 10-15 DEG WARMER THAN NORMAL.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
ABOVE NORMAL TO NEAR-RECORD WARMTH WILL BE THE MAIN STORY THIS
PERIOD...WITH DAYTIME HIGHS FCST +20 TO +30 DEGREES ABOVE CLIMO
BY LATE IN THE WEEKEND. POSSIBLE LOW CLOUDS AND FOG MAY COMPLICATE
THINGS AT FIRST AND WILL ASSESS THIS RISK IN THE SHORT RANGE.
THE GREATEST RISK FOR RAIN WILL LIKELY BE ON MONDAY WITH ABOVE
AVERAGE CONFIDENCE IN THE PCPN PATTERN THIS FAR OUT GIVEN VERY
GOOD MODEL AND ENSEMBLE AGREEMENT. TEMPERATURES ARE FCST TO STAY
RELATIVELY MILD FOR DECEMBER THROUGH MUCH OF NEXT WEEK WITH A COOL
DOWN TO "NEAR NORMAL" POSSIBLE AROUND THE 18-19TH.
&&
.AVIATION /04Z THURSDAY THROUGH MONDAY/...
COLD FRONT SUPPORTED BY MODEST LOOKING UPPER TROF WILL CROSS THE
AIRSPACE OVERNIGHT. AREA OF LIGHT RAIN SHOWERS AHEAD OF THE FRONT
NOW CROSSING WEST TO EAST ACROSS CENTRAL PA. PASSAGE OF THE FRONT
SHOULD FINALLY HELP SCOUR OUT STABLE AMS/LOW LEVEL CLOUDS AND FOG
THAT HAS BEEN IN PLACE OVER PARTS OF CENTRAL PA FOR THE LAST FEW
DAYS. OVERNIGHT AND THE DAY THURSDAY SHOULD START WITH FAIRLY
WIDESPREAD IFR/MVFR CEILINGS AND EVEN SOME FOG OVER EASTERN
AREAS...BUT CONDITIONS WILL IMPROVE TO VFR BY LATE MORNING OR
EARLY AFTERNOON AS THE WEST-SOUTHWEST FLOW DOMINATES THE REGION.
OUTLOOK...
FRI...AREAS OF MORNING FOG. THEN MAINLY VFR.
SAT...MVFR WITH CHC SHRA NW HALF. MAINLY VFR SE.
SUN...MAINLY VFR.
MON...FROPA WITH WIDESPREAD SHOWERS AND MVFR/IFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE/MARTIN
SHORT TERM...LA CORTE/MARTIN
LONG TERM...STEINBUGL
AVIATION...LA CORTE/GARTNER
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1149 PM CST WED DEC 9 2015
.UPDATE...
ISSUED AT 1147 PM CST WED DEC 9 2015
06Z AVIATION DISCUSSION UPDATED BELOW.
UPDATE ISSUED AT 945 PM CST WED DEC 9 2015
SHORT WAVE TROUGH ALONG WITH A SURFACE FRONT/TROUGH WILL BRING
WINDS AROUND TO THE WEST AND INCREASING WITH SCATTERED LIGHT RAIN
SHOWERS DEVELOPING ACROSS THE NORTH TONIGHT. RADAR SHOWING AN
INCREASE IN ECHOES IN NW SD LATE THIS EVENING. ADJUSTED POPS
THROUGH THE NIGHT.
UPDATE ISSUED AT 531 PM CST WED DEC 9 2015
00Z AVIATION DISCUSSION UPDATED BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 243 PM CST WED DEC 9 2015
A FAIRLY ACTIVE PATTERN WITH 2 WEAK SYSTEMS DURING THE SHORT TERM.
HRRR AND RUC BOTH BRING LIGHT PRECIPITATION INTO THE WESTERN CWA
THIS EVENING...WITH PROFILES SUPPORTING A BRIEF PERIOD OF LIGHT RAIN
AHEAD OF THIS WAVE ONCE SATURATION IS ACHIEVED...THUS NOT EXPECTING
MUCH MORE THAN A HUNDREDTH OR TWO. SURFACE TEMPERATURES WILL LIKELY
REMAIN ABOVE FREEZING WITH 925MB TEMPERATURES AROUND +6C AND A
PREDOMINANT WEST WIND. THIS WIND WILL ALSO INCREASE TOWARDS MORNING
WITH 1/2KM WINDS UPWARDS OF 50KTS...HOWEVER BECAUSE OF THE DEGREE OF
COLD ADVECTION...LOW VALUES FOR PRESSURE RISES...AND A 10 TO 12MB
PRESSURE GRADIENT ACROSS THE STATE...ANTICIPATE IT WILL BE DIFFICULT
TO FULLY REALIZE THESE STRONGER WINDS. WILL LEAVE CURRENT HEADLINE
IN PLACE WITH THE REST OF THE CWA POSSIBLY SEEING A FEW GUSTS NEAR
ADVISORY CRITERIA DURING PEAK HEATING.
THE SECOND WEAK WAVE MOVES IN FOR EARLY FRIDAY. WARM ADVECTION WILL
GENERATE ENOUGH LIFT FOR LIGHT PRECIPITATION ALONG AND JUST NORTH OF
THE NORTH DAKOTA/SOUTH DAKOTA STATE LINE DURING THE MORNING
HOURS...BUT AS THE WAVE CONTINUES TO SHEAR APART...PRECIPITATION
INTENSITY WILL LIKELY DROP THROUGH THE MID DAY HOURS. PROFILES ARE
MAINLY SUPPORTIVE OF SNOW...WITH GUIDANCE ESTIMATING AROUND AN INCH
OR TWO JUST NORTH OF THE CWA.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 243 PM CST WED DEC 9 2015
PRECIPITATION CHANCES THIS WEEKEND...AND AGAIN TUESDAY THROUGH
WEDNESDAY WILL BE THE FORECAST CHALLENGES.
THE PERIOD BEGINS WITH AN UPPER LEVEL TROUGH OF LOW PRESSURE
CROSSING THE CENTRAL CONUS. WHILE ALL MODELS SHOW THIS TROUGH...THEY
DIFFER ON THE PLACEMENT OF THE PCPN. THE MODEL RUNS FROM LAST
NIGHT...WHICH SHOWED DRY CONDITIONS PER THE ECMWF/GEM...HAVE FLIPPED
WITH THE 12Z RUN. THE GFS NOW KEEPS THE CWA DRY...WHILE THE
ECMWF/GEM BRINGS LIGHT SNOW TO THE EASTERN HALF OF THE CWA SATURDAY
THROUGH SUNDAY MORNING. PREFERRED A DRY SOLUTION FOR THE WEEKEND
BASED ON THE NAEFS...WHICH SHOWS A MORE SOUTHEASTERLY SOLUTION.
AFTER A MOSTLY DRY SUNDAY AND MONDAY...MODELS AGREE FAIRLY WELL WITH
A STORM SYSTEM IMPACTING THE REGION TUESDAY THROUGH WEDNESDAY. THIS
STORM COULD BRING WIDESPREAD ACCUMULATING SNOWFALL TO THE REGION. OF
COURSE IT IS FAR TOO SOON TO TALK SNOWFALL AMOUNTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1147 PM CST WED DEC 9 2015
AN UPPER LEVEL LOW PRESSURE TROUGH AND SURFACE FRONT WILL BRING MID
LEVEL CLOUDS...SOME LIGHT RAIN ALONG WITH INCREASING WEST WINDS
THROUGH THE NIGHT INTO THURSDAY AFTERNOON. WEST WINDS WILL BECOME
STRONG AT 20 TO 25 KNOTS WITH GUSTS TO 30 TO 35 KNOTS INTO THURSDAY
AT ALL LOCATIONS...FALLING OFF BY EVENING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM 5 AM TO 2 PM MST THURSDAY FOR SDZ003-015.
MN...NONE.
&&
$$
UPDATE...MOHR
SHORT TERM...CONNELLY
LONG TERM...SD
AVIATION...MOHR
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
246 PM EST THU DEC 10 2015
.SHORT TERM (TONIGHT THROUGH TOMORROW)...
CURRENT WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS INDICATES A
WEAK UPPER LEVEL TROUGH MOVING THROUGH THE OHIO RIVER VALLEY. AT
THE SURFACE...HIGH PRESSURE IS LOCATED TO THE SOUTH ACROSS THE
NORTHERN GULF OF MEXICO. FURTHER TO THE NORTHEAST...A COLD FRONT
CURRENTLY STRETCHES ACROSS THE UPPER MISSISSIPPI RIVER VALLEY
SOUTHWARD INTO THE SOUTHERN PLAINS. ISENTROPIC UPGLIDE WITH
CONTINUED SOUTHERLY TO SOUTHWESTERLY FLOW IN THE LOW LEVELS HAS
KEPT CLOUD COVER ACROSS THE AREA THROUGHOUT MUCH OF DAY.
REGARDLESS...TEMPERATURES HAVE WARMED INTO THE UPPER 50S AND LOW
60S ACROSS THE AREA THIS AFTERNOON. FOR TONIGHT...MODELS INDICATE
THAT THE LOW LEVEL ISENTROPIC ASCENT INCREASES WITH SURFACE
DEWPOINTS IN THE UPPER 40S TO LOW 50S. OVERALL..THE SETUP DOES NOT
LOOK MUCH DIFFERENT FROM LAST NIGHT AND HAVE GONE WITH FOG IN THE
FORECAST. THE LOW LEVEL LIFT SHOULD BE SUFFICIENT ENOUGH FOR SOME
AREAS OF PATCHY DRIZZLE AS WELL. INCLUDED A SLIGHT CHANCE OF RAIN
ACROSS THE SOUTHWESTERN COUNTIES WHERE THE LIFT WILL BE THE
STRONGEST LATE TONIGHT INTO TOMORROW BUT OVERALL EXPECT MOSTLY
DRIZZLE/FOG. WILL HOLD OFF ON ISSUING A DENSE FOG ADVISORY FOR
NOW...BUT ONE MAY BECOME NECESSARY AS THE FORECAST BECOMES A BIT
CLEARER.
THE COLD FRONT CURRENTLY TO THE NORTHWEST TRIES TO MOVE SOUTHEAST
TOMORROW BUT STALLS ACROSS THE OHIO RIVER VALLEY AS THE UPPER
LEVEL SUPPORT EXITS TO THE NORTHEAST. UPPER LEVEL HEIGHTS WILL
REMAIN HIGH WITH CONTINUED WARM AIR ADVECTION IN THE LOW LEVELS.
TEMPERATURES HAVE BEEN A COUPLE OF DEGREES WARMER THAN THE OVERALL
GUIDANCE THE LAST COUPLE OF DAYS. THEREFORE...WENT ON THE HIGHER
SIDE OF FORECAST GUIDANCE FOR HIGHS TOMORROW. IF THE FOG CLEARS OUT
BY MID-MORNING...EXPECT MOST LOCATIONS WILL MAKE IT INTO THE UPPER
60S TO LOW 70S.
.LONG TERM (FRIDAY NIGHT THROUGH THURSDAY)...
AN ABNORMALLY WARM PATTERN WILL CONTINUE THROUGH THE WEEKEND AS A
LARGE HIGH PRESSURE RIDGE WILL BE LOCATED OFF THE SOUTHEAST COAST
AND A DEEP TROUGH OVER THE DESERT SOUTHWEST TRANSITIONS TO A CLOSED
LOW OVER THE PLAINS. IN SITU LOW LEVEL MOISTURE WILL LIKELY RESULT
IN LOW CLOUDS/FOG DEVELOPING LATE FRIDAY NIGHT BEFORE DISSIPATING
WITH MIXING LATE SATURDAY MORNING. HIGH TEMPERATURES WILL REACH INTO
THE LOWER 70S IN MOST VALLEY SPOTS ON SATURDAY...AND POSSIBLY SUNDAY
AS WELL. INCREASING MID TO HIGH LEVEL CLOUD COVER MAY KEEP SUNDAY`S
TEMPS A LITTLE BELOW SATURDAY.
THE DEEPENING SURFACE LOW OVER THE PLAINS WILL BRING THE SOUTHERLY
LLJ UP TO 40-55 KTS SUNDAY AFTERNOON AND EVENING ACROSS THE
APPALACHIANS. WITH A STABLE LAYER SHOWN IN THE 850-700 MB LAYER IN
FORECAST SOUNDINGS...A MOUNTAIN WAVE EVENT MAY BE POSSIBLE. THE
CURRENT HWO ADDRESSES THE POSSIBILITY OF HIGH WINDS...AND A HIGH
WIND WATCH COULD BE NEEDED AS WE GET CLOSER TO THE EVENT IF THE
CURRENT MODEL TRENDS HOLD. MODEL TIMING OF THE ONSET OF PRECIP
SUNDAY NIGHT IS IN REASONABLY GOOD AGREEMENT...REACHING OUR WESTERN
AREAS AROUND MIDNIGHT. SYNOPTIC FORCING AND SHEAR WILL BE
STRONG...BUT AS IS TYPICAL THIS TIME OF YEAR...INSTABILITY WILL BE
WEAK. LINEAR CONVECTION WITH EMBEDDED CELLS THAT CAN TRANSPORT HIGH
WINDS ALOFT TO THE SURFACE MAY POSE A SEVERE WEATHER THREAT...BUT
WITH SUCH LITTLE INSTABILITY...WILL MENTION JUST A SLIGHT CHANCE OF
THUNDERSTORMS IN SOUTHERN SECTIONS. SURFACE COLD FRONTAL PASSAGE AND
MIDLEVEL TROUGH PASSAGE ON MONDAY MORNING WILL BRING A QUICK END TO
PRECIP CHANCES...WITH NO MORE THAN A CHANCE POP EAST NECESSARY BY
MONDAY AFTERNOON.
WE REMAIN IN A RELATIVELY MILD PATTERN FOR THE REST OF THE PERIOD AS
THE JET STREAM STAYS WELL TO THE NORTH AND THE GENERAL FLOW IN THE
LOW TO MIDLEVELS RETURNS TO SW BEHIND THE DEPARTING SYSTEM. HIGHS IN
THE 50S TO LOWER 60S ARE EXPECTED THROUGH WEDNESDAY...WITH MOSTLY
CLEAR TO PARTLY CLOUDY SKIES. WITH MOISTURE INCREASING AND A BROAD
TROUGH DEVELOPING OVER THE PLAINS IN THE GFS AND THE ECMWF...WILL
START OFF THURSDAY WITH CHANCE POPS.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 52 69 55 72 / 10 20 10 10
KNOXVILLE MCGHEE TYSON AIRPORT, TN 51 69 54 71 / 10 10 10 10
OAK RIDGE, TN 51 67 53 70 / 10 10 10 10
TRI CITIES AIRPORT, TN 43 67 45 69 / 10 10 10 10
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
MA/DGS
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1138 PM CST WED DEC 9 2015
.UPDATE...
ISSUED A DENSE FOG ADVISORY FOR THE SOUTHWEST ZONES. KLBX...KBY
AND KPSX ARE ALL AT 1/4 MILE. 43
&&
.PREV DISCUSSION... /ISSUED 1132 PM CST WED DEC 9 2015/
AVIATION...
PATCHY AREAS OF FOG AND DENSE FOG HAVE DEVELOPED OVER PORTIONS OF
SE TEXAS AT 05Z...INCLUDING VLIFR CONDITIONS ALREADY AT KLBX.
MODEL SOUNDINGS AND SREF PROBABILITIES SHOW A HIGH PROBABILITY
OF IFR AND LIFR CONDITIONS DEVELOPING BETWEEN 06Z AND 11Z. HAVE
SOME RESERVATIONS AS TO THE TYPE /FOG OR LOW CEILINGS/ AS WINDS
JUST OFF THE SURFACE WERE BETWEEN 15 AND 20 KNOTS FROM 500 TO 1000
FEET AS SEEN BY THE HGX VAD WINDS. AT LEAST LOW CEILINGS SHOULD
DEVELOP...BUT GIVEN THE FOG ALREADY IN PLACE AT LBX DECIDED TO
INSERT A TEMPO GROUP REFLECTING THE GUIDANCE TIMES FOR THE WORST
FOG VISIBILITY RESTRICTIONS.
MODEL SOUNDINGS THEN SHOW A SLOW IMPROVEMENT DURING THE MID AND
LATE MORNING WITH VFR CONDITIONS POSSIBLE THROUGHOUT THE
AFTERNOON. HOWEVER...THERE ARE SOME INDICATIONS THAT MVFR
CONDITIONS MAY PERSIST THROUGH THE AFTERNOON AND THAT AT LEAST IFR
CONDITIONS WILL DEVELOP SHORTLY AFTER SUNSET THURSDAY EVENING.
40
PREV DISCUSSION... /ISSUED 902 PM CST WED DEC 9 2015/
DISCUSSION...
SREF ENSEMBLE GUIDANCE AND HRRR SUGGEST FOG WILL DEVELOP A BIT
LATER TONIGHT BUT KBYY AND KLBX ARE ALREADY DOWN TO A 1/4 MILE.
00Z SOUNDINGS FROM CRP AND LCH LOOK A LITTLE LESS FAVORABLE FOR
FOG DEVELOPMENT AS THE TEMP INVERSION AT 900 MB LOOKS A BIT WEAKER
AND THERE COULD BE A LITTLE MORE VERTICAL MIXING. SATELLITE
IMAGERY ALSO SHOWING A SWATH OF CLOUDINESS MOVING ACROSS WHICH
WILL AT LEAST BRIEFLY IMPEDE RADIATIONAL COOLING. WILL CONTINUE TO
WATCH TRENDS AND FEEL A DENSE FOG ADVISORY WILL PROBABLY BE NEEDED
FROM ABOUT 11 PM TO 9 AM THURSDAY MORNING. WILL WAIT FOR A FEW
MORE SITES TO REPORT LOWER VISIBILITY AND ISSUE THE NPW A BIT
LATER THIS EVENING.
LOOKING AHEAD TO THE WEEKEND...A VERY STRONG STORM SYSTEM
APPROACHES THE REGION SAT NIGHT. JET DYNAMICS LOOK STRONG WITH A
LOW LEVEL JET OF 50-60 KNOTS AND SE TX WILL ALSO LIE IN A
DEPARTING 140 KNOT RRQ. SOME OF THE STORMS WILL BECOME STRONG
WITH DAMAGING WINDS. HELICITY VALUES WILL EXCEED 200 M/S SO THERE
COULD ALSO BE A THREAT FOR ISOLATED TORNADOES.
LASTLY...WOULD LIKE TO THANK THE CORPUS CHRISTI OFFICE FOR
PROVIDING BACK UP SERVICE FOR US TODAY. THEY WERE AWESOME. 43
CLIMATE...
ALTHO THE CALENDAR SAYS IT IS DECEMBER...IT HARDLY FEELS DECEMBER
LIKE. HIGH TEMPS ON FRIDAY WILL WARM INTO THE LOWER 80S AND WILL
APPROACH RECORD VALUES AT HOUSTON BUSH AND HOUSTON HOBBY. BELOW
ARE THE RECORDS FOR ALL 4 CLIMATE SITES FOR FRIDAY DEC 11TH.
SITE FCST HIGH REC HIGH NORM HIGH
BUSH IAH 82 83 2007 65
HOU HOBBY 82 82 2007 65
COL STATION 80 82 2007 63
GALVESTON 75 78 2007 64
BACK ON DEC 10TH 2008...AN UPPER LEVEL DISTURBANCE BROUGHT A BAND
OF SNOW TO SE TX WITH 2-5 INCHES OF SNOW GENERALLY EAST OF I-45.
BAYTOWN...LA PORTE AND LIBERTY ALL RECORDED 4 INCHES OF SNOW. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 51 79 63 80 67 / 10 10 10 10 20
HOUSTON (IAH) 55 80 65 82 67 / 10 10 10 10 20
GALVESTON (GLS) 61 73 66 75 68 / 10 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 9 AM CST THURSDAY FOR THE FOLLOWING
ZONES: BRAZORIA...JACKSON...MATAGORDA...WHARTON.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
1042 PM MST FRI DEC 11 2015
.UPDATE...UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
A STRONG PACIFIC LOW PRESSURE SYSTEM AND COLD FRONT WILL MOVE
THROUGH THE REGION TONIGHT AND SATURDAY...GENERATING COOLER AND
WINDY CONDITIONS. A CHANCE OF SHOWERS ARE ALSO FORECAST MAINLY OVER
PORTIONS OF SOUTH CENTRAL ARIZONA FROM THIS EVENING THROUGH AT LEAST
MIDDAY ON SATURDAY...WITH ACCUMULATING SNOW POSSIBLE ABOVE 5000 FEET
OVER THE HIGHER TERRAIN EAST OF PHOENIX. CLEAR AND COLDER WEATHER IS
THEN EXPECTED SUNDAY...WITH ANOTHER COLD FRONT FORECAST TO MOVE INTO
THE REGION ON MONDAY. A MUCH COLDER AIRMASS IS FORECAST TO SETTLE
OVER THE REGION FROM TUESDAY INTO THURSDAY...POSSIBLY GENERATING
SOME OF THE COLDEST LOW TEMPERATURES SO FAR THIS SEASON.
&&
.DISCUSSION...
LATEST MESOANALYSIS SHOWS THE MID-TROPOSPHERIC TROUGH AXIS ACROSS THE
IMPERIAL VALLEY BUT PROGRESSING STEADILY EASTWARD. TWELVE-HOUR HEIGHT
FALLS OF NEARLY 180 M HAVE BEEN OBSERVED ACROSS THE NORTHERN BAJA
PENINSULA. THE BREEZY CONDITIONS WERE SLOW TO MATERIALIZE BEHIND THE
COLD FRONT THAT MOVED THROUGH CENTRAL AZ THIS AFTERNOON...THOUGH
WINDS HAVE PICKED UP OVER THE PAST FEW HOURS. MEANWHILE...AREAS OF
LIGHT PRECIPITATION ARE FILLING IN ACROSS CENTRAL AZ IN RESPONSE TO
STRONG FORCING FOR ASCENT ASSOCIATED WITH WELL-DEFINED PVA ACROSS THE
LOWER CO RIVER VALLEY.
HI-RES GUIDANCE INCLUDING LATEST RUNS OF THE HRRR CONTINUE TO
INDICATE THAT THE BEST CHANCE OF PRECIPITATION WILL BE ACROSS
NORTHERN MARICOPA COUNTY AND EAST OF PHOENIX IN THE HIGHER TERRAIN OF
GILA COUNTY THROUGH SATURDAY MORNING. QPF WAS INCREASED THIS EVENING
FOR THE 06-12Z PERIOD ACROSS THE HIGHER ELEVATIONS BASED ON THE
LATEST MODEL CONSENSUS. A FEW INCHES OF SNOW ARE LIKELY ABOVE 5K FT
AND A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR THESE AREAS.
LATEST SPC GUIDANCE ALSO SUGGESTS THAT AN ISOLATED LIGHTNING STRIKE
IS POSSIBLE IN THE STRONGEST CELLS.
.PREVIOUS DISCUSSION...
TONIGHT THROUGH SUNDAY...
A STRONG...AND COLD PACIFIC TROF CONTINUES TO APPROACH ARIZONA AT
THIS HOUR...WITH RAINFALL NOW BEING REPORTED ACROSS THE SOUTHERN CA
COASTAL REGIONS...AND ACROSS SOUTHERN NV AND EXTREME NW AZ. AHEAD OF
THE MAIN TROF AXIS...THE SFC COLD FRONT IS NOW MOVING INTO WESTERN
AZ...WITH LOCALLY GUSTY WINDS OCCURRING AT SOME LOCATIONS DURING THE
FRONTAL PASSAGE. ALTHOUGH THIS SYSTEM DOES NOT CONTAIN TOO MUCH
MOISTURE (PWATS MAINLY AOB 0.60 INCH)...THE COMBINATION OF STRONG
DYNAMICS/MAJOR HEIGHT FALLS (24HR 500MB HEIGHT FALLS IN THE 200-250M
RANGE ACROSS SOUTH-CENTRAL AZ) AND STRONG COOLING THROUGH THE COLUMN
IS EXPECTED TO ALLOW THE SYSTEM TO MAXIMIZE THE USE OF ITS AVAILABLE
MOISTURE. IT APPEARS THE BEST CHANCE FOR MEASURABLE PRECIP WILL BE
FROM THIS EVENING THROUGH ABOUT MIDDAY ON SATURDAY...WITH THE NCEP
SREF PLUME MEAN SHOWING TOTAL QPF AMOUNTS RANGING FROM AROUND 0.10
OF AN INCH OVER THE LOWER DESERTS OF SOUTH-CENTRAL AZ UP TO AS MUCH
AS 0.50 OF AN INCH OVER THE HIGHER TERRAIN EAST OF PHOENIX.
ALONG WITH THE RAINFALL...MUCH COLDER AIR MOVING INTO THE REGION IS
EXPECTED TO DROP SNOW LEVELS AOB 5000 FEET BY EARLY SAT
MORNING...WHICH WILL BE EARLY ENOUGH TO ALLOW THE RAIN TO CHANGE TO
SNOW BEFORE IT ENDS...WITH 2-4 INCHES POSSIBLE ABOVE 5000 FEET OVER
SOUTHERN GILA COUNTY. 850MB TEMPS...THAT ARE EXPECTED TO FALL AS LOW
AS 0C...WILL MAKE IT VERY DIFFICULT FOR FOR HIGHS TO GET MUCH ABOVE
60F ACROSS THE LOWER DESERTS OF SOUTH-CENTRAL AZ. SKIES ARE EXPECTED
TO CLEAR SAT NIGHT AS THE MAIN UPPER TROF MOVES OFF TO THE
EAST...WITH LOWS SUNDAY MORNING FALLING INTO THE 30S AT MANY LOWER
DESERT LOCATIONS...WITH TEMPERATURES NEAR...OR JUST BELOW FREEZING
LIKELY AT THE COLDEST LOCATIONS.
MONDAY THROUGH THURSDAY...
ANOTHER...EVEN COLDER AIRMASS IS EXPECTED TO MOVE INTO THE REGION
DURING THIS PERIOD...AS A 2ND UPPER TROF MOVES INTO THE REGION FROM
THE EASTERN GULF OF ALASKA. THIS SYSTEM WILL BE TAKING A MORE
EASTERLY TRACK THAN THE ONE THAT WILL BE AFFECTING US OVER THE
WEEKEND...WHICH WILL ALLOW IT TO TAP VERY COLD AIR THAT IS NOW
PARKED OVER ALASKA/NW CANADA. CURRENT EURO AND GFS FORECASTS...AND
MOST OF THEIR MEMBERS ARE IN VERY GOOD AGREEMENT ON THE TIMING AND
INTENSITY OF THIS UPCOMING COLD SNAP. BOTH THE EURO AND GFS
OPERATIONAL RUNS DROP 700MB TEMPS INTO THE -10C TO -13C RANGE ACROSS
OUR CWA BY MONDAY EVENING...THEN HOLD IT IN THIS RANGE THROUGH EARLY
WED MORNING BEFORE TEMPERATURES GRADUALLY MODERATE INTO THURSDAY.
THE COMBINATION OF THE VERY COLD AIR ALOFT AND A DRY AIRMASS (SFC
DEWPOINTS IN THE TEENS AND LOW 20S) WILL ALLOW MANY LOWER DESERT
LOCATIONS TO SEE LOWS AOB FREEZING ON WED AND THU MORNING...WITH THE
COLDEST LOCATIONS SEEING LOWS WELL DOWN IN THE 20S...WITH FREEZE
WARNINGS LIKELY NEEDED DURING THIS PERIOD. HIGHS DURING THIS PERIOD
WILL ME MOSTLY IN THE MID TO UPPER 50S ACROSS THE LOWER DESERTS.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
A COLD FRONT MOVED THROUGH EARLIER TODAY RESULTING IN SOUTHWESTERLY
BREEZES...LOWERING MID LEVEL CEILINGS AND THE ONSET OF SCATTERED
AREAS OF LIGHT TO MODERATE RAIN AND RAIN SHOWERS. CURRENT RADAR
INDICATES MOSTLY LIGHT RAIN AND RAIN SHOWERS FILLING IN AND MOVING
NORTHEAST. ALONG WITH THE RAIN EXPECT SOME OVERNIGHT BREEZINESS AND
CEILINGS NEAR 050. BY MID MORNING EXPECT CEILINGS TO IMPROVE TO MID
LEVELS WITH WEST AND SOUTHWESTERLY BREEZES INCREASING WITH GUSTS TO
ABOUT 20 KNOTS DURING THE AFTERNOON. SKIES WILL BECOME MOSTLY CLEAR
BY EVENING WITH LIGHT WEST AND SOUTHWESTERLY WINDS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST DURING THE PERIOD
EXPECT LINGERING OVERNIGHT SOUTHWESTERLY BREEZES IN IMPERIAL AND
MOSTLY NORTHWESTERLY BREEZES AT BLYTHE. BY MIDDAY IT WILL BECOME
VERY WINDY WITH NORTHWESTERLY WIND GUSTS TO THE MID 20S WITH SKIES
REMAINING CLEAR.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
TEMPERATURES WILL REMAIN WELL BELOW NORMAL THROUGH THE PERIOD AS A
COUPLE OF LOW PRESSURE TROUGHS AFFECT THE REGION. A CHANCE OF
SHOWERS TO MAINLY HIGHER TERRAIN LOCATIONS NORTH AND EAST OF PHOENIX
IS POSSIBLE ON MONDAY WITH EVERY OTHER DAY STAYING PRECIP FREE. THE
COOL TEMPERATURES WILL ALLOW FOR HIGHER HUMIDITIES WITH MINIMUM
AFTERNOON VALUES ONLY FALLING INTO A 20 TO 40 PERCENT RANGE. GUSTY
NORTHWESTERLY WINDS ARE LIKELY ON MONDAY AND TUESDAY...ESPECIALLY
AFFECTING THE LOWER COLORADO RIVER VALLEY.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...WINTER WEATHER ADVISORY UNTIL NOON MST SATURDAY FOR AZZ024.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...PERCHA
AVIATION...SAWTELLE
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS TUCSON AZ
945 PM MST FRI DEC 11 2015
.SYNOPSIS...SHOWERS AND MOUNTAIN SNOW SHOWERS WILL CONTINUE ACROSS
SOUTHEAST ARIZONA INTO SATURDAY. MUCH COLDER TEMPERATURES WILL ALSO
OCCUR THIS WEEKEND. ANOTHER SYSTEM WILL BRING A FEW VALLEY RAIN AND
MOUNTAIN SNOW SHOWERS MONDAY AND MONDAY NIGHT WITH DRY CONDITIONS
RETURNING BY MIDWEEK. TEMPERATURES WILL REMAIN WELL BELOW AVERAGE
MUCH OF THE UPCOMING WEEK.
&&
.DISCUSSION...VALLEY SHOWERS AND MOUNTAINS SNOW SHOWERS HAVE BEEN ON
THE INCREASE THIS EVENING. RAINFALL AMOUNTS WEST OF TUCSON HAVE
GENERALLY BEEN LESS THAN 0.10" ALTHOUGH THERE ARE LOCALIZED SPOTS UP
TO 0.20". BASED ON RAWS DATA THE SNOW LEVEL IS SOMEWHERE BETWEEN
8500 AND 9000 FEET. CAMERA NEAR MT LEMMON HAS SHOWED SOME MINOR SNOW
ACCUMULATION. A LIGHTING STRIKE OCCURRED NEAR KITT PEAK EARLIER IN
THE EVENING. THE HRRR RUNS SINCE LATE THIS AFTERNOON HAVE BEEN
HANDLING THE OVERALL EVOLUTION OF SHOWER DEVELOPMENT RATHER NICELY
THIS EVENING. SHOWER ACTIVITY WILL CONTINUE TO EXPAND IN AREAL
COVERAGE OVERNIGHT AS TROF AXIS AND ASSOCIATED HEIGHT FALLS/COLD MID-
LEVEL TEMPS MOVES OVER THE AREA. THE LIQUID QPF FORECAST FOR THE
NEXT 12-18 HOURS MAY BE A TOUCH TOO LOW IN SPOTS. THE EVENING RUNS
OF THE HRRR HAVE AREAS OF 0.25" TO 0.60" WITH LOCALLY HIGHER
AMOUNTS. 00Z NAM 12 HR QPF KINDA SIMILAR WHILE THE NAMDNG25 IS
HITTING THE CHIRICAHUA MOUNTAINS A LITTLE HARDER THAN CURRENTLY
FORECAST. THE WILL RUN OUT AN UPDATE TO ADD SLIGHT CHANCE OF
THUNDERSTORMS...INCREASE SOME LIQUID QPF AND SNOWFALL
AMOUNTS...ESPECIALLY ACROSS THE SOUTHERN MTNS. WINTER WEATHER
ADVISORY ABOVE 5000 FEET WILL REMAIN IN EFFECT FOR THE MOUNTAINS
FROM TUCSON NORTHEAST INTO SATURDAY. WITH ABOVE THINKING ON THE
CHIRICAHUA MOUNTAINS WILL ADD THEM TO THE WINTER WEATHER ADVISORY
BUT HAVE A LATER STARTING TIME.
FOR SATURDAY...WE MAY BE ENDING SHOWER ACTIVITY A LITTLE TOO QUICK.
SOMETHING FOR THE MID-SHIFT CREW TO PONDER. WHAT WILL BE NOTICEABLE
ON SATURDAY WILL BE THE DRAMATICALLY COOLER TEMPERATURES WITH HIGHS
10-20 DEGREES COLDER THAN TODAY. IN FACT MOST LOCATIONS FROM TUCSON
EAST WILL LIKELY SEE THEIR DAILY HIGHS OCCURRING BETWEEN MIDNIGHT
AND 3 AM.
SEE PREVIOUS DISCUSSION BELOW FOR FURTHER FORECAST DETAILS
FOR SATURDAY NIGHT INTO NEXT WEEK.
&&
.AVIATION...VALID THRU 13/00Z.
EXPECT SCATTERED TO NUMEROUS -SHRA AND HIGHER TERRAIN -SHSN INTO
SATURDAY MORNING. PRECIP WILL END AT KTUS BY ABOUT 18Z SATURDAY BUT
CONTINUE EAST OF KTUS INTO SATURDAY AFTERNOON. MVFR CONDITIONS AND
OCCASIONAL IFR CONDITIONS WILL EXIST THIS EVENING INTO SATURDAY
MORNING...ESPECIALLY NEAR HIGHER TERRAIN. OTHERWISE...CLOUD DECKS
WILL LOWER TO BETWEEN 8-12K FT AGL THIS EVENING INTO SATURDAY
MORNING. SURFACE WIND FROM KTUS WWD WILL DIMINISH TO LESS THAN 10
KTS BY 12/06Z. SURFACE WIND EAST OF KTUS WILL REMAIN SLY/SWLY AT 12-
18 KTS WITH GUSTS OF 25 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...VALLEY RAIN AND MOUNTAIN SNOW SHOWERS WILL EXPAND
ACROSS SOUTHEAST ARIZONA OVERNIGHT INTO SATURDAY ALONG WITH MUCH
COOLER TEMPERATURES. EXPECT PRECIPITATION TO END FROM WEST-TO-EAST
BY SATURDAY EVENING. GUSTY NORTHWEST WINDS WILL OCCUR SATURDAY
MAINLY EAST OF TUCSON AND ESPECIALLY IN THE UPPER GILA RIVER VALLEY
INCLUDING SAFFORD. DRY CONDITIONS WILL OCCUR SUNDAY. THERE IS A
SLIGHT CHANCE OF VALLEY RAIN AND MOUNTAIN SHOWERS MONDAY AND MONDAY
NIGHT FOR AREAS MAINLY NORTH AND EAST OF TUCSON...ALONG WITH ANOTHER
ROUND OF GUSTY AFTERNOON SOUTHWEST WINDS. DRY CONDITIONS WITH LIGHT
TERRAIN DRIVEN 20-FOOT WINDS WILL THEN PREVAIL THROUGH THE END OF
NEXT WEEK.
&&
.PREV DISCUSSION... A SLIGHT CHANCE OF SNOW SHOWERS CONTINUES MAINLY
ACROSS THE WHITE MOUNTAINS SAT EVENING...THEN DRY CONDITIONS WILL
OCCUR AREA-WIDE LATE SAT NIGHT THRU SUN NIGHT. THE NEXT UPPER TROUGH
IS THEN PROGGED TO MOVE EWD ACROSS THE GREAT BASIN SUN NIGHT...THEN
ACROSS ARIZONA MON. THERE WERE SOME DIFFERENCES AMONGST THE MODELS
REGARDING PRECIP POTENTIAL ASSOCIATED WITH THIS SYSTEM MON INTO MON
NIGHT. GIVEN THESE DIFFERENCES...OPTED FOR ONLY VERY MINOR
MODIFICATIONS TO POPS.
THUS...THERE IS A SLIGHT CHANCE OF VALLEY RAIN/MOUNTAIN SNOW SHOWERS
ACROSS MUCH OF THE AREA MON...THEN A SLIGHT CHANCE OF VALLEY RAIN/
MOUNTAIN SNOW SHOWERS CONTINUES ACROSS ERN SECTIONS MON NIGHT. HAVE
MAINTAINED A SLIGHT CHANCE OF SNOW SHOWERS ACROSS THE WHITE
MOUNTAINS TUE. DRY CONDITIONS WILL THEN PREVAIL AREA-WIDE TUE NIGHT-
FRI.
MUCH COOLER TEMPS WILL OCCUR SAT...THEN DAYTIME TEMPS WILL AVERAGE
ABOUT 10-15 DEGS BELOW NORMAL SUN-WED. MARKEDLY WARMER TEMPS ARE ON
TAP LATE NEXT WEEK. MEANWHILE...FREEZING TEMPS OR PERHAPS A HARD
FREEZE MAY OCCUR FOR THE TUCSON METRO AREA LATE TUE NIGHT/EARLY WED
MORNING AND AGAIN LATE WED NIGHT/EARLY THUR MORNING.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL TO 5 PM MST SATURDAY FOR
AZZ510-511-514 ABOVE 5000 FEET.
WINTER WEATHER ADVISORY 1 AM TO 5 PM SATURDAY FOR AZZ512 ABOVE
5000 FEET.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
937 PM MST FRI DEC 11 2015
.SYNOPSIS...
A STRONG PACIFIC LOW PRESSURE SYSTEM AND COLD FRONT WILL MOVE
THROUGH THE REGION TONIGHT AND SATURDAY...GENERATING COOLER AND
WINDY CONDITIONS. A CHANCE OF SHOWERS ARE ALSO FORECAST MAINLY OVER
PORTIONS OF SOUTH CENTRAL ARIZONA FROM THIS EVENING THROUGH AT LEAST
MIDDAY ON SATURDAY...WITH ACCUMULATING SNOW POSSIBLE ABOVE 5000 FEET
OVER THE HIGHER TERRAIN EAST OF PHOENIX. CLEAR AND COLDER WEATHER IS
THEN EXPECTED SUNDAY...WITH ANOTHER COLD FRONT FORECAST TO MOVE INTO
THE REGION ON MONDAY. A MUCH COLDER AIRMASS IS FORECAST TO SETTLE
OVER THE REGION FROM TUESDAY INTO THURSDAY...POSSIBLY GENERATING
SOME OF THE COLDEST LOW TEMPERATURES SO FAR THIS SEASON.
&&
.DISCUSSION...
LATEST MESOANALYSIS SHOWS THE MID-TROPOSPHERIC TROUGH AXIS ACROSS THE
IMPERIAL VALLEY BUT PROGRESSING STEADILY EASTWARD. TWELVE-HOUR HEIGHT
FALLS OF NEARLY 180 M HAVE BEEN OBSERVED ACROSS THE NORTHERN BAJA
PENINSULA. THE BREEZY CONDITIONS WERE SLOW TO MATERIALIZE BEHIND THE
COLD FRONT THAT MOVED THROUGH CENTRAL AZ THIS AFTERNOON...THOUGH
WINDS HAVE PICKED UP OVER THE PAST FEW HOURS. MEANWHILE...AREAS OF
LIGHT PRECIPITATION ARE FILLING IN ACROSS CENTRAL AZ IN RESPONSE TO
STRONG FORCING FOR ASCENT ASSOCIATED WITH WELL-DEFINED PVA ACROSS THE
LOWER CO RIVER VALLEY.
HI-RES GUIDANCE INCLUDING LATEST RUNS OF THE HRRR CONTINUE TO
INDICATE THAT THE BEST CHANCE OF PRECIPITATION WILL BE ACROSS
NORTHERN MARICOPA COUNTY AND EAST OF PHOENIX IN THE HIGHER TERRAIN OF
GILA COUNTY THROUGH SATURDAY MORNING. QPF WAS INCREASED THIS EVENING
FOR THE 06-12Z PERIOD ACROSS THE HIGHER ELEVATIONS BASED ON THE
LATEST MODEL CONSENSUS. A FEW INCHES OF SNOW ARE LIKELY ABOVE 5K FT
AND A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR THESE AREAS.
LATEST SPC GUIDANCE ALSO SUGGESTS THAT AN ISOLATED LIGHTNING STRIKE
IS POSSIBLE IN THE STRONGEST CELLS.
.PREVIOUS DISCUSSION...
TONIGHT THROUGH SUNDAY...
A STRONG...AND COLD PACIFIC TROF CONTINUES TO APPROACH ARIZONA AT
THIS HOUR...WITH RAINFALL NOW BEING REPORTED ACROSS THE SOUTHERN CA
COASTAL REGIONS...AND ACROSS SOUTHERN NV AND EXTREME NW AZ. AHEAD OF
THE MAIN TROF AXIS...THE SFC COLD FRONT IS NOW MOVING INTO WESTERN
AZ...WITH LOCALLY GUSTY WINDS OCCURRING AT SOME LOCATIONS DURING THE
FRONTAL PASSAGE. ALTHOUGH THIS SYSTEM DOES NOT CONTAIN TOO MUCH
MOISTURE (PWATS MAINLY AOB 0.60 INCH)...THE COMBINATION OF STRONG
DYNAMICS/MAJOR HEIGHT FALLS (24HR 500MB HEIGHT FALLS IN THE 200-250M
RANGE ACROSS SOUTH-CENTRAL AZ) AND STRONG COOLING THROUGH THE COLUMN
IS EXPECTED TO ALLOW THE SYSTEM TO MAXIMIZE THE USE OF ITS AVAILABLE
MOISTURE. IT APPEARS THE BEST CHANCE FOR MEASURABLE PRECIP WILL BE
FROM THIS EVENING THROUGH ABOUT MIDDAY ON SATURDAY...WITH THE NCEP
SREF PLUME MEAN SHOWING TOTAL QPF AMOUNTS RANGING FROM AROUND 0.10
OF AN INCH OVER THE LOWER DESERTS OF SOUTH-CENTRAL AZ UP TO AS MUCH
AS 0.50 OF AN INCH OVER THE HIGHER TERRAIN EAST OF PHOENIX.
ALONG WITH THE RAINFALL...MUCH COLDER AIR MOVING INTO THE REGION IS
EXPECTED TO DROP SNOW LEVELS AOB 5000 FEET BY EARLY SAT
MORNING...WHICH WILL BE EARLY ENOUGH TO ALLOW THE RAIN TO CHANGE TO
SNOW BEFORE IT ENDS...WITH 2-4 INCHES POSSIBLE ABOVE 5000 FEET OVER
SOUTHERN GILA COUNTY. 850MB TEMPS...THAT ARE EXPECTED TO FALL AS LOW
AS 0C...WILL MAKE IT VERY DIFFICULT FOR FOR HIGHS TO GET MUCH ABOVE
60F ACROSS THE LOWER DESERTS OF SOUTH-CENTRAL AZ. SKIES ARE EXPECTED
TO CLEAR SAT NIGHT AS THE MAIN UPPER TROF MOVES OFF TO THE
EAST...WITH LOWS SUNDAY MORNING FALLING INTO THE 30S AT MANY LOWER
DESERT LOCATIONS...WITH TEMPERATURES NEAR...OR JUST BELOW FREEZING
LIKELY AT THE COLDEST LOCATIONS.
MONDAY THROUGH THURSDAY...
ANOTHER...EVEN COLDER AIRMASS IS EXPECTED TO MOVE INTO THE REGION
DURING THIS PERIOD...AS A 2ND UPPER TROF MOVES INTO THE REGION FROM
THE EASTERN GULF OF ALASKA. THIS SYSTEM WILL BE TAKING A MORE
EASTERLY TRACK THAN THE ONE THAT WILL BE AFFECTING US OVER THE
WEEKEND...WHICH WILL ALLOW IT TO TAP VERY COLD AIR THAT IS NOW
PARKED OVER ALASKA/NW CANADA. CURRENT EURO AND GFS FORECASTS...AND
MOST OF THEIR MEMBERS ARE IN VERY GOOD AGREEMENT ON THE TIMING AND
INTENSITY OF THIS UPCOMING COLD SNAP. BOTH THE EURO AND GFS
OPERATIONAL RUNS DROP 700MB TEMPS INTO THE -10C TO -13C RANGE ACROSS
OUR CWA BY MONDAY EVENING...THEN HOLD IT IN THIS RANGE THROUGH EARLY
WED MORNING BEFORE TEMPERATURES GRADUALLY MODERATE INTO THURSDAY.
THE COMBINATION OF THE VERY COLD AIR ALOFT AND A DRY AIRMASS (SFC
DEWPOINTS IN THE TEENS AND LOW 20S) WILL ALLOW MANY LOWER DESERT
LOCATIONS TO SEE LOWS AOB FREEZING ON WED AND THU MORNING...WITH THE
COLDEST LOCATIONS SEEING LOWS WELL DOWN IN THE 20S...WITH FREEZE
WARNINGS LIKELY NEEDED DURING THIS PERIOD. HIGHS DURING THIS PERIOD
WILL ME MOSTLY IN THE MID TO UPPER 50S ACROSS THE LOWER DESERTS.
&&
.AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND
KSDL... SURFACE COLD FRONT WILL MOVE THROUGH THE CENTRAL DESERTS
LATER THIS AFTERNOON AND THROUGH THE EARLY EVENING HOURS...LEADING
TO AN INCREASE IN BREEZY WEST WINDS WITH OCCASIONAL GUSTS TO 25KT OR
MORE EXPECTED. BEHIND THE FRONT...CIGS WILL STEADILY LOWER AS THE
MAIN UPPER TROF SETTLES INTO EASTERN ARIZONA...BY MIDNIGHT WE SHOULD
SEE SCT CIGS DOWN TO AROUND 6K FEET WITH SCATTERED LIGHT SHOWERS
DEVELOPING. AFTER MIDNIGHT CIGS MAY LOWER ADDITIONALLY...POSSIBLY
DOWN TO AROUND 3K FEET ALTHOUGH CIGS THAT LOW WILL PROBABLY STAY
NORTH AND EAST OF KPHX. EXPECT PARTIAL CLEARING FROM THE WEST BY MID
MORNING ON SATURDAY EVENTUALLY BECOMING PARTLY TO MOSTLY SUNNY WITH
LINGERING CU/SC AROUND 6-8K FEET BY MID AFTERNOON.
LOCALLY BREEZY WEST WIND LIKELY THROUGH MIDNIGHT WITH WIND BECOMING
LIGHTER AND SOUTH/SOUTHEAST AFTER 2AM OR SO. WINDS RETURNING TO THE
WEST/NORTHWEST BY SAT AFTERNOON BUT LIGHTER THAN THIS EVENING.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
PASSING LOW PRESSURE SYSTEM WILL BRING BREEZY/LOCALLY WINDY
CONDITIONS THIS AFTERNOON...ESPECIALLY AT KIPL...BUT NOT MUCH IN
TERMS OF PRECIP. MOST CLOUD DECKS WILL BE AOA 8K FEET WITH BKN DECKS
MOSTLY AOA 10-12K FEET. MAY SEE A STRAY SHOWER NEAR KBLH THIS
AFTERNOON AND EVENING...BUT NOTHING AFTER MIDNIGHT. WINDS HAVE NOT
BEEN AS STRONG AS EXPECTED AT KIPL TODAY BUT THERE MAY BE A FEW
GUSTS TO NEAR 30KT AT KIPL INTO THE EARLY EVENING BEFORE THEY
GRADUALLY TAPER OFF. LOCALLY BREEZY NORTH TO NORTHWEST WINDS SHOULD
SET IN OVER THE WESTERN DESERTS...ESPECIALLY KBLH...BY LATE MORNING
ON SUNDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
TEMPERATURES WILL REMAIN WELL BELOW NORMAL THROUGH THE PERIOD AS A
COUPLE OF LOW PRESSURE TROUGHS AFFECT THE REGION. A CHANCE OF
SHOWERS TO MAINLY HIGHER TERRAIN LOCATIONS NORTH AND EAST OF PHOENIX
IS POSSIBLE ON MONDAY WITH EVERY OTHER DAY STAYING PRECIP FREE. THE
COOL TEMPERATURES WILL ALLOW FOR HIGHER HUMIDITIES WITH MINIMUM
AFTERNOON VALUES ONLY FALLING INTO A 20 TO 40 PERCENT RANGE. GUSTY
NORTHWESTERLY WINDS ARE LIKELY ON MONDAY AND TUESDAY...ESPECIALLY
AFFECTING THE LOWER COLORADO RIVER VALLEY.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...WINTER WEATHER ADVISORY UNTIL NOON MST SATURDAY FOR AZZ024.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...PERCHA
AVIATION...CB
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
134 AM EST SAT DEC 12 2015
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE FAIR AND WARM WEATHER THROUGH SUNDAY.
A WEAK FRONT WILL PROVIDE A CHANCE OF SHOWERS LATE SUNDAY NIGHT
AND MONDAY. ANOTHER FRONT TO PROVIDE A CHANCE OF SHOWERS WEDNESDAY
AND THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
THE SURFACE PRESSURE RIDGE AXIS WILL REMAIN JUST SOUTH OF THE
FORECAST AREA THROUGH TONIGHT. FLAT UPPER RIDGING WILL CONTINUE
AND SATELLITE TRENDS INDICATE THIN CIRRUS WILL CONTINUE SPILLING
OVER THE RIDGE AND INTO THE FORECAST AREA. SHALLOW LOW-LEVEL
MOISTURE AND NOCTURNAL COOLING WILL HELP CAUSE AREAS OF FOG DURING
THE EARLY MORNING HOURS. THE LAMP GUIDANCE SUGGESTED WIDESPREAD
FOG BUT OTHER MODELS WERE LESS AGGRESSIVE. THE HRRR INDICATED FOG
MAINLY TO THE WEST OF THE FORECAST AREA BUT THE TREND IN THE HRRR
HAS BEEN MORE FOG COVERAGE. WE HAVE INCLUDED FOG IN THE FORECAST
THROUGH THE EARLY MORNING. A DENSE FOG ADVISORY MAY BE NEEDED.
LOWS NEAR OR JUST ABOVE 50 DEGREES ARE EXPECTED.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
UPPER AND SURFACE HIGHS OVER THE REGION TONIGHT INTO EARLY
SUNDAY. CONTINUED FAIR WEATHER WITH WELL ABOVE NORMAL TEMPS. FOG
POSSIBLE AGAIN LATE TONIGHT/EARLY SUNDAY...BUT AN INCREASE IN LOW
LEVEL SOUTHERLY FLOW LATE TONIGHT COULD PROVIDE MORE OF A STRATUS
THREAT. UPPER/SURFACE HIGHS TO SHIFT TO OUR EAST SUN/SUN NT...AS
UPPER TROUGH TO OUR WEST LIFTS NE TOWARDS THE MID/UPPER MISS
VALLEY. NEAR RECORD HIGH TEMPS POSSIBLE SUNDAY. INCREASING LOW
LEVEL SOUTHERLY FLOW/ISENTROPIC LIFT TO DEVELOP OVER OUR REGION
LATE SUNDAY NIGHT AHEAD OF AN APPROACHING WEAK FRONT...WITH SOME
LIGHT PRECIP POSSIBLE.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
WEAK FRONT WILL MOVE THROUGH MONDAY. LATEST MODELS TRENDING
TOWARDS SLOWING DOWN THE TIMING OF THE FRONT AS UPPER ENERGY IS
WELL TO THE NORTH BY THAT TIME...WITH A SW FLOW ALOFT. ASSOCIATED
PRECIP ACTIVITY/CONVECTION TO OUR WEST ALONG THE FRONT EXPECTED TO
WEAKEN AS IT APPROACHES OUR REGION AS BEST UPPER DYNAMICS SHIFT TO
THE NORTH. SURFACE AND ELEVATED INSTABILITIES STILL PROGGED TO BE
WEAK FOR OUR FA...PRECLUDING NEED FOR THUNDER MENTION AT THIS
TIME FOR OUR FA. HIGH CHANCE TO LOW LIKELY POPS CONTINUE TO LOOK
OK WITH THE FROPA. WITH FROPA TRENDING LATER IN THE DAY...BUMPED
UP MAX TEMPS MON. MODELS TRENDING TOWARDS STALLING THE FRONT JUST
TO OUR SOUTH TUE. WILL MAINTAIN FAIR WEATHER FORECAST FOR TUE.
STILL ABOVE NORMAL TEMPS EXPECTED TUE AS A SW UPPER FLOW REMAINS
WITH FLAT UPPER RIDGE OVER THE E COAST. LATEST GFS/ECWMF APPEAR TO
BE IN GOOD AGREEMENT WITH UPPER TROUGH MOVING EAST INTO THE
CENTRAL CONUS...WITH UPPER RIDGE SHIFTING TO OUR EAST...BY
WED/THU...BRINGING MAIN UPPER FLOW CLOSER TO OUR REGION WITH
EMBEDDED ENERGY LEADING TO MOISTURE RETURN ANTICIPATED FOR LATE
WED INTO EARLY FRI. FOR NOW...CHANCE POPS APPEAR OK.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
WEAK HIGH PRESSURE REMAINS ANCHORED OVER THE REGION. SOME
SCATTERED CIRRUS EXPECTED TO CONTINUE TO MOVE OVER THE AREA
THROUGH THE PERIOD...SPILLING OVER THE TOP OF A BUILDING UPPER
RIDGE AXIS TO THE WEST.
STRONG RADIATIONAL COOLING CONDITIONS IN PLACE UNDER MOSTLY CLEAR
SKIES AND CALM WINDS WITH PLENTY OF MID LEVEL DRY AIR IN PLACE HAS
LED TO SEVERAL AIRPORTS ALREADY REPORTING RESTRICTIONS DUE TO FOG.
SATELLITE IMAGERY SHOWS SOME 4-6 KFT CLOUDS MOVING THROUGH THE
UPSTATE AND INTO THE NORTHWESTERN MIDLANDS AS OF 06Z. THESE
CLOUDS COULD IMPACT THE FOG POTENTIAL BUT ARE EXPECTED TO BE
TEMPORARY. WILL CARRY LIFR CONDITIONS AGS/OGB DUE TO FOG TO START
THE FORECAST PERIOD WHILE CAE/CUB/DNL START VFR/MVFR AND GRADUALLY
LOWER DURING THE 08Z-10Z TIME FRAME WHERE DENSE FOG IS EXPECTED TO
DEVELOP ACROSS MOST TERMINALS EXCEPT MAYBE DNL.
FOG WILL LIKELY LINGER THROUGH 13-14Z BEFORE CONDITIONS RETURN TO
VFR AS HEATING AND MIXING SHOULD RESULT IN A RETURN TO VFR
CONDITIONS BEGINNING AROUND 14Z. LIGHT WEST TO SOUTHWESTERLY WINDS
DEVELOPING BY 15Z. NO CHANCES OF RAIN WITH BUILDING UPPER RIDGE
AND SURFACE HIGH PRESSURE IN PLACE.
EXTENDED AVIATION OUTLOOK...A WEAK FRONT MOVING INTO THE AREA
EARLY NEXT WEEK MAY BRING RESTRICTIONS.
&&
.CLIMATE...
CURRENT INDICATIONS ARE THAT MAX TEMPS TODAY WILL NOT BREAK DAILY
RECORD HIGHS...BUT RECORD HIGH TEMPS MAY POSSIBLY BE REACHED
SUNDAY.
NORMAL MAX TEMPS TODAY/SUNDAY...
CAE...59/59. AGS...61/60.
FORECAST MAX TEMPS TODAY/SUNDAY...
CAE...77/78. AGS...78/80.
RECORD MAX TEMPS TODAY/SUNDAY...
CAE...81/80. AGS...82/81.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
106 AM EST SAT DEC 12 2015
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE FAIR AND WARM WEATHER THROUGH SUNDAY.
A WEAK FRONT WILL PROVIDE A CHANCE OF SHOWERS LATE SUNDAY NIGHT
AND MONDAY. ANOTHER FRONT TO PROVIDE A CHANCE OF SHOWERS WEDNESDAY
AND THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE SURFACE PRESSURE RIDGE AXIS WILL REMAIN JUST SOUTH OF THE
FORECAST AREA THROUGH TONIGHT. FLAT UPPER RIDGING WILL CONTINUE
AND SATELLITE TRENDS INDICATE THIN CIRRUS WILL CONTINUE SPILLING
OVER THE RIDGE AND INTO THE FORECAST AREA. SHALLOW LOW-LEVEL
MOISTURE AND NOCTURNAL COOLING WILL HELP CAUSE AREAS OF FOG DURING
THE EARLY MORNING HOURS. THE LAMP GUIDANCE SUGGESTED WIDESPREAD
FOG BUT OTHER MODELS WERE LESS AGGRESSIVE. THE HRRR INDICATED FOG
MAINLY TO THE WEST OF THE FORECAST AREA BUT THE TREND IN THE HRRR
HAS BEEN MORE FOG COVERAGE. WE HAVE INCLUDED FOG IN THE FORECAST
THROUGH THE EARLY MORNING. A DENSE FOG ADVISORY MAY BE NEEDED.
LOWS NEAR OR JUST ABOVE 50 DEGREES ARE EXPECTED.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
DRY WEATHER AND ABOVE NORMAL TEMPERATURES WILL PERSIST SATURDAY
THROUGH SATURDAY NIGHT. UPPER RIDGE WILL REMAIN OVER THE
SOUTHEASTERN STATES...AS UPPER TROUGH/CLOSED LOW CROSSES THE
WESTERN CONUS. THIS WILL LEAD TO A CONTINUED WARMING TREND FOR
OUR REGION. SURFACE HIGH PRESSURE CENTERED OVER NORTHERN FLORIDA
WILL LIFT NORTH TOWARDS THE CAROLINAS SATURDAY. FAVORED WARMER
TEMPERATURES INDICATED BY THE MAV MOS WITH HIGHS IN THE MID TO
UPPER 70S AND LOWS IN THE UPPER 40S TO LOWER 50S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
THE UPPER-LEVEL RIDGE AND SURFACE HIGH PRESSURE WILL MOVE OFF THE
COAST SUNDAY AS AN UPPER LOW LIFTS NORTHEAST FROM THE GREAT PLAINS
INTO THE GREAT LAKES REGION SUNDAY INTO MONDAY. THIS WILL DRAG A
FRONTAL BOUNDARY THROUGH THE FORECAST AREA MONDAY. PRECIPITATION
TO OUR WEST ALONG THE FRONT EXPECTED TO WEAKEN AS IT APPROACHES
OUR REGION AS BEST UPPER DYNAMICS SHIFT TO THE NORTH. INCREASING
LOW-LEVEL SOUTHERLY FLOW/ISENTROPIC LIFT TO DEVELOP OVER OUR
REGION LATE SUNDAY NIGHT AHEAD OF THE APPROACHING WEAK FRONT.
SURFACE AND ELEVATED INSTABILITIES PROGGED TO BE QUITE WEAK ACROSS
THE MIDLANDS AND CSRA...THUS NO MENTION OF THUNDER.
HIGH CHANCE TO LOW LIKELY POPS CONTINUE WITH THE FRONTAL PASSAGE
MONDAY. DRY HIGH PRESSURE WILL BUILD INTO THE REGION MONDAY NIGHT
INTO TUESDAY. ABOVE NORMAL TEMPS WILL CONTINUE TUESDAY GIVEN
SOUTHWEST FLOW ALOFT WITH WEAK UPPER RIDGING OVER THE SOUTHEASTERN
STATES.
GFS/ECMWF IN AGREEMENT WITH UPPER TROUGH MOVING EAST INTO THE
CENTRAL CONUS...WITH UPPER RIDGE SHIFTING TO OUR EAST WEDNESDAY.
SURFACE FRONT PROGGED TO CROSS THE AREA THURSDAY. STILL SOME
TIMING DIFFERENCES WITH THE GFS INDICATING THE FROPA THURSDAY AND
THE ECMWF SLOWER...INDICATING THE FRONT MOVING EAST OF THE AREA
FRIDAY. INCREASING MOISTURE/ISENTROPIC LIFT AHEAD OF THE FRONT MAY
LEAD TO SOME LIGHT PRECIP WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT.
GIVEN MODEL DIFFERENCES WILL KEEP CHANCE OF SHOWERS THURSDAY INTO
FRIDAY. ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH
THURSDAY...COOLING TO THE 50S FOR FRIDAY.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
WEAK HIGH PRESSURE REMAINS ANCHORED OVER THE REGION. SOME
SCATTERED CIRRUS EXPECTED TO CONTINUE TO MOVE OVER THE AREA
THROUGH THE PERIOD...SPILLING OVER THE TOP OF A BUILDING UPPER
RIDGE AXIS TO THE WEST.
STRONG RADIATIONAL COOLING CONDITIONS IN PLACE UNDER MOSTLY CLEAR
SKIES AND CALM WINDS WITH PLENTY OF MID LEVEL DRY AIR IN PLACE HAS
LED TO SEVERAL AIRPORTS ALREADY REPORTING RESTRICTIONS DUE TO FOG.
SATELLITE IMAGERY SHOWS SOME 4-6 KFT CLOUDS MOVING THROUGH THE
UPSTATE AND INTO THE NORTHWESTERN MIDLANDS AS OF 06Z. THESE
CLOUDS COULD IMPACT THE FOG POTENTIAL BUT ARE EXPECTED TO BE
TEMPORARY. WILL CARRY LIFR CONDITIONS AGS/OGB DUE TO FOG TO START
THE FORECAST PERIOD WHILE CAE/CUB/DNL START VFR/MVFR AND GRADUALLY
LOWER DURING THE 08Z-10Z TIME FRAME WHERE DENSE FOG IS EXPECTED TO
DEVELOP ACROSS MOST TERMINALS EXCEPT MAYBE DNL.
FOG WILL LIKELY LINGER THROUGH 13-14Z BEFORE CONDITIONS RETURN TO
VFR AS HEATING AND MIXING SHOULD RESULT IN A RETURN TO VFR
CONDITIONS BEGINNING AROUND 14Z. LIGHT WEST TO SOUTHWESTERLY WINDS
DEVELOPING BY 15Z. NO CHANCES OF RAIN WITH BUILDING UPPER RIDGE
AND SURFACE HIGH PRESSURE IN PLACE.
EXTENDED AVIATION OUTLOOK...A WEAK FRONT MOVING INTO THE AREA
EARLY NEXT WEEK MAY BRING RESTRICTIONS.
&&
.CLIMATE...
FORECAST MAX TEMPS SAT/SUN
CAE...77/79
AGS...78/79
NORMAL MAX TEMPS SAT/SUN
CAE...59/59
AGS...61/60
RECORD MAX TEMPS SAT/SUN
CAE...81/80
AGS...82/81
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
331 AM CST SAT DEC 12 2015
.SHORT TERM...
331 AM CST
THROUGH SUNDAY NIGHT...
EXCEEDINGLY TRICKY FORECAST IN THE SHORT TERM...PARTICULARLY WITH
RESPECT TO FOG AND TEMPS.
A SET-UP FAR MORE TYPICAL OF LATE MARCH OR EARLY APRIL WILL PLAY
HAVOC ON TEMP FORECAST AND LIKELY RESULT IN DENSE LAKE FOG
DEVELOPING. WARM FRONT HAS LIFTED NORTH AND LIES JUST NORTH OF I-80
EARLY THIS MORNING. DENSE FOG HAS BEEN PATCHY SO FAR AND CONFINED TO
AREAS MAINLY WEST AND SOUTHWEST OF OUR CWA THUS FAR...HOWEVER SHORT
RANGE GUIDANCE STILL SUGGESTS THAT THE DENSE FOG COULD EXPAND IN
COVERAGE AND IMPACT MAINLY OUR WESTERN AND SOUTHWESTERN COUNTIES
THIS MORNING. WILL TAKE A WAIT AND SEE APPROACH ON THIS GIVEN HOW
LACKLUSTER THIS MORNING`S FOG EVENT HAS BEEN THUS FAR.
WEAK SURFACE LOW OVER IOWA IS PROGGED TO DISSIPATE TODAY WITH
SURFACE CYCLOGENESIS TAKES PLACE OVER THE SOUTHERN HIGH PLAINS.
AS THE LOW WEAKENS...LOOK FOR SURFACE FRONTOLYSIS TO BEGIN WITH
WARMFRONT OVER OUR CWA. AS THE SYNOPTIC FRONT WEAKENS IT WILL OPEN
THE DOOR FOR LAKE MICHIGAN`S CHILLING EFFECTS TO TAKE OVER LATER
THIS AFTERNOON AND EVENING. WEAK AND WEAKENING PRESSURE GRADIENT IN
THE VICINITY OF THE WEAKENING FRONT WILL LIKELY ALLOW A LAKE BREEZE
FRONT TO DEVELOP THIS AFTERNOON DUE IN PART TO THE INCREASINGLY
LARGE THERMAL DIFFERENTIAL BETWEEN CHILLY MARINE AIR MASS OVER THE
LAKE AND UNSEASONABLY WARM AND ALMOST HUMID AIR OVER LAND. AS THE
COOL MARINE AIR ENCOUNTERS 50F+ DEWPOINTS IT APPEARS TO BE A CLASSIC
SET-UP FOR VERY DENSE MARINE FOG TO DEVELOP AND SEEP INLAND THIS
EVENING AS THE CHILLY MARINE AIR ENCOUNTERS NOT MUCH RESISTANCE AND
IT ABLE TO SPREAD PRETTY FAR INLAND. IF IT WEREN`T FOR
UNCERTAINTIES REGARDING TIMING OF FOG STARTING AND ENDING...WOULD
PROBABLY BE ISSUING A DENSE FOG ADVISORY NOW FOR THIS EVENING FOR
PORTIONS OF NE IL. DENSE FOG COULD DEVELOP FARTHER INLAND THIS
EVENING AWAY FROM THE MARINE LAYER...MAINLY NEAR AND TO THE NORTH
OF THE WEAKEN WARM FRONT. CONFIDENCE IN DENSE FOG DEVELOPING HERE
IS LOWER.
MODEL THAT HAS BEEN BEST FITTING THE CONCEPTUAL MODEL OF HOW I
EXPECT THINGS TO EVOLVE TODAY HAS BEEN THE EXPERIMENTAL HRRR AND
HAVE USED A TIME LAGGED ENSEMBLE APPROACH WITH THIS MODEL TO
POPULATE SHORT TERM HOURLY TEMP/DEWPOINT/WIND GRIDS INTO THIS
EVENING. DESPITE CLOUD COVER STILL EXPECT TEMPS TO WARM UP NICELY
TODAY...ESPECIALLY SOUTHERN CWA WHERE THEY ARE SOLIDLY IN THE WARM
SECTOR. WARMING TREND IN TEMPS WILL LIKELY BE ABRUPTLY HALTED NEAR
THE LAKE BY EARLY-MID AFTERNOON WHEN LAKE BREEZE FRONT BEGINS MOVING
INLAND AND KNOCKING TEMPS BACK INTO THE 40S NEAR THE LAKE AND
RESULTING IN FALLING TEMPS EVEN WELL INLAND BY EARLY EVENING. TOUGH
CALL ON HOW QUICKLY TEMPS WILL WARM IN CHICAGO BEFORE LAKE AIR
SPREADS INLAND...BUT EXPERIMENTAL HRRR SUGGESTS ORD WILL PROBABLY
NOT GET MUCH ABOVE MID TO MAYBE UPPER 50S BEFORE TEMPS FALL LATE IN
THE EVENING WITH FOG...PROBABLY DENSE LIKELY TO FOLLOW.
TONIGHT...SOUTHERN PLAINS CYCLONE WILL BEGIN MOVING NORTH AND THE
NOW LAKE RE-ENFORCED WARM FRONT WILL BEGIN TO STRENGTHEN AGAIN AND
STRENGTHENING PRESSURE FALLS SHOULD CAUSE THE FRONT TO BEGIN MOVING
NORTH AGAIN. SHOULD BEHAVE LIKE A TYPICAL MARCH WARM FRONT BECOMING
SOMEWHAT CONTORTED AROUND LAKE MICHIGAN WITH NORTH SHORE AREAS
LIKELY BEING THE LAST AREA IN OUR CWA TO MAKE IT INTO THE WARM
SECTOR. EXPECT FOG TO PRIMARILY BE A PROBLEM AHEAD OF THE WARM FRONT
WITH DRAMATICALLY IMPROVING VISIBILITIES AS THE WARM FRONT LIFTS
NORTHWARD. TEMPS IN THE WARM SECTOR TONIGHT WILL LIKELY HOLD IN THE
UPPER 50S TO LOWER 60S...WITH A RAPID RISE IN TEMPERATURES FROM THE
40S TO NEAR 60 EXPECTED IN THE CHICAGO AREA OVERNIGHT AS THE WARM
FRONT LIFTS NORTH.
PRECIP-WISE...NOT EXPECTED MUCH MEASURABLE PRECIP UNTIL TONIGHT.
COULD BE SOME DRIZZLE WITH THE DENSE MARINE FOG AND HRRR SUGGESTS A
FEW LIGHT SHOWERS LATE THIS AFTERNOON IN VICINITY OF THE WARM FRONT.
TONIGHT...THE MAIN FOCUS FOR SHOWERS AND SOME THUNDERSTORMS LOOKS TO
REMAIN MOSTLY TO THE WEST OF OUR CWA CLOSER TO THE STRONG ISENTROPIC
ASCENT AND NEAR THE NOSE OF THE LOW LEVEL JET. STILL EXPECT SOME OF
THIS SHOWER ACTIVITY TO MAKE IT INTO MAINLY NORTH CENTRAL ILLINOIS
WITH A LESSER THREAT OF SHOWERS OVER THE REMAINDER OF THE CWA.
SUNDAY SHOULD BE WINDY AND UNSEASONABLY WARM WITH A PERIOD OR TWO OF
SHOWERS LIKELY...ESPECIALLY WESTERN AND NORTHERN PORTIONS OF THE
AREA. DEPENDING ON THE COVERAGE OF SHOWERS...WE COULD MAKE A RUN AT
THE RECORD HIGHS FOR THE DAY...THOUGH DECIDED TO KEEP TEMPS SOMEWHAT
CONSERVATIVE IN THE GRIDS FOR NOW WITH MAINLY LOW 60S NORTH AND MID
60S SOUTH. ADDITIONAL SHOWERS ARE EXPECTED SUNDAY NIGHT AS FAIRLY
STRONG COLD FRONT EVENTUALLY MOVES ACROSS THE AREA. MAJORITY OF
SUNDAY NIGHT WILL BE WINDY AND UNSEASONABLY WARM WITH TEMPS CLOSE TO
IF NOT IN THE 60S BEFORE COLD FRONT MOVES THROUGH CLOSER TO DAWN
RESULTING IN LOW TEMPS NOT OCCURRING UNTIL AFTER SUNRISE.
IZZI
&&
.LONG TERM...
331 AM CST
MONDAY THROUGH FRIDAY...
WINDY AND MUCH COOLER WEATHER IS ON TAP FOR MONDAY WITH SHOWERS IN
THE MORNING LIKELY TAPERING OFF AND ENDING BY OR PERHAPS DURING THE
EARLY AFTERNOON. WE SHOULD GET A BRIEF BREAK BETWEEN SYSTEM TUESDAY
WITH DRY CONDITIONS AND CONTINUED ABOVE NORMAL TEMPS...BUT MUCH LESS
SO THAN THIS WEEKEND.
NEXT SYSTEM MOVES THROUGH MIDWEEK...BUT AT THIS POINT LOOKS PRETTY
MOISTURE STARVED AS IT WILL BE FAST ON THE HEELS OF THE WEEKEND
SYSTEM WHICH SHOULD BE PRETTY EFFECTIVE AT SCOURING OUT THE
MOISTURE. IN THE WAKE OF THIS STORM IT LOOKS LIKE WE WILL GET A
TASTE OF MORE TYPICAL DECEMBER TEMPERATURES FOR A FEW DAYS LATER
THIS WEEK INTO THE WEEKEND WITH HIGHS NOT GETTING OUT OF THE 30S. IN
FACT...IF THE ECMWF VERIFIES FRIDAY/SATURDAY MAY NOT EVEN REACH 30F
FOR HIGHS WHICH WILL FEEL VERY COLD AFTER THIS WEEKEND`S NEAR RECORD
WARMTH BUT IN REALITY WILL ONLY BE A FEW DEGREES COLDER THAN NORMAL.
MEDIUM RANGE MODELS SUGGEST THAT THE LONGWAVE TROUGH RESPONSIBLE FOR
THE TASTE OF WINTER WILL BE PROGRESSIVE WITH A MODELS AND CPC BOTH
SUGGESTING A RETURN TO ABOVE AVERAGE TEMPERATURES CHRISTMAS WEEK.
IZZI
&&
.CLIMATE...
NEAR RECORD TEMPERATURES ARE FORECAST FOR THE AREA THROUGH
SUNDAY. HERE ARE THE CURRENT RECORD HIGH TEMPERATURES AND WARMEST
LOW TEMPERATURES ON RECORD FOR CHICAGO AND ROCKFORD.
CHICAGO:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 61 (1877) 48 (1968)
DEC 13 67 (1975) 46 (1920)
---------------------------------
ROCKFORD:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 60 (1991) 43 (1968)
DEC 13 57 (1975) 40 (1920)
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* IFR STRATUS THIS MORNING. SHOULD BE A BRIEF PERIOD OF VFR OR
HIGH END MVFR CIGS EARLY THIS AFTN BEFORE ANOTHER ROUND OF IFR-
LIFR STRATUS.
* MVFR VSBY ALSO MOVES IN EARLY THIS MORNING. AFTER A BRIEF PERIOD
OF VFR CONDITIONS EARLY THIS AFTN...VSBY DROPS BACK TO IFR TO
PERHAPS VLIFR THIS EVENING.
* EAST TO MAYBE NE WINDS THIS AFTN LESS THAN 10 KT.
JEE
//DISCUSSION...UPDATED 06Z...
A LOW IS WEAKENING OVER NORTHERN MISSOURI AND A WARM FRONT LIES
JUST SOUTH OF MDW THROUGH NORTHERN IL. THE WARM FRONT WILL VERY
SLOWLY LIFT NORTH THROUGH THIS MORNING AND EVENTUALLY STALL OUT
SOMEWHERE NEAR THE IL/WI STATE LINE. DO NOT HAVE A LOT OF
CONFIDENCE IN HOW FAR NORTH THE FRONT GETS AS GUIDANCE VARIES
GREATLY.
HAVE MUCH HIGHER CONFIDENCE IN STRATUS HANGING AROUND THROUGH THE
MORNING AND SITES HAVING MVFR VSBY OR BETTER TONIGHT. THE STRATUS
SEEMS TO BE INHIBITING DENSE FOG FROM FORMING WITH THE DENSER FOG
FORMING UNDER CLEAR OR SCT SKIES ACROSS WEST CENTRAL IL AND IOWA.
WINDS SHOULD BACK TO SOUTH THIS MORNING BEHIND THE WARM FRONT.
GUIDANCE SUGGESTS THERE SHOULD BE A VERY BRIEF PERIOD OF VFR
CONDITIONS EARLY THIS AFTERNOON BEFORE WINDS BECOME EAST AGAIN.
EXPECTING COOLER AIR OFF OF THE LAKE TO HIT THE MOIST AIR BEHIND
THE FRONT AND FORM ANOTHER IFR TO LIFR STRATUS LAYER AND DENSE
FOG. WINDS MAY EVEN VEER FARTHER NE THAN CURRENTLY FORECAST...BUT
HAVE HIGH CONFIDENCE IN FOG TONIGHT. SINCE FOG DID NOT PAN OUT
TONIGHT...ONLY WENT DOWN TO 3/4-1/2 SM FOR NOW...BUT THINKING
1/4SM FOG WILL FORM ACROSS THE REGION AND PERSIST INTO EARLY
SUNDAY MORNING IF NOT LATER.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MEDIUM CONFIDENCE IN VSBY TRENDS AND VALUES THROUGH THIS
MORNING.
* HIGH CONFIDENCE IN DENSE FOG TONIGHT...MEDIUM CONFIDENCE IN
TIMING.
* HIGH CONFIDENCE IN STRATUS TRENDS AND VALUES...MEDIUM CONFIDENCE
IN TIMING OF POTENTIAL VFR WINDOW AND HOW LONG IT WILL LAST.
* HIGH CONFIDENCE IN WIND SPEEDS...MEDIUM CONFIDENCE IN HOW FAR
NORTH WINDS WILL GO THIS AFTN.
JEE
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
* SUNDAY...RA. IFR CIGS/VIS. STRONG/GUSTY SOUTH/SOUTHEAST WINDS.
* MONDAY...SHRA/MVFR LIKELY. STRONG/GUSTY WEST/SOUTHWEST WINDS.
* TUESDAY...DRY/VFR. SOUTHERLY WINDS.
* WEDNESDAY...DRY/VFR. GUSTY SOUTHWEST WINDS.
* THURSDAY...DRY/VFR. WESTERLY WINDS.
&&
.MARINE...
301 AM CST
A DENSE FOG ADVISORY WILL LIKELY BE NEEDED FOR THE SOUTHERN HALF OF
THE LAKE TODAY. HOWEVER...I HAVE LOW CONFIDENCE IN WHEN THE DENSE
FOG WILL DEVELOP AND HOW LONG IT WILL PERSIST INTO THIS AFTERNOON OR
EVENING SO I WILL NOT BE ISSUING A DENSE FOG ADVISORY NOW. BOATERS
SHOULD BE PREPARED FOR DENSE FOG AND SEVERELY REDUCED VISIBILITIES.
A WEAKENING LOW IS OVER IOWA AND THE LOW WILL WEAKEN BEFORE ENTERING
ILLINOIS TODAY. A WARM FRONT LIES JUST SOUTH OF THE THIS MORNING AND
WILL SHIFT NORTH BUT REMAIN OVER THE SOUTHERN END OF THE LAKE
THROUGH SUNDAY. DENSE FOG IS EXPECTED TO FORM BEHIND THE FRONT. A
LAKE BREEZE WILL LIKELY FORM THIS AFTERNOON ALONG THE IL SHORE. THE
NEXT LOW FORMS OVER THE SOUTHERN PLAINS EARLY SUNDAY MORNING WITH
WINDS BECOMING SOUTHEAST ACROSS THE SOUTHERN HALF OF THE LAKE. EAST
WINDS TO 30 KT ARE EXPECTED ACROSS THE NORTHERN HALF OF THE LAKE.
SOUTHEAST WINDS INCREASE TO 30 KT SUNDAY. A SMALL CRAFT ADVISORY
WILL BE NEEDED FOR SUNDAY POTENTIALLY THROUGH MONDAY
EVENING...HOWEVER THERE MAY BE A PERIOD OF GALES MONDAY SO WILL HOLD
OFF ON ISSUING A SMALL CRAFT ADVISORY NOW.
SOUTHEAST WINDS INCREASE TO LOW END GALES SUNDAY NIGHT. THE LOW
SHIFTS NORTH OVER WISCONSIN MONDAY WITH SOUTH TO SOUTHWEST GALES
MAINLY OVER THE SOUTHERN END OF THE LAKE. MAY SEE A FEW GALE FORCE
GUSTS ACROSS THE NORTHERN END. THE LOW PASSES OVER THE NORTHERN END
OF THE LAKE MONDAY EVENING AND NIGHT WITH WINDS BECOMING WEST BEHIND
IT. THE NEXT LOW FORMS OVER THE PLAINS TUESDAY. GUIDANCE SUGGESTS
THIS LOW WILL HAVE A SIMILAR PATH TO THE LOW THIS WEEKEND OR SHIFT
NORTH ACROSS MINNESOTA. EITHER WAY SOUTH TO SOUTHWEST WINDS
INCREASE TO AT LEAST 30 KT WEDNESDAY WITH GALES POSSIBLE ACROSS THE
SOUTHERN HALF OF THE LAKE. ANOTHER SMALL CRAFT ADVISORY MAY BE
NEEDED AS WELL. WEST WINDS 15-25 KT ARE THEN EXPECTED THROUGH LATE
NEXT WEEK.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1156 PM CST FRI DEC 11 2015
.UPDATE...
ISSUED AT 859 PM CST FRI DEC 11 2015
A warm frontal feature is poised just north of I-64 approaching
central IL this evening with widespread low cloud cover and a few
reports of drizzle ahead of it through central IL. Behind the
front...some clearing at low levels is noted in the
observations...especially southwest of Springfield, and may need
to adjust forecasts to account for this. However...any clearing of
skies may lead to increased fog density. Otherwise...very warm
temperatures mainly in the 50s expected overnight...potentially
leading to a few record warm minimum temperatures.
&&
.SHORT TERM...(Tonight)
ISSUED AT 239 PM CST FRI DEC 11 2015
Overcast low clouds below 2k ft and patchy fog and drizzle lifting
northward from southern into central IL and reaching north of
Lincoln by mid afternoon. These low clouds and will overspread rest
of northern CWA next few hours. HRRR model has been handling this
quicker timing of arrival of IFR clouds well and even have a few
sites with vsbys below 1 mile with Paris the lowest at 1/2 mile in
fog. South to southeast winds advecting low level moisture northward
into central IL this afternoon and this to continue tonight with
patchy drizzle as well. Continue slight chances of light rain
showers over central and eastern IL tonight though mostly a trace
event tonight.
A 1000 mb surface low pressure over southeast Nebraska will weaken
to 1010 mb as it moves into south central IA by dawn Sat. One warm
front near I-74 to lift into northern IL tonight while another warm
front near I-70 will slowly lift northward across central IL
tonight. Weak lift along with boundary to develop very light
precipitation along with areas of fog and patchy drizzle especially
east of the IL river with very moist low levels from surface up to
850 mb. SSE winds 5-10 mph and low clouds will not allow temps to
drop too much tonight. Unseasonably mild lows range from around 50F
nw of the IL river to the upper 50s in southeast IL from I-70
southeast.
.LONG TERM...(Saturday through Friday)
ISSUED AT 239 PM CST FRI DEC 11 2015
Models finally in better agreement with timing of the approaching
system for this weekend. However, all models still have trended a
little slower with the system as it moves into and through the CWA.
Before the main system gets here, light, warm advection type pcpn
will move across the state during the day on Sat. This will include
cloudy skies and much warmer temps...with some sites reaching or
exceeding record temps. Then the main punch of the pcpn will begin
late Sat night and continue through Sunday and Sun night. Models
have also trended with less pcpn through the period, but still
showing around an inch in the east and over 1.5 inches west of I-55.
The heaviest pcpn looks to be Sun afternoon and Sun evening. The
pcpn will diminish on Monday, with just chance pops for mainly Mon
morning. By afternoon, things should push to the east and northeast.
Besides the record warmth on Sat, Sunday highs will also be quite
warm...well above normal for middle of Dec. Once the system moves
through, temps will decrease but still be above normal.
The main focus for next week, Mon night through Friday, will be the
slightly cooler temps and then the decreasing temps back to normal
for later in the week. With the upper level flow remaining
southwesterly in the extended, another wave or two will move
northeast through the flow. However, with the gulf being blocked,
there should be limited moisture in the area for any weak system to
work with. So, only slight chc pops expected for when the weak wave
moves through, which will be Tue night through Wed night. Besides
this, dry weather is expected most of the area through most of the
week.
Temps will stay above normal through about Wed and then fall to
around normal for the end of the week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
ISSUED AT 1156 PM CST FRI DEC 11 2015
Overcast ceilings mainly IFR-MVFR range from around KMQB-KPRG
northward with low level clearing to the south behind a warm
frontal boundary. Patchy dense fog to the north...and widespread
MVFR visibilities to the south. Overnight...KPIA-KBMI-KCMI will be
most likely to see dense fog with the boundary in the
vicinity...however patchy dense fog to the south will also be
possible. Some improvement in ceilings/visibility possible for
afternoon...but ceilings unlikely to rise much over lower-end
MVFR. Gradually trending toward better chances for light rain
showers after 15Z saturday as increasing moist southerly flow
develops. Winds primarily ESE 6-10 kts turning southerly
overnight after warm frontal passage.
&&
.CLIMATE...
ISSUED AT 300 AM CST FRI DEC 10 2015
Record highs for the weekend:
Location Today Saturday Sunday
DEC 11 DEC 12 DEC 13
---------- --------- --------- ---------
Bloomington 65 (1949) 65 (1896) 63 (1975)
Champaign 64 (1949) 62 (1991) 64 (1975)
Charleston 66 (1931) 67 (1949) 64 (1991)
Decatur 65 (1949) 65 (1929) 66 (1975)
Effingham 60 (1979) 67 (1929) 65 (1991)
Lincoln 66 (1949) 64 (1929) 64 (1975)
Peoria 64 (1949) 62 (1991) 63 (1975)
Springfield 67 (1949) 64 (1929) 67 (1948)
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Onton
SHORT TERM...07
LONG TERM...Auten
AVIATION...Onton
CLIMATE...Geelhart
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
421 AM EST SAT DEC 12 2015
.SYNOPSIS...
WELL ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE
WEEKEND...WITH THE CHANCE FOR A PASSING SHOWER TODAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A WARM FRONT WILL GLIDE THROUGH THE REGION THIS MORNING...OPENING
THE DOOR FOR STRONG WARM AIR ADVECTION. LIMITED UPPER LEVEL
SUPPORT WILL KEEP SHOWER CHANCES LOW AND HAVE CONTINUED WITH THE
PREVIOUS IDEA OF SLIGHT CHANCE/LOW CHANCE POPS TODAY. FRONT MOVES
INTO NEW YORK STATE THIS AFTERNOON...AND AN UPPER LEVEL RIDGE WILL
SLOWLY BUILD OVER THE OHIO VALLEY. THIS WILL DECREASE RAIN
CHANCES...SO ANY LINGERING POPS WILL BE HIGHLIGHTED OVER THE
NORTHERN THIRD OF THE AREA. CLOUD COVER WILL BE TRICKY AS MODEL
SOUNDINGS KEEP THE LAYER BELOW 5000FT SATURATED THROUGHOUT THE
DAY. HOWEVER...WITH STRONG WARM AIR ADVECTION...TEMPERATURES WILL
BE WELL ABOVE NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
WITH THE UPPER LEVEL RIDGE IN CONTROL TONIGHT...AND THE WARM
FRONT WELL NORTH OF THE AREA...HAVE GONE WITH A DRY FORECAST
INCLUDING VERY MILD TEMPERATURES FOR MID DECEMBER. REGION WILL
REMAIN IN THE WARM SECTOR THROUGH SUNDAY NIGHT. THIS WILL KEEP THE
AREA DRY AND EVENTUALLY DECREASE CLOUD COVER FROM SOUTH TO NORTH
ON SUNDAY AFTERNOON. TEMPERATURES SHOULD REACH CLOSE TO 20 TO 25
DEGREES ABOVE NORMAL ON SUNDAY.
MODELS CONTINUE TO SLOW EASTWARD MOVEMENT OF MONDAY`S COLD
FRONT...HOLDING PASSAGE OFF UNTIL LATE MONDAY MORNING/AFTERNOON.
EVEN AT THIS TIME...THERE ARE STILL SOME MINOR DIFFERENCES
BETWEEN MODEL SOLUTIONS ON TIMING...SO FELT A BLEND WAS PRUDENT
WITH THIS FEATURE. GUSTY WINDS ARE POSSIBLE ALONG AND BEHIND THE
FRONT AS A STRONG LOW-LEVEL JET WILL ACCOMPANY THE BOUNDARY.
WOULD THINK THE BEST CHANCE FOR STRONGER GUSTS WOULD ARRIVE LATER
ON MONDAY/MONDAY NIGHT WHEN THE COLD AIR ADVECTION TAKES OVER.
EVEN WITH WIDESPREAD CLOUD COVER AND SHOWERS MONDAY...HIGHS WILL
STILL BE ABOUT 20 DEGREES ABOVE NORMAL.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
COLD POOL STRATOCU WILL SETTLE IN OVER THE REGION MONDAY NIGHT AND
TUESDAY. TEMPERATURES WILL BEGIN TO WORK THEIR WAY BACK TO NORMAL
LEVELS. THE NEXT SYSTEM WILL SWING THROUGH THE AREA THURSDAY.
MODELS HAVE NOT YET COME TO AN AGREEMENT ON TIMING AND HOW MUCH
PRECIPITATION WILL ACCOMPANY THE BOUNDARY. WILL USE A BLEND OF
MODEL SOLUTIONS FOR MOST OF THE LONG TERM. DOES APPEAR THAT THE
WEEK WILL END ON A NOTICEABLY COLDER NOTE.
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
DETERIORATION TO MVFR CIGS IS ANTICIPATED THIS MRNG WITH PASSAGE
OF A WARM FRONT...BUT VFR IS ANTICIPATED BY AFTERNOON AS AREA
TERMINALS SHOULD BE WELL WITHIN THE WARM SECTOR. LATEST NAM AND
GFS SOLNS ARE NOT AS PESSIMISSTIC AS PREVIOUS AND WILL FOLLOW
THAT TREND WITH HRRR LOW CLD COVER AS LGT SFC WIND VEERS TO THE S
AND SSW TWD MIDDAY.
.OUTLOOK...SUNDAY THROUGH WEDNESDAY/...
THE NXT CHC FOR GENL RESTRICTIONS IS EXPECTED WITH THE APCH AND
PASSAGE OF A MONDAY CDFNT.
&&
.CLIMATE...
RECORD HIGHS FOR PITTSBURGH
DECEMBER 12TH 65 IN 2007
DECEMBER 13TH 71 IN 1901
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
1233 AM EST SAT DEC 12 2015
.SYNOPSIS...
WELL ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE
WEEKEND...WITH THE CHANCE FOR A PASSING SHOWER TODAY.
&&
.NEAR TERM /THROUGH TODAY/...
MINOR ADJUSTMENTS TO OVERNIGHT POPS AND TEMPERATURES. REST OF THE
FORECAST IN GOOD SHAPE.
A WARM FRONT WILL GLIDE THROUGH THE REGION THIS MORNING...OPENING
THE DOOR FOR STRONG WARM AIR ADVECTION. LIMITED UPPER LEVEL
SUPPORT WILL KEEP SHOWER CHANCES LOW AND HAVE CONTINUED WITH THE
PREVIOUS IDEA OF SLIGHT CHANCE/LOW CHANCE POPS TODAY. FRONT MOVES
INTO NEW YORK STATE THIS AFTERNOON...AND AN UPPER LEVEL RIDGE WILL
SLOWLY BUILD OVER THE OHIO VALLEY. THIS WILL DECREASE RAIN
CHANCES...SO ANY LINGERING POPS WILL BE HIGHLIGHTED OVER THE
NORTHERN THIRD OF THE AREA. CLOUD COVER WILL BE TRICKY AS MODEL
SOUNDINGS KEEP THE LAYER BELOW 5000FT SATURATED THROUGHOUT THE
DAY. HOWEVER...WITH STRONG WARM AIR ADVECTION...TEMPERATURES WILL
BE WELL ABOVE NORMAL.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
WITH THE UPPER LEVEL RIDGE IN CONTROL TONIGHT...AND WARM FRONT
WELL NORTH OF THE AREA...HAVE GONE WITH A DRY FORECAST WITH VERY
MILD TEMPERATURES FOR MID DECEMBER. REGION WILL REMAIN IN THE WARM
SECTOR THROUGH SUNDAY NIGHT. THIS WILL KEEP THE AREA DRY AND
EVENTUALLY DECREASE CLOUD COVER FROM SOUTH TO NORTH ON SUNDAY
AFTERNOON. TEMPERATURES SHOULD REACH CLOSE TO 20 TO 25 DEGREES
ABOVE NORMAL ON SUNDAY.
MODELS CONTINUE TO SLOW EASTWARD MOVEMENT OF MONDAY`S COLD
FRONT...HOLDING PASSAGE OFF UNTIL LATE MONDAY MORNING/AFTERNOON.
EVEN AT THIS TIME...THERE ARE STILL SOME MINOR DIFFERENCES
BETWEEN MODEL SOLUTIONS ON TIMING...SO FELT A BLEND WAS PRUDENT
WITH THIS FEATURE. GUSTY WINDS ARE POSSIBLE ALONG AND BEHIND THE
FRONT AS A STRONG LOW-LEVEL JET WILL ACCOMPANY THE BOUNDARY.
WOULD THINK THE BEST CHANCE FOR STRONGER GUSTS WOULD ARRIVE LATER
ON MONDAY WHEN THE COLD AIR ADVECTION TAKES OVER. EVEN WITH
WIDESPREAD CLOUD COVER AND SHOWERS MONDAY...HIGHS WILL STILL BE
ABOUT 20 DEGREES ABOVE NORMAL.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
COLD POOL STRATOCU WILL SETTLE IN OVER THE REGION MONDAY NIGHT AND
TUESDAY. TEMPERATURES WILL BEGIN TO WORK THEIR WAY BACK TO NORMAL
LEVELS. THE NEXT SYSTEM WILL SWING THROUGH THE AREA THURSDAY.
MODELS HAVE NOT YET COME TO AN AGREEMENT ON TIMING AND HOW MUCH
PRECIPITATION WILL ACCOMPANY THE BOUNDARY. WILL USE A BLEND OF
MODEL SOLUTIONS FOR MOST OF THE LONG TERM. DOES APPEAR THAT THE
WEEK WILL END ON A NOTICEABLY COLDER NOTE.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
DETERIORATION TO MVFR CIGS IS ANTICIPATED THIS MRNG WITH PASSAGE
OF A WARM FRONT...BUT VFR IS ANTICIPATED BY AFTERNOON AS AREA
TERMINALS SHOULD BE WELL WITHIN THE WARM SECTOR. LATEST NAM AND
GFS SOLNS ARE NOT AS PESSIMISSTIC AS PREVIOUS AND WILL FOLLOW
THAT TREND WITH HRRR LOW CLD COVER AS LGT SFC WIND VEERS TO THE S
AND SSW TWD MIDDAY.
.OUTLOOK...SUNDAY THROUGH WEDNESDAY/...
THE NXT CHC FOR GENL RESTRICTIONS IS EXPECTED WITH THE APCH AND
PASSAGE OF A MONDAY CDFNT.
&&
.CLIMATE...
RECORD HIGHS FOR PITTSBURGH
DECEMBER 12TH 65 IN 2007
DECEMBER 13TH 71 IN 1901
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1141 PM EST FRI DEC 11 2015
.SYNOPSIS...
WELL ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE
WEEKEND...WITH THE CHANCE FOR A PASSING SHOWER TODAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
MINOR ADJUSTMENTS TO OVERNIGHT POPS AND TEMPERATURES. REST OF THE
FORECAST IN GOOD SHAPE.
A WARM FRONT WILL GLIDE THROUGH THE REGION THIS MORNING...OPENING
THE DOOR FOR STRONG WARM AIR ADVECTION. LIMITED UPPER LEVEL
SUPPORT WILL KEEP SHOWER CHANCES LOW AND HAVE CONTINUED WITH THE
PREVIOUS IDEA OF SLIGHT CHANCE/LOW CHANCE POPS TODAY. FRONT MOVES
INTO NEW YORK STATE THIS AFTERNOON...AND AN UPPER LEVEL RIDGE WILL
SLOWLY BUILD OVER THE OHIO VALLEY. THIS WILL DECREASE RAIN
CHANCES...SO ANY LINGERING POPS WILL BE HIGHLIGHTED OVER THE
NORTHERN THIRD OF THE AREA. CLOUD COVER WILL BE TRICKY AS MODEL
SOUNDINGS KEEP THE LAYER BELOW 5000FT SATURATED THROUGHOUT THE
DAY. HOWEVER...WITH STRONG WARM AIR ADVECTION...TEMPERATURES WILL
BE WELL ABOVE NORMAL.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
WITH THE UPPER LEVEL RIDGE IN CONTROL TONIGHT...AND WARM FRONT
WELL NORTH OF THE AREA...HAVE GONE WITH A DRY FORECAST WITH VERY
MILD TEMPERATURES FOR MID DECEMBER. REGION WILL REMAIN IN THE WARM
SECTOR THROUGH SUNDAY NIGHT. THIS WILL KEEP THE AREA DRY AND
EVENTUALLY DECREASE CLOUD COVER FROM SOUTH TO NORTH ON SUNDAY
AFTERNOON. TEMPERATURES SHOULD REACH CLOSE TO 20 TO 25 DEGREES
ABOVE NORMAL ON SUNDAY.
MODELS CONTINUE TO SLOW EASTWARD MOVEMENT OF MONDAY`S COLD
FRONT...HOLDING PASSAGE OFF UNTIL LATE MONDAY MORNING/AFTERNOON.
EVEN AT THIS TIME...THERE ARE STILL SOME MINOR DIFFERENCES
BETWEEN MODEL SOLUTIONS ON TIMING...SO FELT A BLEND WAS PRUDENT
WITH THIS FEATURE. GUSTY WINDS ARE POSSIBLE ALONG AND BEHIND THE
FRONT AS A STRONG LOW-LEVEL JET WILL ACCOMPANY THE BOUNDARY.
WOULD THINK THE BEST CHANCE FOR STRONGER GUSTS WOULD ARRIVE LATER
ON MONDAY WHEN THE COLD AIR ADVECTION TAKES OVER. EVEN WITH
WIDESPREAD CLOUD COVER AND SHOWERS MONDAY...HIGHS WILL STILL BE
ABOUT 20 DEGREES ABOVE NORMAL.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
COLD POOL STRATOCU WILL SETTLE IN OVER THE REGION MONDAY NIGHT AND
TUESDAY. TEMPERATURES WILL BEGIN TO WORK THEIR WAY BACK TO NORMAL
LEVELS. THE NEXT SYSTEM WILL SWING THROUGH THE AREA THURSDAY.
MODELS HAVE NOT YET COME TO AN AGREEMENT ON TIMING AND HOW MUCH
PRECIPITATION WILL ACCOMPANY THE BOUNDARY. WILL USE A BLEND OF
MODEL SOLUTIONS FOR MOST OF THE LONG TERM. DOES APPEAR THAT THE
WEEK WILL END ON A NOTICEABLY COLDER NOTE.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
DETERIORATION TO MVFR CIGS IS ANTICIPATED THIS MRNG WITH PASSAGE
OF A WARM FRONT...BUT VFR IS ANTICIPATED BY AFTERNOON AS AREA
TERMINALS SHOULD BE WELL WITHIN THE WARM SECTOR. LATEST NAM AND
GFS SOLNS ARE NOT AS PESSIMISSTIC AS PREVIOUS AND WILL FOLLOW
THAT TREND WITH HRRR LOW CLD COVER AS LGT SFC WIND VEERS TO THE S
AND SSW TWD MIDDAY.
.OUTLOOK...SUNDAY THROUGH WEDNESDAY/...
THE NXT CHC FOR GENL RESTRICTIONS IS EXPECTED WITH THE APCH AND
PASSAGE OF A MONDAY CDFNT.
&&
.CLIMATE...
RECORD HIGHS FOR PITTSBURGH
DECEMBER 12TH 65 IN 2007
DECEMBER 13TH 71 IN 1901
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15/22
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
331 AM EST SAT DEC 12 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM EST SAT DEC 12 2015
...QUIET WEATHER TODAY BEFORE SIGNIFICANT RAINFALL SUNDAY INTO
MONDAY...
WEAK E-NE UPSLOPE FLOW CONTINUES...ALLOWING FOR SNOW SHOWERS ALONG
NORTH CENTRAL UPPER MICHIGAN AS WELL AS IN THE KEWEENAW. IT IS
ACTUALLY INTERESTING THAT THE PRECIPITATION IS SNOW RATHER THAN
DRIZZLE/FREEZING DRIZZLE AS IT WOULD SEEM HARD TO IMAGINE MUCH ICE
NUCLEI IN THE SHALLOW /2000 FT/ AND RELATIVELY WARM /-4C/ CLOUD.
SHORT TERM NWP DOES NOT SUGGEST ANY SEEDING FROM HIGHER CLOUD IS
POSSIBLE. GIVEN A SIMILAR THERMAL AND MOISTURE PROFILE THIS
MORNING...WILL MAINTAIN SLIGHT CHANCE OF SN/DZ/FZDZ THROUGH NOON.
THEN...THE HRRR SUGGESTS THAT ANY REMAINING DRIZZLE WILL END WITH
SOME SLIGHT LOW LEVEL MIXING.
LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST TONIGHT.
STRONG WARM ADVECTION AND ISENTROPIC LIFT WILL MOVE NORTHWARD INTO
THE UPPER GREAT LAKES BY SUNDAY MORNING. THE 00Z NWP SEEM BE BE IN
EXCELLENT AGREEMENT IN BRINGING RAIN ACROSS MUCH OF THE SOUTHERN
HALF OF THE U.P. AFT 09Z AND TO THE MAJORITY OF UPPER MI EXCEPT THE
KEWEENAW AND THE EASTERN 1/3 BY 12Z. AS SUCH...WILL KEEP POPS
MINIMAL THIS EVENING...THE RAPIDLY RAISE TO LIKELY ACROSS THE WEST
AND CENTRAL BTWN 09-12Z. IN FACT...WILL GO WITH CATEGORICAL POPS
FOR FAR SOUTHERN MENOMINEE COUNTY BY 12Z.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 443 PM EST FRI DEC 11 2015
MODELS SUGGEST THAT AN ACTIVE PROGRESSIVE PATTERN WILL ALLOW COLDER
AIR OVER THE WEST TO SLIDE INTO THE THE CNTRL CONUS BY LATER NEXT
WEEK. AS A RESULT...TEMPS STARTING OUT WELL ABOVE NORMAL...NEAR
RECORD VALUES INTO MONDAY WILL DROP OFF TO CLOSER TO NORMAL VALUES BY
THU-FRI.
SATURDAY NIGHT THROUGH MONDAY...A STRONG SRN STREAM SYSTEM IS
EXPECTED TO LIFT FROM THE SRN PLAINS TO THE WRN LAKES. THE 12Z/11
ECMWF REMAINS SLOWER WITH THE SYSTEM COMPARED TO THE 12Z GFS/GEM
WITH THE OCCLUDED SFC LOW SLIDING OFF TO THE EAST THROUGH UPPER MI
LATE MON INSTEAD OF LIFTING THE SFC LOW INTO LAKE SUPERIOR MONDAY.
HOWEVER...EITHER SCENARIO WILL BRING PLENTY OF WARM AIR INTO THE CWA
TO SUPPORT ONLY RAIN THROUGH SUN NIGHT. VERY STRONG MOISTURE
ADVECTION WILL PUSH PWAT VALUES TO CLIMATOLOGICALLY EXTREME VALUES
NEAR 1.30 INCH OR TO ABOUT A 6.0 SIGMA STANDARDIZED ANOMALY. TOTAL
RAINFALL AMOUNTS THROUGH IN THE 2 TO 3 INCH RANGE WILL BE POSSIBLE
ACROSS THE CWA WITH THE HEAVIEST AMOUNTS LIKELY OVER THE WEST HALF.
THE INITIAL BATCH OF RAIN WILL BE SUPPORTED BY AN AREA OF 290K-300K
ISENTROPIC LIFT WITH RAIN SPREADING TO THE NORTH THROUGH THE CWA AFT
06Z SUN. ADDITIONAL PERIODS OF RAIN SUN WILL BE SUPPORTED AS WEAKER
SHORTWAVES AHEAD OF THE MAIN SYSTEM LIFT TO THE NORTH. THE HEAVIEST
RAIN IS EXPECTED FROM SUN NIGHT INTO EARLY MONDAY WITH STRONG DEEP
LAYER QVECTOR CONV AND UPPER LEVEL DIV AS THE MID LEVEL LOW LIFTS TO
NE IA AND SRN WI. A BLEND OF THE GFS/ECMWF MAX TEMP ALOFT USED IN
DEFINING PCPN TYPE THROUGH MONDAY. A GRADUAL MIX TO WET SNOW FROM
WEST TO EAST WILL BE POSSIBLE OVER THE WEST MON MORNING AND CNTRL
UPPER MI BY LATE AFTERNOON AND EVENING. SNOW AMOUNTS OF A FEW INCHES
MAY BE POSSIBLE. HOWEVER...GIVEN THE SIGNIFICANT MODEL DIFFERENCES
CONFIDENCE IS LOW.
TUE-FRI...THE GFS/GEFS AND ECMWF SUGGEST ANOTHER SHORTWAVE AND SFC
LOW WILL LIFT FROM THE CNTRL PLAINS TO THE UPPER MS VALLEY AND LAKE
SUPERIOR BY WED. WARMER AIR TO THE EAST OF THE CONSENSUS LOW TRACK
WILL FAVOR MAINLY RAIN OVER THE EAST HALF OF UPPER MI WITH SNOW OVER
WEST. THE ECMWF WAS AGAIN SLIGHTLY WARMER THAN THE GFS/GEM. IN THE
WAKE OF THE SYSTEM...COLDER AIR MOVES IN THE 850 MB TEMPS TO AROUND
-15C. THIS WILL SUPPORT INCREASING LES CHANCES FOR W TO NW FLOW
FAVORED LOCATIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1233 AM EST SAT DEC 12 2015
AT THE LEAST...LOW TO MID RANGE MVFR CIGS ARE EXPECTED AT ALL SITES
THROUGH THE PERIOD AS MOISTURE REMAINS TRAPPED BELOW AN INVERSION.
DUE TO UPSLOPE EASTERLY FLOW...LOWER CIGS ALONG WITH FOG AND
POSSIBLY SOME DZ/FZDZ COULD FORM LATER TONIGHT AT KSAW AND
KCMX...BUT CONFIDENCE ON THE EXTENT REMAINS LOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 330 AM EST SAT DEC 12 2015
AS LOW PRESSURE OVER THE CENTRAL PLAINS DEVELOPS AND MOVES NORTHEAST
TODAY...EXPECT EAST-NORTHEAST WINDS TO SLOWLY INCREASE TODAY...WITH
WINDS OF 25KT ACROSS THE WEST HALF BY THIS EVENING. AS THE LOW
CONTINUES TO MOVE NORTHEAST TOWARD THE GREAT LAKES LATER TONIGHT
INTO SUNDAY NIGHT...WINDS WILL CONTINUE TO INCREASE WITH WINDS OF
GALE FORCE ACROSS THE WEST HALF BY SUNDAY AFTERNOON. NE GALES WILL
CONTINUE INTO MONDAY NIGHT ACROSS THE WEST HALF AND MAY ALSO SPREAD
TO THE EAST HALF ON MONDAY AFTERNOON AS THE LOW FINALLY MOVES
NORTHEAST OF THE AREA AND COLDER AIR FILTERS ACROSS THE LAKE ON
NORTHERLY WINDS. WINDS WILL SUBSIDE TO 20 KT BY TUESDAY BEFORE
ANOTHER LOW PRESSURE SYSTEM DEVELOPS AND MOVES INTO THE UPPER GREAT
LAKES FOR WEDNESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SUNDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
LSZ162-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...JLB
AVIATION...JLA
MARINE...MRD
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1056 PM CST FRI DEC 11 2015
.UPDATE...
ISSUED AT 1047 PM CST FRI DEC 11 2015
UPDATED TO INCLUDE 06Z AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 340 PM CST FRI DEC 11 2015
THE SHORT TERM IS DEFINITELY THE CALM BEFORE THE STORM WITH THE
BIG CHANGE MADE THROUGH THE DAY SATURDAY BEING TO REDUCE POPS
THROUGHOUT THE PERIOD.
THIS AFTERNOON...THE SFC RIDGE THAT WORKED ACROSS MN THIS MORNING
IS NOW WORKING ACROSS WI...WITH EASTERLY LOW LEVEL WINDS SETTING
UP AS LEE CYCLOGENESIS SLOWLY EVOLVES ACROSS COLORADO. LEAD
SHORTWAVE EMANATING FROM THE MAIN WRN THROUGH IS WORKING ACROSS
CENTRAL NODAK THIS AFTERNOON AND IS ON ITS WAY FOR SOUTHERN
MANITOBA. PRECIP ASSOCIATED WITH THIS WAVE HAS BEEN TIED TO
MOISTURE AND ISENTROPIC LIFT ON THE 295K SFC...AND THE RAP SHOWS
THIS AREA OF FORCING/MOISTURE HEADING FOR NW MN...SO REMOVED WHAT
LITTLE POPS WE HAD FOR TODAY AND THIS EVENING ACROSS WESTERN AND
CENTRAL MN.
LATER TONIGHT...WE WILL SEE ANOTHER AREA OF PRECIP PUSH NORTH ON
THE LEADING EDGE OF THE FIRST MOISTURE SURGE. THERE WILL LIKELY
BE AN AREA OF DRIZZLE/LIGHT RAIN ASSOCIATED WITH IT...BUT PRIMARY
MOISTURE TRANSPORT AT 925MB WILL BE GOING FROM EASTERN IOWA TOWARD
THE MICH/WI BORDER. AS A RESULT...KEPT THE FORECAST DRY FOR
TONIGHT ACROSS THE ENTIRE MPX CWA...AS ANY DZ/RA PRODUCTION LOOKS
TO OCCUR SOUTHEAST OF OUR FORECAST AREA.
FOR SATURDAY...CONTINUED THE TREND OF DRYING THE FORECAST AS
WELL...AS GUIDANCE IS IN GOOD AGREEMENT ON THE BULK OF THE PRECIP
WITH THIS WEEKENDS SYSTEM COMING AFTER 00Z SUNDAY /SATURDAY
EVENING/. THE ONE EXCEPTION IS THE DEVELOPMENT OF A BAND OF
ELEVATED FGEN IN THE H7-H6 LAYER SATURDAY AFTERNOON. MOST
GUIDANCE...CAM AND NON-CAM ALIKE...SHOW A BAND OF PRECIP
DEVELOPING IN WRN MN AND WORKING UP TO CENTRAL MN DURING THE
AFTERNOON...SO THIS WAS WHERE PRECIP MENTION WAS MAINTAINED...
EVERYWHERE ELSE WE KEPT DRY UNTIL WE GET INTO SATURDAY EVENING...
WHEN THINGS LOOK TO GO DOWNHILL PRETTY QUICK. LOOKS PLENTY WARM
ENOUGH SATURDAY AFTERNOON TO KEEP THE VAST MAJORITY OF THE PRECIP
WE SEE AS RAIN...THOUGH WE MAY SEE A SNOWFLAKE OR TWO MIX IN OUT
TOWARD ALEXANDRIA. WITH RAIN EXPECTED TO DOMINATE...REMOVED ANY
SNOW ACCUMULATIONS FROM SATURDAY AS WELL.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 340 PM CST FRI DEC 11 2015
WIDESPREAD RAIN IS STILL ON TRACK FOR THE WEEKEND INTO MONDAY WITH
1-3 INCHES OF RAIN IN THE EASTERN FORECAST AREA...TAPERING TO
ABOUT A HALF INCH OF LIQUID IN WESTERN MN. AT THIS POINT...WESTERN
MN IS THE MOST SUSCEPTIBLE TO A FEW INCHES OF SNOW GIVEN THE
COOLER TEMPERATURE PROFILE IN THIS AREA.
THE NAM AND ECMWF HAVE BEEN DIALED IN WITH ONLY SMALL WOBBLES IN
THE SURFACE LOW TRACK OVER THE PAST 3 RUNS GOING BACK TO LAST
NIGHT. THE GFS HAS SHOWN A LITTLE MORE RUN-TO-RUN VARIABILITY OVER
THE PAST 3-4 RUNS. AS PREVIOUS DISCUSSIONS HAVE MENTIONED...THE
FORECAST LOW TRACK HAS THE LOOK OF A MAJOR WINTER STORM...ITS
SIMPLY TOO WARM. BOTH THE 60HR CIPS ANALOG FROM THE NAM AND THE
72HR ANALOG FROM THE GFS SUGGEST WE SHOULD BE GETTING READY TO
ISSUE WINTER STORM WATCH HEADLINES ACROSS MOST OF OUR MINNESOTA
COUNTIES...AGAIN NOT EVEN CLOSE WITH THESE TEMPERATURES. WHAT WE
ARE CONFIDENT IN...IS WIDESPREAD 1"+ RAIN TOTALS ACROSS EASTERN
MN AND WESTERN WI. WE NOW HAVE 100% RAIN IN THE FORECAST FOR
SEVERAL PERIODS SAT-MON. SOUTHEAST MN AND WESTERN WI COULD GET A
FEW RUMBLES OF THUNDER AS WELL.
THE MODEL CONSENSUS IS FOR A LOW TRACK OUT OF THE SOUTHERN PLAINS
ACROSS NORTHEAST IA AND INTO NORTHERN WI FROM SATURDAY NIGHT INTO
MONDAY MORNING. THERE WILL BE TWO MAIN BURSTS OF PRECIP...THE
FIRST IS WITH THE MOISTURE SURGE AND ISENTROPIC LIFT SATURDAY
NIGHT...FOLLOWED BY A RELATIVE LULL...AND THE SECOND SURGE SUNDAY
MORNING/AFTERNOON WITH THE CLASSIC FLUID DEFORMATION - THIS LINGERS
INTO MONDAY. THE ONE AREA OF CONCERN IS IN WESTERN MN...WHERE SOME
OF THE MODEL GUIDANCE HAS TRENDED A BIT COOLER. AS IT STANDS
NOW...WE ARE FORECASTING 1-3" OF SNOW NEAR AND WEST OF A LINE FROM
GRANITE FALLS...TO SAUK CENTRE...TO STAPLES - WITH A WINTRY MIX OF
PRECIP. THE COLD SIDE OF THIS SYSTEM ISN/T AS COLD AS WE MIGHT
EXPECT...WHICH IS WHY WE AREN`T GOING WITH HIGHER SNOW TOTALS AT
THIS POINT. HOWEVER...STRONG SYSTEMS LIKE THIS THAT DEEPEN AS
THEY LIFT OUT OF THE PLAINS CAN DYNAMICALLY LOWER THE FREEZING
LEVEL AND GIVE YOU A QUICKER CHANGEOVER TO SNOW. IF THAT WERE TO
HAPPEN...LOCATIONS SUCH AS ALEXANDRIA...GRANITE FALLS AND BENSON
COULD END UP WITH SEVERAL INCHES OF SNOW - MAYBE AS MUCH AS 6".
WE`LL CONTINUE TO WATCH OUR WESTERN MN AREA CLOSELY. THE
FORECAST SOUNDINGS DEFINITELY SHOW MORE SLEET IN THESE AREAS AS
WELL BECAUSE THEY HAVE COOLED BUT CONTINUE TO SHOW A WARM LAYER
ALOFT.
THE TRAILING SYSTEM TUESDAY NIGHT AND WEDNESDAY STILL LOOKS
COOLER WITH A BETTER CHANCE FOR SNOW. IT HAS A VERY SIMILAR TRACK
TO THE WEEKEND STORM...HOWEVER...IT IS ALSO DRIER AND FASTER. WE
WILL LEAVE IT THERE AND TAKE THIS ONE SYSTEM AT A TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1047 PM CST FRI DEC 11 2015
LOW SWATH OF CLOUDS HAS RETREATED JUST FAR ENOUGH...ALONG WITH
HIGH CLOUDS MOVING IN FROM THE S...SUCH THAT THE ERN 3 TAFS
/KMSP-KRNH-KEAU/ HAVE JUMPED UP TO VFR CONDS WITH CLOUDS ARND
SCT015 WHILE THE WRN 3 TAFS REMAIN UNDER LOWER MVFR TO IFR
CEILINGS. WITH A STRONG SLY SURGE OF MOISTURE MOVING INTO THE AREA
OVERNIGHT THRU TMRW...AM EXPECTING THE LOWER CLOUDS TO FILL BACK
IN SO WILL LOOK FOR ALL SITES TO HAVE IFR-OR-WORSE CEILINGS BY
DAYBREAK SAT MRNG. THE IFR CEILINGS WILL THEN REMAIN IN PLACE ALL
DAY SAT THRU SAT EVE AHEAD OF THE FIRST BATCH OF RAIN EXPECTED TO
REACH THE AREA TMRW EVE. HAVE STAGGERED THE START TIME OF THE -RA
FOR NOW BUT THIS MAY WELL NEED TO BE ADJUSTED SLIGHTLY IN LATER
TAF ISSUANCES. WINDS TO REMAIN OUT OF THE ENE IN THE 5-10 KT
RANGE.
KMSP...KMSP MANAGED TO FIND ITSELF IN THE CLEAR EARLIER THIS
EVENING BUT AM NOT EXPECTING THAT TO LAST BEYOND 09Z-10Z. AM
EXPECTING IFR CEILINGS TO RETURN BY DAYBREAK SAT MRNG AND REMAIN
THERE THROUGH AT LEAST TMRW EVE.
/OUTLOOK FOR KMSP/
SUN...IFR WITH PERIODS OF RA. WINDS NE TO N 10-15 KTS.
MON...MVFR/IFR. -RA/-SN POSSIBLE EARLY. WINDS NW 15-20 KTS.
TUE...VFR EARLY. MVFR/IFR WITH CHC -SN LATE. WINDS E 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
UPDATE...JPC
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...JPC
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1123 PM CST FRI DEC 11 2015
.UPDATE:
Issued at 937 PM CST Fri Dec 11 2015
Updated forecast to include areas of fog across the northern CWA
where visibility ranges from 1/4SM at IRK to 4SM at UIN. Have also
updated for latest temperature and dewpoint trends. Walked outside
a few minutes ago and everything is soaked as low level moisture
continues to increase and condense on the cooler ground.
CVKING
&&
.SHORT TERM: (Through Late Tonight)
Issued at 336 PM CST Fri Dec 11 2015
Forecast problem for tonight is sky cover and possibility of fog.
Low clouds have mostly cleared out of central Missouri, but are
hanging tough across eastern Missouri and much of southern and
central Illinois. Model guidance has been less than helpful so far
in forecasting these low clouds...though the HRRR has been the best
so far. HRRR has the low clouds continuing to push northeast this
evening, but high clouds will likely persist over the area. The net
effect for the public forecast will still be a mostly cloudy to
cloudy sky regardless of what the low clouds ultimately decide to
do. While there could be some fog tonight, boundary layer winds
look too strong to support truly dense fog...except possibly over
the eastern Ozarks. However, it`s more likely that low visibility
will be caused by low clouds which are forecast to redevelop over
the higher terrain. South-southwest flow combined with clouds will
keep lows well above normal tonight. MOS guidance in the low to mid
50s looks very reasonable.
Carney
.LONG TERM: (Saturday through Next Friday)
Issued at 336 PM CST Fri Dec 11 2015
(Saturday through Monday)
Operational models are showing a slightly slower motion of the upper
low toward the area over the weekend which will result in a slower
onset of the steadier showers on Saturday night and Sunday. Before
then, still expect chances of light rain to increase during the day
on Saturday as transport of moisture from the Gulf increases via
40kt low level jet. Then showers and scattered thunderstorms will
spread across the area on Saturday night and Sunday as strong
moisture convergence moves from west to east across the area
under enhanced ascent caused by negatively tilting mid level
trough. The rain will continue into Sunday night before ending
during the day Monday as the trough lifts out of the area.
While temperatures will cool off slightly over the weekend because
of the rain, they will remain above normal because of the warm
sector. There will not be much of diurnal swing because of the
clouds and rain.
(Tuesday through Friday)
The GFS and ECMWF are depicting similar solutions to yesterday with
an upper low moving from the southern Rockies into the Great Lakes
at midweek. Most of the dynamics look to be staying to the
northwest of our area with this system, and the most of the moisture
will be staying to the south, so precipitation will be limited. The
system will still pull a cold front through the area on Wednesday
with 850mb temperatures falling to around -10C on the ECMWF by
Friday behind it. This still confirms that temperatures will go
from well above normal on Tuesday to near mid December normals by
Friday.
Britt
&&
.AVIATION: (For the 06z TAFs through 06z Saturday Night)
Issued at 1113 PM CST Fri Dec 11 2015
Latest obs from UIN suggest that wrmfnt has lifted N of terminal.
If the fnt remains N of the terminal, expect VFR conditions to
persist thru sunrise. However, can not rule out the fnt dropping
back S. If this occurs, FG at terminal will be possible and
probably LIFR visbys or lower.
COU is expected to have MVFR cigs, with some FG possible, late
tonight into Sat morning. These cigs shud lift during the morning
and become VFR with a swly wind.
SUS/CPS...have added mention of LLWS. LLJ may diminish slightly
overnight, but is expected to be around 40 kts. If sites remain
decoupled, anticipate at least some FG to develop late tonight and
lift to ST after sunrise as a secondary sfc trof moves thru the
area.
Specifics for KSTL: Expect VFR conditions overnight with MVFR
clouds developing Sat morning and lifting thru the day. Winds will
remain sly to sswly until Sat eve when they back to ssely.
Tilly
&&
.CLIMATE:
Record max temps through the weekend...
FRI 12/11 SAT 12/12 SUN 12/13
STL 70/1979 70/1991 73/1948
COU 73/1949 74/1889 75/1948
UIN 69/1949 67/1991 67/1948
Record hi lows through the weekend...
FRI 12/11 SAT 12/12 SUN 12/13
STL 53/1965 55/1929 56/1889
COU 55/1965 46/1929 55/1889
UIN 55/1965 42/1991 50/1927
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...Dense Fog Advisory until 10 AM CST Saturday FOR Knox MO-Lewis MO-
Shelby MO.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1205 AM CST SAT DEC 12 2015
.UPDATE...
ISSUED AT 1205 AM CST SAT DEC 12 2015
THE LATEST WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH NOW LIFTING
TO THE NORTHERN BORDER AND SLOWLY SHIFTING INTO SOUTHERN CANADA.
LOCAL RADAR AND SURFACE OBSERVATIONS CONTINUE TO ADVERTISE LIGHT
SNOW MAINLY NORTH OF HIGHWAY 2...WITH LIGHT FREEZING DRIZZLE FROM
TIOGA INTO WATFORD CITY. THE 00Z NAM 4KM BUFKIT SOUNDINGS AT
WILLISTON AND WATFORD CITY SHOW ENOUGH VERTICAL MOTION WITHIN THE
SUPERCOOLED WATER DROPLET SPECTRUM PORTION OF THE SOUNDING FOR
POSSIBLE LIGHT FREEZING DRIZZLE...AND WILL MAINTAIN THAT IN THE
FORECAST AND SPS/SPECIAL WEATHER STATEMENT THAT WAS ISSUED EARLIER.
THIS HAS SUPPORT FROM CURRENT/PREVIOUS OBSERVATIONS AND LATEST
WEBCAMS AS WELL AS THE BUFKIT SOUNDINGS THROUGH 15Z SATURDAY. THE
FORECAST REMAINS ON TRACK WITH LOW CLOUDS DOMINATING ALL BUT THE FAR
SOUTHWEST OVERNIGHT INTO SATURDAY...WHICH WILL REMAIN MOSTLY CLEAR
TO PARTLY CLOUDY.
UPDATE ISSUED AT 933 PM CST FRI DEC 11 2015
MAIN CHANGE FOR LATE EVENING UPDATE WAS TO ADJUST BACK EDGE OF
SNOW A BIT OVER THE NORTH. OTHERWISE...REMAINDER OF FORECAST
REMAINS GOOD WITH THE POSSIBILITY OF FOG AND FREEZING
DRIZZLE...WITH SOME VERY LIGHT FREEZING DRIZZLE CURRENTLY BEING
OBSERVED AT NWS BISMARCK.
UPDATE ISSUED AT 757 PM CST FRI DEC 11 2015
HAVE SENT OUT A QUICK UPDATE TO ADD PATCHY FREEZING DRIZZLE TO THE
FORECAST OVER MUCH OF THE AREA. SOME LIGHT DRIZZLE STARTED AT THE
OFFICE WITHIN THE PAST HOUR. THIS IS SUPPORTED IN LATEST MODEL
RUN FORECAST SOUNDINGS SHOWING LACK OF ICE CRYSTALS IN SHALLOWER
CLOUD LAYER AS AREA OF SNOW EXITS TO THE NORTHEAST. UPDATES HAVE
BEEN SENT.
UPDATE ISSUED AT 618 PM CST FRI DEC 11 2015
SNOW CONTINUES TO GRADUALLY DIMINISH OVER THE AREA WITH THE BACK
EDGE RUNNING ALONG AND NEAR HIGHWAY 52. THIS TREND WILL CONTINUE
THROUGH THIS EVENING AS UPPER LOW/TROUGH CONTINUES TO LIFT TO THE
NORTH-NORTHEAST. WITH THE FRESH SNOW AND PLENTY OF LOW LEVEL
MOISTURE IN PLACE HAVE BROADENED OUT THE POSSIBILITY OF FOG THIS
EVENING AND OVERNIGHT. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 241 PM CST FRI DEC 11 2015
LATEST RADAR LOOPS HAVE THE BACK EDGE OF THE PRECIPITATION
APPROACHING A NEW SALEM TO BEULAH LINE. EXPECT THE SNOW TO END
WEST OF THE MISSOURI RIVER BY 4 PM. RADAR LOOPS ALSO SHOW THE
SYSTEM MAY BE LIFTING NORTH A BIT FASTER NOW SO THE SNOW WILL
PROGRESSIVELY END THIS EVENING NORTH. EXPECT STORM TOTALS 2 TO 3
INCHES ACROSS CENTRAL NORTH DAKOTA AND 1 TO 2 INCHES NORTH.
ISOLATED 4 INCH AMOUNTS ARE POSSIBLE SOUTH CENTRAL SUCH AS
BISMARCK.
TONIGHT WITH LOW LEVEL MOISTURE IN PLACE WILL SEE CLOUDS ALL BUT
THE FAR SOUTHWEST WHERE A SOUTHWEST WIND COMPONENT AT H925-850 MAY
ERODE CLOUD DECK A BIT. OTHERWISE CLOUDY. BASED ON THE HRRR KEPT
SOME FOG IN AFTER MIDNIGHT THROUGH SATURDAY MORNING WEST CENTRAL
AND SOUTH.
ON SATURDAY WILL DONT SEE ANYTHING THAT WILL CLEAR CLOUDS SO
CLOUDY EXCEPT FOR THE FAR SOUTHWEST. HIGHS WILL BE LIMITED TO THE
LOWER 30S EXCEPT MID TO UPPER 30S SOUTHWEST.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 241 PM CST FRI DEC 11 2015
SATURDAY NIGHT A LONGWAVE TROUGH IS WELL ESTABLISHED OVER THE
ROCKIES TO 4-CORNERS AREA. SHORTWAVE ENERGY MOVING NORTHEASTWARD
UPSTREAM OF THE TROUGH GLANCES THE JAMES RIVER VALLEY SATURDAY NIGHT
INTO SUNDAY MORNING. AREAS SOUTH OF JAMESTOWN COULD RECEIVE 1/2 INCH
TO AN INCH OF SNOW.
ATTENTION THEN TURNS TO THE NEXT STORM SYSTEM MOVING EAST ACROSS THE
ROCKIES. ON SUNDAY ANOTHER LONGWAVE TROUGH MOVES INTO THE WEST COAST
AND DIGS SOUTH TOWARDS CALIFORNIA. THE SYSTEM CONTINUES TO DEEPEN AS
IT MOVES ACROSS THE ROCKIES SUNDAY NIGHT AND MONDAY. UNCERTAINTIES
CONTINUE REGARDING PLACEMENT/TIMING OF THIS SYSTEM...BUT MODEL
CONSENSUS WOULD SUGGEST THE LEADING EDGE OF SHORTWAVE ENERGY AND
MOISTURE REACHING THE WESTERN DAKOTAS MONDAY AFTERNOON/EVENING. THE
MODELS DEVELOP THE STORM SYSTEM SUCH THAT THE TRACK OF THE MID-LEVEL
LOW MOVES FROM COLORADO ACROSS THE CENTRAL PLAINS TO EASTERN SOUTH
DAKOTA BY TUESDAY AFTERNOON AND INTO MINNESOTA TUESDAY NIGHT. THIS
LATEST RUN OF THE MODELS SUGGESTS SOUTHERN NORTH DAKOTA COULD
RECEIVE MODERATE SNOW AMOUNTS WITH LIGHT AMOUNTS IN THE NORTHWEST
AND NORTH CENTRAL...AND THIS OCCURRING OVER A PERIOD FROM MONDAY
AFTERNOON THROUGH TUESDAY NIGHT/WEDNESDAY MORNING. THIS TRACK WOULD
SUGGEST THAT AREAS SOUTH AND EAST OF OUR AREA WOULD RECEIVE THE BULK
OF PRECIPITATION WITH THIS SYSTEM.
ANOTHER SHORTWAVE DIVES SOUTHEAST OUT OF ALBERTA/SASKATCHEWAN
WEDNESDAY/THURSDAY...BUT WITH MUCH LESS MOISTURE AND ONLY SLIGHT
CHANCES OF LIGHT SNOW/FLURRIES.
A COOLING TREND THROUGH THE LONG TERM...WITH SEASONABLE TEMPERATURES
EXPECTED BY THE MIDDLE AND END OF NEXT WEEK...WITH HIGHS IN THE 20S
AND LOWS IN THE SINGLE DIGITS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1205 AM CST SAT DEC 12 2015
ALL TERMINALS EXCEPT KDIK WILL REMAIN IN A MVFR/IFR CIG STATUS THROUGH
THE TAF PERIOD. EXPECT POCKETS OF LIGHT FREEZING DRIZZLE AT KISN
THROUGH 15Z SATURDAY. OTHERWISE VCFG WILL ACCOMPANY THE LOW
CLOUDS...WITH PERIODIC MVFR TO IFR VSBYS FAVORING KMOT/KJMS
THROUGH SATURDAY MORNING. KDIK WILL REMAIN ON THE FRINGE OF MVFR
CIGS/VSBYS...AND WILL BE MONITORED CLOSELY FOR ANY CHANGES.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...WAA
LONG TERM...JV
AVIATION...KS
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
232 AM CST SAT DEC 12 2015
.SHORT TERM...
MAIN CONCERN FOR THE SHORT TERM PERIOD WILL BE INCREASING CHANCES
FOR RAIN SHOWERS AND THUNDERSTORMS...WITH A BRIEF WINDOW FOR A FEW
STORMS TO POSSIBLY NEAR STRONG LEVELS.
SFC TEMPS PER 08Z METARS WERE MILD FOR THIS TIME OF YEAR /40S AND
50S/ COURTESY OF S-SW SFC WINDS...WHICH IS A WIND COMPONENT
CONDUCIVE FOR DRY AND WARM CONDITIONS. HOWEVER...DEWPOINTS IN THE
40S EXISTED ACROSS THE LOW ROLLING PLAINS AS THE WIND WAS MORE FROM
THE S-SE THUS AIDING TO FILTER IN GULF MOISTURE. IN FACT...LOW
CLOUDS AND/OR FOG WERE NOTED ACROSS THE BIG COUNTRY REGION...WHICH
MAY HAVE A CHANCE AT SPREADING TOWARDS THE ROLLING PLAINS AOA
SUNRISE. THE HRRR IS MOST AGGRESSIVE IN THE STRATUS DECK/FOG MAKING
IT AS FAR NW TO KLBB...WITH OTHER SOLUTIONS MAINTAINING THE IT TO
THE LOW ROLLING PLAINS AND PERHAPS THE SRN SOUTH PLAINS. HENCE WILL
BE KEEPING AN EYE ON TRENDS FOR THE NEXT SEVERAL HOURS.
THE STORM SYSTEM OF INTEREST IS AN UA TROUGH DRAPED FROM THE GREAT
BASIN TO ACROSS WRN AZ EARLY THIS MORNING. MOST MODEL SOLUTIONS
AGREE THAT THIS SYSTEM WILL BE RATHER PROGRESSIVE...AS IT IS PROGGED
TO BE ACROSS ERN AZ/WRN NM THIS AFTN TO ACROSS CNTRL NM THIS
EVENING...AND FINALLY ACROSS THE PANHANDLE REGION LATE TONIGHT/EARLY
SUN MORNING...ALL THE WHILE EVOLVING TO MORE OF A CLOSED OFF STATE.
THE ECMWF STILL REMAINS THE OUTLIER WITH IT BEING SLIGHTLY SLOWER
AND FARTHER SOUTH VERSUS THE NAM AND GFS SOLUTIONS. THIS AFTN-
EVENING AS THE SYSTEM DRAWS NEAR...ITS SFC COUNTERPART WILL RESPOND
BY DEEPENING AND THEREFORE PROMOTE A TIGHTENED PRESSURE GRADIENT
WHILST TRANSLATING EAST ACROSS THE CWA. MOS GUIDANCE HINTS AT SFC
WIND SPEEDS OF 15-25 MPH OUT OF THE W-SW...WITH THE BREEZIEST
CONDITIONS NOTED ON THE CAPROCK. OFF THE CAPROCK...SFC WINDS WILL BE
OUT OF THE S-SE. PERSISTENT SWRLY FLOW ALOFT AIDING IN TRANSPORTING
HIGH LEVEL CIRRUS CLOUD COVER WILL BE SLOW TO CLEAR OUT FROM WEST TO
EAST...WHERE IF THERE WERE CLEAR SKIES...WIND CONDITIONS COULD BE A
LOT WORSE. CLOUD COVER WILL BE LAST TO CLEAR OUT ACROSS THE ERN
ZONES GIVEN THE FAVORABLE UPSLOPE WIND COMPONENT.
CONCURRENTLY...A 160 KT 250 MB JET MAX WILL MOVE ACROSS THE
CWA...PROVIDING UL SUPPORT AND ENCOURAGE THE DEVELOPMENT OF SHOWERS
AND THUNDERSTORMS MOVING IN FROM WEST TO EAST. MID-LEVEL INSTABILITY
IS NOT VERY IMPRESSIVE /400-600 J/KG/ BUT THE 0-6 KM BULK SHEAR OF
40-70 KTS AND A SLIGHT COOLING IN THE MID-LEVELS /STEEPENING LAPSE
RATES/ DO SUGGEST SOME THUNDERSTORMS APPROACHING STRONG LEVELS
/HAIL AND WIND THE PRIMARY THREATS/ PARTICULARLY ACROSS THE ROLLING
PLAINS...COINCIDING WITH THE BEST MOISTURE AND MID-LEVEL INSTABILITY.
KEEP IN MIND...IF THE CLOUD COVER HANGS AROUND A LITTLE LONGER THAN
ANTICIPATED ACROSS THE ROLLING PLAINS...THE LITTLE BIT OF MID-LEVEL
INSTABILITY MAY NOT BE ENOUGH TO OVERCOME THE CAPPED ATMOSPHERE AND
THUS STRONG THUNDERSTORMS MAY NOT BECOME REALIZED. THE LLJ KICKING
UP INTO THE 40-50 KT RANGE WILL MAINTAIN STORMS ACROSS THE ROLLING
PLAINS THIS EVENING-TONIGHT WHILST THE REMAINDER OF THE CWA BECOMES
ENVELOPED BY DRY-SLOTTING /W-SW WINDS/. SOUNDING PROFILES INDICATE
THIS SCENARIO RATHER WELL WITH TOP-DOWN MOISTENING OCCURRING THIS
AFTN-EVENING...AND DRYING ENSUING IN THE MID AND UPPER LEVELS BY
TONIGHT. LCL/S ARE A BIT LOW ACROSS THE FAR ROLLING PLAINS WHICH
RAISES CONCERNS FOR A TORNADO RISK. HOWEVER...THE AMOUNT OF 0-6 KM
BULK SHEAR MIGHT BE TOO MUCH OF A GOOD THING...AS IT COULD PREVENT
STORMS FROM MAINTAINING GOOD STRUCTURE.
500 MB HEIGHT FALLS WILL LEAD TO A COOLER ALBEIT STILL UNSEASONABLY
WARM SATURDAY...WITH HIGHS IN THE 60S AND 70S...FOLLOWED BY LOWS IN
THE 30S AND 40S.
.LONG TERM...
COULD SEE A FEW LIGHT RAIN OR SNOW SHOWERS SUNDAY MORNING ACROSS THE
FAR SRN PANHANDLE AS THE CLOSED LOW SLOWLY EJECTS TO THE ENE ACROSS
THE PANHANDLE TO NWRN OKLAHOMA. HOWEVER...MAIN STORY TURNING OUT TO
BE WIND AS TIGHT LOW TO MID LEVEL HEIGHT GRADIENT ON THE S/SW FLANKS
OF THE UPPER LOW WILL LIKELY TRANSLATE INTO AT LEAST 20-30 MPH RANGE
ACROSS MUCH OF THE FCST AREA IN LINE WITH MOS VALUES AS COLD
ADVECTION WILL LIMIT THE POTENTIAL FOR 50 KT MID LEVEL WINDS TO MIX
TO THE SFC.
AFTER SHORT WAVE RIDGING BRINGS A WARMER AND LESS WINDY DAY
MONDAY...ANOTHER UPPER LOW PROGGED TO MOVE ACROSS THE COLORADO
ROCKIES MONDAY NIGHT AND ONTO THE CNTL HIGH PLAINS DURING THE DAY
TUESDAY. MODELS CURRENTLY PROGGING RAPID CYCLOGENESIS SERN COLO/SWRN
KANSAS EARLY TUESDAY WITH A MID LEVEL JET STREAK ON THE ORDER OF 50
TO 70 KTS ROTATING OVER THE SRN HIGH PLAINS DURING THE DAY TUESDAY.
DEEP COLD ADVECTION WILL AGAIN LIMIT POTENTIAL FOR MIXING TO THE
SFC...BUT AGAIN POTENTIAL EXISTS FOR AT LEAST 20-30 MPH TO BE
REALIZED.
BEYOND TUESDAY...A BROAD LONG WAVE UPPER TROUGH OVER THE WRN CONUS
WILL SHIFT EWD TO THE PLAINS WEDNESDAY LEAVING DRY AND UNEVENTFUL
NWLY FLOW OVER THE FCST AREA THROUGH THE END OF THE WEEK. COLD FRONT
OF CANADIAN ORIGIN BEHIND TUESDAYS UPPER LOW WILL BRING COLDER AIR
INTO THE REGION WITH TEMPS FINALLY REVERTING TO BELOW NORMAL
WEDNESDAY AND THURSDAY BEFORE MODERATING TO END THE WEEK.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
29/07
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
856 AM MST SAT DEC 12 2015
.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO SLOWLY MOVE THROUGH THE REGION
TODAY...RESULTING IN MOUNTAIN RAIN AND SNOW SHOWERS AND SUBSTANTIALLY
COOLER TEMPERATURES. ANOTHER FAST MOVING STORM SYSTEM WILL MOVE
THROUGH THE AREA ON MONDAY...USHERING IN ANOTHER ROUND OF COLD TEMPS
WHICH WILL LAST MUCH OF THE UPCOMING WEEK. SOME OF THE COLDEST LOW
TEMPERATURES OF THE SEASON ARE ANTICIPATED BY THE MIDDLE OF NEXT
WEEK.
&&
.DISCUSSION...
MID MORNING WATER VAPOR IMAGERY REVEALS LOW PRESSURE OVER SOUTHERN
ARIZONA WITH QUITE A BIT OF MOISTURE OVER THE ARIZONA/NEW MEXICO
BORDER AND POINTS EAST. WRAP-AROUND/DEFORMATION RAIN AND SNOW SHOWERS
ARE NOTED ON RADAR EAST OF PHOENIX THIS MORNING AND AT LEAST A FEW
SPOTS ABOVE 4500 FT HAVE SEEN MINOR ACCUMULATIONS EAST/SOUTH OF
GLOBE. RAIN HAS CEASED FOR THE MOST PART ACROSS THE LOWER DESERTS
/SANS A FEW SHOWERS AROUND SUPERIOR/ AND VIS IMAGERY ALONG WITH
WEBCAMS SUGGEST RAPID CLEARING IS MAKING ITS WAY INTO THE WEST VALLEY
AS OF 1545Z.
OPERATIONAL GLOBAL MODELS...LOCAL WRFS...AND SEVERAL RECENT RUNS OF
THE HRRR CONTINUE TO SHOW PRECIPITATION OVER THE MOUNTAINS NORTH/EAST
OF PHOENIX THROUGH AT LEAST MID AFTERNOON AS THE UPPER LEVEL
CIRCULATION SLIDES THROUGH THE AREA. DRY ADVECTION ACROSS THE WESTERN
2/3RDS OF THE FORECAST AREA WILL RESULT IN NEAR-ZERO CHANCES OF
PRECIPITATION FOR THE REST OF THE DAY /INCLUDING FROM PHOENIX
WESTWARD/...BUT THE MOUNTAINS EAST OF TOWN WILL SEE AT LEAST 60-70
PERCENT CHANCES THROUGH MID AFTERNOON. WITH SNOW LEVELS ALREADY
AROUND 5000FT AND OBSERVED SNOWFALL AROUND THIS ELEVATION...WILL NOT
BE MAKING ANY ADJUSTMENTS TO THE INHERITED WINTER WEATHER ADVISORY.
WHILE THERE COULD BE A STRAY RAIN OR SNOW SHOWER AT THE CONCLUSION
OF THE ADVISORY PERIOD...DRY ADVECTION WILL RAPIDLY PUT THE BRAKES ON
ANY LINGERING PRECIPITATION AFTER 00Z.
TEMPS LOOK IN GOOD SHAPE. BLENDED BIAS CORRECTED AND RAW GUIDANCE ALL
POINTING AT HIGHS BETWEEN 58-61 IN THE PHOENIX AREA AND IN THE UPPER
60S ACROSS SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA. ASIDE FROM
MINOR ADJUSTMENTS BASED ON OBSERVATIONAL TRENDS...NO CHANGES
NECESSARY TO TEMPERATURES.
&&
.PREVIOUS DISCUSSION...
SUNDAY...
A FAST MOVING HIGH PRESSURE SYSTEM WILL TRANSITION THROUGH
THE REGION AHEAD OF ANOTHER STRONG AND COLD PACIFIC WEATHER SYSTEM
FOR MONDAY. CLEAR SKIES AND COOL TEMPERATURES ARE FORECAST SUNDAY.
MONDAY...
ANOTHER STRONG PACIFIC WEATHER SYSTEM WILL MOVE INTO THE REGION
MONDAY MORNING. ALTHOUGH MOST DYNAMICS/UPPER LEVEL FORCING
WILL OCCUR OVER CENTRAL AND NORTHERN AZ MONDAY MORNING...A MOISTURE
RICH FRONTAL BAND WITH PRECIP WILL TRANSITION FIRST THROUGH
SOUTHEAST CA/COLORADO RIVER VALLEY LATE SUNDAY NIGHT...THEN
ACROSS SOUTH CENTRAL AZ INCLUDING PHOENIX MONDAY MORNING AND
AFTERNOON. THE SNOW LEVEL ON MONDAY WILL FALL TO BETWEEN 4000-4500
FEET...WITH LIGHT ACCUMULATION...HOWEVER THE REAL STORY IS MUCH
COLDER AND DRIER AIR FOLLOWING ON TUESDAY AND WEDNESDAY FOR
POSSIBLE NIGHT-TIME FREEZE WARNINGS.
TUESDAY AND WEDNESDAY...
A MUCH COLDER AND DRIER AIRMASS WILL SETTLE OVER THE REGION BEHIND
MONDAYS FRONTAL SYSTEM. MORNING TEMPERATURES ON THE LOWER DESERTS
TUESDAY AND WEDNESDAY COULD DROP INTO THE LOWER 20S TO MIDDLE 30S.
FREEZE WARNINGS MAY BE POSTED.
THURSDAY THROUGH SATURDAY...
EXCEPT FOR PERIOD OF HIGH CLOUDS...DRY NORTHWEST FLOW AND WARMER
TEMPERATURES ALOFT WILL START A WARMING TREND. CONSIDERABLE HIGH
CLOUDS AT TIMES SHOULD SERVE TO KEEP NIGHT TIME TEMPERATURES A BIT
WARMER.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
LINGERING SCT TO BKN CIGS AT AROUND 6K FEET EXPECTED INTO THIS
AFTERNOON WITH VERY LITTLE CHANCE OF ANY SHOWERS AFFECTING PHOENIX
TERMINALS. SKIES WILL CLEAR OUT AFTER SUNSET THIS EVENING. WINDS WILL
BE MOSTLY LIGHT AND SOMEWHAT VARIABLE THIS MORNING...TURNING
SOUTHWESTERLY AND BECOMING BREEZY AT TIMES THIS AFTERNOON. WINDS WILL
DIMINISH THIS EVENING AND EVENTUALLY SHIFT OUT OF THE EAST BY AROUND
MIDNIGHT.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SOME LINGERING CIGS AT KBLH THIS MORNING BEFORE SKIES CLEAR OUT BY
AROUND NOON TODAY. WINDS WILL BE GUSTY AT TIMES DURING THE DAYTIME
HOURS AND MAINLY OUT OF THE NORTHWEST. GUSTS WILL APPROACH 25-30 KTS
AT KBLH AND CLOSER TO 20 KTS AT KIPL BEFORE WINDS GRADUALLY DIMINISH
LATER THIS EVENING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
TEMPERATURES WILL REMAIN WELL BELOW NORMAL THROUGH THURSDAY WITH A
GRADUAL WARM UP COMMENCING FRIDAY. A DEEP LOW PRESSURE TROUGH WILL
AFFECT THE DESERT SOUTHWEST THROUGH MUCH OF NEXT WEEK BEFORE EXITING
LATE IN THE WEEK. THIS WILL BRING A CHANCE OF SHOWERS TO THE DESERTS ON
MONDAY WITH RAIN OR SNOW SHOWERS OVER HIGHER TERRAIN LOCATIONS.
FAIRLY MOIST CONDITIONS ON MONDAY WILL GIVE WAY TO DRYING STARTING
TUESDAY AS MINIMUM HUMIDITIES DROP INTO A 15 TO 30 PERCENT RANGE FOR
THE REST OF THE WEEK. GUSTY NORTHWESTERLY WINDS ARE LIKELY ON MONDAY
AND TUESDAY...ESPECIALLY AFFECTING THE LOWER COLORADO RIVER VALLEY.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR AZZ024.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS/VASQUEZ
AVIATION...KUHLMAN
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
825 AM MST SAT DEC 12 2015
.UPDATE...
ISSUED AT 822 AM MST SAT DEC 12 2015
QUARTER MILE VISIBILITY REPORTED AT GJT AND NUCLA...THEREFORE
ISSUED A DENSE FOG ADVISORY FOR THE NEXT COUPLE OF HOURS FOR THESE
AREAS. ALSO ADDED ZONE 11 ANTICIPATING VISIBILITY TO DECREASE ONCE
THE SNOW COMPLETELY ENDS SHORTLY ALONG THE HIGHWAY 50 CORRIDOR
FROM WHITEWATER THROUGH MONTROSE.
UPDATE ISSUED AT 654 AM MST SAT DEC 12 2015
STEADY SNOW HAS ENDED ACROSS EASTERN UTAH AND NORTHWEST
COLORADO...SO CANCELLED ADVISORIES AND WARNINGS IN UT ZONES 25 AND
28...AND CO ZONES 1...2 AND 3. THE POSSIBILITY OF A FEW FLURRIES
STILL EXISTS BUT THESE AREAS WILL NOT SEE ANY ADDITIONAL SNOW
ACCUMULATION. RAP AND HRRR INDICATING CONTINUATION OF SNOW ALONG
I-70 EAST OF GLENWOOD SPRINGS...IN THE SAN JUANS AND ALONG THE
CONTINENTAL DIVIDE.
UPDATE ISSUED AT 329 AM MST SAT DEC 12 2015
LATEST REPORT FROM DURANGO DISPATCH INDICATED 1 INCH OF SNOW
STICKING TO ROAD SURFACES WHILE WEBCAMS SHOWED SIMILAR CONDITIONS
AROUND TOWN. LATEST 06Z NAM CONTINUES TO SHOW BAND OF PRECIP OVER
MUCH OF SOUTHERN VALLEYS PERSISTING THROUGH MUCH OF THE DAY. IR
IMAGERY SHOWING PLENTY OF MOISTURE OVER THAT AREA AND MORE TO
COME FROM NEW MEXICO. SOME ENHANCEMENT CAN ALSO BE SEEN INDICATING
A GOOD POSSIBILITY FOR HEAVIER SNOWFALL. WATER VAPOR FURTHER
CORROBORATES THIS IDEA. WENT AHEAD AND ISSUED ADVISORIES FOR ALL
SOUTHERN VALLEYS FOR 2 TO 4 INCHES WITH HIGHER AMOUNTS POSSIBLE
FOR HIGHER ELEVATIONS. TEMPS CONTINUE TO HOVER AROUND FREEZING SO
WITH DAYBREAK...WOULD EXPECT SNOW ON ROADS TO MELT FAIRLY QUICKLY
WITH LITTLE IMPACT. IF THIS OCCURS...HIGHLIGHTS CAN BE TAKEN DOWN
EARLY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 256 AM MST SAT DEC 12 2015
ANOTHER STORM IS EXCEEDING EXPECTATIONS IN SEVERAL AREAS. WE WERE
DEALING WITH A HEAVY SNOW BAND RELATED TO A WELL FORMED MID LEVEL
FRONTOGENESIS BAND ACROSS NORTHWEST COLORADO WHICH DUMPED UP TO A
FOOT OF NEW SNOW IN LOWER ELEVATIONS. NOW WE LOOK UPSTREAM AT THE
APPROACHING MAIN LOW PRESSURE SYSTEM ANALYZED AT 00Z OVER SOUTHERN
NEVADA...AND AT 06Z SATELLITE IMAGERY SUGGESTS THIS CIRCULATION
HAS MOVED TO CENTRAL ARIZONA. WOULD HAVE TO SAY THE TRENDS ARE
SLOWER AND FARTHER SOUTH WITH THIS SYSTEM THAN MODELS SUGGESTED
YESTERDAY. WITH THE CYCLONE STILL TO THE WEST THETA SURFACES
SUGGEST A NEW WARM CONVEYOR BELT DELIVERING A GOOD SHOT OF
MOISTURE INTO WESTERN COLORADO THIS MORNING. THIS IS MORE THAN
APPARENT WITH THE RECENT ENHANCEMENTS ON THE REGIONAL RADAR MOSAIC
AND IR SATELLITE IMAGERY OVER EASTERN ARIZONA. THE BIG FORECAST
CHALLENGE IS WHAT DOES THAT MEAN FOR OUR AREA. THE MOISTURE
ADVECTION AND CONSTANT STREAM OF VIRGA OR LIGHT SHOWERS THIS
EVENING HAS CLOSED THE DEW POINT GAP ACROSS THE SOUTHERN VALLEYS
WHERE TEMPERATURES ARE STILL IN THE UPPER 30S. THE REAL COLD AIR
IS STILL BEING HELD BACK BY THE FLOW ALOFT SO PRECIPITATION TYPE
IS STILL QUITE TRICKY FOR THE SOUTHERN VALLEYS AS RAIN MAY HOLD
OUT LONGER THAN ANTICIPATED OR JUST TURN INTO MELTING SNOW. FOR
NOW WILL SIDE WITH THE TRENDS OF NEAR AN INCH OF THE DURANGO
AIRPORT WITH HIGHER AMOUNTS NEAR THE FOOTHILLS. PAGOSA SPRINGS
WILL SEE ANYWHERE FROM TO 1 INCH TO 3 INCHES NEAR THE HILLS. THE
PROBLEM AREAS DOWN SOUTH WILL MOST LIKELY BE THE HIGH SPOTS ALONG
HWY 160 LIKE THE MANCOS HILL AREA. THIS WCB WILL ALSO CONTAIN
BETTER INSTABILITY AS SEEN IN EPV FIELDS AND THIS SHOULD BE
RELEASED BY THE INCREASING LARGE SCALE ASCENT OVER THE SOUTHERN
CWA AS THE MID LEVEL CIRCULATION PASSES THROUGH FROM MID MORNING
ONWARD. COMPLICATED SITUATION AND EXPECT CHANGES TO GOING FORECAST
THROUGH THE DAY AS SOME OF THE VARIABLES BECOME MORE CLEAR. THE
SOUTHERN MOUNTAINS MAY BE IN FOR MORE SNOW THAN PREVIOUSLY
FORECAST AND WILL BE MONITORING FOR UPGRADES IF IMPACTS TO PASSES
BECOME MORE APPARENT. WE DID INCLUDE THE GUNNISON BASIN IN THE
LATEST WSW AS THIS MOISTURE PLUME WILL BE DIRECTED AT CERRO SUMMIT
AND THE BLACK CANYON AREA. THE SYSTEM SLOWLY PULLS EAST OF THE
DIVIDE THIS EVENING BEFORE STRENGTHENING IN THE LEE SIDE. DID KEEP
SOME HIGHER POPS INTO THIS EVENING TO ACCOUNT FOR THE SLOWER
MOVEMENT. OVERALL THE PCPN SHOULD BE DONE BY MIDNIGHT WITH A DRY
SUNDAY ON TAP. TEMPERATURES AND NEW SNOWFALL WILL BE THE MAIN
CHALLENGE ALONG WITH AREAS OF FOG DEVELOPING IN THE VALLEYS AND
BASINS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 256 AM MST SAT DEC 12 2015
RIDGING THAT BUILT IN SUNDAY WILL BE OVERHEAD SUNDAY NIGHT AND
QUICKLY SHIFT EASTWARD AS THE NEXT TROUGH APPROACHES FROM THE
WEST. MODELS IN FAIRLY GOOD AGREEMENT WITH EVOLUTION OF THIS
SYSTEM AND LOOKS SOMEWHAT SIMILAR TO THE STORM AFFECTING THE
REGION RIGHT NOW. SUBTLE DIFFERENCES EXIST OF COURSE BUT THE MAIN
GIST OF A COLD FRONT BRINGING WIDESPREAD SNOWFALL REMAINS. MAIN
DIFFERENCES WITH THIS SYSTEM WILL BE THAT COLD AIR WILL ALREADY BE
IN PLACE FROM THE PREVIOUS FRONT AND WILL ONLY BE REINFORCED FROM
THIS SECOND SYSTEM.
AS FAR AS DETAILS ARE CONCERNED...PRECIP WILL BEGIN MONDAY
MORNING FOR ERN UTAH AND SHIFT EASTWARD AS THE DAY PROGRESSES. BY
EVENING MOST...IF NOT ALL...AREAS WILL SEE SOME PRECIPITATION AS
THE CLOSED LOW AND ASSOD LIFT ARE POISED TO MOVE INTO WRN CO.
PLENTY OF THINGS CAN CHANGE BETWEEN NOW AND THEN THOUGH INCLUDING
THE LOW OPENING UP...UPPER LEVEL SUPPORT WANING...BEST LIFT SHIFTS
NORTH OR SOUTH...SO WILL HAVE TO SEE IF MODELS REMAIN CONSTANT IN
THIS OUTCOME. FOR NOW...6 TO 10 INCHES FOR THE MTNS AND 1 TO 3
INCHES FOR SOME VALLEYS LOOKS GOOD.
SNOWFALL WILL CONTINUE INTO TUESDAY BUT WITH BEST LIFT HAVING
SHIFTED TO THE PLAINS...ANTICIPATE A MORE SHOWERY NATURE TO
PRECIP. NORTHERLY FLOW WILL ALSO USHER IN COLDER AIR TO THE
REGION. SOME MTN SHOWERS...ESPECIALLY UP NORTH...MAY CONTINUE
THROUGH WEDNESDAY MORNING BUT ANTICIPATE MORE FLURRIES THAN
ANYTHING ELSE. MOST AREAS WILL SEE PARTLY CLOUDY SKIES AND MUCH
COLDER TEMPERATURES THAT WILL BE WELL BELOW NORMAL. AFTER
THAT...LITTLE PIECES OF WEAK ENERGY WILL DROP DOWN FROM THE NW
CAUSING SOME LIGHT SNOWFALL OVER THE PARK/GORE RANGES THROUGH
FRIDAY BUT AGAIN...NOT MUCH ACCUMULATION EXPECTED. EXPECT MORE
CLOUDS N OF I-70 THAN S DUE TO THESE DISTURBANCES. TEMPERATURES
WILL REMAIN BELOW NORMAL THROUGH LONG TERM PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 256 AM MST SAT DEC 12 2015
WIDESPREAD IFR CONDITIONS AND BELOW ARE BEING EXPERIENCED AT MOST
ASOS SITES THIS MORNING. ODD MAN OUT IS KVEL WHICH WILL LIKELY
STAY VFR SINCE THE FRONT HAS PASSED TO THE EAST. LOW CIGS/VIS
STILL POSSIBLE FOR THAT AERODROME SATURDAY NIGHT INTO SUNDAY
MORNING HOWEVER DUE TO FOG. SPEAKING OF...FOG POSSIBLE FOR MANY
TAF LOCATIONS THIS MORNING AND AGAIN TONIGHT. A HEAVIER BAND OF
PRECIP WILL CONTINUE TO SHIFT EASTWARD TODAY ALLOWING IMPROVING
CONDITIONS FOR KCNY...KGJT...KMTJ AND KRIL WHILE REMAINING TAF
SITES WILL LIKELY SEE CONTINUED PRECIP AND LOW FLIGHT CONDITIONS.
BY 21Z...MVFR/IFR CONDITIONS WILL HAVE LARGELY SHIFTED TO THE
CONTINENTAL DIVIDE.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ005-
008>010-012-014-018-019-022-023.
DENSE FOG ADVISORY UNTIL 10 AM MST THIS MORNING FOR COZ006-011-
020.
WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR COZ004-013.
WINTER WEATHER ADVISORY UNTIL NOON MST TODAY FOR COZ007.
UT...NONE.
&&
$$
UPDATE...JAM
SHORT TERM...15
LONG TERM...TGR
AVIATION...TGR
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
654 AM MST SAT DEC 12 2015
.UPDATE...
ISSUED AT 654 AM MST SAT DEC 12 2015
STEADY SNOW HAS ENDED ACROSS EASTERN UTAH AND NORTHWEST
COLORADO...SO CANCELLED ADVISORIES AND WARNINGS IN UT ZONES 25 AND
28...AND CO ZONES 1...2 AND 3. THE POSSIBILITY OF A FEW FLURRIES
STILL EXISTS BUT THESE AREAS WILL NOT SEE ANY ADDITIONAL SNOW
ACCUMULATION. RAP AND HRRR INDICATING CONTINUATION OF SNOW ALONG
I-70 EAST OF GLENWOOD SPRINGS...IN THE SAN JUANS AND ALONG THE
CONTINENTAL DIVIDE.
UPDATE ISSUED AT 329 AM MST SAT DEC 12 2015
LATEST REPORT FROM DURANGO DISPATCH INDICATED 1 INCH OF SNOW
STICKING TO ROAD SURFACES WHILE WEBCAMS SHOWED SIMILAR CONDITIONS
AROUND TOWN. LATEST 06Z NAM CONTINUES TO SHOW BAND OF PRECIP OVER
MUCH OF SOUTHERN VALLEYS PERSISTING THROUGH MUCH OF THE DAY. IR
IMAGERY SHOWING PLENTY OF MOISTURE OVER THAT AREA AND MORE TO
COME FROM NEW MEXICO. SOME ENHANCEMENT CAN ALSO BE SEEN INDICATING
A GOOD POSSIBILITY FOR HEAVIER SNOWFALL. WATER VAPOR FURTHER
CORROBORATES THIS IDEA. WENT AHEAD AND ISSUED ADVISORIES FOR ALL
SOUTHERN VALLEYS FOR 2 TO 4 INCHES WITH HIGHER AMOUNTS POSSIBLE
FOR HIGHER ELEVATIONS. TEMPS CONTINUE TO HOVER AROUND FREEZING SO
WITH DAYBREAK...WOULD EXPECT SNOW ON ROADS TO MELT FAIRLY QUICKLY
WITH LITTLE IMPACT. IF THIS OCCURS...HIGHLIGHTS CAN BE TAKEN DOWN
EARLY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 256 AM MST SAT DEC 12 2015
ANOTHER STORM IS EXCEEDING EXPECTATIONS IN SEVERAL AREAS. WE WERE
DEALING WITH A HEAVY SNOW BAND RELATED TO A WELL FORMED MID LEVEL
FRONTOGENESIS BAND ACROSS NORTHWEST COLORADO WHICH DUMPED UP TO A
FOOT OF NEW SNOW IN LOWER ELEVATIONS. NOW WE LOOK UPSTREAM AT THE
APPROACHING MAIN LOW PRESSURE SYSTEM ANALYZED AT 00Z OVER SOUTHERN
NEVADA...AND AT 06Z SATELLITE IMAGERY SUGGESTS THIS CIRCULATION
HAS MOVED TO CENTRAL ARIZONA. WOULD HAVE TO SAY THE TRENDS ARE
SLOWER AND FARTHER SOUTH WITH THIS SYSTEM THAN MODELS SUGGESTED
YESTERDAY. WITH THE CYCLONE STILL TO THE WEST THETA SURFACES
SUGGEST A NEW WARM CONVEYOR BELT DELIVERING A GOOD SHOT OF
MOISTURE INTO WESTERN COLORADO THIS MORNING. THIS IS MORE THAN
APPARENT WITH THE RECENT ENHANCEMENTS ON THE REGIONAL RADAR MOSAIC
AND IR SATELLITE IMAGERY OVER EASTERN ARIZONA. THE BIG FORECAST
CHALLENGE IS WHAT DOES THAT MEAN FOR OUR AREA. THE MOISTURE
ADVECTION AND CONSTANT STREAM OF VIRGA OR LIGHT SHOWERS THIS
EVENING HAS CLOSED THE DEW POINT GAP ACROSS THE SOUTHERN VALLEYS
WHERE TEMPERATURES ARE STILL IN THE UPPER 30S. THE REAL COLD AIR
IS STILL BEING HELD BACK BY THE FLOW ALOFT SO PRECIPITATION TYPE
IS STILL QUITE TRICKY FOR THE SOUTHERN VALLEYS AS RAIN MAY HOLD
OUT LONGER THAN ANTICIPATED OR JUST TURN INTO MELTING SNOW. FOR
NOW WILL SIDE WITH THE TRENDS OF NEAR AN INCH OF THE DURANGO
AIRPORT WITH HIGHER AMOUNTS NEAR THE FOOTHILLS. PAGOSA SPRINGS
WILL SEE ANYWHERE FROM TO 1 INCH TO 3 INCHES NEAR THE HILLS. THE
PROBLEM AREAS DOWN SOUTH WILL MOST LIKELY BE THE HIGH SPOTS ALONG
HWY 160 LIKE THE MANCOS HILL AREA. THIS WCB WILL ALSO CONTAIN
BETTER INSTABILITY AS SEEN IN EPV FIELDS AND THIS SHOULD BE
RELEASED BY THE INCREASING LARGE SCALE ASCENT OVER THE SOUTHERN
CWA AS THE MID LEVEL CIRCULATION PASSES THROUGH FROM MID MORNING
ONWARD. COMPLICATED SITUATION AND EXPECT CHANGES TO GOING FORECAST
THROUGH THE DAY AS SOME OF THE VARIABLES BECOME MORE CLEAR. THE
SOUTHERN MOUNTAINS MAY BE IN FOR MORE SNOW THAN PREVIOUSLY
FORECAST AND WILL BE MONITORING FOR UPGRADES IF IMPACTS TO PASSES
BECOME MORE APPARENT. WE DID INCLUDE THE GUNNISON BASIN IN THE
LATEST WSW AS THIS MOISTURE PLUME WILL BE DIRECTED AT CERRO SUMMIT
AND THE BLACK CANYON AREA. THE SYSTEM SLOWLY PULLS EAST OF THE
DIVIDE THIS EVENING BEFORE STRENGTHENING IN THE LEE SIDE. DID KEEP
SOME HIGHER POPS INTO THIS EVENING TO ACCOUNT FOR THE SLOWER
MOVEMENT. OVERALL THE PCPN SHOULD BE DONE BY MIDNIGHT WITH A DRY
SUNDAY ON TAP. TEMPERATURES AND NEW SNOWFALL WILL BE THE MAIN
CHALLENGE ALONG WITH AREAS OF FOG DEVELOPING IN THE VALLEYS AND
BASINS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 256 AM MST SAT DEC 12 2015
RIDGING THAT BUILT IN SUNDAY WILL BE OVERHEAD SUNDAY NIGHT AND
QUICKLY SHIFT EASTWARD AS THE NEXT TROUGH APPROACHES FROM THE
WEST. MODELS IN FAIRLY GOOD AGREEMENT WITH EVOLUTION OF THIS
SYSTEM AND LOOKS SOMEWHAT SIMILAR TO THE STORM AFFECTING THE
REGION RIGHT NOW. SUBTLE DIFFERENCES EXIST OF COURSE BUT THE MAIN
GIST OF A COLD FRONT BRINGING WIDESPREAD SNOWFALL REMAINS. MAIN
DIFFERENCES WITH THIS SYSTEM WILL BE THAT COLD AIR WILL ALREADY BE
IN PLACE FROM THE PREVIOUS FRONT AND WILL ONLY BE REINFORCED FROM
THIS SECOND SYSTEM.
AS FAR AS DETAILS ARE CONCERNED...PRECIP WILL BEGIN MONDAY
MORNING FOR ERN UTAH AND SHIFT EASTWARD AS THE DAY PROGRESSES. BY
EVENING MOST...IF NOT ALL...AREAS WILL SEE SOME PRECIPITATION AS
THE CLOSED LOW AND ASSOD LIFT ARE POISED TO MOVE INTO WRN CO.
PLENTY OF THINGS CAN CHANGE BETWEEN NOW AND THEN THOUGH INCLUDING
THE LOW OPENING UP...UPPER LEVEL SUPPORT WANING...BEST LIFT SHIFTS
NORTH OR SOUTH...SO WILL HAVE TO SEE IF MODELS REMAIN CONSTANT IN
THIS OUTCOME. FOR NOW...6 TO 10 INCHES FOR THE MTNS AND 1 TO 3
INCHES FOR SOME VALLEYS LOOKS GOOD.
SNOWFALL WILL CONTINUE INTO TUESDAY BUT WITH BEST LIFT HAVING
SHIFTED TO THE PLAINS...ANTICIPATE A MORE SHOWERY NATURE TO
PRECIP. NORTHERLY FLOW WILL ALSO USHER IN COLDER AIR TO THE
REGION. SOME MTN SHOWERS...ESPECIALLY UP NORTH...MAY CONTINUE
THROUGH WEDNESDAY MORNING BUT ANTICIPATE MORE FLURRIES THAN
ANYTHING ELSE. MOST AREAS WILL SEE PARTLY CLOUDY SKIES AND MUCH
COLDER TEMPERATURES THAT WILL BE WELL BELOW NORMAL. AFTER
THAT...LITTLE PIECES OF WEAK ENERGY WILL DROP DOWN FROM THE NW
CAUSING SOME LIGHT SNOWFALL OVER THE PARK/GORE RANGES THROUGH
FRIDAY BUT AGAIN...NOT MUCH ACCUMULATION EXPECTED. EXPECT MORE
CLOUDS N OF I-70 THAN S DUE TO THESE DISTURBANCES. TEMPERATURES
WILL REMAIN BELOW NORMAL THROUGH LONG TERM PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 256 AM MST SAT DEC 12 2015
WIDESPREAD IFR CONDITIONS AND BELOW ARE BEING EXPERIENCED AT MOST
ASOS SITES THIS MORNING. ODD MAN OUT IS KVEL WHICH WILL LIKELY
STAY VFR SINCE THE FRONT HAS PASSED TO THE EAST. LOW CIGS/VIS
STILL POSSIBLE FOR THAT AERODROME SATURDAY NIGHT INTO SUNDAY
MORNING HOWEVER DUE TO FOG. SPEAKING OF...FOG POSSIBLE FOR MANY
TAF LOCATIONS THIS MORNING AND AGAIN TONIGHT. A HEAVIER BAND OF
PRECIP WILL CONTINUE TO SHIFT EASTWARD TODAY ALLOWING IMPROVING
CONDITIONS FOR KCNY...KGJT...KMTJ AND KRIL WHILE REMAINING TAF
SITES WILL LIKELY SEE CONTINUED PRECIP AND LOW FLIGHT CONDITIONS.
BY 21Z...MVFR/IFR CONDITIONS WILL HAVE LARGELY SHIFTED TO THE
CONTINENTAL DIVIDE.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ005-
008>010-012-014-018-019-022-023.
WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR COZ004-013.
WINTER WEATHER ADVISORY UNTIL NOON MST TODAY FOR COZ007.
UT...NONE.
&&
$$
UPDATE...JAM
SHORT TERM...15
LONG TERM...TGR
AVIATION...TGR
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1101 AM EST SAT DEC 12 2015
.UPDATE...
16Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN AMPLIFIED UPPER LEVEL
PATTERN OVER THE CONUS TO START OUT THE WEEKEND. PATTERN IS
HIGHLIGHTED BY DEEP/SHARP TROUGHING OVER THE INTER-MOUNTAIN WEST
FOLLOWED BY DOWNSTREAM RIDGING OVER THE EASTERN HALF OF THE
NATION. THE FLORIDA PENINSULA RESIDES UNDER THE BASE OF THIS RIDGE
AND UNDER SOME FAIRLY IMPRESSIVE HEIGHTS FOR THE MIDDLE OF
DECEMBER. H5 HEIGHTS OVER THE CENTRAL PART OF THE STATE ARE AROUND
590DM OFF THE MORNING KTBW SOUNDING...AND THIS REPRESENTS A VALUE
ABOVE THE 90TH PERCENTILE FOR DECEMBER. THE 12Z KTBW SOUNDING
SHOWED A DEFINED SUBSIDENCE INVERSION AROUND 700MB...SEPARATING A
SHALLOW LAYER OF ATLANTIC MOISTURE FROM A VERY DRY COLUMN ALOFT.
NEEDLESS TO SAY...WITH SUCH A STRONG AND STACKED AREA OF RIDGING
ALOFT...OUR FORECAST AREA IS WELL PROTECTED FROM ANY INCLEMENT
SENSIBLE WEATHER FOR TODAY.
ALSO...WITH THE STRONG RIDGE ALOFT AND DECENT LOW LEVEL CONDITIONS
FOR DIURNAL MIXING...TEMPERATURES WILL TOP OUT WELL ABOVE NORMAL
FOR THIS TIME OF YEAR. MANY LOCATIONS WILL FIND THEMSELVES AS MUCH
AS 10 DEGREES ABOVE NORMAL THIS AFTERNOON...AND THESE
UNSEASONABLE VALUES WILL CONTINUE FOR THE OVERNIGHT AND AGAIN ON
SUNDAY.
THE REST OF TODAY WILL FEATURE MOSTLY SUNNY SKIES BECOME PARTY
SUNNY FOR A TIME DURING THE AFTERNOON. TEMPERATURES CLIMB INTO THE
LOW 80S FOR MANY SPOTS AWAY FROM THE IMMEDIATE COAST...WITH EVEN A
FEW MIDDLE 80S DOWN TOWARD FORT MYERS. TEMPERATURES TONIGHT
REMAINING IN THE 60S FOR JUST ABOUT ALL LOCATIONS (PERHAPS A FEW
COOLER SPOTS IN THE UPPER 50S FOR LEVY COUNTY).
ALTHOUGH THE UPPER RIDGE WILL NOT BE QUITE AS STRONG BY
SUNDAY...WE WILL STILL BE LOOKING AT HEIGHTS WELL ABOVE
NORMAL...AND IT WILL STILL BE PLENTY IN CONTROL TO PROTECT OUR
REGION FROM ANY MID/UPPER LEVEL SYNOPTIC FORCING FOR LIFT. THE
CHANGE IN PATTERN THAT WE WILL SEE FOR SUNDAY WILL OCCUR IN THE
VERY LOWEST LEVELS OF THE COLUMN. A WEAK INVERTED TROUGH SEEN
CURRENTLY OUT TOWARD THE BAHAMAS IS SHOWN BY MOST ENSEMBLE MEMBERS
TO MIGRATE WESTWARD THROUGH THE NEXT 24 HOURS TO A POSITION OVER
THE SOUTHERN HALF OF THE FL PENINSULA SUNDAY AFTERNOON. A SLIGHT
INCREASE IN COLUMN MOISTURE BELOW 700MB IS FORECAST TO ARRIVE WITH
THIS FEATURE...ALONG A SWATH OF MODEST ISENTROPIC UPGLIDE ALONG
THE 300-310K SURFACES. EXTENT OF LIFT (ALTHOUGH IT IS SHALLOW)
COMBINED WITH THE ADDED SURFACE FOCUS UNDER THE TROUGH APPEARS
SUFFICIENT TO SUPPORT SOME WIDELY SCATTERED LIGHT SHOWERS TO THE
SOUTH OF THE I-4 CORRIDOR SUNDAY AFTERNOON/EARLY EVENING. AS
MENTIONED ALL THE MOISTURE IS SHALLOW...AND HENCE THE SHOWERS WILL
ALSO BE SHALLOW AND LIGHT...WITH PROB ONLY A COUPLE HUNDREDTHS OF
AN INCH FOR ANY LOCATION THAT DOES SEE A BRIEF SHOWER.
THEREFORE...THE IMPACT TO ANY OUTDOOR ACTIVITIES LOOKS NEGLIGIBLE.
THE SOUTHERN HALF OF THE AREA SHOULD CERTAINLY EXPECT TO SEE LESS
SUN FOR SUNDAY AS A COMBINATION OF CUMULUS AND STRATOCU ARE LIKELY
TO FILL IN QUITE QUICKLY. CURRENT GRIDS HAVE 20-30% SHOWER
COVERAGE...AND BASED ON AVAILABLE 12Z GUIDANCE DO NOT SEE MUCH
REASON TO MAKE MANY SIGNIFICANT CHANGES WITH THIS FORECAST
PACKAGE.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGH THE AFTERNOON AND EVENING
HOURS TODAY ACROSS WEST-CENTRAL AND SOUTHWEST FLORIDA. EASTERLY
TERMINALS WILL SEE EASTERLY WINDS AND A FEW-SCT CUMULUS FIELD
DEVELOPING DURING THE AFTERNOON. POTENTIAL FOR PATCHY AREAS OF FOG
TO IMPACT SITES SUCH AS KLAL/KPGD AFTER 08Z TONIGHT...HOWEVER...
BETTER CHANCES FOR FOG AND ASSOCIATED RESTRICTIONS LOOK TO REMAIN
NORTH OF THE FORECAST TERMINALS. EARLY FOG LIFTS BY 14Z...FOLLOWED
BY VFR CONDITIONS THROUGH SUNDAY AFTERNOON.
&&
.MARINE...
HIGH PRESSURE TO THE NORTH OF THE COASTAL WATERS WILL
KEEP MODERATE EAST WINDS IN PLACE THROUGH THE WEEKEND. A COLD
FRONT WILL APPROACH THE AREA AND STALL OVER THE NORTHEAST GULF
OF MEXICO DURING THE EARLY PART OF NEXT WEEK. CHANCES FOR SHOWERS
WILL INCREASE MONDAY INTO TUESDAY ASSOCIATED WITH THIS FRONT.
WINDS AND SEAS ARE GENERALLY EXPECTED TO REMAIN BELOW HEADLINE
CRITERIA.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 82 67 81 68 / 0 0 10 10
FMY 84 67 82 70 / 0 0 30 20
GIF 81 66 82 68 / 0 10 20 20
SRQ 81 66 81 69 / 0 0 20 10
BKV 83 64 83 67 / 0 0 10 10
SPG 81 67 80 70 / 0 0 10 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH MONDAY EVENING FOR COASTAL
MANATEE-COASTAL SARASOTA-PINELLAS.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION/MARINE...MROCZKA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
958 AM CST SAT DEC 12 2015
.SHORT TERM...
331 AM CST
THROUGH SUNDAY NIGHT...
EXCEEDINGLY TRICKY FORECAST IN THE SHORT TERM...PARTICULARLY WITH
RESPECT TO FOG AND TEMPS.
A SET-UP FAR MORE TYPICAL OF LATE MARCH OR EARLY APRIL WILL PLAY
HAVOC ON TEMP FORECAST AND LIKELY RESULT IN DENSE LAKE FOG
DEVELOPING. WARM FRONT HAS LIFTED NORTH AND LIES JUST NORTH OF I-80
EARLY THIS MORNING. DENSE FOG HAS BEEN PATCHY SO FAR AND CONFINED TO
AREAS MAINLY WEST AND SOUTHWEST OF OUR CWA THUS FAR...HOWEVER SHORT
RANGE GUIDANCE STILL SUGGESTS THAT THE DENSE FOG COULD EXPAND IN
COVERAGE AND IMPACT MAINLY OUR WESTERN AND SOUTHWESTERN COUNTIES
THIS MORNING. WILL TAKE A WAIT AND SEE APPROACH ON THIS GIVEN HOW
LACKLUSTER THIS MORNING`S FOG EVENT HAS BEEN THUS FAR.
WEAK SURFACE LOW OVER IOWA IS PROGGED TO DISSIPATE TODAY WITH
SURFACE CYCLOGENESIS TAKES PLACE OVER THE SOUTHERN HIGH PLAINS.
AS THE LOW WEAKENS...LOOK FOR SURFACE FRONTOLYSIS TO BEGIN WITH
WARMFRONT OVER OUR CWA. AS THE SYNOPTIC FRONT WEAKENS IT WILL OPEN
THE DOOR FOR LAKE MICHIGAN`S CHILLING EFFECTS TO TAKE OVER LATER
THIS AFTERNOON AND EVENING. WEAK AND WEAKENING PRESSURE GRADIENT IN
THE VICINITY OF THE WEAKENING FRONT WILL LIKELY ALLOW A LAKE BREEZE
FRONT TO DEVELOP THIS AFTERNOON DUE IN PART TO THE INCREASINGLY
LARGE THERMAL DIFFERENTIAL BETWEEN CHILLY MARINE AIR MASS OVER THE
LAKE AND UNSEASONABLY WARM AND ALMOST HUMID AIR OVER LAND. AS THE
COOL MARINE AIR ENCOUNTERS 50F+ DEWPOINTS IT APPEARS TO BE A CLASSIC
SET-UP FOR VERY DENSE MARINE FOG TO DEVELOP AND SEEP INLAND THIS
EVENING AS THE CHILLY MARINE AIR ENCOUNTERS NOT MUCH RESISTANCE AND
IT ABLE TO SPREAD PRETTY FAR INLAND. IF IT WEREN`T FOR
UNCERTAINTIES REGARDING TIMING OF FOG STARTING AND ENDING...WOULD
PROBABLY BE ISSUING A DENSE FOG ADVISORY NOW FOR THIS EVENING FOR
PORTIONS OF NE IL. DENSE FOG COULD DEVELOP FARTHER INLAND THIS
EVENING AWAY FROM THE MARINE LAYER...MAINLY NEAR AND TO THE NORTH
OF THE WEAKEN WARM FRONT. CONFIDENCE IN DENSE FOG DEVELOPING HERE
IS LOWER.
MODEL THAT HAS BEEN BEST FITTING THE CONCEPTUAL MODEL OF HOW I
EXPECT THINGS TO EVOLVE TODAY HAS BEEN THE EXPERIMENTAL HRRR AND
HAVE USED A TIME LAGGED ENSEMBLE APPROACH WITH THIS MODEL TO
POPULATE SHORT TERM HOURLY TEMP/DEWPOINT/WIND GRIDS INTO THIS
EVENING. DESPITE CLOUD COVER STILL EXPECT TEMPS TO WARM UP NICELY
TODAY...ESPECIALLY SOUTHERN CWA WHERE THEY ARE SOLIDLY IN THE WARM
SECTOR. WARMING TREND IN TEMPS WILL LIKELY BE ABRUPTLY HALTED NEAR
THE LAKE BY EARLY-MID AFTERNOON WHEN LAKE BREEZE FRONT BEGINS MOVING
INLAND AND KNOCKING TEMPS BACK INTO THE 40S NEAR THE LAKE AND
RESULTING IN FALLING TEMPS EVEN WELL INLAND BY EARLY EVENING. TOUGH
CALL ON HOW QUICKLY TEMPS WILL WARM IN CHICAGO BEFORE LAKE AIR
SPREADS INLAND...BUT EXPERIMENTAL HRRR SUGGESTS ORD WILL PROBABLY
NOT GET MUCH ABOVE MID TO MAYBE UPPER 50S BEFORE TEMPS FALL LATE IN
THE EVENING WITH FOG...PROBABLY DENSE LIKELY TO FOLLOW.
TONIGHT...SOUTHERN PLAINS CYCLONE WILL BEGIN MOVING NORTH AND THE
NOW LAKE RE-ENFORCED WARM FRONT WILL BEGIN TO STRENGTHEN AGAIN AND
STRENGTHENING PRESSURE FALLS SHOULD CAUSE THE FRONT TO BEGIN MOVING
NORTH AGAIN. SHOULD BEHAVE LIKE A TYPICAL MARCH WARM FRONT BECOMING
SOMEWHAT CONTORTED AROUND LAKE MICHIGAN WITH NORTH SHORE AREAS
LIKELY BEING THE LAST AREA IN OUR CWA TO MAKE IT INTO THE WARM
SECTOR. EXPECT FOG TO PRIMARILY BE A PROBLEM AHEAD OF THE WARM FRONT
WITH DRAMATICALLY IMPROVING VISIBILITIES AS THE WARM FRONT LIFTS
NORTHWARD. TEMPS IN THE WARM SECTOR TONIGHT WILL LIKELY HOLD IN THE
UPPER 50S TO LOWER 60S...WITH A RAPID RISE IN TEMPERATURES FROM THE
40S TO NEAR 60 EXPECTED IN THE CHICAGO AREA OVERNIGHT AS THE WARM
FRONT LIFTS NORTH.
PRECIP-WISE...NOT EXPECTED MUCH MEASURABLE PRECIP UNTIL TONIGHT.
COULD BE SOME DRIZZLE WITH THE DENSE MARINE FOG AND HRRR SUGGESTS A
FEW LIGHT SHOWERS LATE THIS AFTERNOON IN VICINITY OF THE WARM FRONT.
TONIGHT...THE MAIN FOCUS FOR SHOWERS AND SOME THUNDERSTORMS LOOKS TO
REMAIN MOSTLY TO THE WEST OF OUR CWA CLOSER TO THE STRONG ISENTROPIC
ASCENT AND NEAR THE NOSE OF THE LOW LEVEL JET. STILL EXPECT SOME OF
THIS SHOWER ACTIVITY TO MAKE IT INTO MAINLY NORTH CENTRAL ILLINOIS
WITH A LESSER THREAT OF SHOWERS OVER THE REMAINDER OF THE CWA.
SUNDAY SHOULD BE WINDY AND UNSEASONABLY WARM WITH A PERIOD OR TWO OF
SHOWERS LIKELY...ESPECIALLY WESTERN AND NORTHERN PORTIONS OF THE
AREA. DEPENDING ON THE COVERAGE OF SHOWERS...WE COULD MAKE A RUN AT
THE RECORD HIGHS FOR THE DAY...THOUGH DECIDED TO KEEP TEMPS SOMEWHAT
CONSERVATIVE IN THE GRIDS FOR NOW WITH MAINLY LOW 60S NORTH AND MID
60S SOUTH. ADDITIONAL SHOWERS ARE EXPECTED SUNDAY NIGHT AS FAIRLY
STRONG COLD FRONT EVENTUALLY MOVES ACROSS THE AREA. MAJORITY OF
SUNDAY NIGHT WILL BE WINDY AND UNSEASONABLY WARM WITH TEMPS CLOSE TO
IF NOT IN THE 60S BEFORE COLD FRONT MOVES THROUGH CLOSER TO DAWN
RESULTING IN LOW TEMPS NOT OCCURRING UNTIL AFTER SUNRISE.
IZZI
&&
.LONG TERM...
331 AM CST
MONDAY THROUGH FRIDAY...
WINDY AND MUCH COOLER WEATHER IS ON TAP FOR MONDAY WITH SHOWERS IN
THE MORNING LIKELY TAPERING OFF AND ENDING BY OR PERHAPS DURING THE
EARLY AFTERNOON. WE SHOULD GET A BRIEF BREAK BETWEEN SYSTEM TUESDAY
WITH DRY CONDITIONS AND CONTINUED ABOVE NORMAL TEMPS...BUT MUCH LESS
SO THAN THIS WEEKEND.
NEXT SYSTEM MOVES THROUGH MIDWEEK...BUT AT THIS POINT LOOKS PRETTY
MOISTURE STARVED AS IT WILL BE FAST ON THE HEELS OF THE WEEKEND
SYSTEM WHICH SHOULD BE PRETTY EFFECTIVE AT SCOURING OUT THE
MOISTURE. IN THE WAKE OF THIS STORM IT LOOKS LIKE WE WILL GET A
TASTE OF MORE TYPICAL DECEMBER TEMPERATURES FOR A FEW DAYS LATER
THIS WEEK INTO THE WEEKEND WITH HIGHS NOT GETTING OUT OF THE 30S. IN
FACT...IF THE ECMWF VERIFIES FRIDAY/SATURDAY MAY NOT EVEN REACH 30F
FOR HIGHS WHICH WILL FEEL VERY COLD AFTER THIS WEEKEND`S NEAR RECORD
WARMTH BUT IN REALITY WILL ONLY BE A FEW DEGREES COLDER THAN NORMAL.
MEDIUM RANGE MODELS SUGGEST THAT THE LONGWAVE TROUGH RESPONSIBLE FOR
THE TASTE OF WINTER WILL BE PROGRESSIVE WITH A MODELS AND CPC BOTH
SUGGESTING A RETURN TO ABOVE AVERAGE TEMPERATURES CHRISTMAS WEEK.
IZZI
&&
.CLIMATE...
NEAR RECORD TEMPERATURES ARE FORECAST FOR THE AREA THROUGH
SUNDAY. HERE ARE THE CURRENT RECORD HIGH TEMPERATURES AND WARMEST
LOW TEMPERATURES ON RECORD FOR CHICAGO AND ROCKFORD.
CHICAGO:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 61 (1877) 48 (1968)
DEC 13 67 (1975) 46 (1920)
---------------------------------
ROCKFORD:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 60 (1991) 43 (1968)
DEC 13 57 (1975) 40 (1920)
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* SMALL FLUCTUATIONS IN LIFR/IFR VSBY THROUGH LATE MORNING WITH
GRADUAL IMPROVEMENT MIDDAY.
* IFR CIGS LIKELY THROUGH THE AFTERNOON THOUGH SHORT PERIOD OF
MVFR CIGS POSSIBLE AT MDW.
* VERY LOW CIGS AND DENSE FOG LIKELY TO ROLL IN OFF LAKE LATE THIS
AFTERNOON OR EARLY THIS EVENING. CONCERNED THAT 1/4-1/2SM VSBY
MAY ARRIVE IN THE 22-00Z TIME FRAME VS. AFTER 00Z CURRENTLY
FORECAST.
MDB
//DISCUSSION...UPDATED 16Z...
LITTLE CHANGE IN CONDITIONS OVER THE LAST FEW HOURS SUPPORTING THE
IDEA THAT IMPROVEMENT IN CIG/VSBY WILL BE SLOW INTO THE AFTERNOON.
NEAR TERM GUIDANCE STILL PUSHES THE WARM FRONTAL BOUNDARY
NORTHWARD INTO THE EARLY AFTERNOON. OBS ACROSS NORTH-CENTRAL IL DO
SHOW THIS OCCURRING MARKED BY AN INCREASE IN TEMPS/DEWPOINTS. THE
PROBLEM IS THAT AREAS TO THE SOUTH BEHIND THE FRONT ARE STILL
STILL SEEING VERY LOW CIGS/VSBY. HAVE SLOWED THE RATE OF
IMPROVEMENT OF CIGS/VSBY IN THE TAFS AND ALSO LOWERED CONDITIONS
THROUGH THE AFTERNOON WHEN THE FRONT SHOULD BE TO THE NORTH.
THE INLAND MOVEMENT OF LAKE INFLUENCED AIR IS STILL A CONCERN AS
WELL. TIMING OF THE SHIFT TO NORTHEAST WINDS AT EACH TERMINAL
STILL LOOKS REASONABLE BUT AM CONCERNED THAT VSBY MAY FALL
DRASTICALLY SOONER THAN IN THE CURRENT TAFS. WOULD NOT BE
SURPRISED TO SEE VSBY IN THE 1/4-1/2SM VSBY WITHIN AN HOUR OR SO
OF THE WIND SHIFT AND POTENTIALLY FALLING INTO THE 1/8-1/4SM RANGE
THIS EVENING. WILL CONTINUE TO MONITOR THIS AND REFINE WITH THE
UPCOMING TAFS.
MDB
FROM 12Z...
WARM FRONT CURRENTLY SITTING BETWEEN ORD AND MDW WILL DRIFT SLOWLY
NORTH HEADING INTO THE EARLY AFTERNOON. PRIOR TO THE FRONT MOVING
THROUGH ORD EXPECT LIFR CIGS AND AT LEAST IFR VSBY WITH A CHANCE
FOR A PERIOD OF LIFR VSBY THIS MORNING BEFORE SOME IMPROVEMENT
TAKES PLACE MIDDAY INTO MID AFTERNOON AS WARM FRONT ATTEMPTS TO
MOVE THROUGH ORD. MDW SHOULD REMAIN SOUTH OF THE FRONT AND SHOULD
SEE IMPROVEMENT TO MVFR CONDITIONS BY MID-LATE MORNING WHICH
SHOULD PERSIST THROUGH MUCH OF THE AFTERNOON.
WEAK FRONT SHOULD ALLOW A LAKE BREEZE FRONT TO DEVELOP AND SURGE
INLAND LATE THIS AFTERNOON AND EFFECTIVELY PUSH THE WARM FRONT
BACK SOUTH OF THE TERMINALS BETWEEN 22Z-00Z. AS THE LAKE CHILLED
AIR ENCOUNTERS THE INCREDIBLY MOIST AIR MASS LOOK FOR DENSE FOG TO
FORM INITIALLY ALONG THE LAKE FRONT AND LIKELY SPREADING TO
ORD/MDW EARLY THIS EVENING. TIMING OF WHEN DENSE FOG ARRIVES IS
HARD TO PIN DOWN...BUT SYNOPTICALLY THE SET UP STRONGLY FAVORS
DENSE FOG. FOR NOW JUST TOOK ORD AND MDW DOWN TO 1/2SM PREVAILING
DUE TO INHERENT UNCERTAINTIES WHEN FORECASTING FOG...HOWEVER
WOULDNT BE AT ALL SURPRISED TO SEE MANY HOURS OF 1/8SM TO 1/4SM
TONIGHT PRIOR TO WARM FRONT MOVING BACK NORTH THROUGH THE
TERMINALS AFTER MIDNIGHT. CIGS/VSBY SHOULD IMPROVE RAPIDLY WHEN
THE WARM FRONT LIFTS BACK NORTH ACROSS THE TERMINALS LATE TONIGHT.
LIGHT WINDS IN VICINITY OF FRONT THIS MORNING SHOULD TEND TO
BECOME LIGHT SOUTHERLY SOUTH OF THE WARM FRONT LATE THIS MORNING
INTO THIS AFTERNOON...FOLLOWED BY SHIFT TO NORTHEAST 5-10KT BEHIND
THE LAKE ENHANCED FRONT LATE THIS AFTERNOON WITH LIGHT NE WINDS
MUCH OF THE NIGHT BEFORE VEERING EAST PRIOR TO A SHIFT TO SOUTH
AS WARM FRONT LIFTS BACK NORTH LATE TONIGHT.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM-HIGH CONFIDENCE IN OVERALL CIGS/VSBY TRENDS WITH MEDIUM
CONFIDENCE THAT IFR CIGS AND MVFR VSBY PREVAILS FOR A TIME THIS
AFTERNOON.
* MEDIUM-HIGH CONFIDENCE IN DENSE FOG BY THIS EVENING...LOW-MEDIUM
CONFIDENCE ON TIMING OF ARRIVAL AND DEPARTURE OF DENSE FOG. LOW
BUT INCREASING CONFIDENCE THAT ARRIVAL OF 1/2SM OR LOWER VSBY
WILL BE FASTER THAN INDICATED IN 16Z TAF.
* HIGH CONFIDENCE IN WINDS STAYING PRIMARILY BELOW 10KT...LOWER
CONFIDENCE IN PRECISE DIRECTIONS AS FRONT WAVERS AROUND REGION.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PERIODIC SHRA. IFR LIKELY.
MONDAY...PERIODIC SHRA IN THE MORNING. MVFR CIGS.
TUESDAY...VFR.
WEDNESDAY...SMALL CHANCE OF SHRA/MVFR CIGS.
THURSDAY AND FRIDAY...MVFR CIGS A GOOD BET.
IZZI
&&
.MARINE...
301 AM CST
A DENSE FOG ADVISORY WILL LIKELY BE NEEDED FOR THE SOUTHERN HALF OF
THE LAKE TODAY. HOWEVER...I HAVE LOW CONFIDENCE IN WHEN THE DENSE
FOG WILL DEVELOP AND HOW LONG IT WILL PERSIST INTO THIS AFTERNOON OR
EVENING SO I WILL NOT BE ISSUING A DENSE FOG ADVISORY NOW. BOATERS
SHOULD BE PREPARED FOR DENSE FOG AND SEVERELY REDUCED VISIBILITIES.
A WEAKENING LOW IS OVER IOWA AND THE LOW WILL WEAKEN BEFORE ENTERING
ILLINOIS TODAY. A WARM FRONT LIES JUST SOUTH OF THE THIS MORNING AND
WILL SHIFT NORTH BUT REMAIN OVER THE SOUTHERN END OF THE LAKE
THROUGH SUNDAY. DENSE FOG IS EXPECTED TO FORM BEHIND THE FRONT. A
LAKE BREEZE WILL LIKELY FORM THIS AFTERNOON ALONG THE IL SHORE. THE
NEXT LOW FORMS OVER THE SOUTHERN PLAINS EARLY SUNDAY MORNING WITH
WINDS BECOMING SOUTHEAST ACROSS THE SOUTHERN HALF OF THE LAKE. EAST
WINDS TO 30 KT ARE EXPECTED ACROSS THE NORTHERN HALF OF THE LAKE.
SOUTHEAST WINDS INCREASE TO 30 KT SUNDAY. A SMALL CRAFT ADVISORY
WILL BE NEEDED FOR SUNDAY POTENTIALLY THROUGH MONDAY
EVENING...HOWEVER THERE MAY BE A PERIOD OF GALES MONDAY SO WILL HOLD
OFF ON ISSUING A SMALL CRAFT ADVISORY NOW.
SOUTHEAST WINDS INCREASE TO LOW END GALES SUNDAY NIGHT. THE LOW
SHIFTS NORTH OVER WISCONSIN MONDAY WITH SOUTH TO SOUTHWEST GALES
MAINLY OVER THE SOUTHERN END OF THE LAKE. MAY SEE A FEW GALE FORCE
GUSTS ACROSS THE NORTHERN END. THE LOW PASSES OVER THE NORTHERN END
OF THE LAKE MONDAY EVENING AND NIGHT WITH WINDS BECOMING WEST BEHIND
IT. THE NEXT LOW FORMS OVER THE PLAINS TUESDAY. GUIDANCE SUGGESTS
THIS LOW WILL HAVE A SIMILAR PATH TO THE LOW THIS WEEKEND OR SHIFT
NORTH ACROSS MINNESOTA. EITHER WAY SOUTH TO SOUTHWEST WINDS
INCREASE TO AT LEAST 30 KT WEDNESDAY WITH GALES POSSIBLE ACROSS THE
SOUTHERN HALF OF THE LAKE. ANOTHER SMALL CRAFT ADVISORY MAY BE
NEEDED AS WELL. WEST WINDS 15-25 KT ARE THEN EXPECTED THROUGH LATE
NEXT WEEK.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL NOON
SATURDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-
LMZ777-LMZ779 UNTIL 9 AM SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
824 AM CST SAT DEC 12 2015
.SHORT TERM...
331 AM CST
THROUGH SUNDAY NIGHT...
EXCEEDINGLY TRICKY FORECAST IN THE SHORT TERM...PARTICULARLY WITH
RESPECT TO FOG AND TEMPS.
A SET-UP FAR MORE TYPICAL OF LATE MARCH OR EARLY APRIL WILL PLAY
HAVOC ON TEMP FORECAST AND LIKELY RESULT IN DENSE LAKE FOG
DEVELOPING. WARM FRONT HAS LIFTED NORTH AND LIES JUST NORTH OF I-80
EARLY THIS MORNING. DENSE FOG HAS BEEN PATCHY SO FAR AND CONFINED TO
AREAS MAINLY WEST AND SOUTHWEST OF OUR CWA THUS FAR...HOWEVER SHORT
RANGE GUIDANCE STILL SUGGESTS THAT THE DENSE FOG COULD EXPAND IN
COVERAGE AND IMPACT MAINLY OUR WESTERN AND SOUTHWESTERN COUNTIES
THIS MORNING. WILL TAKE A WAIT AND SEE APPROACH ON THIS GIVEN HOW
LACKLUSTER THIS MORNING`S FOG EVENT HAS BEEN THUS FAR.
WEAK SURFACE LOW OVER IOWA IS PROGGED TO DISSIPATE TODAY WITH
SURFACE CYCLOGENESIS TAKES PLACE OVER THE SOUTHERN HIGH PLAINS.
AS THE LOW WEAKENS...LOOK FOR SURFACE FRONTOLYSIS TO BEGIN WITH
WARMFRONT OVER OUR CWA. AS THE SYNOPTIC FRONT WEAKENS IT WILL OPEN
THE DOOR FOR LAKE MICHIGAN`S CHILLING EFFECTS TO TAKE OVER LATER
THIS AFTERNOON AND EVENING. WEAK AND WEAKENING PRESSURE GRADIENT IN
THE VICINITY OF THE WEAKENING FRONT WILL LIKELY ALLOW A LAKE BREEZE
FRONT TO DEVELOP THIS AFTERNOON DUE IN PART TO THE INCREASINGLY
LARGE THERMAL DIFFERENTIAL BETWEEN CHILLY MARINE AIR MASS OVER THE
LAKE AND UNSEASONABLY WARM AND ALMOST HUMID AIR OVER LAND. AS THE
COOL MARINE AIR ENCOUNTERS 50F+ DEWPOINTS IT APPEARS TO BE A CLASSIC
SET-UP FOR VERY DENSE MARINE FOG TO DEVELOP AND SEEP INLAND THIS
EVENING AS THE CHILLY MARINE AIR ENCOUNTERS NOT MUCH RESISTANCE AND
IT ABLE TO SPREAD PRETTY FAR INLAND. IF IT WEREN`T FOR
UNCERTAINTIES REGARDING TIMING OF FOG STARTING AND ENDING...WOULD
PROBABLY BE ISSUING A DENSE FOG ADVISORY NOW FOR THIS EVENING FOR
PORTIONS OF NE IL. DENSE FOG COULD DEVELOP FARTHER INLAND THIS
EVENING AWAY FROM THE MARINE LAYER...MAINLY NEAR AND TO THE NORTH
OF THE WEAKEN WARM FRONT. CONFIDENCE IN DENSE FOG DEVELOPING HERE
IS LOWER.
MODEL THAT HAS BEEN BEST FITTING THE CONCEPTUAL MODEL OF HOW I
EXPECT THINGS TO EVOLVE TODAY HAS BEEN THE EXPERIMENTAL HRRR AND
HAVE USED A TIME LAGGED ENSEMBLE APPROACH WITH THIS MODEL TO
POPULATE SHORT TERM HOURLY TEMP/DEWPOINT/WIND GRIDS INTO THIS
EVENING. DESPITE CLOUD COVER STILL EXPECT TEMPS TO WARM UP NICELY
TODAY...ESPECIALLY SOUTHERN CWA WHERE THEY ARE SOLIDLY IN THE WARM
SECTOR. WARMING TREND IN TEMPS WILL LIKELY BE ABRUPTLY HALTED NEAR
THE LAKE BY EARLY-MID AFTERNOON WHEN LAKE BREEZE FRONT BEGINS MOVING
INLAND AND KNOCKING TEMPS BACK INTO THE 40S NEAR THE LAKE AND
RESULTING IN FALLING TEMPS EVEN WELL INLAND BY EARLY EVENING. TOUGH
CALL ON HOW QUICKLY TEMPS WILL WARM IN CHICAGO BEFORE LAKE AIR
SPREADS INLAND...BUT EXPERIMENTAL HRRR SUGGESTS ORD WILL PROBABLY
NOT GET MUCH ABOVE MID TO MAYBE UPPER 50S BEFORE TEMPS FALL LATE IN
THE EVENING WITH FOG...PROBABLY DENSE LIKELY TO FOLLOW.
TONIGHT...SOUTHERN PLAINS CYCLONE WILL BEGIN MOVING NORTH AND THE
NOW LAKE RE-ENFORCED WARM FRONT WILL BEGIN TO STRENGTHEN AGAIN AND
STRENGTHENING PRESSURE FALLS SHOULD CAUSE THE FRONT TO BEGIN MOVING
NORTH AGAIN. SHOULD BEHAVE LIKE A TYPICAL MARCH WARM FRONT BECOMING
SOMEWHAT CONTORTED AROUND LAKE MICHIGAN WITH NORTH SHORE AREAS
LIKELY BEING THE LAST AREA IN OUR CWA TO MAKE IT INTO THE WARM
SECTOR. EXPECT FOG TO PRIMARILY BE A PROBLEM AHEAD OF THE WARM FRONT
WITH DRAMATICALLY IMPROVING VISIBILITIES AS THE WARM FRONT LIFTS
NORTHWARD. TEMPS IN THE WARM SECTOR TONIGHT WILL LIKELY HOLD IN THE
UPPER 50S TO LOWER 60S...WITH A RAPID RISE IN TEMPERATURES FROM THE
40S TO NEAR 60 EXPECTED IN THE CHICAGO AREA OVERNIGHT AS THE WARM
FRONT LIFTS NORTH.
PRECIP-WISE...NOT EXPECTED MUCH MEASURABLE PRECIP UNTIL TONIGHT.
COULD BE SOME DRIZZLE WITH THE DENSE MARINE FOG AND HRRR SUGGESTS A
FEW LIGHT SHOWERS LATE THIS AFTERNOON IN VICINITY OF THE WARM FRONT.
TONIGHT...THE MAIN FOCUS FOR SHOWERS AND SOME THUNDERSTORMS LOOKS TO
REMAIN MOSTLY TO THE WEST OF OUR CWA CLOSER TO THE STRONG ISENTROPIC
ASCENT AND NEAR THE NOSE OF THE LOW LEVEL JET. STILL EXPECT SOME OF
THIS SHOWER ACTIVITY TO MAKE IT INTO MAINLY NORTH CENTRAL ILLINOIS
WITH A LESSER THREAT OF SHOWERS OVER THE REMAINDER OF THE CWA.
SUNDAY SHOULD BE WINDY AND UNSEASONABLY WARM WITH A PERIOD OR TWO OF
SHOWERS LIKELY...ESPECIALLY WESTERN AND NORTHERN PORTIONS OF THE
AREA. DEPENDING ON THE COVERAGE OF SHOWERS...WE COULD MAKE A RUN AT
THE RECORD HIGHS FOR THE DAY...THOUGH DECIDED TO KEEP TEMPS SOMEWHAT
CONSERVATIVE IN THE GRIDS FOR NOW WITH MAINLY LOW 60S NORTH AND MID
60S SOUTH. ADDITIONAL SHOWERS ARE EXPECTED SUNDAY NIGHT AS FAIRLY
STRONG COLD FRONT EVENTUALLY MOVES ACROSS THE AREA. MAJORITY OF
SUNDAY NIGHT WILL BE WINDY AND UNSEASONABLY WARM WITH TEMPS CLOSE TO
IF NOT IN THE 60S BEFORE COLD FRONT MOVES THROUGH CLOSER TO DAWN
RESULTING IN LOW TEMPS NOT OCCURRING UNTIL AFTER SUNRISE.
IZZI
&&
.LONG TERM...
331 AM CST
MONDAY THROUGH FRIDAY...
WINDY AND MUCH COOLER WEATHER IS ON TAP FOR MONDAY WITH SHOWERS IN
THE MORNING LIKELY TAPERING OFF AND ENDING BY OR PERHAPS DURING THE
EARLY AFTERNOON. WE SHOULD GET A BRIEF BREAK BETWEEN SYSTEM TUESDAY
WITH DRY CONDITIONS AND CONTINUED ABOVE NORMAL TEMPS...BUT MUCH LESS
SO THAN THIS WEEKEND.
NEXT SYSTEM MOVES THROUGH MIDWEEK...BUT AT THIS POINT LOOKS PRETTY
MOISTURE STARVED AS IT WILL BE FAST ON THE HEELS OF THE WEEKEND
SYSTEM WHICH SHOULD BE PRETTY EFFECTIVE AT SCOURING OUT THE
MOISTURE. IN THE WAKE OF THIS STORM IT LOOKS LIKE WE WILL GET A
TASTE OF MORE TYPICAL DECEMBER TEMPERATURES FOR A FEW DAYS LATER
THIS WEEK INTO THE WEEKEND WITH HIGHS NOT GETTING OUT OF THE 30S. IN
FACT...IF THE ECMWF VERIFIES FRIDAY/SATURDAY MAY NOT EVEN REACH 30F
FOR HIGHS WHICH WILL FEEL VERY COLD AFTER THIS WEEKEND`S NEAR RECORD
WARMTH BUT IN REALITY WILL ONLY BE A FEW DEGREES COLDER THAN NORMAL.
MEDIUM RANGE MODELS SUGGEST THAT THE LONGWAVE TROUGH RESPONSIBLE FOR
THE TASTE OF WINTER WILL BE PROGRESSIVE WITH A MODELS AND CPC BOTH
SUGGESTING A RETURN TO ABOVE AVERAGE TEMPERATURES CHRISTMAS WEEK.
IZZI
&&
.CLIMATE...
NEAR RECORD TEMPERATURES ARE FORECAST FOR THE AREA THROUGH
SUNDAY. HERE ARE THE CURRENT RECORD HIGH TEMPERATURES AND WARMEST
LOW TEMPERATURES ON RECORD FOR CHICAGO AND ROCKFORD.
CHICAGO:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 61 (1877) 48 (1968)
DEC 13 67 (1975) 46 (1920)
---------------------------------
ROCKFORD:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 60 (1991) 43 (1968)
DEC 13 57 (1975) 40 (1920)
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* SMALL FLUCTUATIONS IN LIFR/IFR VSBY THROUGH LATE MORNING WITH
GRADUAL IMPROVEMENT MIDDAY.
* PERIOD OF MVFR CONDITIONS POSSIBLE...ESPECIALLY AT MDW MIDDAY INTO
THE AFTERNOON.
* VERY LOW CIGS AND DENSE FOG LIKELY TO ROLL IN OFF LAKE LATE
THIS AFTERNOON OR EARLY THIS EVENING.
MDB
//DISCUSSION...UPDATED 14Z...
VSBY HAS CREPT DOWNWARD OVER THE LAST HOUR OR SO WITH SOME SMALL
FLUCTUATIONS NOTED IN SOME OBS. EXPECT THAT OCCASIONAL 1/4SM VSBY
WILL BE LIKELY RFD/DPA WITH MDW POTENTIALLY SEEING 1/2SM BRIEFLY
BEFORE 16Z BUT PROBABLY HOLDING IN THE 3/4-1SM RANGE. ORD MAY ALSO
SEE BRIEF 1/2-3/4SM BUT PROBABLY HOLD STEADIER IN THE 3/4-1SM
RANGE. GYY SHOULD BE IFR BUT LOOKS TO HAVE A LOWER CHANCE OF
SEEING SUB 1SM VSBY. TIMING OF IMPROVEMENT REMAINS TRICKY AND
HAVE SLOWED THE IMPROVEMENT GIVEN THE VERY MOIST AIRMASS AND VERY
LOW CONDITIONS UPSTREAM TO THE SOUTH. MVFR CIGS MAY BE TOUGH TO
COME BY FOR ANY LENGTH OF TIME THIS AFTERNOON. STILL EXPECT THE
FLOW TO TURN OFF THE LAKE LATER THIS AFTERNOON SUPPORTING A RETURN
TO VERY LOW VSBY AT ORD/MDW/GYY WITH A SLOWER DECREASE FURTHER
INLAND THIS EVENING AS THE WARM FRONT SETS UP TO THE SOUTH AGAIN.
CURRENT TIMING IN TAF MAY NEED TWEAKING.
MDB
FROM 12Z...
WARM FRONT CURRENTLY SITTING BETWEEN ORD AND MDW WILL DRIFT SLOWLY
NORTH HEADING INTO THE EARLY AFTERNOON. PRIOR TO THE FRONT MOVING
THROUGH ORD EXPECT LIFR CIGS AND AT LEAST IFR VSBY WITH A CHANCE
FOR A PERIOD OF LIFR VSBY THIS MORNING BEFORE SOME IMPROVEMENT
TAKES PLACE MIDDAY INTO MID AFTERNOON AS WARM FRONT ATTEMPTS TO
MOVE THROUGH ORD. MDW SHOULD REMAIN SOUTH OF THE FRONT AND SHOULD
SEE IMPROVEMENT TO MVFR CONDITIONS BY MID-LATE MORNING WHICH
SHOULD PERSIST THROUGH MUCH OF THE AFTERNOON.
WEAK FRONT SHOULD ALLOW A LAKE BREEZE FRONT TO DEVELOP AND SURGE
INLAND LATE THIS AFTERNOON AND EFFECTIVELY PUSH THE WARM FRONT
BACK SOUTH OF THE TERMINALS BETWEEN 22Z-00Z. AS THE LAKE CHILLED
AIR ENCOUNTERS THE INCREDIBLY MOIST AIR MASS LOOK FOR DENSE FOG TO
FORM INITIALLY ALONG THE LAKE FRONT AND LIKELY SPREADING TO
ORD/MDW EARLY THIS EVENING. TIMING OF WHEN DENSE FOG ARRIVES IS
HARD TO PIN DOWN...BUT SYNOPTICALLY THE SET UP STRONGLY FAVORS
DENSE FOG. FOR NOW JUST TOOK ORD AND MDW DOWN TO 1/2SM PREVAILING
DUE TO INHERENT UNCERTAINTIES WHEN FORECASTING FOG...HOWEVER
WOULDNT BE AT ALL SURPRISED TO SEE MANY HOURS OF 1/8SM TO 1/4SM
TONIGHT PRIOR TO WARM FRONT MOVING BACK NORTH THROUGH THE
TERMINALS AFTER MIDNIGHT. CIGS/VSBY SHOULD IMPROVE RAPIDLY WHEN
THE WARM FRONT LIFTS BACK NORTH ACROSS THE TERMINALS LATE TONIGHT.
LIGHT WINDS IN VICINITY OF FRONT THIS MORNING SHOULD TEND TO
BECOME LIGHT SOUTHERLY SOUTH OF THE WARM FRONT LATE THIS MORNING
INTO THIS AFTERNOON...FOLLOWED BY SHIFT TO NORTHEAST 5-10KT BEHIND
THE LAKE ENHANCED FRONT LATE THIS AFTERNOON WITH LIGHT NE WINDS
MUCH OF THE NIGHT BEFORE VEERING EAST PRIOR TO A SHIFT TO SOUTH
AS WARM FRONT LIFTS BACK NORTH LATE TONIGHT.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM-HIGH CONFIDENCE IN OVERALL CIGS/VSBY TRENDS.
* MEDIUM-HIGH CONFIDENCE IN DENSE FOG BY THIS EVENING...LOW-MEDIUM
CONFIDENCE ON TIMING OF ARRIVAL AND DEPARTURE OF DENSE FOG.
* HIGH CONFIDENCE IN WINDS STAYING PRIMARILY BELOW 10KT...LOWER
CONFIDENCE IN PRECISE DIRECTIONS AS FRONT WAVERS AROUND REGION.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PERIODIC SHRA. IFR LIKELY.
MONDAY...PERIODIC SHRA IN THE MORNING. MVFR CIGS.
TUESDAY...VFR.
WEDNESDAY...SMALL CHANCE OF SHRA/MVFR CIGS.
THURSDAY AND FRIDAY...MVFR CIGS A GOOD BET.
IZZI
&&
.MARINE...
301 AM CST
A DENSE FOG ADVISORY WILL LIKELY BE NEEDED FOR THE SOUTHERN HALF OF
THE LAKE TODAY. HOWEVER...I HAVE LOW CONFIDENCE IN WHEN THE DENSE
FOG WILL DEVELOP AND HOW LONG IT WILL PERSIST INTO THIS AFTERNOON OR
EVENING SO I WILL NOT BE ISSUING A DENSE FOG ADVISORY NOW. BOATERS
SHOULD BE PREPARED FOR DENSE FOG AND SEVERELY REDUCED VISIBILITIES.
A WEAKENING LOW IS OVER IOWA AND THE LOW WILL WEAKEN BEFORE ENTERING
ILLINOIS TODAY. A WARM FRONT LIES JUST SOUTH OF THE THIS MORNING AND
WILL SHIFT NORTH BUT REMAIN OVER THE SOUTHERN END OF THE LAKE
THROUGH SUNDAY. DENSE FOG IS EXPECTED TO FORM BEHIND THE FRONT. A
LAKE BREEZE WILL LIKELY FORM THIS AFTERNOON ALONG THE IL SHORE. THE
NEXT LOW FORMS OVER THE SOUTHERN PLAINS EARLY SUNDAY MORNING WITH
WINDS BECOMING SOUTHEAST ACROSS THE SOUTHERN HALF OF THE LAKE. EAST
WINDS TO 30 KT ARE EXPECTED ACROSS THE NORTHERN HALF OF THE LAKE.
SOUTHEAST WINDS INCREASE TO 30 KT SUNDAY. A SMALL CRAFT ADVISORY
WILL BE NEEDED FOR SUNDAY POTENTIALLY THROUGH MONDAY
EVENING...HOWEVER THERE MAY BE A PERIOD OF GALES MONDAY SO WILL HOLD
OFF ON ISSUING A SMALL CRAFT ADVISORY NOW.
SOUTHEAST WINDS INCREASE TO LOW END GALES SUNDAY NIGHT. THE LOW
SHIFTS NORTH OVER WISCONSIN MONDAY WITH SOUTH TO SOUTHWEST GALES
MAINLY OVER THE SOUTHERN END OF THE LAKE. MAY SEE A FEW GALE FORCE
GUSTS ACROSS THE NORTHERN END. THE LOW PASSES OVER THE NORTHERN END
OF THE LAKE MONDAY EVENING AND NIGHT WITH WINDS BECOMING WEST BEHIND
IT. THE NEXT LOW FORMS OVER THE PLAINS TUESDAY. GUIDANCE SUGGESTS
THIS LOW WILL HAVE A SIMILAR PATH TO THE LOW THIS WEEKEND OR SHIFT
NORTH ACROSS MINNESOTA. EITHER WAY SOUTH TO SOUTHWEST WINDS
INCREASE TO AT LEAST 30 KT WEDNESDAY WITH GALES POSSIBLE ACROSS THE
SOUTHERN HALF OF THE LAKE. ANOTHER SMALL CRAFT ADVISORY MAY BE
NEEDED AS WELL. WEST WINDS 15-25 KT ARE THEN EXPECTED THROUGH LATE
NEXT WEEK.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL NOON
SATURDAY.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
548 AM CST SAT DEC 12 2015
.SHORT TERM...
331 AM CST
THROUGH SUNDAY NIGHT...
EXCEEDINGLY TRICKY FORECAST IN THE SHORT TERM...PARTICULARLY WITH
RESPECT TO FOG AND TEMPS.
A SET-UP FAR MORE TYPICAL OF LATE MARCH OR EARLY APRIL WILL PLAY
HAVOC ON TEMP FORECAST AND LIKELY RESULT IN DENSE LAKE FOG
DEVELOPING. WARM FRONT HAS LIFTED NORTH AND LIES JUST NORTH OF I-80
EARLY THIS MORNING. DENSE FOG HAS BEEN PATCHY SO FAR AND CONFINED TO
AREAS MAINLY WEST AND SOUTHWEST OF OUR CWA THUS FAR...HOWEVER SHORT
RANGE GUIDANCE STILL SUGGESTS THAT THE DENSE FOG COULD EXPAND IN
COVERAGE AND IMPACT MAINLY OUR WESTERN AND SOUTHWESTERN COUNTIES
THIS MORNING. WILL TAKE A WAIT AND SEE APPROACH ON THIS GIVEN HOW
LACKLUSTER THIS MORNING`S FOG EVENT HAS BEEN THUS FAR.
WEAK SURFACE LOW OVER IOWA IS PROGGED TO DISSIPATE TODAY WITH
SURFACE CYCLOGENESIS TAKES PLACE OVER THE SOUTHERN HIGH PLAINS.
AS THE LOW WEAKENS...LOOK FOR SURFACE FRONTOLYSIS TO BEGIN WITH
WARMFRONT OVER OUR CWA. AS THE SYNOPTIC FRONT WEAKENS IT WILL OPEN
THE DOOR FOR LAKE MICHIGAN`S CHILLING EFFECTS TO TAKE OVER LATER
THIS AFTERNOON AND EVENING. WEAK AND WEAKENING PRESSURE GRADIENT IN
THE VICINITY OF THE WEAKENING FRONT WILL LIKELY ALLOW A LAKE BREEZE
FRONT TO DEVELOP THIS AFTERNOON DUE IN PART TO THE INCREASINGLY
LARGE THERMAL DIFFERENTIAL BETWEEN CHILLY MARINE AIR MASS OVER THE
LAKE AND UNSEASONABLY WARM AND ALMOST HUMID AIR OVER LAND. AS THE
COOL MARINE AIR ENCOUNTERS 50F+ DEWPOINTS IT APPEARS TO BE A CLASSIC
SET-UP FOR VERY DENSE MARINE FOG TO DEVELOP AND SEEP INLAND THIS
EVENING AS THE CHILLY MARINE AIR ENCOUNTERS NOT MUCH RESISTANCE AND
IT ABLE TO SPREAD PRETTY FAR INLAND. IF IT WEREN`T FOR
UNCERTAINTIES REGARDING TIMING OF FOG STARTING AND ENDING...WOULD
PROBABLY BE ISSUING A DENSE FOG ADVISORY NOW FOR THIS EVENING FOR
PORTIONS OF NE IL. DENSE FOG COULD DEVELOP FARTHER INLAND THIS
EVENING AWAY FROM THE MARINE LAYER...MAINLY NEAR AND TO THE NORTH
OF THE WEAKEN WARM FRONT. CONFIDENCE IN DENSE FOG DEVELOPING HERE
IS LOWER.
MODEL THAT HAS BEEN BEST FITTING THE CONCEPTUAL MODEL OF HOW I
EXPECT THINGS TO EVOLVE TODAY HAS BEEN THE EXPERIMENTAL HRRR AND
HAVE USED A TIME LAGGED ENSEMBLE APPROACH WITH THIS MODEL TO
POPULATE SHORT TERM HOURLY TEMP/DEWPOINT/WIND GRIDS INTO THIS
EVENING. DESPITE CLOUD COVER STILL EXPECT TEMPS TO WARM UP NICELY
TODAY...ESPECIALLY SOUTHERN CWA WHERE THEY ARE SOLIDLY IN THE WARM
SECTOR. WARMING TREND IN TEMPS WILL LIKELY BE ABRUPTLY HALTED NEAR
THE LAKE BY EARLY-MID AFTERNOON WHEN LAKE BREEZE FRONT BEGINS MOVING
INLAND AND KNOCKING TEMPS BACK INTO THE 40S NEAR THE LAKE AND
RESULTING IN FALLING TEMPS EVEN WELL INLAND BY EARLY EVENING. TOUGH
CALL ON HOW QUICKLY TEMPS WILL WARM IN CHICAGO BEFORE LAKE AIR
SPREADS INLAND...BUT EXPERIMENTAL HRRR SUGGESTS ORD WILL PROBABLY
NOT GET MUCH ABOVE MID TO MAYBE UPPER 50S BEFORE TEMPS FALL LATE IN
THE EVENING WITH FOG...PROBABLY DENSE LIKELY TO FOLLOW.
TONIGHT...SOUTHERN PLAINS CYCLONE WILL BEGIN MOVING NORTH AND THE
NOW LAKE RE-ENFORCED WARM FRONT WILL BEGIN TO STRENGTHEN AGAIN AND
STRENGTHENING PRESSURE FALLS SHOULD CAUSE THE FRONT TO BEGIN MOVING
NORTH AGAIN. SHOULD BEHAVE LIKE A TYPICAL MARCH WARM FRONT BECOMING
SOMEWHAT CONTORTED AROUND LAKE MICHIGAN WITH NORTH SHORE AREAS
LIKELY BEING THE LAST AREA IN OUR CWA TO MAKE IT INTO THE WARM
SECTOR. EXPECT FOG TO PRIMARILY BE A PROBLEM AHEAD OF THE WARM FRONT
WITH DRAMATICALLY IMPROVING VISIBILITIES AS THE WARM FRONT LIFTS
NORTHWARD. TEMPS IN THE WARM SECTOR TONIGHT WILL LIKELY HOLD IN THE
UPPER 50S TO LOWER 60S...WITH A RAPID RISE IN TEMPERATURES FROM THE
40S TO NEAR 60 EXPECTED IN THE CHICAGO AREA OVERNIGHT AS THE WARM
FRONT LIFTS NORTH.
PRECIP-WISE...NOT EXPECTED MUCH MEASURABLE PRECIP UNTIL TONIGHT.
COULD BE SOME DRIZZLE WITH THE DENSE MARINE FOG AND HRRR SUGGESTS A
FEW LIGHT SHOWERS LATE THIS AFTERNOON IN VICINITY OF THE WARM FRONT.
TONIGHT...THE MAIN FOCUS FOR SHOWERS AND SOME THUNDERSTORMS LOOKS TO
REMAIN MOSTLY TO THE WEST OF OUR CWA CLOSER TO THE STRONG ISENTROPIC
ASCENT AND NEAR THE NOSE OF THE LOW LEVEL JET. STILL EXPECT SOME OF
THIS SHOWER ACTIVITY TO MAKE IT INTO MAINLY NORTH CENTRAL ILLINOIS
WITH A LESSER THREAT OF SHOWERS OVER THE REMAINDER OF THE CWA.
SUNDAY SHOULD BE WINDY AND UNSEASONABLY WARM WITH A PERIOD OR TWO OF
SHOWERS LIKELY...ESPECIALLY WESTERN AND NORTHERN PORTIONS OF THE
AREA. DEPENDING ON THE COVERAGE OF SHOWERS...WE COULD MAKE A RUN AT
THE RECORD HIGHS FOR THE DAY...THOUGH DECIDED TO KEEP TEMPS SOMEWHAT
CONSERVATIVE IN THE GRIDS FOR NOW WITH MAINLY LOW 60S NORTH AND MID
60S SOUTH. ADDITIONAL SHOWERS ARE EXPECTED SUNDAY NIGHT AS FAIRLY
STRONG COLD FRONT EVENTUALLY MOVES ACROSS THE AREA. MAJORITY OF
SUNDAY NIGHT WILL BE WINDY AND UNSEASONABLY WARM WITH TEMPS CLOSE TO
IF NOT IN THE 60S BEFORE COLD FRONT MOVES THROUGH CLOSER TO DAWN
RESULTING IN LOW TEMPS NOT OCCURRING UNTIL AFTER SUNRISE.
IZZI
&&
.LONG TERM...
331 AM CST
MONDAY THROUGH FRIDAY...
WINDY AND MUCH COOLER WEATHER IS ON TAP FOR MONDAY WITH SHOWERS IN
THE MORNING LIKELY TAPERING OFF AND ENDING BY OR PERHAPS DURING THE
EARLY AFTERNOON. WE SHOULD GET A BRIEF BREAK BETWEEN SYSTEM TUESDAY
WITH DRY CONDITIONS AND CONTINUED ABOVE NORMAL TEMPS...BUT MUCH LESS
SO THAN THIS WEEKEND.
NEXT SYSTEM MOVES THROUGH MIDWEEK...BUT AT THIS POINT LOOKS PRETTY
MOISTURE STARVED AS IT WILL BE FAST ON THE HEELS OF THE WEEKEND
SYSTEM WHICH SHOULD BE PRETTY EFFECTIVE AT SCOURING OUT THE
MOISTURE. IN THE WAKE OF THIS STORM IT LOOKS LIKE WE WILL GET A
TASTE OF MORE TYPICAL DECEMBER TEMPERATURES FOR A FEW DAYS LATER
THIS WEEK INTO THE WEEKEND WITH HIGHS NOT GETTING OUT OF THE 30S. IN
FACT...IF THE ECMWF VERIFIES FRIDAY/SATURDAY MAY NOT EVEN REACH 30F
FOR HIGHS WHICH WILL FEEL VERY COLD AFTER THIS WEEKEND`S NEAR RECORD
WARMTH BUT IN REALITY WILL ONLY BE A FEW DEGREES COLDER THAN NORMAL.
MEDIUM RANGE MODELS SUGGEST THAT THE LONGWAVE TROUGH RESPONSIBLE FOR
THE TASTE OF WINTER WILL BE PROGRESSIVE WITH A MODELS AND CPC BOTH
SUGGESTING A RETURN TO ABOVE AVERAGE TEMPERATURES CHRISTMAS WEEK.
IZZI
&&
.CLIMATE...
NEAR RECORD TEMPERATURES ARE FORECAST FOR THE AREA THROUGH
SUNDAY. HERE ARE THE CURRENT RECORD HIGH TEMPERATURES AND WARMEST
LOW TEMPERATURES ON RECORD FOR CHICAGO AND ROCKFORD.
CHICAGO:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 61 (1877) 48 (1968)
DEC 13 67 (1975) 46 (1920)
---------------------------------
ROCKFORD:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 60 (1991) 43 (1968)
DEC 13 57 (1975) 40 (1920)
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* IFR/LIFR CIGS AND SOME FOG LIKELY THIS MORNING
* PERIOD OF MVFR CONDITIONS LIKELY...ESPECIALLY AT MDW LATE
MORNING INTO THE AFTERNOON
* VERY LOW CIGS AND DENSE FOG LIKELY TO ROLL IN OFF LAKE LATE
THIS AFTERNOON OR EARLY THIS EVENING
IZZI
//DISCUSSION...UPDATED 12Z...
WARM FRONT CURRENTLY SITTING BETWEEN ORD AND MDW WILL DRIFT SLOWLY
NORTH HEADING INTO THE EARLY AFTERNOON. PRIOR TO THE FRONT MOVING
THROUGH ORD EXPECT LIFR CIGS AND AT LEAST IFR VSBY WITH A CHANCE
FOR A PERIOD OF LIFR VSBY THIS MORNING BEFORE SOME IMPROVEMENT
TAKES PLACE MIDDAY INTO MID AFTERNOON AS WARM FRONT ATTEMPTS TO
MOVE THROUGH ORD. MDW SHOULD REMAIN SOUTH OF THE FRONT AND SHOULD
SEE IMPROVEMENT TO MVFR CONDITIONS BY MID-LATE MORNING WHICH
SHOULD PERSIST THROUGH MUCH OF THE AFTERNOON.
WEAK FRONT SHOULD ALLOW A LAKE BREEZE FRONT TO DEVELOP AND SURGE
INLAND LATE THIS AFTERNOON AND EFFECTIVELY PUSH THE WARM FRONT
BACK SOUTH OF THE TERMINALS BETWEEN 22Z-00Z. AS THE LAKE CHILLED
AIR ENCOUNTERS THE INCREDIBLY MOIST AIR MASS LOOK FOR DENSE FOG TO
FORM INITIALLY ALONG THE LAKE FRONT AND LIKELY SPREADING TO
ORD/MDW EARLY THIS EVENING. TIMING OF WHEN DENSE FOG ARRIVES IS
HARD TO PIN DOWN...BUT SYNOPTICALLY THE SET UP STRONGLY FAVORS
DENSE FOG. FOR NOW JUST TOOK ORD AND MDW DOWN TO 1/2SM PREVAILING
DUE TO INHERENT UNCERTAINTIES WHEN FORECASTING FOG...HOWEVER
WOULDNT BE AT ALL SURPRISED TO SEE MANY HOURS OF 1/8SM TO 1/4SM
TONIGHT PRIOR TO WARM FRONT MOVING BACK NORTH THROUGH THE
TERMINALS AFTER MIDNIGHT. CIGS/VSBY SHOULD IMPROVE RAPIDLY WHEN
THE WARM FRONT LIFTS BACK NORTH ACROSS THE TERMINALS LATE TONIGHT.
LIGHT WINDS IN VICINITY OF FRONT THIS MORNING SHOULD TEND TO
BECOME LIGHT SOUTHERLY SOUTH OF THE WARM FRONT LATE THIS MORNING
INTO THIS AFTERNOON...FOLLOWED BY SHIFT TO NORTHEAST 5-10KT BEHIND
THE LAKE ENHANCED FRONT LATE THIS AFTERNOON WITH LIGHT NE WINDS
MUCH OF THE NIGHT BEFORE VEERING EAST PRIOR TO A SHIFT TO SOUTH
AS WARM FRONT LIFTS BACK NORTH LATE TONIGHT.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM-HIGH CONFIDENCE IN OVERALL CIGS/VSBY TRENDS
* MEDIUM-HIGH CONFIDENCE IN DENSE FOG BY THIS EVENING...LOW-MEDIUM
CONFIDENCE ON TIMING OF ARRIVAL AND DEPARTURE OF DENSE FOG
* HIGH CONFIDENCE IN WINDS STAYING PRIMARILY BELOW 10KT...LOWER
CONFIDENCE IN PRECISE DIRECTIONS AS FRONT WAVERS AROUND REGION
IZZI
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PERIODIC SHRA. IFR LIKELY.
MONDAY...PERIODIC SHRA IN THE MORNING. MVFR CIGS.
TUESDAY...VFR.
WEDNESDAY...SMALL CHANCE OF SHRA/MVFR CIGS.
THURSDAY AND FRIDAY...MVFR CIGS A GOOD BET.
IZZI
&&
.MARINE...
301 AM CST
A DENSE FOG ADVISORY WILL LIKELY BE NEEDED FOR THE SOUTHERN HALF OF
THE LAKE TODAY. HOWEVER...I HAVE LOW CONFIDENCE IN WHEN THE DENSE
FOG WILL DEVELOP AND HOW LONG IT WILL PERSIST INTO THIS AFTERNOON OR
EVENING SO I WILL NOT BE ISSUING A DENSE FOG ADVISORY NOW. BOATERS
SHOULD BE PREPARED FOR DENSE FOG AND SEVERELY REDUCED VISIBILITIES.
A WEAKENING LOW IS OVER IOWA AND THE LOW WILL WEAKEN BEFORE ENTERING
ILLINOIS TODAY. A WARM FRONT LIES JUST SOUTH OF THE THIS MORNING AND
WILL SHIFT NORTH BUT REMAIN OVER THE SOUTHERN END OF THE LAKE
THROUGH SUNDAY. DENSE FOG IS EXPECTED TO FORM BEHIND THE FRONT. A
LAKE BREEZE WILL LIKELY FORM THIS AFTERNOON ALONG THE IL SHORE. THE
NEXT LOW FORMS OVER THE SOUTHERN PLAINS EARLY SUNDAY MORNING WITH
WINDS BECOMING SOUTHEAST ACROSS THE SOUTHERN HALF OF THE LAKE. EAST
WINDS TO 30 KT ARE EXPECTED ACROSS THE NORTHERN HALF OF THE LAKE.
SOUTHEAST WINDS INCREASE TO 30 KT SUNDAY. A SMALL CRAFT ADVISORY
WILL BE NEEDED FOR SUNDAY POTENTIALLY THROUGH MONDAY
EVENING...HOWEVER THERE MAY BE A PERIOD OF GALES MONDAY SO WILL HOLD
OFF ON ISSUING A SMALL CRAFT ADVISORY NOW.
SOUTHEAST WINDS INCREASE TO LOW END GALES SUNDAY NIGHT. THE LOW
SHIFTS NORTH OVER WISCONSIN MONDAY WITH SOUTH TO SOUTHWEST GALES
MAINLY OVER THE SOUTHERN END OF THE LAKE. MAY SEE A FEW GALE FORCE
GUSTS ACROSS THE NORTHERN END. THE LOW PASSES OVER THE NORTHERN END
OF THE LAKE MONDAY EVENING AND NIGHT WITH WINDS BECOMING WEST BEHIND
IT. THE NEXT LOW FORMS OVER THE PLAINS TUESDAY. GUIDANCE SUGGESTS
THIS LOW WILL HAVE A SIMILAR PATH TO THE LOW THIS WEEKEND OR SHIFT
NORTH ACROSS MINNESOTA. EITHER WAY SOUTH TO SOUTHWEST WINDS
INCREASE TO AT LEAST 30 KT WEDNESDAY WITH GALES POSSIBLE ACROSS THE
SOUTHERN HALF OF THE LAKE. ANOTHER SMALL CRAFT ADVISORY MAY BE
NEEDED AS WELL. WEST WINDS 15-25 KT ARE THEN EXPECTED THROUGH LATE
NEXT WEEK.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012 UNTIL NOON SATURDAY.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS MARQUETTE MI
633 AM EST SAT DEC 12 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM EST SAT DEC 12 2015
...QUIET WEATHER TODAY BEFORE SIGNIFICANT RAINFALL SUNDAY INTO
MONDAY...
WEAK E-NE UPSLOPE FLOW CONTINUES...ALLOWING FOR SNOW SHOWERS ALONG
NORTH CENTRAL UPPER MICHIGAN AS WELL AS IN THE KEWEENAW. IT IS
ACTUALLY INTERESTING THAT THE PRECIPITATION IS SNOW RATHER THAN
DRIZZLE/FREEZING DRIZZLE AS IT WOULD SEEM HARD TO IMAGINE MUCH ICE
NUCLEI IN THE SHALLOW /2000 FT/ AND RELATIVELY WARM /-4C/ CLOUD.
SHORT TERM NWP DOES NOT SUGGEST ANY SEEDING FROM HIGHER CLOUD IS
POSSIBLE. GIVEN A SIMILAR THERMAL AND MOISTURE PROFILE THIS
MORNING...WILL MAINTAIN SLIGHT CHANCE OF SN/DZ/FZDZ THROUGH NOON.
THEN...THE HRRR SUGGESTS THAT ANY REMAINING DRIZZLE WILL END WITH
SOME SLIGHT LOW LEVEL MIXING.
LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST TONIGHT.
STRONG WARM ADVECTION AND ISENTROPIC LIFT WILL MOVE NORTHWARD INTO
THE UPPER GREAT LAKES BY SUNDAY MORNING. THE 00Z NWP SEEM BE BE IN
EXCELLENT AGREEMENT IN BRINGING RAIN ACROSS MUCH OF THE SOUTHERN
HALF OF THE U.P. AFT 09Z AND TO THE MAJORITY OF UPPER MI EXCEPT THE
KEWEENAW AND THE EASTERN 1/3 BY 12Z. AS SUCH...WILL KEEP POPS
MINIMAL THIS EVENING...THE RAPIDLY RAISE TO LIKELY ACROSS THE WEST
AND CENTRAL BTWN 09-12Z. IN FACT...WILL GO WITH CATEGORICAL POPS
FOR FAR SOUTHERN MENOMINEE COUNTY BY 12Z.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 533 AM EST SAT DEC 12 2015
MODELS ADVERTISE AN ACTIVE PROGRESSIVE PATTERN FOR THE LONG TERM
STARTING OUT WITH A STRONG LOW PRESSURE SYSTEM FROM THE PLAINS
LIFTING NE INTO THE UPPER GREAT LAKES FOR SUNDAY AND MONDAY FOLLOWED
BY ANOTHER PLAINS SYSTEM MOVING IN FOR TUE NIGHT AND WED. THIS
SECOND SYSTEM IS FOLLOWED BY A SERIES OF CLIPPER SHORTWAVES WHICH
WILL BRING IN COLDER AIR FM NW CANADA BY LATE NEXT WEEK. AS A
RESULT...TEMPS WILL START OUT WELL ABOVE NORMAL WITH NEAR RECORD
VALUES INTO MONDAY BUT WILL THEN DROP OFF CLOSER TO NORMAL VALUES BY
THU-FRI.
SUNDAY THROUGH MONDAY...A STRONG SRN STREAM SYSTEM IS EXPECTED TO
LIFT FROM THE SRN PLAINS TO THE WRN LAKES. THE 00Z/12 ECMWF IS
PERHAPS SLIGHTLY SLOWER INITIALLY THAN 00Z GFS AND CANADIAN WITH
ARRIVAL OF OCCLUDING SFC LOW LATE MONDAY BUT OTHERWISE MODELS
GENERALLY IN GOOD AGREEMENT. ALL MODELS SHOW A SIMILAR TRACK ACROSS
THE CENTRAL U.P. ON MONDAY BRINGING PLENTY OF WARM AIR INTO THE CWA
TO SUPPORT MOSTLY RAIN THROUGH MONDAY. VERY STRONG MOISTURE
ADVECTION WILL PUSH PWAT VALUES TO CLIMATOLOGICALLY EXTREME VALUES
NEAR 1.20 INCH OR TO ABOUT A 6.0 SIGMA STANDARDIZED ANOMALY. THIS
STRONG MOISTURE ADVECTION COMBINED WITH STRONG DEEP LAYER Q-VECTOR
CONVERGENCE AND ENHANCED 700 MB FGEN IN RESPONSE TO INCREASED UPPER
DIVERGENCE FROM COUPLED UPPER JET STRUCTURE WILL LIKELY LEAD TO
STORM TOTAL RAINFALL AMOUNTS THROUGH PERIOD IN THE 2 TO 3 INCH RANGE
ACROSS THE CWA WITH THE HEAVIEST AMOUNTS LIKELY OVER THE WEST HALF
SUN NIGHT INTO MONDAY. THE INITIAL BATCH OF RAIN ON SUNDAY WILL
PRIMARILY BE SUPPORTED BY AN AREA OF 290K-300K ISENTROPIC LIFT WITH
RAIN SPREADING TO THE NORTH THROUGH THE CWA.
MON NIGHT-FRI...MODEL THICKNESS/SOUNDINGS AND WET BULB ZERO
CALCULATIONS SUGGEST RAIN WILL FINALLY BEGIN TO CHANGE TO SNOW FROM
WEST TO EAST MON NIGHT INTO TUE...BUT BY THIS TIME MODELS INDICATE
THAT THE HEAVIER PCPN ASSOC WITH THE COMMA HEAD/DEFORMATION AREA OF
SYSTEM WILL HAVE EXITED TO THE EAST. SO ANY SNOW WE GET FROM THIS
SYSTEM LOOKS LIKE IT WILL BE LIGHT (LESS THAN AN INCH) AND CONFINED
TO THE WEST. AFTER LIGHT LES ON TUESDAY IN N-NE FLOW ALONG LAKE
SUPERIOR COUNTIES...MODELS SHOW ANOTHER SHORTWAVE AND ASSOC SFC LOW
APPROACHING FROM THE CENTRAL PLAINS AND UPPER MS VALLEY ON WED. WITH
MODELS TRENDING EVEN FARTHER WEST WITH THIS SYSTEM RAIN IS MORE
LIKELY CENTRAL AND EAST WITH A RAIN/SNOW MIX WEST. A SERIES OF
CLIPPER SHORTWAVES IN THE WAKE OF THE MIDWEEK SYSTEM...WILL BRING IN
COLDER AIR AS 850 MB TEMPS LOWER TO -15C OR COLDER BY FRIDAY. THIS
WILL SUPPORT INCREASING LES CHANCES FOR WESTERLY FLOW FAVORED
LOCATIONS...PARTICULARLY OVER THE KEWEENAW WHERE ADVISORY LES SNOWS
MAY BE POSSIBLE FROM LATE THU INTO FRI.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 632 AM EST SAT DEC 12 2015
LOWER END MVFR AND LOCALIZED IFR CONDITIONS ARE ONGOING AT TIME. AM
ACTUALLY SURPRISED THAT SAW IS NOT LOWER THAN MVFR WITH THE UPSLOPE
E-NE FLOW. HOWEVER...EXPECT CONDITIONS TO BE IN THE IFR/LOW MVFR
RANGE THROUGHOUT THE DAY TODAY. DEEPER MOISTURE RETURNS TO THE AREA
TONIGHT AHEAD OF THE LOW PRESSURE SYSTEM. EXPECT IFR CIGS TO SPREAD
ACROSS THE ENTIRE AREA OVERNIGHT WITH RAIN DEVELOPING LATE. COULD
SEE LIFR CONDITIONS ON SUNDAY WITH MODERATE RAIN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 330 AM EST SAT DEC 12 2015
AS LOW PRESSURE OVER THE CENTRAL PLAINS DEVELOPS AND MOVES NORTHEAST
TODAY...EXPECT EAST-NORTHEAST WINDS TO SLOWLY INCREASE TODAY...WITH
WINDS OF 25KT ACROSS THE WEST HALF BY THIS EVENING. AS THE LOW
CONTINUES TO MOVE NORTHEAST TOWARD THE GREAT LAKES LATER TONIGHT
INTO SUNDAY NIGHT...WINDS WILL CONTINUE TO INCREASE WITH WINDS OF
GALE FORCE ACROSS THE WEST HALF BY SUNDAY AFTERNOON. NE GALES WILL
CONTINUE INTO MONDAY NIGHT ACROSS THE WEST HALF AND MAY ALSO SPREAD
TO THE EAST HALF ON MONDAY AFTERNOON AS THE LOW FINALLY MOVES
NORTHEAST OF THE AREA AND COLDER AIR FILTERS ACROSS THE LAKE ON
NORTHERLY WINDS. WINDS WILL SUBSIDE TO 20 KT BY TUESDAY BEFORE
ANOTHER LOW PRESSURE SYSTEM DEVELOPS AND MOVES INTO THE UPPER GREAT
LAKES FOR WEDNESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SUNDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
LSZ162-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...VOSS
AVIATION...MRD
MARINE...MRD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
535 AM EST SAT DEC 12 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM EST SAT DEC 12 2015
...QUIET WEATHER TODAY BEFORE SIGNIFICANT RAINFALL SUNDAY INTO
MONDAY...
WEAK E-NE UPSLOPE FLOW CONTINUES...ALLOWING FOR SNOW SHOWERS ALONG
NORTH CENTRAL UPPER MICHIGAN AS WELL AS IN THE KEWEENAW. IT IS
ACTUALLY INTERESTING THAT THE PRECIPITATION IS SNOW RATHER THAN
DRIZZLE/FREEZING DRIZZLE AS IT WOULD SEEM HARD TO IMAGINE MUCH ICE
NUCLEI IN THE SHALLOW /2000 FT/ AND RELATIVELY WARM /-4C/ CLOUD.
SHORT TERM NWP DOES NOT SUGGEST ANY SEEDING FROM HIGHER CLOUD IS
POSSIBLE. GIVEN A SIMILAR THERMAL AND MOISTURE PROFILE THIS
MORNING...WILL MAINTAIN SLIGHT CHANCE OF SN/DZ/FZDZ THROUGH NOON.
THEN...THE HRRR SUGGESTS THAT ANY REMAINING DRIZZLE WILL END WITH
SOME SLIGHT LOW LEVEL MIXING.
LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST TONIGHT.
STRONG WARM ADVECTION AND ISENTROPIC LIFT WILL MOVE NORTHWARD INTO
THE UPPER GREAT LAKES BY SUNDAY MORNING. THE 00Z NWP SEEM BE BE IN
EXCELLENT AGREEMENT IN BRINGING RAIN ACROSS MUCH OF THE SOUTHERN
HALF OF THE U.P. AFT 09Z AND TO THE MAJORITY OF UPPER MI EXCEPT THE
KEWEENAW AND THE EASTERN 1/3 BY 12Z. AS SUCH...WILL KEEP POPS
MINIMAL THIS EVENING...THE RAPIDLY RAISE TO LIKELY ACROSS THE WEST
AND CENTRAL BTWN 09-12Z. IN FACT...WILL GO WITH CATEGORICAL POPS
FOR FAR SOUTHERN MENOMINEE COUNTY BY 12Z.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 533 AM EST SAT DEC 12 2015
MODELS ADVERTISE AN ACTIVE PROGRESSIVE PATTERN FOR THE LONG TERM
STARTING OUT WITH A STRONG LOW PRESSURE SYSTEM FROM THE PLAINS
LIFTING NE INTO THE UPPER GREAT LAKES FOR SUNDAY AND MONDAY FOLLOWED
BY ANOTHER PLAINS SYSTEM MOVING IN FOR TUE NIGHT AND WED. THIS
SECOND SYSTEM IS FOLLOWED BY A SERIES OF CLIPPER SHORTWAVES WHICH
WILL BRING IN COLDER AIR FM NW CANADA BY LATE NEXT WEEK. AS A
RESULT...TEMPS WILL START OUT WELL ABOVE NORMAL WITH NEAR RECORD
VALUES INTO MONDAY BUT WILL THEN DROP OFF CLOSER TO NORMAL VALUES BY
THU-FRI.
SUNDAY THROUGH MONDAY...A STRONG SRN STREAM SYSTEM IS EXPECTED TO
LIFT FROM THE SRN PLAINS TO THE WRN LAKES. THE 00Z/12 ECMWF IS
PERHAPS SLIGHTLY SLOWER INITIALLY THAN 00Z GFS AND CANADIAN WITH
ARRIVAL OF OCCLUDING SFC LOW LATE MONDAY BUT OTHERWISE MODELS
GENERALLY IN GOOD AGREEMENT. ALL MODELS SHOW A SIMILAR TRACK ACROSS
THE CENTRAL U.P. ON MONDAY BRINGING PLENTY OF WARM AIR INTO THE CWA
TO SUPPORT MOSTLY RAIN THROUGH MONDAY. VERY STRONG MOISTURE
ADVECTION WILL PUSH PWAT VALUES TO CLIMATOLOGICALLY EXTREME VALUES
NEAR 1.20 INCH OR TO ABOUT A 6.0 SIGMA STANDARDIZED ANOMALY. THIS
STRONG MOISTURE ADVECTION COMBINED WITH STRONG DEEP LAYER Q-VECTOR
CONVERGENCE AND ENHANCED 700 MB FGEN IN RESPONSE TO INCREASED UPPER
DIVERGENCE FROM COUPLED UPPER JET STRUCTURE WILL LIKELY LEAD TO
STORM TOTAL RAINFALL AMOUNTS THROUGH PERIOD IN THE 2 TO 3 INCH RANGE
ACROSS THE CWA WITH THE HEAVIEST AMOUNTS LIKELY OVER THE WEST HALF
SUN NIGHT INTO MONDAY. THE INITIAL BATCH OF RAIN ON SUNDAY WILL
PRIMARILY BE SUPPORTED BY AN AREA OF 290K-300K ISENTROPIC LIFT WITH
RAIN SPREADING TO THE NORTH THROUGH THE CWA.
MON NIGHT-FRI...MODEL THICKNESS/SOUNDINGS AND WET BULB ZERO
CALCULATIONS SUGGEST RAIN WILL FINALLY BEGIN TO CHANGE TO SNOW FROM
WEST TO EAST MON NIGHT INTO TUE...BUT BY THIS TIME MODELS INDICATE
THAT THE HEAVIER PCPN ASSOC WITH THE COMMA HEAD/DEFORMATION AREA OF
SYSTEM WILL HAVE EXITED TO THE EAST. SO ANY SNOW WE GET FROM THIS
SYSTEM LOOKS LIKE IT WILL BE LIGHT (LESS THAN AN INCH) AND CONFINED
TO THE WEST. AFTER LIGHT LES ON TUESDAY IN N-NE FLOW ALONG LAKE
SUPERIOR COUNTIES...MODELS SHOW ANOTHER SHORTWAVE AND ASSOC SFC LOW
APPROACHING FROM THE CENTRAL PLAINS AND UPPER MS VALLEY ON WED. WITH
MODELS TRENDING EVEN FARTHER WEST WITH THIS SYSTEM RAIN IS MORE
LIKELY CENTRAL AND EAST WITH A RAIN/SNOW MIX WEST. A SERIES OF
CLIPPER SHORTWAVES IN THE WAKE OF THE MIDWEEK SYSTEM...WILL BRING IN
COLDER AIR AS 850 MB TEMPS LOWER TO -15C OR COLDER BY FRIDAY. THIS
WILL SUPPORT INCREASING LES CHANCES FOR WESTERLY FLOW FAVORED
LOCATIONS...PARTICULARLY OVER THE KEWEENAW WHERE ADVISORY LES SNOWS
MAY BE POSSIBLE FROM LATE THU INTO FRI.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1233 AM EST SAT DEC 12 2015
AT THE LEAST...LOW TO MID RANGE MVFR CIGS ARE EXPECTED AT ALL SITES
THROUGH THE PERIOD AS MOISTURE REMAINS TRAPPED BELOW AN INVERSION.
DUE TO UPSLOPE EASTERLY FLOW...LOWER CIGS ALONG WITH FOG AND
POSSIBLY SOME DZ/FZDZ COULD FORM LATER TONIGHT AT KSAW AND
KCMX...BUT CONFIDENCE ON THE EXTENT REMAINS LOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 330 AM EST SAT DEC 12 2015
AS LOW PRESSURE OVER THE CENTRAL PLAINS DEVELOPS AND MOVES NORTHEAST
TODAY...EXPECT EAST-NORTHEAST WINDS TO SLOWLY INCREASE TODAY...WITH
WINDS OF 25KT ACROSS THE WEST HALF BY THIS EVENING. AS THE LOW
CONTINUES TO MOVE NORTHEAST TOWARD THE GREAT LAKES LATER TONIGHT
INTO SUNDAY NIGHT...WINDS WILL CONTINUE TO INCREASE WITH WINDS OF
GALE FORCE ACROSS THE WEST HALF BY SUNDAY AFTERNOON. NE GALES WILL
CONTINUE INTO MONDAY NIGHT ACROSS THE WEST HALF AND MAY ALSO SPREAD
TO THE EAST HALF ON MONDAY AFTERNOON AS THE LOW FINALLY MOVES
NORTHEAST OF THE AREA AND COLDER AIR FILTERS ACROSS THE LAKE ON
NORTHERLY WINDS. WINDS WILL SUBSIDE TO 20 KT BY TUESDAY BEFORE
ANOTHER LOW PRESSURE SYSTEM DEVELOPS AND MOVES INTO THE UPPER GREAT
LAKES FOR WEDNESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SUNDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
LSZ162-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...VOSS
AVIATION...JLA
MARINE...MRD
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
544 AM CST SAT DEC 12 2015
.UPDATE...12Z AVIATION UPDATE BELOW.
&&
.AVIATION...GENERALLY MVFR CEILINGS AROUND 1200-1800 FEET
PREVAIL EARLY THIS MORNING ACROSS SOUTH-CENTRAL TEXAS. COULD SEE
SOME LOCATIONS DROP INTO IFR THROUGH THE MORNING HOURS WITH
PATCHY -DZ AND ISOLATED -SHRA DEVELOPING. MVFR CEILINGS LIKELY
TO CONTINUE AT AUS AND SAT THROUGH THE AFTERNOON HOURS. S TO SE
WINDS GRADUALLY INCREASING AFTER 15Z...BECOMING GUSTY 20-25 KTS
THROUGH THE AFTERNOON. IFR CEILINGS MAY DEVELOP AFTER SUNSET AT
SAT/AUS. A SQUALL LINE IS FORECAST TO MOVE THROUGH DRT 02Z-04Z AND
SAT/AUS 07Z-09Z. STRONG TO SEVERE STRAIGHT-LINE WIND GUSTS MAY
ACCOMPANY THE LINE OF STORMS. A COLD FRONT WILL SWEEP THROUGH THE
AREA BEHIND THE SQUALL LINE...WITH NW WINDS DEVELOPING...PRECIP
ENDING AND CEILINGS BECOMING VFR.
&&
.PREV DISCUSSION... /ISSUED 419 AM CST SAT DEC 12 2015/
SHORT TERM (TODAY THROUGH SUNDAY)...
SEVERE WEATHER AND LOCALLY HEAVY RAINFALL IS EXPECTED MAINLY
TONIGHT. RADAR LOOP CONFIRMS THE APPROACH OF A LEAD SHORT-WAVE
DISTURBANCE FROM MEXICO AND AHEAD OF A DEEP UPPER TROUGH
APPROACHING TX FROM THE PACIFIC. MODEL INDICATIONS OF INCREASING
MID LEVEL MOISTURE LEADS TO PWAT VALUES JUMPING UP TO 2 INCHES
OVER THE COASTAL PRAIRIES BY MIDDAY...WITH HIGH RAIN CHANCES
COVERING MUCH OF THE EASTERN HALF OF TX. AS NOTED BY SPC THE HIGH
AMOUNT OF MOISTURE SHOULD LIMIT THE POTENTIAL FOR DAYTIME
SEVERITY...WITH NEAR CONTINUOUS CLOUDINESS LIMITING STORM
STRENGTH. SHOULD BREAKS IN THE CLOUDS OCCUR THERE IS A SMALL
POTENTIAL FOR LOW TOPPED SUPERCELLS GIVEN THE FORECAST
HELICITIES.
INCREASING LOW TO MID LEVEL WINDS IN ADVANCE OF THE APPROACHING
UPPER TROUGH WILL SET UP BEST LOW LEVEL CONVERGENCE OVER THE I-45
CORRIDOR FOR HIGHEST QPF AMOUNTS...BUT SOME OF THE HIGHER RES DATA
DEPICTS AN AREA OF POTENTIAL TRAINING EXTENDING SW INTO OUR FAR
EASTERN COUNTIES. THE FINAL FORECAST HOUR OF THE HRRR SUGGESTS
INCREASED TRAINING POTENTIAL BY 23Z WITH OTHER HIGH-RES SOLUTIONS
CONTINUING A LOCALLY HEAVY RAIN THREAT OVER EASTERN COUNTIES IN
THE EVENING. FAST STORM MOTIONS ARE EXPECTED TO OFFSET THE
TRAINING PROBLEM...BUT THE HIGH PWAT ENVIRONMENT IS STILL LIKELY
TO DUMP ISOLATED DOWNPOURS OF AROUND 2 INCHES BEFORE MIDNIGHT.
BASED ON WHAT DEVELOPS LATE THIS AFTERNOON...LATER SHIFTS MAY NEED
TO MONITOR FOR A POSSIBLE FLASH FLOOD WATCH OVER EASTERN
COUNTIES...AS A MORE WIDESPREAD ROUND OF RAIN ARRIVES LATE
TONIGHT.
MODELS AND THE WPC SHOW A PRETTY CONSISTENT QPF PATTERN WITH
GENERALLY TWO ENHANCED CLUSTERS OF CONVECTION...AND THE LATTER
ROUND OF RAIN IS LIKELY TO PRODUCE A NEAR SOLID LINE OF STRONG TO
SEVERE STORMS WITH VERY HEAVY RAINFALL RATES. AGAIN THE MOTIONS
WILL BE FAST SO WE/RE EXPECTING A QUICK 1 TO 2 INCHES OF RAIN
FALLING IN A SHORT TIME FOLLOWED BY A BRIEF PERIOD OF MODERATE
RAIN. BY THE END OF THE RAIN EVENT SUNDAY MORNING...A FEW SPOTS
WELL TO THE EAST OF AUSTIN COULD RECEIVE 4 INCHES. BOWING SEGMENTS
WITH THE OVERNIGHT ROUND OF RAIN WILL BE DRIVEN BY THE UPPER
TROUGH AND COULD LEAD TO DAMAGING WINDS AND AN ISOLATED TORNADO
THREAT. THE SPC HAS EXPANDED THE SLIGHT RISK AREA FOR ALL BUT THE
COUNTIES ALONG THE RIO GRANDE...AND OUR FORECAST MENTIONS SEVERE
STORMS AS POSSIBLE OVER ALL AREAS.
LIGHTEST RAINFALL AMOUNTS AND STORM POTENTIAL BEING NEAR THE RIO
GRANDE COULD LEAD TO OUR NEXT THREAT CONCERN FOR DAYTIME SUNDAY.
SHOULD AREAS NEAR THE RIO GRANDE FAIL TO RECEIVE SIGNIFICANT
RAINFALL...WINDY AND DRY CONDITIONS BEHIND THE FRONT WOULD PRODUCE
FAVORABLE CONDITIONS FOR THE SPREAD OF FIRES. MODEL RUNS ARE
TRENDING WETTER AND FARTHER WEST WITH HIGHER RAIN CHANCES...SO
THIS CONCERN COULD POSSIBLY DECREASE GOING FORWARD. THE
DOWNSLOPING WESTERLY WINDS WILL LIKELY KEEP HIGH TEMPERATURES
ABOVE SEASONAL NORMS SUNDAY.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
DECREASING WESTERLY WINDS AND THE ADVANCE OF MUCH DRIER AIR INTO
THE AREA WILL TAKE OVERNIGHT TEMPERATURES BACK TO NEAR NORMALS FOR
MONDAY MORNING. WARMING SW WINDS RETURN FOR MONDAY INTO
TUESDAY...AND SOME MOISTURE POOLING OVER THE COASTAL PRAIRIES
COULD LEAD TO A FEW SHOWERS FORMING TUESDAY INTO EARLY WEDNESDAY.
BROAD TROUGHING DEVELOPING OVER THE U.S. BY THIS TIME WILL BRING A
COLD FRONT THROUGH TX AND TAKE TEMPERATURES BELOW SEASONAL NORMALS
FOR THE REST OF THE WORK WEEK. CURRENT MIN FORECAST TEMPERATURES
SHOW FREEZES POSSIBLE MAINLY OVER AREAS THAT ALREADY HAD THEM IN
NOVEMBER.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 76 54 68 47 71 / 70 90 40 - 0
AUSTIN BERGSTROM INTL AIRPORT 77 54 68 41 71 / 70 90 40 - 0
NEW BRAUNFELS MUNI AIRPORT 78 53 70 41 72 / 60 90 30 0 0
BURNET MUNI AIRPORT 74 50 66 42 70 / 50 80 20 0 0
DEL RIO INTL AIRPORT 76 51 70 39 72 / 10 60 0 0 0
GEORGETOWN MUNI AIRPORT 75 52 65 41 70 / 60 90 40 - 0
HONDO MUNI AIRPORT 77 54 72 37 72 / 40 80 20 0 0
SAN MARCOS MUNI AIRPORT 77 53 69 42 71 / 70 90 40 - 0
LA GRANGE - FAYETTE REGIONAL 78 58 66 45 72 / 80 90 60 - 0
SAN ANTONIO INTL AIRPORT 78 55 71 43 73 / 60 80 20 0 0
STINSON MUNI AIRPORT 78 56 72 41 72 / 60 80 20 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...RUNYEN
SYNOPTIC/GRIDS...OAKS
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
522 AM CST SAT DEC 12 2015
.AVIATION...
SCT-BKN MVFR DECKS WELL SOUTH OF ALL TERMINALS COULD SPREAD AND
IMPACT KCDS LATER THIS MORNING THROUGH MID-AFTERNOON. WILL
MAINTAIN A MVFR CIG MENTION AT KCDS AT THIS TIME. OTHERWISE...VFR
CONDITIONS ARE EXPECTED WITH WEST TO SOUTHWEST WIND SPEEDS
INCREASING TO BETWEEN 15-20 KTS SUSTAINED DURING THE AFTERNOON.
WIND SPEEDS WILL DECLINE SHORTLY AFTER SUNSET THOUGH WILL STAY UP
A BIT IN THE 10-15 KT RANGE. STORM SYSTEM APPROACHING THE AREA
FROM THE WEST WILL PROMOTE INCREASING CHANCES FOR -SHRA/-TSRA.
CONFIDENCE IS HIGH ENOUGH TO INSERT A PROB30 AT KCDS WITH THIS TAF
CYCLE. WILL OF COURSE AMEND AS NECESSARY.
&&
.PREV DISCUSSION... /ISSUED 232 AM CST SAT DEC 12 2015/
SHORT TERM...
MAIN CONCERN FOR THE SHORT TERM PERIOD WILL BE INCREASING CHANCES
FOR RAIN SHOWERS AND THUNDERSTORMS...WITH A BRIEF WINDOW FOR A FEW
STORMS TO POSSIBLY NEAR STRONG LEVELS.
SFC TEMPS PER 08Z METARS WERE MILD FOR THIS TIME OF YEAR /40S AND
50S/ COURTESY OF S-SW SFC WINDS...WHICH IS A WIND COMPONENT
CONDUCIVE FOR DRY AND WARM CONDITIONS. HOWEVER...DEWPOINTS IN THE
40S EXISTED ACROSS THE LOW ROLLING PLAINS AS THE WIND WAS MORE FROM
THE S-SE THUS AIDING TO FILTER IN GULF MOISTURE. IN FACT...LOW
CLOUDS AND/OR FOG WERE NOTED ACROSS THE BIG COUNTRY REGION...WHICH
MAY HAVE A CHANCE AT SPREADING TOWARDS THE ROLLING PLAINS AOA
SUNRISE. THE HRRR IS MOST AGGRESSIVE IN THE STRATUS DECK/FOG MAKING
IT AS FAR NW TO KLBB...WITH OTHER SOLUTIONS MAINTAINING THE IT TO
THE LOW ROLLING PLAINS AND PERHAPS THE SRN SOUTH PLAINS. HENCE WILL
BE KEEPING AN EYE ON TRENDS FOR THE NEXT SEVERAL HOURS.
THE STORM SYSTEM OF INTEREST IS AN UA TROUGH DRAPED FROM THE GREAT
BASIN TO ACROSS WRN AZ EARLY THIS MORNING. MOST MODEL SOLUTIONS
AGREE THAT THIS SYSTEM WILL BE RATHER PROGRESSIVE...AS IT IS PROGGED
TO BE ACROSS ERN AZ/WRN NM THIS AFTN TO ACROSS CNTRL NM THIS
EVENING...AND FINALLY ACROSS THE PANHANDLE REGION LATE TONIGHT/EARLY
SUN MORNING...ALL THE WHILE EVOLVING TO MORE OF A CLOSED OFF STATE.
THE ECMWF STILL REMAINS THE OUTLIER WITH IT BEING SLIGHTLY SLOWER
AND FARTHER SOUTH VERSUS THE NAM AND GFS SOLUTIONS. THIS AFTN-
EVENING AS THE SYSTEM DRAWS NEAR...ITS SFC COUNTERPART WILL RESPOND
BY DEEPENING AND THEREFORE PROMOTE A TIGHTENED PRESSURE GRADIENT
WHILST TRANSLATING EAST ACROSS THE CWA. MOS GUIDANCE HINTS AT SFC
WIND SPEEDS OF 15-25 MPH OUT OF THE W-SW...WITH THE BREEZIEST
CONDITIONS NOTED ON THE CAPROCK. OFF THE CAPROCK...SFC WINDS WILL BE
OUT OF THE S-SE. PERSISTENT SWRLY FLOW ALOFT AIDING IN TRANSPORTING
HIGH LEVEL CIRRUS CLOUD COVER WILL BE SLOW TO CLEAR OUT FROM WEST TO
EAST...WHERE IF THERE WERE CLEAR SKIES...WIND CONDITIONS COULD BE A
LOT WORSE. CLOUD COVER WILL BE LAST TO CLEAR OUT ACROSS THE ERN
ZONES GIVEN THE FAVORABLE UPSLOPE WIND COMPONENT.
CONCURRENTLY...A 160 KT 250 MB JET MAX WILL MOVE ACROSS THE
CWA...PROVIDING UL SUPPORT AND ENCOURAGE THE DEVELOPMENT OF SHOWERS
AND THUNDERSTORMS MOVING IN FROM WEST TO EAST. MID-LEVEL INSTABILITY
IS NOT VERY IMPRESSIVE /400-600 J/KG/ BUT THE 0-6 KM BULK SHEAR OF
40-70 KTS AND A SLIGHT COOLING IN THE MID-LEVELS /STEEPENING LAPSE
RATES/ DO SUGGEST SOME THUNDERSTORMS APPROACHING STRONG LEVELS
/HAIL AND WIND THE PRIMARY THREATS/ PARTICULARLY ACROSS THE ROLLING
PLAINS...COINCIDING WITH THE BEST MOISTURE AND MID-LEVEL INSTABILITY.
KEEP IN MIND...IF THE CLOUD COVER HANGS AROUND A LITTLE LONGER THAN
ANTICIPATED ACROSS THE ROLLING PLAINS...THE LITTLE BIT OF MID-LEVEL
INSTABILITY MAY NOT BE ENOUGH TO OVERCOME THE CAPPED ATMOSPHERE AND
THUS STRONG THUNDERSTORMS MAY NOT BECOME REALIZED. THE LLJ KICKING
UP INTO THE 40-50 KT RANGE WILL MAINTAIN STORMS ACROSS THE ROLLING
PLAINS THIS EVENING-TONIGHT WHILST THE REMAINDER OF THE CWA BECOMES
ENVELOPED BY DRY-SLOTTING /W-SW WINDS/. SOUNDING PROFILES INDICATE
THIS SCENARIO RATHER WELL WITH TOP-DOWN MOISTENING OCCURRING THIS
AFTN-EVENING...AND DRYING ENSUING IN THE MID AND UPPER LEVELS BY
TONIGHT. LCL/S ARE A BIT LOW ACROSS THE FAR ROLLING PLAINS WHICH
RAISES CONCERNS FOR A TORNADO RISK. HOWEVER...THE AMOUNT OF 0-6 KM
BULK SHEAR MIGHT BE TOO MUCH OF A GOOD THING...AS IT COULD PREVENT
STORMS FROM MAINTAINING GOOD STRUCTURE.
500 MB HEIGHT FALLS WILL LEAD TO A COOLER ALBEIT STILL UNSEASONABLY
WARM SATURDAY...WITH HIGHS IN THE 60S AND 70S...FOLLOWED BY LOWS IN
THE 30S AND 40S.
LONG TERM...
COULD SEE A FEW LIGHT RAIN OR SNOW SHOWERS SUNDAY MORNING ACROSS THE
FAR SRN PANHANDLE AS THE CLOSED LOW SLOWLY EJECTS TO THE ENE ACROSS
THE PANHANDLE TO NWRN OKLAHOMA. HOWEVER...MAIN STORY TURNING OUT TO
BE WIND AS TIGHT LOW TO MID LEVEL HEIGHT GRADIENT ON THE S/SW FLANKS
OF THE UPPER LOW WILL LIKELY TRANSLATE INTO AT LEAST 20-30 MPH RANGE
ACROSS MUCH OF THE FCST AREA IN LINE WITH MOS VALUES AS COLD
ADVECTION WILL LIMIT THE POTENTIAL FOR 50 KT MID LEVEL WINDS TO MIX
TO THE SFC.
AFTER SHORT WAVE RIDGING BRINGS A WARMER AND LESS WINDY DAY
MONDAY...ANOTHER UPPER LOW PROGGED TO MOVE ACROSS THE COLORADO
ROCKIES MONDAY NIGHT AND ONTO THE CNTL HIGH PLAINS DURING THE DAY
TUESDAY. MODELS CURRENTLY PROGGING RAPID CYCLOGENESIS SERN COLO/SWRN
KANSAS EARLY TUESDAY WITH A MID LEVEL JET STREAK ON THE ORDER OF 50
TO 70 KTS ROTATING OVER THE SRN HIGH PLAINS DURING THE DAY TUESDAY.
DEEP COLD ADVECTION WILL AGAIN LIMIT POTENTIAL FOR MIXING TO THE
SFC...BUT AGAIN POTENTIAL EXISTS FOR AT LEAST 20-30 MPH TO BE
REALIZED.
BEYOND TUESDAY...A BROAD LONG WAVE UPPER TROUGH OVER THE WRN CONUS
WILL SHIFT EWD TO THE PLAINS WEDNESDAY LEAVING DRY AND UNEVENTFUL
NWLY FLOW OVER THE FCST AREA THROUGH THE END OF THE WEEK. COLD FRONT
OF CANADIAN ORIGIN BEHIND TUESDAYS UPPER LOW WILL BRING COLDER AIR
INTO THE REGION WITH TEMPS FINALLY REVERTING TO BELOW NORMAL
WEDNESDAY AND THURSDAY BEFORE MODERATING TO END THE WEEK.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
29
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
419 AM CST SAT DEC 12 2015
.SHORT TERM (TODAY THROUGH SUNDAY)...
SEVERE WEATHER AND LOCALLY HEAVY RAINFALL IS EXPECTED MAINLY
TONIGHT. RADAR LOOP CONFIRMS THE APPROACH OF A LEAD SHORT-WAVE
DISTURBANCE FROM MEXICO AND AHEAD OF A DEEP UPPER TROUGH
APPROACHING TX FROM THE PACIFIC. MODEL INDICATIONS OF INCREASING
MID LEVEL MOISTURE LEADS TO PWAT VALUES JUMPING UP TO 2 INCHES
OVER THE COASTAL PRAIRIES BY MIDDAY...WITH HIGH RAIN CHANCES
COVERING MUCH OF THE EASTERN HALF OF TX. AS NOTED BY SPC THE HIGH
AMOUNT OF MOISTURE SHOULD LIMIT THE POTENTIAL FOR DAYTIME
SEVERITY...WITH NEAR CONTINUOUS CLOUDINESS LIMITING STORM
STRENGTH. SHOULD BREAKS IN THE CLOUDS OCCUR THERE IS A SMALL
POTENTIAL FOR LOW TOPPED SUPERCELLS GIVEN THE FORECAST
HELICITIES.
INCREASING LOW TO MID LEVEL WINDS IN ADVANCE OF THE APPROACHING
UPPER TROUGH WILL SET UP BEST LOW LEVEL CONVERGENCE OVER THE I-45
CORRIDOR FOR HIGHEST QPF AMOUNTS...BUT SOME OF THE HIGHER RES DATA
DEPICTS AN AREA OF POTENTIAL TRAINING EXTENDING SW INTO OUR FAR
EASTERN COUNTIES. THE FINAL FORECAST HOUR OF THE HRRR SUGGESTS
INCREASED TRAINING POTENTIAL BY 23Z WITH OTHER HIGH-RES SOLUTIONS
CONTINUING A LOCALLY HEAVY RAIN THREAT OVER EASTERN COUNTIES IN
THE EVENING. FAST STORM MOTIONS ARE EXPECTED TO OFFSET THE
TRAINING PROBLEM...BUT THE HIGH PWAT ENVIRONMENT IS STILL LIKELY
TO DUMP ISOLATED DOWNPOURS OF AROUND 2 INCHES BEFORE MIDNIGHT.
BASED ON WHAT DEVELOPS LATE THIS AFTERNOON...LATER SHIFTS MAY NEED
TO MONITOR FOR A POSSIBLE FLASH FLOOD WATCH OVER EASTERN
COUNTIES...AS A MORE WIDESPREAD ROUND OF RAIN ARRIVES LATE
TONIGHT.
MODELS AND THE WPC SHOW A PRETTY CONSISTENT QPF PATTERN WITH
GENERALLY TWO ENHANCED CLUSTERS OF CONVECTION...AND THE LATTER
ROUND OF RAIN IS LIKELY TO PRODUCE A NEAR SOLID LINE OF STRONG TO
SEVERE STORMS WITH VERY HEAVY RAINFALL RATES. AGAIN THE MOTIONS
WILL BE FAST SO WE/RE EXPECTING A QUICK 1 TO 2 INCHES OF RAIN
FALLING IN A SHORT TIME FOLLOWED BY A BRIEF PERIOD OF MODERATE
RAIN. BY THE END OF THE RAIN EVENT SUNDAY MORNING...A FEW SPOTS
WELL TO THE EAST OF AUSTIN COULD RECEIVE 4 INCHES. BOWING SEGMENTS
WITH THE OVERNIGHT ROUND OF RAIN WILL BE DRIVEN BY THE UPPER
TROUGH AND COULD LEAD TO DAMAGING WINDS AND AN ISOLATED TORNADO
THREAT. THE SPC HAS EXPANDED THE SLIGHT RISK AREA FOR ALL BUT THE
COUNTIES ALONG THE RIO GRANDE...AND OUR FORECAST MENTIONS SEVERE
STORMS AS POSSIBLE OVER ALL AREAS.
LIGHTEST RAINFALL AMOUNTS AND STORM POTENTIAL BEING NEAR THE RIO
GRANDE COULD LEAD TO OUR NEXT THREAT CONCERN FOR DAYTIME SUNDAY.
SHOULD AREAS NEAR THE RIO GRANDE FAIL TO RECEIVE SIGNIFICANT
RAINFALL...WINDY AND DRY CONDITIONS BEHIND THE FRONT WOULD PRODUCE
FAVORABLE CONDITIONS FOR THE SPREAD OF FIRES. MODEL RUNS ARE
TRENDING WETTER AND FARTHER WEST WITH HIGHER RAIN CHANCES...SO
THIS CONCERN COULD POSSIBLY DECREASE GOING FORWARD. THE
DOWNSLOPING WESTERLY WINDS WILL LIKELY KEEP HIGH TEMPERATURES
ABOVE SEASONAL NORMS SUNDAY.
&&
.LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
DECREASING WESTERLY WINDS AND THE ADVANCE OF MUCH DRIER AIR INTO
THE AREA WILL TAKE OVERNIGHT TEMPERATURES BACK TO NEAR NORMALS FOR
MONDAY MORNING. WARMING SW WINDS RETURN FOR MONDAY INTO
TUESDAY...AND SOME MOISTURE POOLING OVER THE COASTAL PRAIRIES
COULD LEAD TO A FEW SHOWERS FORMING TUESDAY INTO EARLY WEDNESDAY.
BROAD TROUGHING DEVELOPING OVER THE U.S. BY THIS TIME WILL BRING A
COLD FRONT THROUGH TX AND TAKE TEMPERATURES BELOW SEASONAL NORMALS
FOR THE REST OF THE WORK WEEK. CURRENT MIN FORECAST TEMPERATURES
SHOW FREEZES POSSIBLE MAINLY OVER AREAS THAT ALREADY HAD THEM IN
NOVEMBER.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 76 54 68 47 71 / 70 90 40 - 0
AUSTIN BERGSTROM INTL AIRPORT 77 54 68 41 71 / 70 90 40 - 0
NEW BRAUNFELS MUNI AIRPORT 78 53 70 41 72 / 60 90 30 0 0
BURNET MUNI AIRPORT 74 50 66 42 70 / 50 80 20 0 0
DEL RIO INTL AIRPORT 76 51 70 39 72 / 10 60 0 0 0
GEORGETOWN MUNI AIRPORT 75 52 65 41 70 / 60 90 40 - 0
HONDO MUNI AIRPORT 77 54 72 37 72 / 40 80 20 0 0
SAN MARCOS MUNI AIRPORT 77 53 69 42 71 / 70 90 40 - 0
LA GRANGE - FAYETTE REGIONAL 78 58 66 45 72 / 80 90 60 - 0
SAN ANTONIO INTL AIRPORT 78 55 71 43 73 / 60 80 20 0 0
STINSON MUNI AIRPORT 78 56 72 41 72 / 60 80 20 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...RUNYEN
SYNOPTIC/GRIDS...OAKS
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
243 PM CST SAT DEC 12 2015
.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
HAVE CONTINUED TO SEE A MOSTLY CLOUDY DAY AROUND THE STATE
TODAY...WITH ONLY A FEW BREAKS IN THE CLOUDS NOTED ACROSS EXTREME SE
ARKANSAS. BREEZY SE WINDS ARE BEING SEEN AROUND THE STATE...AND
TEMPERATURES WARMED INTO THE LOWER TO MID 70S.
HAVE BEGUN TO SEE A FEW ISOLATED SHOWERS POP UP AROUND THE STATE
THIS AFTERNOON. MODEL SOUNDINGS ARE ACTUALLY SHOWING SURFACE BASED
CAPE VALUES A BIT HIGHER THAN PREVIOUSLY ADVERTISED...HOWEVER SB
CAPE VALUES ARE STILL 500 J/KG OR LESS. LIMITED SB CAPE COMBINED
WITH POOR MID LEVEL LAPSE RATES WILL LIKELY LIMIT THE DEVELOPMENT OF
ANY SEVERE WEATHER TONIGHT.
HIRES MODELS CONTINUE TO SHOW TWO ROUNDS OF HEAVY
PRECIPITATION...WITH THE FIRST ROUND FORECAST FOR TONIGHT.
HOWEVER...BOTH THE HIRES AND MORE COARSE MODELS CONTINUE TO TREND
THE AXIS OF HEAVIEST PRECPITATION FURTHER TO THE WEST. IN FACT THE
PAST FEW RUNS OF THE HRRR HAS MUCH OF ARKANSAS MISSING OUT
COMPLETELY ON THE FIRST ROUND OF HEAVY PRECIPITATION. ALSO OF
CONCERN TONIGHT WILL BE BREEZY CONDITIONS. AT THIS POINT WILL NOT
ISSUE A LAKE WIND ADVISORY...AS WINDS SHOULD BE JUST BELOW LAKE WIND
CRITERIA.
TEMPERATURES WILL BE WARM OVERNIGHT...WITH READINGS DROPPING VERY
LITTLE. MUCH OF THE WESTERN HALF OF THE STATE WILL SEE SUNDAY HIGH
TEMPERATURES OCCUR EARLY SUNDAY MORNING WITH TEMPERATURES FALLING
FOR MUCH OF THE DAY. ACROSS THE EASTERN HALF OF THE
STATE...TEMPERATURE TRENDS WILL BE NEAR DIURNAL AS THIS SYSTEM HAS
SLOWED QUITE A BIT. BEST PRECIPITATION CHANCES FOR CENTRAL AND
EASTERN ARKANSAS WILL LIKELY HOLD OFF UNTIL THE SUNDAY AFTERNOON
HOURS WITH PRECIPITATION COMING TO AN END DURING THE OVERNIGHT
HOURS. PRECIPITATION CHANCES WILL LINGER ACROSS NORTHERN ARKANSAS
EARLY MONDAY AS THE UPPER LOW SWINGS THROUGH THE AREA.
BEHIND THIS SYSTEM...TEMPERATURES WILL FALL BUT STILL REMAIN ABOVE
NORMAL. PRECIPITATION CHANCES WILL RETURN TO THE FORECAST TO ROUND
OUT THE SHORT TERM AS THE NEXT COLD FRONT APPROACHES ARKANSAS.
&&
.LONG TERM...WEDNESDAY THROUGH SATURDAY
A NEW STORM SYS WL BE PASSING WELL N OF AR ON WED...WITH A SWD
TRAILING CDFNT PUSHING E OF THE FA. A FEW SHOWERS WL LINGER OVR SERN
AR EARLY WED...OTHERWISE COOLER AND DRIER CONDS WL PREVAIL.
A WEAK UPR LVL SYSTEM WL TRACK EWD ACRS THE AREA THU NGT AND EARLY
FRI...WITH JUST SOME MID AND HIGH CLOUDS ACCOMPANYING IT. TEMPS WL
BEGIN TO SLOLY MODERATE HEADING INTO NEXT WEEKEND AS HIGH PRES
SHIFTS EWD...WITH LGT S/SWLY WINDS RETURNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 65 70 46 60 / 50 100 60 0
CAMDEN AR 67 69 44 66 / 60 100 20 0
HARRISON AR 63 65 42 57 / 90 100 40 10
HOT SPRINGS AR 67 68 44 62 / 80 100 20 0
LITTLE ROCK AR 66 69 45 63 / 50 90 40 0
MONTICELLO AR 68 72 48 64 / 30 100 40 0
MOUNT IDA AR 66 68 42 63 / 90 100 20 0
MOUNTAIN HOME AR 63 69 44 60 / 80 100 50 10
NEWPORT AR 64 71 47 60 / 30 100 60 10
PINE BLUFF AR 66 71 46 63 / 40 100 40 0
RUSSELLVILLE AR 66 67 43 61 / 90 100 30 0
SEARCY AR 65 70 44 60 / 40 100 50 0
STUTTGART AR 66 71 47 62 / 30 100 50 0
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...65 / LONG TERM...44
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
127 PM MST SAT DEC 12 2015
.UPDATE...
ISSUED AT 127 PM MST SAT DEC 12 2015
LOW PRESSURE HAS CLOSED OFF OVER NORTHWESTERN NM...PUMPING
MOISTURE FROM SOUTH TO NORTH ACROSS CENTRAL COLORADO. WE ARE
BEGINNING TO SEE SOME WRAP-AROUND ENHANCEMENT ON RADAR ALONG THE
PARACHUTE TO NUCLA AREA...THOUGH NOT MUCH TO SPEAK OF AT THIS
POINT. WITH MOST OF THE DYNAMICS GONE WITH THIS SYSTEM ACROSS
EXTREME WESTERN COLORADO...ADDITIONAL SNOWFALL WILL TURN INTO AN
OROGRAPHIC EVENT THIS EVENING. DECIDED TO EXTEND NORTHERN SAN
JUANS ADVISORY UNTIL MIDNIGHT TONIGHT...WITH A SLIGHT GORGE
SIGNATURE ON THE SOUNDINGS. THAT BEING SAID...NOT EXPECTING A
GIANT GORGE EVENT...BUT RATHER SOME ENHANCEMENT FROM JUST SOUTH OF
OURAY UP TO THE MONUMENT ON HIGHWAY 550 FOR A FEW HOURS THIS
EVENING.
ALL OTHER WARNINGS AND ADVISORIES WILL END AT 6PM UNLESS OTHERWISE
CANCELLED EARLIER. THE SNOW IS EXPECTED TO END FROM NORTH TO SOUTH
AS THE CLOSED LOW PROGRESSES EASTWARD THROUGH THE NIGHT. AREAS OF
FOG ARE EXPECTED TONIGHT IN THE USUAL LOCATIONS...THE UINTA
BASIN...ALONG THE I-70 CORRIDOR BETWEEN GREEN RIVER AND
PALISADE...GRAND JUNCTION TO RIDGWAY CORRIDOR...AND THE SOUTHWEST
CO VALLEYS.
UPDATE ISSUED AT 953 AM MST SAT DEC 12 2015
VISIBILITY HAS BEEN INCREASING ACROSS THE GRAND VALLEY AND PARADOX
VALLEY. HAVE DROPPED DENSE FOG ADVISORIES JUST A BIT EARLY TO
ACCOMODATE FOR CURRENT CONDITIONS AND IMPROVEMENT EXPECTED DURING
THE AFTERNOON HOURS. ALSO DROPPED ZONE 7 WINTER WX ADVISORY EARLY
DUE TO THE END OF THE STEADY SNOW. LIGHT SNOW SHOWERS ARE STILL
POSSIBLE IN THIS AREA THROUGH THIS AFTERNOON. KEPT ZONE 22 IN
ADVISORY THROUGH THIS EVENING DESPITE CURRENT BREAK IN SHOWERS AT
DURANGO. HRRR AND RAP INDICATE ADDITIONAL SHOWERS IN THE ANIMAS
VALLEY THIS EVENING AS PRECIP BEGINS TO WRAP AROUND
COUNTERCLOCKWISE. WILL KEEP AN EYE ON TO SEE IF THESE EXPECTATIONS
CHANGE WITH FUTURE CONDITIONS AND MODEL RUNS.
UPDATE ISSUED AT 822 AM MST SAT DEC 12 2015
QUARTER MILE VISIBILITY REPORTED AT GJT AND NUCLA...THEREFORE
ISSUED A DENSE FOG ADVISORY FOR THE NEXT COUPLE OF HOURS FOR THESE
AREAS. ALSO ADDED ZONE 11 ANTICIPATING VISIBILITY TO DECREASE ONCE
THE SNOW COMPLETELY ENDS SHORTLY ALONG THE HIGHWAY 50 CORRIDOR
FROM WHITEWATER THROUGH MONTROSE.
UPDATE ISSUED AT 654 AM MST SAT DEC 12 2015
STEADY SNOW HAS ENDED ACROSS EASTERN UTAH AND NORTHWEST
COLORADO...SO CANCELLED ADVISORIES AND WARNINGS IN UT ZONES 25 AND
28...AND CO ZONES 1...2 AND 3. THE POSSIBILITY OF A FEW FLURRIES
STILL EXISTS BUT THESE AREAS WILL NOT SEE ANY ADDITIONAL SNOW
ACCUMULATION. RAP AND HRRR INDICATING CONTINUATION OF SNOW ALONG
I-70 EAST OF GLENWOOD SPRINGS...IN THE SAN JUANS AND ALONG THE
CONTINENTAL DIVIDE.
UPDATE ISSUED AT 329 AM MST SAT DEC 12 2015
LATEST REPORT FROM DURANGO DISPATCH INDICATED 1 INCH OF SNOW
STICKING TO ROAD SURFACES WHILE WEBCAMS SHOWED SIMILAR CONDITIONS
AROUND TOWN. LATEST 06Z NAM CONTINUES TO SHOW BAND OF PRECIP OVER
MUCH OF SOUTHERN VALLEYS PERSISTING THROUGH MUCH OF THE DAY. IR
IMAGERY SHOWING PLENTY OF MOISTURE OVER THAT AREA AND MORE TO
COME FROM NEW MEXICO. SOME ENHANCEMENT CAN ALSO BE SEEN INDICATING
A GOOD POSSIBILITY FOR HEAVIER SNOWFALL. WATER VAPOR FURTHER
CORROBORATES THIS IDEA. WENT AHEAD AND ISSUED ADVISORIES FOR ALL
SOUTHERN VALLEYS FOR 2 TO 4 INCHES WITH HIGHER AMOUNTS POSSIBLE
FOR HIGHER ELEVATIONS. TEMPS CONTINUE TO HOVER AROUND FREEZING SO
WITH DAYBREAK...WOULD EXPECT SNOW ON ROADS TO MELT FAIRLY QUICKLY
WITH LITTLE IMPACT. IF THIS OCCURS...HIGHLIGHTS CAN BE TAKEN DOWN
EARLY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 256 AM MST SAT DEC 12 2015
ANOTHER STORM IS EXCEEDING EXPECTATIONS IN SEVERAL AREAS. WE WERE
DEALING WITH A HEAVY SNOW BAND RELATED TO A WELL FORMED MID LEVEL
FRONTOGENESIS BAND ACROSS NORTHWEST COLORADO WHICH DUMPED UP TO A
FOOT OF NEW SNOW IN LOWER ELEVATIONS. NOW WE LOOK UPSTREAM AT THE
APPROACHING MAIN LOW PRESSURE SYSTEM ANALYZED AT 00Z OVER SOUTHERN
NEVADA...AND AT 06Z SATELLITE IMAGERY SUGGESTS THIS CIRCULATION
HAS MOVED TO CENTRAL ARIZONA. WOULD HAVE TO SAY THE TRENDS ARE
SLOWER AND FARTHER SOUTH WITH THIS SYSTEM THAN MODELS SUGGESTED
YESTERDAY. WITH THE CYCLONE STILL TO THE WEST THETA SURFACES
SUGGEST A NEW WARM CONVEYOR BELT DELIVERING A GOOD SHOT OF
MOISTURE INTO WESTERN COLORADO THIS MORNING. THIS IS MORE THAN
APPARENT WITH THE RECENT ENHANCEMENTS ON THE REGIONAL RADAR MOSAIC
AND IR SATELLITE IMAGERY OVER EASTERN ARIZONA. THE BIG FORECAST
CHALLENGE IS WHAT DOES THAT MEAN FOR OUR AREA. THE MOISTURE
ADVECTION AND CONSTANT STREAM OF VIRGA OR LIGHT SHOWERS THIS
EVENING HAS CLOSED THE DEW POINT GAP ACROSS THE SOUTHERN VALLEYS
WHERE TEMPERATURES ARE STILL IN THE UPPER 30S. THE REAL COLD AIR
IS STILL BEING HELD BACK BY THE FLOW ALOFT SO PRECIPITATION TYPE
IS STILL QUITE TRICKY FOR THE SOUTHERN VALLEYS AS RAIN MAY HOLD
OUT LONGER THAN ANTICIPATED OR JUST TURN INTO MELTING SNOW. FOR
NOW WILL SIDE WITH THE TRENDS OF NEAR AN INCH OF THE DURANGO
AIRPORT WITH HIGHER AMOUNTS NEAR THE FOOTHILLS. PAGOSA SPRINGS
WILL SEE ANYWHERE FROM TO 1 INCH TO 3 INCHES NEAR THE HILLS. THE
PROBLEM AREAS DOWN SOUTH WILL MOST LIKELY BE THE HIGH SPOTS ALONG
HWY 160 LIKE THE MANCOS HILL AREA. THIS WCB WILL ALSO CONTAIN
BETTER INSTABILITY AS SEEN IN EPV FIELDS AND THIS SHOULD BE
RELEASED BY THE INCREASING LARGE SCALE ASCENT OVER THE SOUTHERN
CWA AS THE MID LEVEL CIRCULATION PASSES THROUGH FROM MID MORNING
ONWARD. COMPLICATED SITUATION AND EXPECT CHANGES TO GOING FORECAST
THROUGH THE DAY AS SOME OF THE VARIABLES BECOME MORE CLEAR. THE
SOUTHERN MOUNTAINS MAY BE IN FOR MORE SNOW THAN PREVIOUSLY
FORECAST AND WILL BE MONITORING FOR UPGRADES IF IMPACTS TO PASSES
BECOME MORE APPARENT. WE DID INCLUDE THE GUNNISON BASIN IN THE
LATEST WSW AS THIS MOISTURE PLUME WILL BE DIRECTED AT CERRO SUMMIT
AND THE BLACK CANYON AREA. THE SYSTEM SLOWLY PULLS EAST OF THE
DIVIDE THIS EVENING BEFORE STRENGTHENING IN THE LEE SIDE. DID KEEP
SOME HIGHER POPS INTO THIS EVENING TO ACCOUNT FOR THE SLOWER
MOVEMENT. OVERALL THE PCPN SHOULD BE DONE BY MIDNIGHT WITH A DRY
SUNDAY ON TAP. TEMPERATURES AND NEW SNOWFALL WILL BE THE MAIN
CHALLENGE ALONG WITH AREAS OF FOG DEVELOPING IN THE VALLEYS AND
BASINS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 256 AM MST SAT DEC 12 2015
RIDGING THAT BUILT IN SUNDAY WILL BE OVERHEAD SUNDAY NIGHT AND
QUICKLY SHIFT EASTWARD AS THE NEXT TROUGH APPROACHES FROM THE
WEST. MODELS IN FAIRLY GOOD AGREEMENT WITH EVOLUTION OF THIS
SYSTEM AND LOOKS SOMEWHAT SIMILAR TO THE STORM AFFECTING THE
REGION RIGHT NOW. SUBTLE DIFFERENCES EXIST OF COURSE BUT THE MAIN
GIST OF A COLD FRONT BRINGING WIDESPREAD SNOWFALL REMAINS. MAIN
DIFFERENCES WITH THIS SYSTEM WILL BE THAT COLD AIR WILL ALREADY BE
IN PLACE FROM THE PREVIOUS FRONT AND WILL ONLY BE REINFORCED FROM
THIS SECOND SYSTEM.
AS FAR AS DETAILS ARE CONCERNED...PRECIP WILL BEGIN MONDAY
MORNING FOR ERN UTAH AND SHIFT EASTWARD AS THE DAY PROGRESSES. BY
EVENING MOST...IF NOT ALL...AREAS WILL SEE SOME PRECIPITATION AS
THE CLOSED LOW AND ASSOD LIFT ARE POISED TO MOVE INTO WRN CO.
PLENTY OF THINGS CAN CHANGE BETWEEN NOW AND THEN THOUGH INCLUDING
THE LOW OPENING UP...UPPER LEVEL SUPPORT WANING...BEST LIFT SHIFTS
NORTH OR SOUTH...SO WILL HAVE TO SEE IF MODELS REMAIN CONSTANT IN
THIS OUTCOME. FOR NOW...6 TO 10 INCHES FOR THE MTNS AND 1 TO 3
INCHES FOR SOME VALLEYS LOOKS GOOD.
SNOWFALL WILL CONTINUE INTO TUESDAY BUT WITH BEST LIFT HAVING
SHIFTED TO THE PLAINS...ANTICIPATE A MORE SHOWERY NATURE TO
PRECIP. NORTHERLY FLOW WILL ALSO USHER IN COLDER AIR TO THE
REGION. SOME MTN SHOWERS...ESPECIALLY UP NORTH...MAY CONTINUE
THROUGH WEDNESDAY MORNING BUT ANTICIPATE MORE FLURRIES THAN
ANYTHING ELSE. MOST AREAS WILL SEE PARTLY CLOUDY SKIES AND MUCH
COLDER TEMPERATURES THAT WILL BE WELL BELOW NORMAL. AFTER
THAT...LITTLE PIECES OF WEAK ENERGY WILL DROP DOWN FROM THE NW
CAUSING SOME LIGHT SNOWFALL OVER THE PARK/GORE RANGES THROUGH
FRIDAY BUT AGAIN...NOT MUCH ACCUMULATION EXPECTED. EXPECT MORE
CLOUDS N OF I-70 THAN S DUE TO THESE DISTURBANCES. TEMPERATURES
WILL REMAIN BELOW NORMAL THROUGH LONG TERM PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1048 AM MST SAT DEC 12 2015
CHALLENGING SET OF TAFS TODAY WITH THE CLOSED LOW MOVING INTO NEW
MEXICO TODAY...STREAMING PLENTY OF MOISTURE INTO WESTERN COLORADO
FROM THE SOUTH. FREQUENT MTN OBSCURATIONS WILL CONTINUE THROUGH
THE EVENING HOURS...WITH SNOW SHUTTING OFF OVER NORTH CENTRAL
COLORADO AFTER ABOUT 20Z. KCNY...KGJT...AND KMTJ WILL CLEAR OUT
LATER TODAY BUT WILL KEEP THE THREAT OF FOG IN THROUGH 12 TO 15Z
SUNDAY. FOG MAY ALSO DEVELOP AT KVEL TOWARD MORNING...SO ADDED
THIS AS WELL. GENERAL CLEARING WILL OCCUR AFTER 06Z TONIGHT
ALLOWING FOR IMPROVEMENT...ESPECIALLY AFTER 15Z SUNDAY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR COZ018.
WINTER WEATHER ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ005-
008>010-012-014-019-022-023.
WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR COZ004-013.
UT...NONE.
&&
$$
UPDATE...JAM
SHORT TERM...15
LONG TERM...TGR
AVIATION...JAM
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1048 AM MST SAT DEC 12 2015
.UPDATE...
ISSUED AT 953 AM MST SAT DEC 12 2015
VISIBILITY HAS BEEN INCREASING ACROSS THE GRAND VALLEY AND PARADOX
VALLEY. HAVE DROPPED DENSE FOG ADVISORIES JUST A BIT EARLY TO
ACCOMODATE FOR CURRENT CONDITIONS AND IMPROVEMENT EXPECTED DURING
THE AFTERNOON HOURS. ALSO DROPPED ZONE 7 WINTER WX ADVISORY EARLY
DUE TO THE END OF THE STEADY SNOW. LIGHT SNOW SHOWERS ARE STILL
POSSIBLE IN THIS AREA THROUGH THIS AFTERNOON. KEPT ZONE 22 IN
ADVISORY THROUGH THIS EVENING DESPITE CURRENT BREAK IN SHOWERS AT
DURANGO. HRRR AND RAP INDICATE ADDITIONAL SHOWERS IN THE ANIMAS
VALLEY THIS EVENING AS PRECIP BEGINS TO WRAP AROUND
COUNTERCLOCKWISE. WILL KEEP AN EYE ON TO SEE IF THESE EXPECTATIONS
CHANGE WITH FUTURE CONDITIONS AND MODEL RUNS.
UPDATE ISSUED AT 822 AM MST SAT DEC 12 2015
QUARTER MILE VISIBILITY REPORTED AT GJT AND NUCLA...THEREFORE
ISSUED A DENSE FOG ADVISORY FOR THE NEXT COUPLE OF HOURS FOR THESE
AREAS. ALSO ADDED ZONE 11 ANTICIPATING VISIBILITY TO DECREASE ONCE
THE SNOW COMPLETELY ENDS SHORTLY ALONG THE HIGHWAY 50 CORRIDOR
FROM WHITEWATER THROUGH MONTROSE.
UPDATE ISSUED AT 654 AM MST SAT DEC 12 2015
STEADY SNOW HAS ENDED ACROSS EASTERN UTAH AND NORTHWEST
COLORADO...SO CANCELLED ADVISORIES AND WARNINGS IN UT ZONES 25 AND
28...AND CO ZONES 1...2 AND 3. THE POSSIBILITY OF A FEW FLURRIES
STILL EXISTS BUT THESE AREAS WILL NOT SEE ANY ADDITIONAL SNOW
ACCUMULATION. RAP AND HRRR INDICATING CONTINUATION OF SNOW ALONG
I-70 EAST OF GLENWOOD SPRINGS...IN THE SAN JUANS AND ALONG THE
CONTINENTAL DIVIDE.
UPDATE ISSUED AT 329 AM MST SAT DEC 12 2015
LATEST REPORT FROM DURANGO DISPATCH INDICATED 1 INCH OF SNOW
STICKING TO ROAD SURFACES WHILE WEBCAMS SHOWED SIMILAR CONDITIONS
AROUND TOWN. LATEST 06Z NAM CONTINUES TO SHOW BAND OF PRECIP OVER
MUCH OF SOUTHERN VALLEYS PERSISTING THROUGH MUCH OF THE DAY. IR
IMAGERY SHOWING PLENTY OF MOISTURE OVER THAT AREA AND MORE TO
COME FROM NEW MEXICO. SOME ENHANCEMENT CAN ALSO BE SEEN INDICATING
A GOOD POSSIBILITY FOR HEAVIER SNOWFALL. WATER VAPOR FURTHER
CORROBORATES THIS IDEA. WENT AHEAD AND ISSUED ADVISORIES FOR ALL
SOUTHERN VALLEYS FOR 2 TO 4 INCHES WITH HIGHER AMOUNTS POSSIBLE
FOR HIGHER ELEVATIONS. TEMPS CONTINUE TO HOVER AROUND FREEZING SO
WITH DAYBREAK...WOULD EXPECT SNOW ON ROADS TO MELT FAIRLY QUICKLY
WITH LITTLE IMPACT. IF THIS OCCURS...HIGHLIGHTS CAN BE TAKEN DOWN
EARLY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 256 AM MST SAT DEC 12 2015
ANOTHER STORM IS EXCEEDING EXPECTATIONS IN SEVERAL AREAS. WE WERE
DEALING WITH A HEAVY SNOW BAND RELATED TO A WELL FORMED MID LEVEL
FRONTOGENESIS BAND ACROSS NORTHWEST COLORADO WHICH DUMPED UP TO A
FOOT OF NEW SNOW IN LOWER ELEVATIONS. NOW WE LOOK UPSTREAM AT THE
APPROACHING MAIN LOW PRESSURE SYSTEM ANALYZED AT 00Z OVER SOUTHERN
NEVADA...AND AT 06Z SATELLITE IMAGERY SUGGESTS THIS CIRCULATION
HAS MOVED TO CENTRAL ARIZONA. WOULD HAVE TO SAY THE TRENDS ARE
SLOWER AND FARTHER SOUTH WITH THIS SYSTEM THAN MODELS SUGGESTED
YESTERDAY. WITH THE CYCLONE STILL TO THE WEST THETA SURFACES
SUGGEST A NEW WARM CONVEYOR BELT DELIVERING A GOOD SHOT OF
MOISTURE INTO WESTERN COLORADO THIS MORNING. THIS IS MORE THAN
APPARENT WITH THE RECENT ENHANCEMENTS ON THE REGIONAL RADAR MOSAIC
AND IR SATELLITE IMAGERY OVER EASTERN ARIZONA. THE BIG FORECAST
CHALLENGE IS WHAT DOES THAT MEAN FOR OUR AREA. THE MOISTURE
ADVECTION AND CONSTANT STREAM OF VIRGA OR LIGHT SHOWERS THIS
EVENING HAS CLOSED THE DEW POINT GAP ACROSS THE SOUTHERN VALLEYS
WHERE TEMPERATURES ARE STILL IN THE UPPER 30S. THE REAL COLD AIR
IS STILL BEING HELD BACK BY THE FLOW ALOFT SO PRECIPITATION TYPE
IS STILL QUITE TRICKY FOR THE SOUTHERN VALLEYS AS RAIN MAY HOLD
OUT LONGER THAN ANTICIPATED OR JUST TURN INTO MELTING SNOW. FOR
NOW WILL SIDE WITH THE TRENDS OF NEAR AN INCH OF THE DURANGO
AIRPORT WITH HIGHER AMOUNTS NEAR THE FOOTHILLS. PAGOSA SPRINGS
WILL SEE ANYWHERE FROM TO 1 INCH TO 3 INCHES NEAR THE HILLS. THE
PROBLEM AREAS DOWN SOUTH WILL MOST LIKELY BE THE HIGH SPOTS ALONG
HWY 160 LIKE THE MANCOS HILL AREA. THIS WCB WILL ALSO CONTAIN
BETTER INSTABILITY AS SEEN IN EPV FIELDS AND THIS SHOULD BE
RELEASED BY THE INCREASING LARGE SCALE ASCENT OVER THE SOUTHERN
CWA AS THE MID LEVEL CIRCULATION PASSES THROUGH FROM MID MORNING
ONWARD. COMPLICATED SITUATION AND EXPECT CHANGES TO GOING FORECAST
THROUGH THE DAY AS SOME OF THE VARIABLES BECOME MORE CLEAR. THE
SOUTHERN MOUNTAINS MAY BE IN FOR MORE SNOW THAN PREVIOUSLY
FORECAST AND WILL BE MONITORING FOR UPGRADES IF IMPACTS TO PASSES
BECOME MORE APPARENT. WE DID INCLUDE THE GUNNISON BASIN IN THE
LATEST WSW AS THIS MOISTURE PLUME WILL BE DIRECTED AT CERRO SUMMIT
AND THE BLACK CANYON AREA. THE SYSTEM SLOWLY PULLS EAST OF THE
DIVIDE THIS EVENING BEFORE STRENGTHENING IN THE LEE SIDE. DID KEEP
SOME HIGHER POPS INTO THIS EVENING TO ACCOUNT FOR THE SLOWER
MOVEMENT. OVERALL THE PCPN SHOULD BE DONE BY MIDNIGHT WITH A DRY
SUNDAY ON TAP. TEMPERATURES AND NEW SNOWFALL WILL BE THE MAIN
CHALLENGE ALONG WITH AREAS OF FOG DEVELOPING IN THE VALLEYS AND
BASINS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 256 AM MST SAT DEC 12 2015
RIDGING THAT BUILT IN SUNDAY WILL BE OVERHEAD SUNDAY NIGHT AND
QUICKLY SHIFT EASTWARD AS THE NEXT TROUGH APPROACHES FROM THE
WEST. MODELS IN FAIRLY GOOD AGREEMENT WITH EVOLUTION OF THIS
SYSTEM AND LOOKS SOMEWHAT SIMILAR TO THE STORM AFFECTING THE
REGION RIGHT NOW. SUBTLE DIFFERENCES EXIST OF COURSE BUT THE MAIN
GIST OF A COLD FRONT BRINGING WIDESPREAD SNOWFALL REMAINS. MAIN
DIFFERENCES WITH THIS SYSTEM WILL BE THAT COLD AIR WILL ALREADY BE
IN PLACE FROM THE PREVIOUS FRONT AND WILL ONLY BE REINFORCED FROM
THIS SECOND SYSTEM.
AS FAR AS DETAILS ARE CONCERNED...PRECIP WILL BEGIN MONDAY
MORNING FOR ERN UTAH AND SHIFT EASTWARD AS THE DAY PROGRESSES. BY
EVENING MOST...IF NOT ALL...AREAS WILL SEE SOME PRECIPITATION AS
THE CLOSED LOW AND ASSOD LIFT ARE POISED TO MOVE INTO WRN CO.
PLENTY OF THINGS CAN CHANGE BETWEEN NOW AND THEN THOUGH INCLUDING
THE LOW OPENING UP...UPPER LEVEL SUPPORT WANING...BEST LIFT SHIFTS
NORTH OR SOUTH...SO WILL HAVE TO SEE IF MODELS REMAIN CONSTANT IN
THIS OUTCOME. FOR NOW...6 TO 10 INCHES FOR THE MTNS AND 1 TO 3
INCHES FOR SOME VALLEYS LOOKS GOOD.
SNOWFALL WILL CONTINUE INTO TUESDAY BUT WITH BEST LIFT HAVING
SHIFTED TO THE PLAINS...ANTICIPATE A MORE SHOWERY NATURE TO
PRECIP. NORTHERLY FLOW WILL ALSO USHER IN COLDER AIR TO THE
REGION. SOME MTN SHOWERS...ESPECIALLY UP NORTH...MAY CONTINUE
THROUGH WEDNESDAY MORNING BUT ANTICIPATE MORE FLURRIES THAN
ANYTHING ELSE. MOST AREAS WILL SEE PARTLY CLOUDY SKIES AND MUCH
COLDER TEMPERATURES THAT WILL BE WELL BELOW NORMAL. AFTER
THAT...LITTLE PIECES OF WEAK ENERGY WILL DROP DOWN FROM THE NW
CAUSING SOME LIGHT SNOWFALL OVER THE PARK/GORE RANGES THROUGH
FRIDAY BUT AGAIN...NOT MUCH ACCUMULATION EXPECTED. EXPECT MORE
CLOUDS N OF I-70 THAN S DUE TO THESE DISTURBANCES. TEMPERATURES
WILL REMAIN BELOW NORMAL THROUGH LONG TERM PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1048 AM MST SAT DEC 12 2015
CHALLENGING SET OF TAFS TODAY WITH THE CLOSED LOW MOVING INTO NEW
MEXICO TODAY...STREAMING PLENTY OF MOISTURE INTO WESTERN COLORADO
FROM THE SOUTH. FREQUENT MTN OBSCURATIONS WILL CONTINUE THROUGH
THE EVENING HOURS...WITH SNOW SHUTTING OFF OVER NORTH CENTRAL
COLORADO AFTER ABOUT 20Z. KCNY...KGJT...AND KMTJ WILL CLEAR OUT
LATER TODAY BUT WILL KEEP THE THREAT OF FOG IN THROUGH 12 TO 15Z
SUNDAY. FOG MAY ALSO DEVELOP AT KVEL TOWARD MORNING...SO ADDED
THIS AS WELL. GENERAL CLEARING WILL OCCUR AFTER 06Z TONIGHT
ALLOWING FOR IMPROVEMENT...ESPECIALLY AFTER 15Z SUNDAY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ005-
008>010-012-014-018-019-022-023.
WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR COZ004-013.
UT...NONE.
&&
$$
UPDATE...JAM
SHORT TERM...15
LONG TERM...TGR
AVIATION...JAM
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
958 AM MST SAT DEC 12 2015
.UPDATE...
ISSUED AT 953 AM MST SAT DEC 12 2015
VISIBILITY HAS BEEN INCREASING ACROSS THE GRAND VALLEY AND PARADOX
VALLEY. HAVE DROPPED DENSE FOG ADVISORIES JUST A BIT EARLY TO
ACCOMODATE FOR CURRENT CONDITIONS AND IMPROVEMENT EXPECTED DURING
THE AFTERNOON HOURS. ALSO DROPPED ZONE 7 WINTER WX ADVISORY EARLY
DUE TO THE END OF THE STEADY SNOW. LIGHT SNOW SHOWERS ARE STILL
POSSIBLE IN THIS AREA THROUGH THIS AFTERNOON. KEPT ZONE 22 IN
ADVISORY THROUGH THIS EVENING DESPITE CURRENT BREAK IN SHOWERS AT
DURANGO. HRRR AND RAP INDICATE ADDITIONAL SHOWERS IN THE ANIMAS
VALLEY THIS EVENING AS PRECIP BEGINS TO WRAP AROUND
COUNTERCLOCKWISE. WILL KEEP AN EYE ON TO SEE IF THESE EXPECTATIONS
CHANGE WITH FUTURE CONDITIONS AND MODEL RUNS.
UPDATE ISSUED AT 822 AM MST SAT DEC 12 2015
QUARTER MILE VISIBILITY REPORTED AT GJT AND NUCLA...THEREFORE
ISSUED A DENSE FOG ADVISORY FOR THE NEXT COUPLE OF HOURS FOR THESE
AREAS. ALSO ADDED ZONE 11 ANTICIPATING VISIBILITY TO DECREASE ONCE
THE SNOW COMPLETELY ENDS SHORTLY ALONG THE HIGHWAY 50 CORRIDOR
FROM WHITEWATER THROUGH MONTROSE.
UPDATE ISSUED AT 654 AM MST SAT DEC 12 2015
STEADY SNOW HAS ENDED ACROSS EASTERN UTAH AND NORTHWEST
COLORADO...SO CANCELLED ADVISORIES AND WARNINGS IN UT ZONES 25 AND
28...AND CO ZONES 1...2 AND 3. THE POSSIBILITY OF A FEW FLURRIES
STILL EXISTS BUT THESE AREAS WILL NOT SEE ANY ADDITIONAL SNOW
ACCUMULATION. RAP AND HRRR INDICATING CONTINUATION OF SNOW ALONG
I-70 EAST OF GLENWOOD SPRINGS...IN THE SAN JUANS AND ALONG THE
CONTINENTAL DIVIDE.
UPDATE ISSUED AT 329 AM MST SAT DEC 12 2015
LATEST REPORT FROM DURANGO DISPATCH INDICATED 1 INCH OF SNOW
STICKING TO ROAD SURFACES WHILE WEBCAMS SHOWED SIMILAR CONDITIONS
AROUND TOWN. LATEST 06Z NAM CONTINUES TO SHOW BAND OF PRECIP OVER
MUCH OF SOUTHERN VALLEYS PERSISTING THROUGH MUCH OF THE DAY. IR
IMAGERY SHOWING PLENTY OF MOISTURE OVER THAT AREA AND MORE TO
COME FROM NEW MEXICO. SOME ENHANCEMENT CAN ALSO BE SEEN INDICATING
A GOOD POSSIBILITY FOR HEAVIER SNOWFALL. WATER VAPOR FURTHER
CORROBORATES THIS IDEA. WENT AHEAD AND ISSUED ADVISORIES FOR ALL
SOUTHERN VALLEYS FOR 2 TO 4 INCHES WITH HIGHER AMOUNTS POSSIBLE
FOR HIGHER ELEVATIONS. TEMPS CONTINUE TO HOVER AROUND FREEZING SO
WITH DAYBREAK...WOULD EXPECT SNOW ON ROADS TO MELT FAIRLY QUICKLY
WITH LITTLE IMPACT. IF THIS OCCURS...HIGHLIGHTS CAN BE TAKEN DOWN
EARLY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 256 AM MST SAT DEC 12 2015
ANOTHER STORM IS EXCEEDING EXPECTATIONS IN SEVERAL AREAS. WE WERE
DEALING WITH A HEAVY SNOW BAND RELATED TO A WELL FORMED MID LEVEL
FRONTOGENESIS BAND ACROSS NORTHWEST COLORADO WHICH DUMPED UP TO A
FOOT OF NEW SNOW IN LOWER ELEVATIONS. NOW WE LOOK UPSTREAM AT THE
APPROACHING MAIN LOW PRESSURE SYSTEM ANALYZED AT 00Z OVER SOUTHERN
NEVADA...AND AT 06Z SATELLITE IMAGERY SUGGESTS THIS CIRCULATION
HAS MOVED TO CENTRAL ARIZONA. WOULD HAVE TO SAY THE TRENDS ARE
SLOWER AND FARTHER SOUTH WITH THIS SYSTEM THAN MODELS SUGGESTED
YESTERDAY. WITH THE CYCLONE STILL TO THE WEST THETA SURFACES
SUGGEST A NEW WARM CONVEYOR BELT DELIVERING A GOOD SHOT OF
MOISTURE INTO WESTERN COLORADO THIS MORNING. THIS IS MORE THAN
APPARENT WITH THE RECENT ENHANCEMENTS ON THE REGIONAL RADAR MOSAIC
AND IR SATELLITE IMAGERY OVER EASTERN ARIZONA. THE BIG FORECAST
CHALLENGE IS WHAT DOES THAT MEAN FOR OUR AREA. THE MOISTURE
ADVECTION AND CONSTANT STREAM OF VIRGA OR LIGHT SHOWERS THIS
EVENING HAS CLOSED THE DEW POINT GAP ACROSS THE SOUTHERN VALLEYS
WHERE TEMPERATURES ARE STILL IN THE UPPER 30S. THE REAL COLD AIR
IS STILL BEING HELD BACK BY THE FLOW ALOFT SO PRECIPITATION TYPE
IS STILL QUITE TRICKY FOR THE SOUTHERN VALLEYS AS RAIN MAY HOLD
OUT LONGER THAN ANTICIPATED OR JUST TURN INTO MELTING SNOW. FOR
NOW WILL SIDE WITH THE TRENDS OF NEAR AN INCH OF THE DURANGO
AIRPORT WITH HIGHER AMOUNTS NEAR THE FOOTHILLS. PAGOSA SPRINGS
WILL SEE ANYWHERE FROM TO 1 INCH TO 3 INCHES NEAR THE HILLS. THE
PROBLEM AREAS DOWN SOUTH WILL MOST LIKELY BE THE HIGH SPOTS ALONG
HWY 160 LIKE THE MANCOS HILL AREA. THIS WCB WILL ALSO CONTAIN
BETTER INSTABILITY AS SEEN IN EPV FIELDS AND THIS SHOULD BE
RELEASED BY THE INCREASING LARGE SCALE ASCENT OVER THE SOUTHERN
CWA AS THE MID LEVEL CIRCULATION PASSES THROUGH FROM MID MORNING
ONWARD. COMPLICATED SITUATION AND EXPECT CHANGES TO GOING FORECAST
THROUGH THE DAY AS SOME OF THE VARIABLES BECOME MORE CLEAR. THE
SOUTHERN MOUNTAINS MAY BE IN FOR MORE SNOW THAN PREVIOUSLY
FORECAST AND WILL BE MONITORING FOR UPGRADES IF IMPACTS TO PASSES
BECOME MORE APPARENT. WE DID INCLUDE THE GUNNISON BASIN IN THE
LATEST WSW AS THIS MOISTURE PLUME WILL BE DIRECTED AT CERRO SUMMIT
AND THE BLACK CANYON AREA. THE SYSTEM SLOWLY PULLS EAST OF THE
DIVIDE THIS EVENING BEFORE STRENGTHENING IN THE LEE SIDE. DID KEEP
SOME HIGHER POPS INTO THIS EVENING TO ACCOUNT FOR THE SLOWER
MOVEMENT. OVERALL THE PCPN SHOULD BE DONE BY MIDNIGHT WITH A DRY
SUNDAY ON TAP. TEMPERATURES AND NEW SNOWFALL WILL BE THE MAIN
CHALLENGE ALONG WITH AREAS OF FOG DEVELOPING IN THE VALLEYS AND
BASINS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 256 AM MST SAT DEC 12 2015
RIDGING THAT BUILT IN SUNDAY WILL BE OVERHEAD SUNDAY NIGHT AND
QUICKLY SHIFT EASTWARD AS THE NEXT TROUGH APPROACHES FROM THE
WEST. MODELS IN FAIRLY GOOD AGREEMENT WITH EVOLUTION OF THIS
SYSTEM AND LOOKS SOMEWHAT SIMILAR TO THE STORM AFFECTING THE
REGION RIGHT NOW. SUBTLE DIFFERENCES EXIST OF COURSE BUT THE MAIN
GIST OF A COLD FRONT BRINGING WIDESPREAD SNOWFALL REMAINS. MAIN
DIFFERENCES WITH THIS SYSTEM WILL BE THAT COLD AIR WILL ALREADY BE
IN PLACE FROM THE PREVIOUS FRONT AND WILL ONLY BE REINFORCED FROM
THIS SECOND SYSTEM.
AS FAR AS DETAILS ARE CONCERNED...PRECIP WILL BEGIN MONDAY
MORNING FOR ERN UTAH AND SHIFT EASTWARD AS THE DAY PROGRESSES. BY
EVENING MOST...IF NOT ALL...AREAS WILL SEE SOME PRECIPITATION AS
THE CLOSED LOW AND ASSOD LIFT ARE POISED TO MOVE INTO WRN CO.
PLENTY OF THINGS CAN CHANGE BETWEEN NOW AND THEN THOUGH INCLUDING
THE LOW OPENING UP...UPPER LEVEL SUPPORT WANING...BEST LIFT SHIFTS
NORTH OR SOUTH...SO WILL HAVE TO SEE IF MODELS REMAIN CONSTANT IN
THIS OUTCOME. FOR NOW...6 TO 10 INCHES FOR THE MTNS AND 1 TO 3
INCHES FOR SOME VALLEYS LOOKS GOOD.
SNOWFALL WILL CONTINUE INTO TUESDAY BUT WITH BEST LIFT HAVING
SHIFTED TO THE PLAINS...ANTICIPATE A MORE SHOWERY NATURE TO
PRECIP. NORTHERLY FLOW WILL ALSO USHER IN COLDER AIR TO THE
REGION. SOME MTN SHOWERS...ESPECIALLY UP NORTH...MAY CONTINUE
THROUGH WEDNESDAY MORNING BUT ANTICIPATE MORE FLURRIES THAN
ANYTHING ELSE. MOST AREAS WILL SEE PARTLY CLOUDY SKIES AND MUCH
COLDER TEMPERATURES THAT WILL BE WELL BELOW NORMAL. AFTER
THAT...LITTLE PIECES OF WEAK ENERGY WILL DROP DOWN FROM THE NW
CAUSING SOME LIGHT SNOWFALL OVER THE PARK/GORE RANGES THROUGH
FRIDAY BUT AGAIN...NOT MUCH ACCUMULATION EXPECTED. EXPECT MORE
CLOUDS N OF I-70 THAN S DUE TO THESE DISTURBANCES. TEMPERATURES
WILL REMAIN BELOW NORMAL THROUGH LONG TERM PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 256 AM MST SAT DEC 12 2015
WIDESPREAD IFR CONDITIONS AND BELOW ARE BEING EXPERIENCED AT MOST
ASOS SITES THIS MORNING. ODD MAN OUT IS KVEL WHICH WILL LIKELY
STAY VFR SINCE THE FRONT HAS PASSED TO THE EAST. LOW CIGS/VIS
STILL POSSIBLE FOR THAT AERODROME SATURDAY NIGHT INTO SUNDAY
MORNING HOWEVER DUE TO FOG. SPEAKING OF...FOG POSSIBLE FOR MANY
TAF LOCATIONS THIS MORNING AND AGAIN TONIGHT. A HEAVIER BAND OF
PRECIP WILL CONTINUE TO SHIFT EASTWARD TODAY ALLOWING IMPROVING
CONDITIONS FOR KCNY...KGJT...KMTJ AND KRIL WHILE REMAINING TAF
SITES WILL LIKELY SEE CONTINUED PRECIP AND LOW FLIGHT CONDITIONS.
BY 21Z...MVFR/IFR CONDITIONS WILL HAVE LARGELY SHIFTED TO THE
CONTINENTAL DIVIDE.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ005-
008>010-012-014-018-019-022-023.
WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR COZ004-013.
UT...NONE.
&&
$$
UPDATE...JAM
SHORT TERM...15
LONG TERM...TGR
AVIATION...TGR
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
324 PM EST SAT DEC 12 2015
.SYNOPSIS...
20Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN AMPLIFIED UPPER
LEVEL PATTERN OVER THE CONUS. PATTERN IS HIGHLIGHTED BY
DEEP/SHARP TROUGHING OVER THE INTER-MOUNTAIN WEST FOLLOWED BY
DOWNSTREAM RIDGING OVER THE EASTERN HALF OF THE NATION. THE
FLORIDA PENINSULA RESIDES UNDER THE BASE OF THIS RIDGE AND UNDER
SOME FAIRLY IMPRESSIVE HEIGHTS FOR THE MIDDLE OF DECEMBER. H5
HEIGHTS OVER THE CENTRAL PART OF THE STATE ARE AROUND 590DM OFF
THE MORNING KTBW SOUNDING...AND THIS REPRESENTS A VALUE ABOVE THE
90TH PERCENTILE FOR DECEMBER. THE 12Z KTBW SOUNDING SHOWED A
DEFINED SUBSIDENCE INVERSION AROUND 700MB...SEPARATING A SHALLOW
LAYER OF ATLANTIC MOISTURE FROM A VERY DRY COLUMN ALOFT. NEEDLESS
TO SAY...WITH SUCH A STRONG AND STACKED AREA OF RIDGING
ALOFT...OUR FORECAST AREA IS WELL PROTECTED FROM ANY INCLEMENT
SENSIBLE WEATHER THROUGH THE REMAINDER OF THE WEEKEND.
ALSO...WITH THE STRONG RIDGE ALOFT AND DECENT LOW LEVEL CONDITIONS
FOR DIURNAL MIXING...TEMPERATURES HAVE TOPPED OUT WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. MANY LOCATIONS FIND THEMSELVES AS
MUCH AS 10+ DEGREES ABOVE NORMAL THIS AFTERNOON...AND THESE
UNSEASONABLE VALUES WILL CONTINUE FOR THE OVERNIGHT AND AGAIN ON
SUNDAY.
&&
.SHORT TERM (TONIGHT THROUGH SUNDAY)...
TEMPERATURES TONIGHT REMAINING IN THE 60S FOR JUST ABOUT ALL
LOCATIONS (PERHAPS A FEW COOLER SPOTS IN THE UPPER 50S FOR LEVY
COUNTY).
ALTHOUGH THE UPPER RIDGE WILL NOT BE QUITE AS STRONG BY
SUNDAY...WE WILL STILL BE LOOKING AT HEIGHTS WELL ABOVE
NORMAL...AND IT WILL STILL BE PLENTY IN CONTROL TO PROTECT OUR
REGION FROM ANY MID/UPPER LEVEL SYNOPTIC FORCING FOR LIFT. THE
CHANGE IN PATTERN THAT WE WILL SEE FOR SUNDAY WILL OCCUR IN THE
VERY LOWEST LEVELS OF THE COLUMN. A WEAK INVERTED TROUGH SEEN
CURRENTLY OUT TOWARD THE BAHAMAS IS SHOWN BY MOST ENSEMBLE MEMBERS
TO MIGRATE WESTWARD THROUGH THE NEXT 24 HOURS TO A POSITION OVER
THE SOUTHERN HALF OF THE FL PENINSULA SUNDAY AFTERNOON. A SLIGHT
INCREASE IN COLUMN MOISTURE BELOW 700MB IS FORECAST TO ARRIVE WITH
THIS FEATURE...ALONG A SWATH OF MODEST ISENTROPIC UPGLIDE ALONG
THE 300-310K SURFACES. EXTENT OF LIFT (ALTHOUGH IT IS SHALLOW)
COMBINED WITH THE ADDED SURFACE FOCUS UNDER THE TROUGH APPEARS
SUFFICIENT TO SUPPORT SOME WIDELY SCATTERED LIGHT SHOWERS TO THE
SOUTH OF THE I-4 CORRIDOR SUNDAY AFTERNOON/EARLY EVENING. AS
MENTIONED ALL THE MOISTURE IS SHALLOW...AND HENCE THE SHOWERS WILL
ALSO BE SHALLOW AND LIGHT...WITH PROB ONLY A COUPLE HUNDREDTHS OF
AN INCH FOR ANY LOCATION THAT DOES SEE A BRIEF SHOWER.
THEREFORE...THE IMPACT TO ANY OUTDOOR ACTIVITIES LOOKS NEGLIGIBLE.
THE SOUTHERN HALF OF THE AREA SHOULD CERTAINLY EXPECT TO SEE LESS
SUN FOR SUNDAY AS A COMBINATION OF CUMULUS AND STRATOCU ARE LIKELY
TO FILL IN QUITE QUICKLY. CURRENT GRIDS HAVE 20-30% SHOWER
COVERAGE...AND BASED ON AVAILABLE 12Z GUIDANCE DO NOT SEE MUCH
REASON TO MAKE MANY SIGNIFICANT CHANGES WITH THIS FORECAST
PACKAGE.
&&
.LONG TERM...
AN UPPER-LEVEL RIDGE OVER FLORIDA TO END THE WEEKEND WILL SHIFT
EASTWARD THROUGH MONDAY AS AN UPPER-LEVEL LOW TRACKS NORTHEASTWARD
THROUGH THE CENTRAL PLAINS TOWARD THE GREAT LAKES REGION. AT THE
SURFACE...HIGH PRESSURE WILL BEGIN TO PUSH OFF THE EASTERN SEABOARD
AS A COLD FRONT ENTERS THE FLORIDA PANHANDLE REGION. GLOBAL MODELS
CONTINUE TO SHOW A RATHER ILL-DEFINED PASSAGE OF THIS FRONT MONDAY
NIGHT INTO TUESDAY AS THE SUPPORT LIFTS WELL AWAY FROM THE AREA. AS
OF THIS FORECAST PACKAGE...IT DOES NOT LOOK LIKE THE FRONT WILL
ACTUALLY CLEAR THE ENTIRE FORECAST AREA...INSTEAD HANGING UP
SOMEWHERE ACROSS THE CENTRAL PENINSULA. SOME SHOWERS ARE CERTAINLY
POSSIBLE THROUGH WEDNESDAY...BUT HAVE KEPT CHANCE POPS OR LESS WITH
QPF AMOUNTS NOT EXPECTED TO BE ALL THAT HIGH FOR THE MOST PART.
OUR NEXT REAL WEATHER-MAKER LOOKS TO TAKE SHAPE WEDNESDAY NIGHT INTO
THURSDAY AS A DEEPER UPPER-LEVEL TROUGH SWINGS THROUGH THE CENTRAL
PART OF THE COUNTRY WITH SURFACE LOW PRESSURE DEVELOPING ALONG THE
NORTHERN GULF COAST. FOR NOW...MODELS ARE SHOWING THE BEST CHANCES
FOR RAIN THURSDAY INTO FRIDAY...WITH RAIN COMING TO AN END SATURDAY
AS A MUCH COOLER AND DRIER AIR MASS FILTERING INTO THE REGION.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGH THE AFTERNOON AND EVENING
HOURS TODAY ACROSS WEST-CENTRAL AND SOUTHWEST FLORIDA. EASTERLY
TERMINALS WILL SEE EASTERLY WINDS AND A FEW-SCT CUMULUS FIELD
DEVELOPING DURING THE AFTERNOON. POTENTIAL FOR PATCHY AREAS OF FOG
TO IMPACT SITES SUCH AS KLAL/KPGD AFTER 08Z TONIGHT...HOWEVER...
BETTER CHANCES FOR FOG AND ASSOCIATED RESTRICTIONS LOOK TO REMAIN
NORTH OF THE FORECAST TERMINALS. EARLY FOG LIFTS BY 14Z...FOLLOWED
BY VFR CONDITIONS THROUGH SUNDAY AFTERNOON.
&&
.MARINE...
HIGH PRESSURE TO THE NORTH OF THE COASTAL WATERS WILL
KEEP MODERATE EAST WINDS IN PLACE THROUGH THE WEEKEND. A COLD
FRONT WILL APPROACH THE AREA AND STALL OVER THE NORTHEAST GULF
OF MEXICO DURING THE EARLY PART OF NEXT WEEK. CHANCES FOR SHOWERS
WILL INCREASE MONDAY INTO TUESDAY ASSOCIATED WITH THIS FRONT.
WINDS AND SEAS ARE GENERALLY EXPECTED TO REMAIN BELOW HEADLINE
CRITERIA.
&&
.FIRE WEATHER...
HIGH PRESSURE WILL SHIFT OFF THE SOUTHEAST COAST INTO THE ATLANTIC
THROUGH MONDAY ALLOWING WINDS TO SHIFT MORE TO THE SOUTH AHEAD OF
AN APPROACHING FRONT. THIS FRONT WILL STALL ACROSS THE REGION BY
TUESDAY WITH INCREASING CHANCES FOR SCATTERED SHOWERS. RELATIVE
HUMIDITY VALUES WILL REMAIN WELL ABOVE CRITICAL LEVELS THROUGH
THE FORECAST PERIOD...ALTHOUGH DISPERSION INDICES ON SUNDAY ARE
FORECAST TO BE HIGH.
FOG POTENTIAL...
PATCHY FOG IS EXPECTED LATE TONIGHT/EARLY SUNDAY MORNING. THE BEST
CHANCES FOR FOG ON SUNDAY WILL BE TO THE NORTH OF THE I-4
CORRIDOR.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 66 81 69 81 / 0 10 10 10
FMY 67 82 70 84 / 0 30 20 10
GIF 65 81 68 84 / 0 20 20 20
SRQ 66 79 69 80 / 0 20 10 10
BKV 63 81 67 83 / 0 10 10 10
SPG 67 80 70 81 / 0 10 10 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH MONDAY EVENING FOR COASTAL
MANATEE-COASTAL SARASOTA-PINELLAS.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA
LONG TERM...CARLISLE
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
501 PM EST SAT DEC 12 2015
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE FAIR AND WARM WEATHER THROUGH SUNDAY.
A WEAK FRONT WILL BRING A CHANCE OF SHOWERS LATE SUNDAY NIGHT AND
MONDAY. ANOTHER STRONGER COLD FRONT MAY BRING SHOWERS WEDNESDAY
AND THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
FOG MAY OCCUR AGAIN LATE TONIGHT. THERE WAS AGREEMENT BETWEEN
THE MODELS THAT AT LEAST PATCHY FOG WILL OCCUR. THE HRRR SUGGESTED
THE THICKEST AREAS OF FOG WILL OCCUR FROM LANCASTER COUNTY INTO
THE CENTRAL MIDLANDS. DEEPER LOW-LEVEL MOISTURE PROFILES COMPARED
TO LAST NIGHT SUPPORTED THE HRRR. CALM WINDS WITH DRY AIR ALOFT
SHOULD AID STRONG NET RADIATIONAL COOLING. THE GUIDANCE CONSENSUS
SUPPORTED LOWS IN THE UPPER 40S AND LOWER 50S.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
THE NAM AND RAP SHOWED WEAK ISENTROPIC LIFT ALONG THE SOUTHERN SC
COAST SUNDAY MORNING. LOW STRATUS MAY BE A CONCERN AS THEY MOVE
INTO THE EASTERN MIDLANDS AND EVENTUALLY CENTRAL MIDLANDS. FOG AND
LOW STRATUS SHOULD DISSIPATE BY LATE SUNDAY MORNING. HIGHLY
AMPLIFIED UPPER PATTERN TO PERSIST. THE UPPER-LEVEL RIDGE AND
SURFACE HIGH PRESSURE WILL MOVE OFF THE COAST SUNDAY AS AN UPPER
LOW LIFTS NORTHEAST FROM THE GREAT PLAINS INTO THE CENTRAL MS
RIVER VALLEY. INCREASING DEEP SOUTHERLY FLOW/ISENTROPIC LIFT TO
DEVELOP OVER OUR REGION AHEAD OF AN APPROACHING WEAK FRONT. MODELS
INDICATE MORE CLOUDINESS SUNDAY. MOISTURE WILL CONTINUE TO
INCREASE SUNDAY NIGHT WITH PWAT AROUND ONE INCH WITH H85 WINDS
REACHING BETWEEN 30 AND 40 KTS BY LATE SUNDAY NIGHT. KEPT THE
CHANCE FOR SHOWERS LATE SUNDAY NIGHT. NEAR RECORD HIGH TEMPS
POSSIBLE SUNDAY. WILL CONTINUE TO USE WARMER GUIDANCE TEMPERATURES
WITH AFTERNOON HIGHS IN THE MID/UPPER 70S AND LOWS SUNDAY NIGHT
AROUND 60.
WEAK FRONT WILL MOVE THROUGH MONDAY AFTERNOON INTO THE EARLY
EVENING. UPPER ENERGY WILL BE WELL TO OUR NORTH WITH SOUTHWEST
FLOW ALOFT. ASSOCIATED CONVECTION TO OUR WEST ALONG THE FRONT
EXPECTED TO WEAKEN AS IT APPROACHES OUR REGION AS BEST UPPER
DYNAMICS SHIFT TO THE NORTH. SURFACE AND ELEVATED INSTABILITIES
STILL PROGGED TO BE WEAK...PRECLUDING THE MENTION OF THUNDER.
WE KEPT HIGH CHANCE TO LIKELY POPS WITH PRECIP AMOUNTS ONE QUARTER
INCH OR LESS. SHOWERS WILL MOVE EAST OF THE AREA MONDAY EVENING.
SHOULD SEE HIGHS IN THE 70S WITH LOWS MONDAY NIGHT IN THE MID 40S
WEST TO LOWER 50S EAST.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
MODELS TRENDING TOWARDS STALLING THE FRONT JUST TO OUR SOUTH TUESDAY
WITH SURFACE HIGH PRESSURE RETURNING TO THE AREA. TEMPERATURES TO
REMAIN ABOVE NORMAL WITH A SOUTHWEST UPPER FLOW AND UPPER-LEVEL
RIDGE OVER THE EASTERN CONUS.
SURFACE HIGH PRESSURE AND UPPER RIDGING MOVES OFF THE COAST WEDNESDAY
WITH MOISTURE RETURNING FROM THE SOUTH. THE CHANCE FOR SHOWERS RETURN
WEDNESDAY AS MOISTURE OVERRUNS THE STALLED FRONT TO OUR SOUTH.
A STRONGER COLD FRONT CROSSES THE AREA THURSDAY...CONTINUING THE
CHANCE FOR SHOWERS. THE GFS PUSHES THE COLD FRONT OFF THE COAST BY
FRIDAY...ENDING THE CHANCE FOR SHOWERS. THE ECMWF DOES NOT MOVE
THE FRONT OFF THE COAST UNTIL FRIDAY EVENING...THEREFORE HOLDING
THE CHANCE FOR SHOWERS ACROSS THE AREA FRIDAY. THIS PATTERN LOOKS
MORE PROGRESSIVE...SO WE INDICATED A DRY FORECAST FRIDAY.
THE MODELS INDICATE THE BREAK DOWN OF THE PERSISTENT SOUTHEASTERN U.S.
RIDGE BY THE END OF NEXT WEEK. THIS WILL BRING LOWER
HEIGHTS/THICKNESSES TO THE EASTERN SEABOARD AND AN END TO THE
MILD WEATHER. DRY WEATHER AND MORE SEASONABLE TEMPERATURES ARE FORECAST
FRIDAY AND SATURDAY.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
RESTRICTIONS DUE TO FOG AND LOW STRATUS APPEAR LIKELY OVERNIGHT
AND EARLY SUNDAY MORNING.
MODELS ARE COMING TO BETTER AGREEMENT ON FOG DEVELOPMENT
OVERNIGHT. GFS AND NAM GUIDANCE SUGGESTS AT LEAST MVFR FOG TONIGHT
INTO SUNDAY MORNING. HI-RES MODELS INDICATE THAT DENSE FOG MAY BE
MOST LIKELY IN THE NORTHERN HALF OF THE FORECAST AREA. FORECAST
PROFILES SUPPORT THIS SHOWING DEEPER LOW LEVEL MOISTURE THAN LAST
NIGHT FROM LANCASTER INTO THE CENTRAL MIDLANDS. CALM WINDS...DRY
MID LEVELS AND CLEAR SKIES SHOULD AID RADIATIONAL COOLING.
THE NAM AND RAP MODELS SHOW WEAK ISENTROPIC LIFT ALONG THE
SOUTHERN SC COAST SUNDAY MORNING. LOW STRATUS MAY BE A CONCERN
AS THEY MOVE INTO THE EASTERN MIDLANDS AND EVENTUALLY CENTRAL
MIDLANDS. MVFR CEILING RESTRICTIONS APPEAR PROBABLE AT OGB AND
POSSIBLE AT OTHER TAF SITES.
EXTENDED AVIATION OUTLOOK...A COLD FRONT MOVING INTO THE AREA
MAY BRING RESTRICTIONS WEDNESDAY THROUGH THURSDAY.
&&
.CLIMATE...
NORMAL MAX TEMPS SUNDAY...
CAE...59. AGS...60.
RECORD MAX TEMPS SUNDAY...
CAE...80.
AGS...81.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
244 PM EST SAT DEC 12 2015
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE FAIR AND WARM WEATHER THROUGH SUNDAY.
A WEAK FRONT WILL PROVIDE A CHANCE OF SHOWERS LATE SUNDAY NIGHT
AND MONDAY. ANOTHER STRONGER COLD FRONT TO BRING A CHANCE OF
SHOWERS WEDNESDAY AND THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
CONTINUED SOUTHERLY FLOW AND WARM ADVECTION WILL SUPPORT WELL
ABOVE NORMAL TEMPERATURES THIS AFTERNOON. HIGHS FROM THE MID TO
UPPER 70S ARE NEARLY 20 DEGREES ABOVE NORMAL. SOME LOCATIONS MAY
NEAR RECORD VALUES...HOWEVER RECORD HIGHS ARE NOT EXPECTED TO BE
BROKEN TODAY. NO CHANCE FOR RAIN UNDER THE UPPER RIDGE WITH HIGH
PRESSURE IN CONTROL.
TONIGHT...FOG WILL BE POSSIBLE AGAIN TONIGHT INTO EARLY SUNDAY
MORNING. THERE IS GOOD AGREEMENT BETWEEN MODELS THAT AT LEAST
PATCHY FOG WILL OCCUR. THE HRRR SUGGESTS THAT THE THICKEST AREAS
OF FOG WILL OCCUR FROM LANCASTER COUNTY INTO THE CENTRAL MIDLANDS.
DEEPER LO-LEVEL MOISTURE PROFILES THAN LAST NIGHT SUPPORT THE
HRRR. CALM WINDS...DRY MID-LEVELS AND CLEAR SKIES SHOULD AID
RADIATIONAL COOLING.
THE NAM AND RAP MODELS SHOW WEAK ISENTROPIC LIFT ALONG THE
SOUTHERN SC COAST SUNDAY MORNING. LOW STRATUS MAY BE A CONCERN
AS THEY MOVE INTO THE EASTERN MIDLANDS AND EVENTUALLY CENTRAL
MIDLANDS. FOG AND LOW STRATUS MAY DISSIPATE BY LATE SUNDAY
MORNING.
TEMPS...LOW TEMPERATURES WILL BE IN THE 50S TONIGHT.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
HIGHLY AMPLIFIED UPPER PATTERN TO PERSIST. THE UPPER LEVEL RIDGE AND
SURFACE HIGH PRESSURE WILL MOVE OFF THE COAST SUNDAY AS AN UPPER LOW
LIFTS NORTHEAST FROM THE GREAT PLAINS INTO THE CENTRAL MS RIVER VALLEY.
INCREASING DEEP SOUTHERLY FLOW/ISENTROPIC LIFT TO DEVELOP OVER OUR
REGION AHEAD OF AN APPROACHING WEAK FRONT. MODELS INDICATE MORE
CLOUDINESS SUNDAY. MOISTURE WILL CONTINUE TO INCREASE SUNDAY NIGHT
WITH PWAT AROUND ONE INCH AND H85 WINDS REACHING BETWEEN 30-40 KTS
BY LATE SUNDAY NIGHT. KEPT THE CHANCE FOR SHOWERS LATE SUNDAY
NIGHT. NEAR RECORD HIGH TEMPS POSSIBLE SUNDAY. WILL CONTINUE TO
USE WARMER GUIDANCE TEMPERATURES WITH AFTERNOON HIGHS IN THE
MID/UPPER 70S AND LOWS SUNDAY NIGHT AROUND 60.
WEAK FRONT WILL MOVE THROUGH MONDAY AFTERNOON INTO THE EARLY
EVENING. UPPER ENERGY WILL BE WELL TO OUR NORTH WITH SOUTHWEST
FLOW ALOFT. ASSOCIATED CONVECTION TO OUR WEST ALONG THE FRONT
EXPECTED TO WEAKEN AS IT APPROACHES OUR REGION AS BEST UPPER
DYNAMICS SHIFT TO THE NORTH. SURFACE AND ELEVATED INSTABILITIES
STILL PROGGED TO BE WEAK...PRECLUDING THE MENTION OF THUNDER.
WE KEPT HIGH CHANCE TO LIKELY POPS WITH PRECIP AMOUNTS ONE QUARTER
INCH OR LESS. SHOWERS WILL MOVE EAST OF THE AREA MONDAY EVENING.
SHOULD SEE HIGHS IN THE 70S WITH LOWS MONDAY NIGHT IN THE MID 40S
WEST TO LOWER 50S EAST.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
MODELS TRENDING TOWARDS STALLING THE FRONT JUST TO OUR SOUTH TUESDAY
WITH SURFACE HIGH PRESSURE RETURNING TO THE AREA. TEMPERATURES TO
REMAIN ABOVE NORMAL WITH A SOUTHWEST UPPER FLOW AND UPPER LEVEL
RIDGE OVER THE EASTERN CONUS.
SURFACE HIGH PRESSURE AND UPPER RIDGING MOVES OFF THE COAST WEDNESDAY
WITH MOISTURE RETURNING FROM THE SOUTH. THE CHANCE FOR SHOWERS RETURN
WEDNESDAY AS MOISTURE OVERRUNS THE STALLED FRONT TO OUR SOUTH.
A STRONGER COLD FRONT CROSSES THE AREA THURSDAY...CONTINUING THE
CHANCE FOR SHOWERS. THE GFS PUSHES THE COLD FRONT OFF THE COAST BY
FRIDAY...ENDING THE CHANCE FOR SHOWERS. THE ECMWF DOES NOT MOVE
THE FRONT OFF THE COAST UNTIL FRIDAY EVENING...THEREFORE HOLDING
THE CHANCE FOR SHOWERS ACROSS THE AREA FRIDAY. THIS PATTERN LOOKS
MORE PROGRESSIVE...SO WE INDICATED A DRY FORECAST FRIDAY.
THE MODELS INDICATE THE BREAK DOWN OF THE PERSISTENT SOUTHEASTERN U.S.
RIDGE BY THE END OF NEXT WEEK. THIS WILL BRING LOWER
HEIGHTS/THICKNESSES TO THE EASTERN SEABOARD AND AN END TO THE
MILD WEATHER. DRY WEATHER AND MORE SEASONABLE TEMPERATURES ARE FORECAST
FRIDAY AND SATURDAY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
RESTRICTIONS DUE TO FOG AND LOW STRATUS APPEAR LIKELY OVERNIGHT
AND EARLY SUNDAY MORNING.
MOSTLY CLEAR SKIES TODAY WITH DRY HIGH PRESSURE OVERHEAD. WINDS
WILL BE LIGHT AND VARIABLE MOST OF THE DAY...PARTICULARLY IN THE
CSRA.
TONIGHT...MODELS ARE COMING TO BETTER AGREEMENT ON FOG
DEVELOPMENT OVERNIGHT. GFS AND NAM GUIDANCE SUGGESTS AT LEAST MVFR
FOG TONIGHT INTO SUNDAY MORNING. HI-RES MODELS INDICATE THAT
DENSE FOG MAY BE MOST LIKELY IN THE NORTHERN HALF OF THE FORECAST
AREA. FORECAST PROFILES SUPPORT THIS SHOWING DEEPER LOW LEVEL
MOISTURE THAN LAST NIGHT FROM LANCASTER INTO THE CENTRAL MIDLANDS.
CALM WINDS...DRY MID-LEVELS AND CLEAR SKIES SHOULD AID RADIATIONAL
COOLING.
THE NAM AND RAP MODELS SHOW WEAK ISENTROPIC LIFT ALONG THE
SOUTHERN SC COAST SUNDAY MORNING. LOW STRATUS MAY BE A CONCERN
AS THEY MOVE INTO THE EASTERN MIDLANDS AND EVENTUALLY CENTRAL
MIDLANDS. MVFR CEILING RESTRICTIONS APPEAR PROBABLE AT OGB AND
POSSIBLE AT OTHER TAF SITES.
EXTENDED AVIATION OUTLOOK...A WEAK FRONT MOVING INTO THE AREA
EARLY NEXT WEEK MAY BRING RESTRICTIONS.
&&
.CLIMATE...
NORMAL MAX TEMPS SUNDAY...
CAE...59. AGS...60.
RECORD MAX TEMPS SUNDAY...
CAE...80.
AGS...81.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1249 PM EST SAT DEC 12 2015
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE FAIR AND WARM WEATHER THROUGH SUNDAY.
A WEAK FRONT WILL PROVIDE A CHANCE OF SHOWERS LATE SUNDAY NIGHT
AND MONDAY. ANOTHER FRONT TO PROVIDE A CHANCE OF SHOWERS WEDNESDAY
AND THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
CONTINUED SOUTHERLY FLOW AND WARM ADVECTION WILL SUPPORT WELL
ABOVE NORMAL TEMPERATURES THIS AFTERNOON. HIGHS FROM THE MID TO
UPPER 70S ARE NEARLY 20 DEGREES ABOVE NORMAL. SOME LOCATIONS MAY
NEAR RECORD VALUES...HOWEVER RECORD HIGHS ARE NOT EXPECTED TO BE
BROKEN TODAY. NO CHANCE FOR RAIN UNDER THE UPPER RIDGE WITH HIGH
PRESSURE IN CONTROL.
TONIGHT...FOG WILL BE POSSIBLE AGAIN TONIGHT INTO EARLY SUNDAY
MORNING. THERE IS GOOD AGREEMENT BETWEEN MODELS THAT AT LEAST
PATCHY FOG WILL OCCUR. THE HRRR SUGGESTS THAT THE THICKEST AREAS
OF FOG WILL OCCUR FROM LANCASTER COUNTY INTO THE CENTRAL MIDLANDS.
DEEPER LO-LEVEL MOISTURE PROFILES THAN LAST NIGHT SUPPORT THE
HRRR. CALM WINDS...DRY MID-LEVELS AND CLEAR SKIES SHOULD AID
RADIATIONAL COOLING.
THE NAM AND RAP MODELS SHOW WEAK ISENTROPIC LIFT ALONG THE
SOUTHERN SC COAST SUNDAY MORNING. LOW STRATUS MAY BE A CONCERN
AS THEY MOVE INTO THE EASTERN MIDLANDS AND EVENTUALLY CENTRAL
MIDLANDS. FOG AND LOW STRATUS MAY DISSIPATE BY LATE SUNDAY
MORNING.
TEMPS...LOW TEMPERATURES WILL BE IN THE 50S TONIGHT.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
CONTINUED FAIR WEATHER WITH WELL ABOVE NORMAL TEMPS. FOG POSSIBLE
AGAIN LATE TONIGHT/EARLY SUNDAY...BUT AN INCREASE IN LOW LEVEL
SOUTHERLY FLOW LATE TONIGHT COULD PROVIDE MORE OF A STRATUS
THREAT. UPPER/SURFACE HIGHS TO SHIFT TO OUR EAST SUN/SUN NT...AS
UPPER TROUGH TO OUR WEST LIFTS NE TOWARDS THE MID/UPPER MISS
VALLEY. NEAR RECORD HIGH TEMPS POSSIBLE SUNDAY. INCREASING LOW
LEVEL SOUTHERLY FLOW/ISENTROPIC LIFT TO DEVELOP OVER OUR REGION
LATE SUNDAY NIGHT AHEAD OF AN APPROACHING WEAK FRONT...WITH SOME
LIGHT PRECIP POSSIBLE.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
WEAK FRONT WILL MOVE THROUGH MONDAY. LATEST MODELS TRENDING
TOWARDS SLOWING DOWN THE TIMING OF THE FRONT AS UPPER ENERGY IS
WELL TO THE NORTH BY THAT TIME...WITH A SW FLOW ALOFT. ASSOCIATED
PRECIP ACTIVITY/CONVECTION TO OUR WEST ALONG THE FRONT EXPECTED TO
WEAKEN AS IT APPROACHES OUR REGION AS BEST UPPER DYNAMICS SHIFT TO
THE NORTH. SURFACE AND ELEVATED INSTABILITIES STILL PROGGED TO BE
WEAK FOR OUR FA...PRECLUDING NEED FOR THUNDER MENTION AT THIS
TIME FOR OUR FA. HIGH CHANCE TO LOW LIKELY POPS CONTINUE TO LOOK
OK WITH THE FROPA. WITH FROPA TRENDING LATER IN THE DAY...BUMPED
UP MAX TEMPS MON. MODELS TRENDING TOWARDS STALLING THE FRONT JUST
TO OUR SOUTH TUE. WILL MAINTAIN FAIR WEATHER FORECAST FOR TUE.
STILL ABOVE NORMAL TEMPS EXPECTED TUE AS A SW UPPER FLOW REMAINS
WITH FLAT UPPER RIDGE OVER THE E COAST. LATEST GFS/ECWMF APPEAR TO
BE IN GOOD AGREEMENT WITH UPPER TROUGH MOVING EAST INTO THE
CENTRAL CONUS...WITH UPPER RIDGE SHIFTING TO OUR EAST...BY
WED/THU...BRINGING MAIN UPPER FLOW CLOSER TO OUR REGION WITH
EMBEDDED ENERGY LEADING TO MOISTURE RETURN ANTICIPATED FOR LATE
WED INTO EARLY FRI. FOR NOW...CHANCE POPS APPEAR OK.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
RESTRICTIONS DUE TO FOG AND LOW STRATUS APPEAR LIKELY OVERNIGHT
AND EARLY SUNDAY MORNING.
MOSTLY CLEAR SKIES TODAY WITH DRY HIGH PRESSURE OVERHEAD. WINDS
WILL BE LIGHT AND VARIABLE MOST OF THE DAY...PARTICULARLY IN THE
CSRA.
TONIGHT...MODELS ARE COMING TO BETTER AGREEMENT ON FOG
DEVELOPMENT OVERNIGHT. GFS AND NAM GUIDANCE SUGGESTS AT LEAST MVFR
FOG TONIGHT INTO SUNDAY MORNING. HI-RES MODELS INDICATE THAT
DENSE FOG MAY BE MOST LIKELY IN THE NORTHERN HALF OF THE FORECAST
AREA. FORECAST PROFILES SUPPORT THIS SHOWING DEEPER LOW LEVEL
MOISTURE THAN LAST NIGHT FROM LANCASTER INTO THE CENTRAL MIDLANDS.
CALM WINDS...DRY MID-LEVELS AND CLEAR SKIES SHOULD AID RADIATIONAL
COOLING.
THE NAM AND RAP MODELS SHOW WEAK ISENTROPIC LIFT ALONG THE
SOUTHERN SC COAST SUNDAY MORNING. LOW STRATUS MAY BE A CONCERN
AS THEY MOVE INTO THE EASTERN MIDLANDS AND EVENTUALLY CENTRAL
MIDLANDS. MVFR CEILING RESTRICTIONS APPEAR PROBABLE AT OGB AND
POSSIBLE AT OTHER TAF SITES.
EXTENDED AVIATION OUTLOOK...A WEAK FRONT MOVING INTO THE AREA
EARLY NEXT WEEK MAY BRING RESTRICTIONS.
&&
.CLIMATE...
CURRENT INDICATIONS ARE THAT MAX TEMPS TODAY WILL NOT BREAK DAILY
RECORD HIGHS...BUT RECORD HIGH TEMPS MAY POSSIBLY BE REACHED
SUNDAY.
NORMAL MAX TEMPS TODAY/SUNDAY...
CAE...59/59. AGS...61/60.
FORECAST MAX TEMPS TODAY/SUNDAY...
CAE...77/78. AGS...78/80.
RECORD MAX TEMPS TODAY/SUNDAY...
CAE...81/80. AGS...82/81.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
412 PM CST SAT DEC 12 2015
.SHORT TERM...
325 PM CST
THROUGH SUNDAY...
A VERY SEASONALLY ANOMALOUS WEATHER PATTERN WITH MANY FORECAST
CHALLENGES...RANGING FROM RECORD OR NEAR RECORD HIGH
TEMPERATURES...DENSE FOG...ISOLATED THUNDERSTORMS...AND THE
BEGINNINGS OF HEAVY RAIN.
FOR THE REMAINDER OF THE AFTERNOON...THE PROGRESSION OF A STRONG
WARM FRONT THROUGH THE NORTHERN PORTIONS OF THE FORECAST AREA INTO
SOUTHERN WISCONSIN WILL BE THE MAIN DRIVER OF TEMPERATURE TRENDS AND
DENSE FOG. AS OF 3PM CST...STILL OBSERVING DENSE FOG WHERE WINDS
ARE STILL EASTERLY. A LAKE BREEZE HAS ALLOWED FOR SOME OF THE DENSE
FOG OVER LAKE MICHIGAN TO MOVE INLAND INTO LAKE AND COOK COUNTIES
NEAR THE LAKEFRONT AND EXPECT THAT THE DENSE FOG MAY STILL PUSH
INLAND TO ARND THE I-94 CORRIDOR. THE LAKE WILL IMPEDE THE NWD
PROGRESSION OF THE FRONT...ESPECIALLY OVER FAR NERN IL...WHILE LOW
PRESSURE TROUGHING OVER THE MISSOURI VALLEY WILL HELP WINDS OVER
NCNTRL/NWRN IL TURN MORE SOUTHERLY...PUSHING THE WARM FRONT NWD INTO
WISCONSIN OVER THAT AREA.. SO...EXPECT NCNTRL NWRN IL TO SEE
IMPROVING VISIBILITY THROUGH THE EVENING. ALSO...WARMER AIR WILL
CONTINUE TO STREAM NWD ACROSS THE AREA AND TEMPERATURES WILL LIKELY
CONTINUE TO SLOWLY RISE THROUGH THE EVENING BEFORE LEVELING OFF
OVERNIGHT. THERE SHOULD BE LITTLE OR NO DIURNAL COOLING OVERNIGHT
TONIGHT. TEMPERATURES AND DEWPOINTS SHOULD SLOWLY...BUT STEADILY
RISE THROUGH THE EVENING...ESPECIALLY SOUTH OF THE I-88 CORRIDOR.
LOCATIONS SOUTH OF I-80 SHOULD SEE OVERNIGHT TEMPERATURES RISE INTO
THE LOWER 60S BEFORE LEVELING OFF AND LOCATIONS BTWN I-88 AND I-80
SHOULD SEE TEMPS OVERNIGHT IN THE UPPER 50S. FAR NERN IL...CLOSER
TO THE LAKE...WILL REMAIN COOLER AS WINDS SHOULD BE ONSHORE UNTIL
TOMORROW AFTERNOON...WHEN DEEPENING LOW PRESSURE MOVES INTO THE
MISSOURI VALLEY AND THE WARM FRONT SURGES INTO CENTRAL WISCONSIN.
AS THE SFC LOW GETS CLOSER TO THE AREA...FORECAST CONCERNS WILL
SHIFT TO WIND SPEEDS AND THE ONSET OF HEAVIER STEADY RAIN WITH THE
POTENTIAL FOR SOME ISOLATED THUNDERSTORMS. THE LATEST GUIDANCE
SUGGESTS THAT THE AXIS OF HEAVIER RAIN SHOULD SET UP A LITTLE
FARTHER TO THE NORTHWEST THAN PREVIOUSLY ANTICIPATED...BUT STILL
EXPECT STEADY RAIN WITH CATEGORICAL POPS TO APPROACH THE I-39
CORRIDOR DURG THE PRE-DAWN HOURS. EXPECT THE RAIN TO SLOWLY SPREAD
TO THE EAST AND NOT REACH NWRN INDIANA UNTIL THE LATE AFTERNOON OR
EARLY EVENING HOURS. A STRONG SLY LOW LEVEL JET SETTING UP ALONG
THE BAROCLINIC ZONE OF THE COLD FRONT WILL MOVE ACROSS THE AREA
TOMORROW. SUSTAINED WINDS SHOULD STEADILY INCREASE THROUGH THE DAY
TOMORROW AS THE SLY PRESSURE GRADIENT STRENGTHENS AND LOW LEVEL
MIXING ARND RAIN AND ANY THUNDERSTORMS THAT DO MANAGE TO DEVELOP
WILL HELP MIX DOWN STRONGER WINDS FROM THE LOW LEVEL JET...WITH
FREQUENT GUSTS OF 30-35 MPH THROUGH THE DAY TOMORROW. THE LATEST
GUIDANCE IS INDICATING 50KT WINDS ASSOCIATED WITH THE LOW LEVEL
JET...SO OCNL HIGHER GUSTS WILL BE POSSIBLE AS WELL. WITH
PERSISTENT WARM...MOIST ADVECTION EXPECTED TO CONTINUE THROUGH THE
DAY TOMORROW...EXPECT THAT TEMPERATURES SHOULD APPROACH OR EXCEED
RECORD LEVELS...TOPPING OUT IN THE LOWER 60S NORTH OF THE ILLINOIS
OVER MUCH OF THE AREA...WITH TEMPS POSSIBLY PEGGING 65-66F OVER THE
FAR SRN PORTIONS OF THE CWA. THE ANOMALOUS WARMTH SHOULD PERSIST
WELL INTO SUNDAY EVENING...UNTIL THE STRONG COLD FRONT FINALLY
PUSHES THROUGH THE AREA.
KREIN
&&
.LONG TERM...
310 PM CST
SUNDAY NIGHT THROUGH SATURDAY...
THE PRIMARY SURFACE LOW WILL LIFT NORTHEAST ON SUNDAY NIGHT AND
DEEPEN AS IT DOES...FROM NEAR KANSAS CITY IN THE EVENING TO WESTERN
WISCONSIN BY MIDDAY MONDAY. MODEL GUIDANCE IS IN STRONG AGREEMENT
WITH THIS PATH. THE KEY RESULTS WILL BE A WINDY AND MILD SUNDAY
NIGHT...AN AXIS OR TWO OF EFFICIENT WARM SEASON-LIKE RAIN MOVING
OVER SUNDAY NIGHT...AND A WINDY...COOLER...AND SHOWERY MONDAY.
THIS DEEPENING TREND AND THE LOW PATH ON SUNDAY NIGHT WILL RESULT IN
PRESSURE FALLS ENVELOPING THE AREA AND A STOUT SOUTH WIND.
TEMPERATURES LOOK TO HOLD STEADY OR POSSIBLY EVEN RISE THROUGH THE
NIGHT ONCE AGAIN AS THE WARM SECTOR IS REINFORCED. DEW POINTS SHOULD
BE AROUND 60 DEGREES AS WELL...A REMARKABLE 25 DEGREES HIGHER THAN
OUR AVERAGE HIGH TEMPERATURE THIS TIME OF YEAR.
THE DIFFLUENCE ALOFT AND ASSOCIATED LARGE SCALE ASCENT LOOKS TO
SPREAD OVER NORTH CENTRAL ILLINOIS DURING SUNDAY EVENING AND ACROSS
THE ENTIRE AREA OVERNIGHT SUNDAY. PRECIPITABLE WATERS SHOULD BE IN
THE 1.40 INCH PLUS CATEGORY WHICH IS AT RECORD HIGHS FOR THE TIME OF
YEAR. THAT COMBINED WITH WARM CLOUD PROCESSES SHOULD ALLOW FOR
EFFICIENT RAIN PRODUCTION...ALTHOUGH THE STRONGEST FOCUS AT THE NOSE
OF THE 65 KT LOW-LEVEL JET LOOKS TO REMAIN JUST NORTHWEST OF THE
AREA. EVEN WITH THAT BEING THE CASE HAVE STILL GONE A LITTLE HIGHER
THAN A WPC/MODEL RAINFALL AMOUNT BLEND FOR NORTH CENTRAL ILLINOIS
SUNDAY EVENING. IT STILL LOOKS POSSIBLE THAT RAINFALL TOWARD THE
ROCKFORD AREA COULD REACH OR EVEN EXCEED ONE AND A HALF INCHES.
THUNDER POTENTIAL LOOKS SMALLER ACROSS THE REGION THAN
TONIGHT/SUNDAY MORNING DUE TO A HIGHLY SATURATED COLUMN AND MUSHY
LAPSE RATES.
HAVE TRENDED A BIT HIGHER WITH POPS FOR MONDAY AS THE THEME OF
SLOWER-IS-BETTER WITH THIS SYSTEM LOOKS TO BE VERIFYING INTO
MONDAY...ESPECIALLY THROUGH EARLY MONDAY AFTERNOON OR SO WITH THE
UPPER LOW AND WRAPAROUND MOISTURE STILL ACROSS THE AREA. ANY RAIN
SHOWERS SHOULD BECOME MORE SCATTERED INTO LATE IN THE DAY.
TEMPERATURES WILL TAKE A SHARP DROP MONDAY MORNING BUT SHOULD LEVEL
OUT IN THE MID 40S...STILL A WAYS ABOVE NORMAL. WINDS LOOK TO GUST
TO 30 TO 35 MPH AT TIMES DURING THE DAY ADDING A BITE TO THE AIR
ESPECIALLY COMPARED TO RECENT MILD WEATHER.
BEYOND THIS PERIOD IT STILL LOOKS LIKE A MIDWEEK SYSTEM WILL TAKE A
SIMILAR PATH TO ITS PREDECESSOR AND USHER IN MUCH COLDER AIR FOR THE
END OF THE WEEK INTO THE WEEKEND. CONTINUE WITH A LOW CHANCE OF
SHOWERS AHEAD OF ITS COLD FRONT...WHICH NOW WILL INCLUDE THE TUESDAY
NIGHT PERIOD AS WELL. THE BROAD CYCLONIC FLOW AROUND THIS LOOKS TO
SUPPORT COLD ADVECTION AND CLOUDS INTO WEDNESDAY NIGHT AND COULD SEE
A LITTLE BIT OF PATCHY LIGHT SNOW IN NORTHERN AREAS...BUT WITH
FORCING DWINDLING THIS CERTAINLY LOOKS TO BE LIGHT IF IT
MATERIALIZES. FOR TEMPERATURES LATE IN THE WEEK...850MB TEMPERATURES
OF -14C TO -16C LOOK TO SUPPORT AN AIR MASS OF HIGHS STAYING AROUND
OR JUST SHY OF 30 ESPECIALLY BY FRIDAY AND SATURDAY. NIGHTTIME
TEMPERATURES DONT LOOK TO FALL TOO FAR GIVEN THE CONTINUED WIND
FLOW...HOWEVER THAT WIND WILL AGAIN MAKE IT FEEL MUCH COLDER FROM
DECEMBER THUS FAR.
MTF
&&
.CLIMATE...
NEAR RECORD TEMPERATURES ARE FORECAST FOR THE AREA THROUGH
SUNDAY. HERE ARE THE CURRENT RECORD HIGH TEMPERATURES AND WARMEST
LOW TEMPERATURES ON RECORD FOR CHICAGO AND ROCKFORD.
CHICAGO:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 61 (1877) 48 (1968)
DEC 13 67 (1975) 46 (1920)
---------------------------------
ROCKFORD:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 60 (1991) 43 (1968)
DEC 13 57 (1975) 40 (1920)
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* LOW MVFR/IFR CIGS/VIS DROPPING TO LIFR...POSSIBLY VLIFR...BY
EARLY THIS EVENING...THEN IMPROVING OVERNIGHT.
* CHANCE OF SHRA LATE EVENING/OVERNIGHT.
* RAIN DEVELOPING SUNDAY MORNING...CONTINUING THRU SUNDAY NIGHT.
* EASTERLY WINDS UNDER 10KT SHIFTING SOUTHERLY TONIGHT.
* STRONG/GUSTY SOUTH/SOUTHEASTERLY WINDS SUNDAY AFTERNOON INTO
SUNDAY EVENING. CMS
//DISCUSSION...UPDATED 22Z...
WINDS HAVE SHIFTING EASTERLY ACROSS MUCH OF NORTHEAST IL AND FAR
NORTHWEST INDIANA WITH A SLOW DOWNWARD TREND FOR BOTH CIGS AND
VIS. SHORT TERM HRRR INDICATES FOG WITH VIS UNDER 1SM WILL SPREAD
BACK ACROSS ORD/MDW OVER THE NEXT FEW HOURS AND MAINTAINED CURRENT
FORECAST OF TEMPO INTO PREVAILING. HOW LONG THESE LOWER CONDITIONS
PERSIST IS SOMEWHAT UNCERTAIN AS SOUTHERLY WINDS PUSH THE WARM
FRONT BACK NORTH OF MDW LATER THIS EVENING AND OVERNIGHT AT ORD.
THUS THE DURATION COULD BE SHORTER THAN CURRENTLY INDICATED. CMS
PREV DISCUSSION...UPDATED 18Z...
VSBY/CIGS CONTINUE TO SLOWLY IMPROVE LATE THIS MORNING AS WARM
FRONTAL BOUNDARY GRADUALLY SHIFTS NORTHWARD. EXPECT MAINLY IFR
CIGS THROUGH MID AFTERNOON WITH VSBY LOOKING TO PEAK AT MVFR
LEVELS WITH SOME IFR LIKELY LINGERING. A LAKE BOUNDARY WILL PUSH
INLAND LATE THIS AFTERNOON TURNING WINDS NORTHEAST AT ORD/MDW/GYY
WITH DPA/RFD ALSO SEEING A SHIFT TO EAST OR NORTHEAST AS THE WARM
FRONT RE-POSITIONS SOUTHWARD THIS EVENING. THE MAIN CONCERN IS
DENSE FOG MOVING INLAND AS COLD LAKE AIR ENCOUNTERS DEWPOINTS IN
THE MID AND UPPER 50S. EXPECT VSBY TO FAIRLY QUICKLY DROP BELOW
1SM BEHIND THE WIND SHIFT AND ULTIMATELY END UP IN THE 1/4 TO 1/2
SM RANGE BY EARLY EVENING WITH LOWER VSBY POSSIBLE AT TIMES.
TIMING ADJUSTMENTS MAY STILL BE NEEDED WITH LATER TAF UPDATES.
THE FRONT WILL LIFT NORTHWARD AGAIN LATE TONIGHT TURNING WIND
SOUTHERLY AND BRINGING IMPROVEMENT TO VSBY. CIGS MAY REMAIN IFR AS
WELL. SHOWER CHANCES INCREASE WEST AND CANNOT RULE OUT SOME
THUNDER TOO. IFR CIGS MAY CONTINUE THROUGH SUNDAY MORNING WITH
HIGHER SHOWER/THUNDER COVERAGE EXPANDING EASTWARD WITH TIME. SOUTH
WINDS WILL INCREASE MARKEDLY BY AFTERNOON WITH SUSTAINED SPEEDS OF
15-20 KT AND GUSTS OF 25-30 KT POSSIBLE.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM CONFIDENCE FOR CIGS/VIS THIS EVENING...LOW FOR END
TIMING/IMPROVEMENT LATE THIS EVENING/OVERNIGHT.
* MEDIUM FOR SHRA LATER THIS EVENING/OVERNIGHT...LOW FOR TIMING/
DURATION.
* HIGH FOR RAIN DEVELOPING SUNDAY MORNING AND CONTINUING INTO
SUNDAY NIGHT.
* MEDIUM FOR WINDS THRU THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PERIODIC SHRA. IFR LIKELY.
MONDAY...PERIODIC SHRA IN THE MORNING. MVFR CIGS.
TUESDAY...VFR.
WEDNESDAY...SMALL CHANCE OF SHRA/MVFR CIGS.
THURSDAY AND FRIDAY...MVFR CIGS A GOOD BET.
IZZI
&&
.MARINE...
316 PM CST
A FRONTAL BOUNDARY REMAINS DRAPED ACROSS THE FAR SOUTHERN PART OF
THE LAKE LATE SATURDAY AFTERNOON. ALONG AND TO THE SOUTH OF THIS
BOUNDARY IS A HIGHLY ANOMALOUS MOIST AIRMASS FOR THIS TIME OF YEAR.
THAT HAS ALREADY MATERIALIZED IN DENSE FOG ACROSS THE FAR SOUTHERN
PART OF THE LAKE AND ENVISION THAT ONLY THICKENING TONIGHT. ITS
UNCERTAIN IF THAT WILL CREEP NORTHWARD MUCH TONIGHT WITH THE
BOUNDARY NOT EXPECTED TO MOVE MUCH UNTIL LATE IN THE NIGHT. DURING
THE DAY SUNDAY MUCH OF THE LAKE SHOULD SEE FOG...PROBABLY DENSE IN
AREAS. RAIN SHOWER ACTIVITY SHOULD MAINLY HOLD UNTIL AFTER DARK
SUNDAY NIGHT WHICH COMBINED WITH EVEN STRONGER SOUTHERLY WINDS
SHOULD EASE THE THREAT OF DENSE FOG.
INCREASING SOUTHEAST WINDS ON SUNDAY WILL REACH SMALL CRAFT ADVISORY
CRITERIA ALONG THE ILLINOIS AND INDIANA NEARSHORE AREAS. THESE
SHOULD INCREASE EVEN MORE SUNDAY NIGHT AND SPREAD NORTHWARD AS DEEP
LOW PRESSURE MOVES NORTH ACROSS IOWA. A SHARP INVERSION OVER THE
LAKE WILL LIMIT THE MAXIMUM GUST POTENTIAL...BUT A HIGH ENOUGH
SUSTAINED SPEED COULD STILL RESULT IN SOME GUSTS NEARING GALE FORCE.
BEHIND THE COLD FRONT ON MONDAY MORNING INTO THE
AFTERNOON...SOUTHWEST WINDS WILL BE AROUND 30 KT WITH POSSIBLY SOME
SPOTTY GUSTS OF GALE FORCE...AGAIN MAINLY ACROSS THE SOUTH.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ014 UNTIL 3
AM SUNDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-
LMZ777-LMZ779 UNTIL 9 AM SUNDAY.
&&
$$
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WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
304 PM CST SAT DEC 12 2015
.SHORT TERM...(Tonight)
ISSUED AT 304 PM CST SAT DEC 12 2015
Record highs were set in Springfield, Peoria and Lincoln this
afternoon, with Springfield at least reaching 69F and Peoria and
Lincoln reaching at least 67F so far today. A few breaks in the low
clouds along with south winds 8-16 mph and gusts 20-25 mph and a
mild start to the day in the low to mid 50s help set these records.
Temps reached 70F as far north as a Jacksonville to Effingham to
Terre Haute line today while areas north of Peoria reached low to
mid 60s. Record warm lows will likely be set today (Dec 12) as well
and likely again tomorrow (Dec 13). Lows tonight projected to be
close to dewpoints in the upper 50s and lower 60s. These readings
are well above normal lows in the lower 20s central IL and mid
to upper 20s southeast IL.
999 mb surface low pressure over northeast NM and north Texas has a
warm front extending ne into se KS, nw MO and northern IL just south
of I-80 where fog lingers near this boundary. Fog lifted over
northern CWA by midday though broken to overcast low clouds lingered
over central and southeast IL though ceilings lifting to MVFR 1-3k
ft and even VFR above 3k ft. HRRR keeps brunt of fog, including
dense fog, north of central IL tonight as warm front lifts slowly
north toward the WI/IL border by early Sunday morning, while surface
low deepens to 994 mb over the eastern KS/OK border by 15Z/9 am
Sunday. Will have 20-40% chance of showers arriving over western
half of CWA during this evening, then pops increase to likely to
categorical during overnight over IL river valley with isolated
thunderstorms possible west of the IL river by overnight per SPC
day1 outlook. Eastern IL east of I-57 will likely stay dry much of
tonight aside of isolate light rain showers later near I-57.
Rainfall amounts tonight will range from a tenth to quarter inch
over IL river valley and less than a tenth inch along and east of I-
55, with little or no rain tonight from I-57 east. SSE winds 5-15
mph this evening to increase to 10-20 mph during overnight as low
pressure deepens and approaches the Ozarks.
&&
.LONG TERM...(Sunday through Saturday)
ISSUED AT 304 PM CST SAT DEC 12 2015
Models in somewhat better agreement with timing of the pcpn coming
weather system, but still seeing differences where operational ECMWF
is more aggressive and operational NAM is slowest. That puts the GFS
and the Canadian in the middle. Models do look very similar with the
timing of the sfc and upper level fields and features, so have some
confidence in this forecast. Pcpn should be ongoing in the west at
the beginning of tomorrow morning and then continue to move eastward
across the CWA through the day. Southeast parts of the CWA will be
the last to see pcpn and probably will not until sometime in the
late afternoon. Rain should also be moderate to heavy at times and
this will continue into Sun night. Overall QPF amounts with this
system have decreased over the last several days, but looks like now
that over an inch to just over 1.5 inches will be possible west of I-
55, with highest amounts northwest of the Illinois river. Amounts
less than an inch will be likely east of I-55 toward the Indiana
border. Once the low pressure area and upper level system pulls
north into the Great Lakes region, pcpn should come to an end across
the area. Wrap around moisture will keep clouds and lighter pcpn
over the CWA on Monday. But after this, dry weather and decreasing
clouds are expected for Mon night and Tue.
Temps will remain warm Sunday and possible that record highs could
be set again, like today. Temps will decrease for Mon and Tue, but
will still remain above normal for middle Dec. Overnight lows will
also be above normal but be on the decrease from Sun night into Mon
night.
After a brief break in the pcpn with flow remaining out of the
southwest, another weather system will track across the state Tue
night and Wed. This system should be lacking in good moisture with
the best dynamics being northwest of the CWA. This system is
forecast to move quickly through the region, so am sticking with
just slight chance of pcpn over most of the area and chance pcpn in
the central parts for Tue night, and then chance pcpn in the east
and southeast for Wed. Once this weather system moves northeast of
the area, the flow will be changing. Models forecast a mid level
trough to push into the area with cooler high pressure on the sfc.
This will lead to dry weather and cooler temps than what we have
experienced the last week.
Temps will actually drop to below normal for middle Dec for Thur
through Sat. MEX guidance supports cooler, below normal temps, but
believe guidance is too low.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 1159 AM CST SAT DEC 12 2015
Dense fog has lifted along I-74 late this morning and most vsbys
are in the 4-8 mile range at midday, except 2 miles still at BMI.
Vsbys should lift to vfr in next hour or two and some patchy fog
could return again tonight though not as widespread as this
morning due to strong sse winds expected next 24 hours. Ceilings
are 300-500 ft at BMI and PIA while up to 1k ft at DEC and CMI
while after 3k ft (VFR) at SPI. Expect ceilings to gradually lift
over central IL airports to MVFR and even VFR range by mid
afternoon. But IFR to low end MVFR ceilings and MVFR vsbys 3-5
miles to return during tonight into Sunday morning. Most areas
will stay dry tonight with chances of rain showers increasing over
western airports later tonight into Sunday morning while eastern
IL at DEC and CMI likely remains dry through 18Z/Sunday with just
isolated showers possible Sunday morning. SSW winds 10-15 kts with
gusts up to 20 kts this afternoon to veer back to the SSE and
increase to 14-18 kts with gusts 20-24 kts later tonight into
Sunday morning.
&&
.CLIMATE...
ISSUED AT 300 AM CST FRI DEC 10 2015
Record highs for the weekend:
Location Today Sunday
DEC 12 DEC 13
---------- --------- ---------
Bloomington 65 (1896) 63 (1975)
Champaign 62 (1991) 64 (1975)
Charleston 67 (1949) 64 (1991)
Decatur 65 (1929) 66 (1975)
Effingham 67 (1929) 65 (1991)
Lincoln 64 (1929) 64 (1975)
Peoria 62 (1991) 63 (1975)
Springfield 64 (1929) 67 (1948)
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...Auten
AVIATION...07
CLIMATE...Auten
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
221 PM CST SAT DEC 12 2015
.SHORT TERM...
331 AM CST
THROUGH SUNDAY NIGHT...
EXCEEDINGLY TRICKY FORECAST IN THE SHORT TERM...PARTICULARLY WITH
RESPECT TO FOG AND TEMPS.
A SET-UP FAR MORE TYPICAL OF LATE MARCH OR EARLY APRIL WILL PLAY
HAVOC ON TEMP FORECAST AND LIKELY RESULT IN DENSE LAKE FOG
DEVELOPING. WARM FRONT HAS LIFTED NORTH AND LIES JUST NORTH OF I-80
EARLY THIS MORNING. DENSE FOG HAS BEEN PATCHY SO FAR AND CONFINED TO
AREAS MAINLY WEST AND SOUTHWEST OF OUR CWA THUS FAR...HOWEVER SHORT
RANGE GUIDANCE STILL SUGGESTS THAT THE DENSE FOG COULD EXPAND IN
COVERAGE AND IMPACT MAINLY OUR WESTERN AND SOUTHWESTERN COUNTIES
THIS MORNING. WILL TAKE A WAIT AND SEE APPROACH ON THIS GIVEN HOW
LACKLUSTER THIS MORNING`S FOG EVENT HAS BEEN THUS FAR.
WEAK SURFACE LOW OVER IOWA IS PROGGED TO DISSIPATE TODAY WITH
SURFACE CYCLOGENESIS TAKES PLACE OVER THE SOUTHERN HIGH PLAINS.
AS THE LOW WEAKENS...LOOK FOR SURFACE FRONTOLYSIS TO BEGIN WITH
WARMFRONT OVER OUR CWA. AS THE SYNOPTIC FRONT WEAKENS IT WILL OPEN
THE DOOR FOR LAKE MICHIGAN`S CHILLING EFFECTS TO TAKE OVER LATER
THIS AFTERNOON AND EVENING. WEAK AND WEAKENING PRESSURE GRADIENT IN
THE VICINITY OF THE WEAKENING FRONT WILL LIKELY ALLOW A LAKE BREEZE
FRONT TO DEVELOP THIS AFTERNOON DUE IN PART TO THE INCREASINGLY
LARGE THERMAL DIFFERENTIAL BETWEEN CHILLY MARINE AIR MASS OVER THE
LAKE AND UNSEASONABLY WARM AND ALMOST HUMID AIR OVER LAND. AS THE
COOL MARINE AIR ENCOUNTERS 50F+ DEWPOINTS IT APPEARS TO BE A CLASSIC
SET-UP FOR VERY DENSE MARINE FOG TO DEVELOP AND SEEP INLAND THIS
EVENING AS THE CHILLY MARINE AIR ENCOUNTERS NOT MUCH RESISTANCE AND
IT ABLE TO SPREAD PRETTY FAR INLAND. IF IT WEREN`T FOR
UNCERTAINTIES REGARDING TIMING OF FOG STARTING AND ENDING...WOULD
PROBABLY BE ISSUING A DENSE FOG ADVISORY NOW FOR THIS EVENING FOR
PORTIONS OF NE IL. DENSE FOG COULD DEVELOP FARTHER INLAND THIS
EVENING AWAY FROM THE MARINE LAYER...MAINLY NEAR AND TO THE NORTH
OF THE WEAKEN WARM FRONT. CONFIDENCE IN DENSE FOG DEVELOPING HERE
IS LOWER.
MODEL THAT HAS BEEN BEST FITTING THE CONCEPTUAL MODEL OF HOW I
EXPECT THINGS TO EVOLVE TODAY HAS BEEN THE EXPERIMENTAL HRRR AND
HAVE USED A TIME LAGGED ENSEMBLE APPROACH WITH THIS MODEL TO
POPULATE SHORT TERM HOURLY TEMP/DEWPOINT/WIND GRIDS INTO THIS
EVENING. DESPITE CLOUD COVER STILL EXPECT TEMPS TO WARM UP NICELY
TODAY...ESPECIALLY SOUTHERN CWA WHERE THEY ARE SOLIDLY IN THE WARM
SECTOR. WARMING TREND IN TEMPS WILL LIKELY BE ABRUPTLY HALTED NEAR
THE LAKE BY EARLY-MID AFTERNOON WHEN LAKE BREEZE FRONT BEGINS MOVING
INLAND AND KNOCKING TEMPS BACK INTO THE 40S NEAR THE LAKE AND
RESULTING IN FALLING TEMPS EVEN WELL INLAND BY EARLY EVENING. TOUGH
CALL ON HOW QUICKLY TEMPS WILL WARM IN CHICAGO BEFORE LAKE AIR
SPREADS INLAND...BUT EXPERIMENTAL HRRR SUGGESTS ORD WILL PROBABLY
NOT GET MUCH ABOVE MID TO MAYBE UPPER 50S BEFORE TEMPS FALL LATE IN
THE EVENING WITH FOG...PROBABLY DENSE LIKELY TO FOLLOW.
TONIGHT...SOUTHERN PLAINS CYCLONE WILL BEGIN MOVING NORTH AND THE
NOW LAKE RE-ENFORCED WARM FRONT WILL BEGIN TO STRENGTHEN AGAIN AND
STRENGTHENING PRESSURE FALLS SHOULD CAUSE THE FRONT TO BEGIN MOVING
NORTH AGAIN. SHOULD BEHAVE LIKE A TYPICAL MARCH WARM FRONT BECOMING
SOMEWHAT CONTORTED AROUND LAKE MICHIGAN WITH NORTH SHORE AREAS
LIKELY BEING THE LAST AREA IN OUR CWA TO MAKE IT INTO THE WARM
SECTOR. EXPECT FOG TO PRIMARILY BE A PROBLEM AHEAD OF THE WARM FRONT
WITH DRAMATICALLY IMPROVING VISIBILITIES AS THE WARM FRONT LIFTS
NORTHWARD. TEMPS IN THE WARM SECTOR TONIGHT WILL LIKELY HOLD IN THE
UPPER 50S TO LOWER 60S...WITH A RAPID RISE IN TEMPERATURES FROM THE
40S TO NEAR 60 EXPECTED IN THE CHICAGO AREA OVERNIGHT AS THE WARM
FRONT LIFTS NORTH.
PRECIP-WISE...NOT EXPECTED MUCH MEASURABLE PRECIP UNTIL TONIGHT.
COULD BE SOME DRIZZLE WITH THE DENSE MARINE FOG AND HRRR SUGGESTS A
FEW LIGHT SHOWERS LATE THIS AFTERNOON IN VICINITY OF THE WARM FRONT.
TONIGHT...THE MAIN FOCUS FOR SHOWERS AND SOME THUNDERSTORMS LOOKS TO
REMAIN MOSTLY TO THE WEST OF OUR CWA CLOSER TO THE STRONG ISENTROPIC
ASCENT AND NEAR THE NOSE OF THE LOW LEVEL JET. STILL EXPECT SOME OF
THIS SHOWER ACTIVITY TO MAKE IT INTO MAINLY NORTH CENTRAL ILLINOIS
WITH A LESSER THREAT OF SHOWERS OVER THE REMAINDER OF THE CWA.
SUNDAY SHOULD BE WINDY AND UNSEASONABLY WARM WITH A PERIOD OR TWO OF
SHOWERS LIKELY...ESPECIALLY WESTERN AND NORTHERN PORTIONS OF THE
AREA. DEPENDING ON THE COVERAGE OF SHOWERS...WE COULD MAKE A RUN AT
THE RECORD HIGHS FOR THE DAY...THOUGH DECIDED TO KEEP TEMPS SOMEWHAT
CONSERVATIVE IN THE GRIDS FOR NOW WITH MAINLY LOW 60S NORTH AND MID
60S SOUTH. ADDITIONAL SHOWERS ARE EXPECTED SUNDAY NIGHT AS FAIRLY
STRONG COLD FRONT EVENTUALLY MOVES ACROSS THE AREA. MAJORITY OF
SUNDAY NIGHT WILL BE WINDY AND UNSEASONABLY WARM WITH TEMPS CLOSE TO
IF NOT IN THE 60S BEFORE COLD FRONT MOVES THROUGH CLOSER TO DAWN
RESULTING IN LOW TEMPS NOT OCCURRING UNTIL AFTER SUNRISE.
IZZI
&&
.LONG TERM...
331 AM CST
MONDAY THROUGH FRIDAY...
WINDY AND MUCH COOLER WEATHER IS ON TAP FOR MONDAY WITH SHOWERS IN
THE MORNING LIKELY TAPERING OFF AND ENDING BY OR PERHAPS DURING THE
EARLY AFTERNOON. WE SHOULD GET A BRIEF BREAK BETWEEN SYSTEM TUESDAY
WITH DRY CONDITIONS AND CONTINUED ABOVE NORMAL TEMPS...BUT MUCH LESS
SO THAN THIS WEEKEND.
NEXT SYSTEM MOVES THROUGH MIDWEEK...BUT AT THIS POINT LOOKS PRETTY
MOISTURE STARVED AS IT WILL BE FAST ON THE HEELS OF THE WEEKEND
SYSTEM WHICH SHOULD BE PRETTY EFFECTIVE AT SCOURING OUT THE
MOISTURE. IN THE WAKE OF THIS STORM IT LOOKS LIKE WE WILL GET A
TASTE OF MORE TYPICAL DECEMBER TEMPERATURES FOR A FEW DAYS LATER
THIS WEEK INTO THE WEEKEND WITH HIGHS NOT GETTING OUT OF THE 30S. IN
FACT...IF THE ECMWF VERIFIES FRIDAY/SATURDAY MAY NOT EVEN REACH 30F
FOR HIGHS WHICH WILL FEEL VERY COLD AFTER THIS WEEKEND`S NEAR RECORD
WARMTH BUT IN REALITY WILL ONLY BE A FEW DEGREES COLDER THAN NORMAL.
MEDIUM RANGE MODELS SUGGEST THAT THE LONGWAVE TROUGH RESPONSIBLE FOR
THE TASTE OF WINTER WILL BE PROGRESSIVE WITH A MODELS AND CPC BOTH
SUGGESTING A RETURN TO ABOVE AVERAGE TEMPERATURES CHRISTMAS WEEK.
IZZI
&&
.CLIMATE...
NEAR RECORD TEMPERATURES ARE FORECAST FOR THE AREA THROUGH
SUNDAY. HERE ARE THE CURRENT RECORD HIGH TEMPERATURES AND WARMEST
LOW TEMPERATURES ON RECORD FOR CHICAGO AND ROCKFORD.
CHICAGO:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 61 (1877) 48 (1968)
DEC 13 67 (1975) 46 (1920)
---------------------------------
ROCKFORD:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 60 (1991) 43 (1968)
DEC 13 57 (1975) 40 (1920)
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* MVFR CONDITIONS DROPPING BACK TO IFR LATE TODAY AND LIFR
TONIGHT...RIGHT NOW SLIGHTLY MORE FAVORED DROPPING TO LIFR EARLY
THIS EVENING.
* WINDS SHIFT NORTHEAST AT BOTH AIRPORTS LATE THIS AFTERNOON BUT
GENERALLY REMAIN LIGHT. VISIBILITY OF 3/4SM OR LESS EXPECTED
WITH TIMING OF SHIFT STILL THE MAIN QUESTION.
* VISIBILITY IMPROVES AS WINDS TURN SOUTHERLY OVERNIGHT OR EARLY
MONDAY MORNING.
* GUSTY SOUTHWEST WINDS AND SHOWERS EXPECTED SUNDAY WITH IFR CIGS
POTENTIALLY CONTINUING.
MDB/MTF
//DISCUSSION...UPDATED 20Z...
THE FRONTAL BOUNDARY AS OF 20Z REMAINS DRAPED FROM WEST-TO-EAST
JUST NORTH OF I-88...VERY CLOSE TO ORD...AND THROUGH DOWNTOWN
CHICAGO. ALONG AND NORTH OF THIS WILL BE MOST FAVORED FOR DENSE
FOG BY EARLY EVENING...HOWEVER THE MARINE INDUCED FOG REMAINS A
WILDCARD. IF THAT CAN SPREAD INLAND THAT WILL IMPACT MDW AND ORD
FAIRLY QUICKLY TOWARD SUNSET. WEBCAMS CONTINUE TO INDICATE LIFR
CIGS AND IFR /AT TIMES LIFR/ VISIBILITY NEAR THE LAKE FRONT. WILL
CONTINUE TO MONITOR BUT AT THIS TIME HAVE INCHED BACK THE START OF
THE LOWEST CIGS/VISBYS AT ORD/MDW.
MTF
PREV DISCUSSION...UPDATED 18Z...
VSBY/CIGS CONTINUE TO SLOWLY IMPROVE LATE THIS MORNING AS WARM
FRONTAL BOUNDARY GRADUALLY SHIFTS NORTHWARD. EXPECT MAINLY IFR
CIGS THROUGH MID AFTERNOON WITH VSBY LOOKING TO PEAK AT MVFR
LEVELS WITH SOME IFR LIKELY LINGERING. A LAKE BOUNDARY WILL PUSH
INLAND LATE THIS AFTERNOON TURNING WINDS NORTHEAST AT ORD/MDW/GYY
WITH DPA/RFD ALSO SEEING A SHIFT TO EAST OR NORTHEAST AS THE WARM
FRONT RE-POSITIONS SOUTHWARD THIS EVENING. THE MAIN CONCERN IS
DENSE FOG MOVING INLAND AS COLD LAKE AIR ENCOUNTERS DEWPOINTS IN
THE MID AND UPPER 50S. EXPECT VSBY TO FAIRLY QUICKLY DROP BELOW
1SM BEHIND THE WIND SHIFT AND ULTIMATELY END UP IN THE 1/4 TO 1/2
SM RANGE BY EARLY EVENING WITH LOWER VSBY POSSIBLE AT TIMES.
TIMING ADJUSTMENTS MAY STILL BE NEEDED WITH LATER TAF UPDATES.
THE FRONT WILL LIFT NORTHWARD AGAIN LATE TONIGHT TURNING WIND
SOUTHERLY AND BRINGING IMPROVEMENT TO VSBY. CIGS MAY REMAIN IFR AS
WELL. SHOWER CHANCES INCREASE WEST AND CANNOT RULE OUT SOME
THUNDER TOO. IFR CIGS MAY CONTINUE THROUGH SUNDAY MORNING WITH
HIGHER SHOWER/THUNDER COVERAGE EXPANDING EASTWARD WITH TIME. SOUTH
WINDS WILL INCREASE MARKEDLY BY AFTERNOON WITH SUSTAINED SPEEDS OF
15-20 KT AND GUSTS OF 25-30 KT POSSIBLE.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN CIG/VSBY TRENDS TIL 23Z. LOW CONFIDENCE FROM
23Z THROUGH 02Z. MEDIUM CONFIDENCE AFTER THAT POINT.
* MEDIUM CONFIDENCE IN VISIBILITY FALLING TO 3/4SM OR LESS LATE
EARLY-MIDDLE THIS EVENING. LOW IN SPECIFIC TIMING.
* MEDIUM-HIGH CONFIDENCE IN VISIBILITY IMPROVING LATE TONIGHT BUT
LOW-MEDIUM CONFIDENCE IN TIMING AND MAGNITUDE. MEDIUM
CONFIDENCE IN WIND GUSTS SUNDAY. LOW-MEDIUM CONFIDENCE IN CIG
HEIGHTS SUNDAY.
MDB/MTF
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PERIODIC SHRA. IFR LIKELY.
MONDAY...PERIODIC SHRA IN THE MORNING. MVFR CIGS.
TUESDAY...VFR.
WEDNESDAY...SMALL CHANCE OF SHRA/MVFR CIGS.
THURSDAY AND FRIDAY...MVFR CIGS A GOOD BET.
IZZI
&&
.MARINE...
301 AM CST
A DENSE FOG ADVISORY WILL LIKELY BE NEEDED FOR THE SOUTHERN HALF OF
THE LAKE TODAY. HOWEVER...I HAVE LOW CONFIDENCE IN WHEN THE DENSE
FOG WILL DEVELOP AND HOW LONG IT WILL PERSIST INTO THIS AFTERNOON OR
EVENING SO I WILL NOT BE ISSUING A DENSE FOG ADVISORY NOW. BOATERS
SHOULD BE PREPARED FOR DENSE FOG AND SEVERELY REDUCED VISIBILITIES.
A WEAKENING LOW IS OVER IOWA AND THE LOW WILL WEAKEN BEFORE ENTERING
ILLINOIS TODAY. A WARM FRONT LIES JUST SOUTH OF THE THIS MORNING AND
WILL SHIFT NORTH BUT REMAIN OVER THE SOUTHERN END OF THE LAKE
THROUGH SUNDAY. DENSE FOG IS EXPECTED TO FORM BEHIND THE FRONT. A
LAKE BREEZE WILL LIKELY FORM THIS AFTERNOON ALONG THE IL SHORE. THE
NEXT LOW FORMS OVER THE SOUTHERN PLAINS EARLY SUNDAY MORNING WITH
WINDS BECOMING SOUTHEAST ACROSS THE SOUTHERN HALF OF THE LAKE. EAST
WINDS TO 30 KT ARE EXPECTED ACROSS THE NORTHERN HALF OF THE LAKE.
SOUTHEAST WINDS INCREASE TO 30 KT SUNDAY. A SMALL CRAFT ADVISORY
WILL BE NEEDED FOR SUNDAY POTENTIALLY THROUGH MONDAY
EVENING...HOWEVER THERE MAY BE A PERIOD OF GALES MONDAY SO WILL HOLD
OFF ON ISSUING A SMALL CRAFT ADVISORY NOW.
SOUTHEAST WINDS INCREASE TO LOW END GALES SUNDAY NIGHT. THE LOW
SHIFTS NORTH OVER WISCONSIN MONDAY WITH SOUTH TO SOUTHWEST GALES
MAINLY OVER THE SOUTHERN END OF THE LAKE. MAY SEE A FEW GALE FORCE
GUSTS ACROSS THE NORTHERN END. THE LOW PASSES OVER THE NORTHERN END
OF THE LAKE MONDAY EVENING AND NIGHT WITH WINDS BECOMING WEST BEHIND
IT. THE NEXT LOW FORMS OVER THE PLAINS TUESDAY. GUIDANCE SUGGESTS
THIS LOW WILL HAVE A SIMILAR PATH TO THE LOW THIS WEEKEND OR SHIFT
NORTH ACROSS MINNESOTA. EITHER WAY SOUTH TO SOUTHWEST WINDS
INCREASE TO AT LEAST 30 KT WEDNESDAY WITH GALES POSSIBLE ACROSS THE
SOUTHERN HALF OF THE LAKE. ANOTHER SMALL CRAFT ADVISORY MAY BE
NEEDED AS WELL. WEST WINDS 15-25 KT ARE THEN EXPECTED THROUGH LATE
NEXT WEEK.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ003-ILZ004-ILZ005 UNTIL 6 PM SATURDAY.
DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL MIDNIGHT SUNDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-
LMZ777-LMZ779 UNTIL 9 AM SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1145 AM CST SAT DEC 12 2015
.SHORT TERM...
331 AM CST
THROUGH SUNDAY NIGHT...
EXCEEDINGLY TRICKY FORECAST IN THE SHORT TERM...PARTICULARLY WITH
RESPECT TO FOG AND TEMPS.
A SET-UP FAR MORE TYPICAL OF LATE MARCH OR EARLY APRIL WILL PLAY
HAVOC ON TEMP FORECAST AND LIKELY RESULT IN DENSE LAKE FOG
DEVELOPING. WARM FRONT HAS LIFTED NORTH AND LIES JUST NORTH OF I-80
EARLY THIS MORNING. DENSE FOG HAS BEEN PATCHY SO FAR AND CONFINED TO
AREAS MAINLY WEST AND SOUTHWEST OF OUR CWA THUS FAR...HOWEVER SHORT
RANGE GUIDANCE STILL SUGGESTS THAT THE DENSE FOG COULD EXPAND IN
COVERAGE AND IMPACT MAINLY OUR WESTERN AND SOUTHWESTERN COUNTIES
THIS MORNING. WILL TAKE A WAIT AND SEE APPROACH ON THIS GIVEN HOW
LACKLUSTER THIS MORNING`S FOG EVENT HAS BEEN THUS FAR.
WEAK SURFACE LOW OVER IOWA IS PROGGED TO DISSIPATE TODAY WITH
SURFACE CYCLOGENESIS TAKES PLACE OVER THE SOUTHERN HIGH PLAINS.
AS THE LOW WEAKENS...LOOK FOR SURFACE FRONTOLYSIS TO BEGIN WITH
WARMFRONT OVER OUR CWA. AS THE SYNOPTIC FRONT WEAKENS IT WILL OPEN
THE DOOR FOR LAKE MICHIGAN`S CHILLING EFFECTS TO TAKE OVER LATER
THIS AFTERNOON AND EVENING. WEAK AND WEAKENING PRESSURE GRADIENT IN
THE VICINITY OF THE WEAKENING FRONT WILL LIKELY ALLOW A LAKE BREEZE
FRONT TO DEVELOP THIS AFTERNOON DUE IN PART TO THE INCREASINGLY
LARGE THERMAL DIFFERENTIAL BETWEEN CHILLY MARINE AIR MASS OVER THE
LAKE AND UNSEASONABLY WARM AND ALMOST HUMID AIR OVER LAND. AS THE
COOL MARINE AIR ENCOUNTERS 50F+ DEWPOINTS IT APPEARS TO BE A CLASSIC
SET-UP FOR VERY DENSE MARINE FOG TO DEVELOP AND SEEP INLAND THIS
EVENING AS THE CHILLY MARINE AIR ENCOUNTERS NOT MUCH RESISTANCE AND
IT ABLE TO SPREAD PRETTY FAR INLAND. IF IT WEREN`T FOR
UNCERTAINTIES REGARDING TIMING OF FOG STARTING AND ENDING...WOULD
PROBABLY BE ISSUING A DENSE FOG ADVISORY NOW FOR THIS EVENING FOR
PORTIONS OF NE IL. DENSE FOG COULD DEVELOP FARTHER INLAND THIS
EVENING AWAY FROM THE MARINE LAYER...MAINLY NEAR AND TO THE NORTH
OF THE WEAKEN WARM FRONT. CONFIDENCE IN DENSE FOG DEVELOPING HERE
IS LOWER.
MODEL THAT HAS BEEN BEST FITTING THE CONCEPTUAL MODEL OF HOW I
EXPECT THINGS TO EVOLVE TODAY HAS BEEN THE EXPERIMENTAL HRRR AND
HAVE USED A TIME LAGGED ENSEMBLE APPROACH WITH THIS MODEL TO
POPULATE SHORT TERM HOURLY TEMP/DEWPOINT/WIND GRIDS INTO THIS
EVENING. DESPITE CLOUD COVER STILL EXPECT TEMPS TO WARM UP NICELY
TODAY...ESPECIALLY SOUTHERN CWA WHERE THEY ARE SOLIDLY IN THE WARM
SECTOR. WARMING TREND IN TEMPS WILL LIKELY BE ABRUPTLY HALTED NEAR
THE LAKE BY EARLY-MID AFTERNOON WHEN LAKE BREEZE FRONT BEGINS MOVING
INLAND AND KNOCKING TEMPS BACK INTO THE 40S NEAR THE LAKE AND
RESULTING IN FALLING TEMPS EVEN WELL INLAND BY EARLY EVENING. TOUGH
CALL ON HOW QUICKLY TEMPS WILL WARM IN CHICAGO BEFORE LAKE AIR
SPREADS INLAND...BUT EXPERIMENTAL HRRR SUGGESTS ORD WILL PROBABLY
NOT GET MUCH ABOVE MID TO MAYBE UPPER 50S BEFORE TEMPS FALL LATE IN
THE EVENING WITH FOG...PROBABLY DENSE LIKELY TO FOLLOW.
TONIGHT...SOUTHERN PLAINS CYCLONE WILL BEGIN MOVING NORTH AND THE
NOW LAKE RE-ENFORCED WARM FRONT WILL BEGIN TO STRENGTHEN AGAIN AND
STRENGTHENING PRESSURE FALLS SHOULD CAUSE THE FRONT TO BEGIN MOVING
NORTH AGAIN. SHOULD BEHAVE LIKE A TYPICAL MARCH WARM FRONT BECOMING
SOMEWHAT CONTORTED AROUND LAKE MICHIGAN WITH NORTH SHORE AREAS
LIKELY BEING THE LAST AREA IN OUR CWA TO MAKE IT INTO THE WARM
SECTOR. EXPECT FOG TO PRIMARILY BE A PROBLEM AHEAD OF THE WARM FRONT
WITH DRAMATICALLY IMPROVING VISIBILITIES AS THE WARM FRONT LIFTS
NORTHWARD. TEMPS IN THE WARM SECTOR TONIGHT WILL LIKELY HOLD IN THE
UPPER 50S TO LOWER 60S...WITH A RAPID RISE IN TEMPERATURES FROM THE
40S TO NEAR 60 EXPECTED IN THE CHICAGO AREA OVERNIGHT AS THE WARM
FRONT LIFTS NORTH.
PRECIP-WISE...NOT EXPECTED MUCH MEASURABLE PRECIP UNTIL TONIGHT.
COULD BE SOME DRIZZLE WITH THE DENSE MARINE FOG AND HRRR SUGGESTS A
FEW LIGHT SHOWERS LATE THIS AFTERNOON IN VICINITY OF THE WARM FRONT.
TONIGHT...THE MAIN FOCUS FOR SHOWERS AND SOME THUNDERSTORMS LOOKS TO
REMAIN MOSTLY TO THE WEST OF OUR CWA CLOSER TO THE STRONG ISENTROPIC
ASCENT AND NEAR THE NOSE OF THE LOW LEVEL JET. STILL EXPECT SOME OF
THIS SHOWER ACTIVITY TO MAKE IT INTO MAINLY NORTH CENTRAL ILLINOIS
WITH A LESSER THREAT OF SHOWERS OVER THE REMAINDER OF THE CWA.
SUNDAY SHOULD BE WINDY AND UNSEASONABLY WARM WITH A PERIOD OR TWO OF
SHOWERS LIKELY...ESPECIALLY WESTERN AND NORTHERN PORTIONS OF THE
AREA. DEPENDING ON THE COVERAGE OF SHOWERS...WE COULD MAKE A RUN AT
THE RECORD HIGHS FOR THE DAY...THOUGH DECIDED TO KEEP TEMPS SOMEWHAT
CONSERVATIVE IN THE GRIDS FOR NOW WITH MAINLY LOW 60S NORTH AND MID
60S SOUTH. ADDITIONAL SHOWERS ARE EXPECTED SUNDAY NIGHT AS FAIRLY
STRONG COLD FRONT EVENTUALLY MOVES ACROSS THE AREA. MAJORITY OF
SUNDAY NIGHT WILL BE WINDY AND UNSEASONABLY WARM WITH TEMPS CLOSE TO
IF NOT IN THE 60S BEFORE COLD FRONT MOVES THROUGH CLOSER TO DAWN
RESULTING IN LOW TEMPS NOT OCCURRING UNTIL AFTER SUNRISE.
IZZI
&&
.LONG TERM...
331 AM CST
MONDAY THROUGH FRIDAY...
WINDY AND MUCH COOLER WEATHER IS ON TAP FOR MONDAY WITH SHOWERS IN
THE MORNING LIKELY TAPERING OFF AND ENDING BY OR PERHAPS DURING THE
EARLY AFTERNOON. WE SHOULD GET A BRIEF BREAK BETWEEN SYSTEM TUESDAY
WITH DRY CONDITIONS AND CONTINUED ABOVE NORMAL TEMPS...BUT MUCH LESS
SO THAN THIS WEEKEND.
NEXT SYSTEM MOVES THROUGH MIDWEEK...BUT AT THIS POINT LOOKS PRETTY
MOISTURE STARVED AS IT WILL BE FAST ON THE HEELS OF THE WEEKEND
SYSTEM WHICH SHOULD BE PRETTY EFFECTIVE AT SCOURING OUT THE
MOISTURE. IN THE WAKE OF THIS STORM IT LOOKS LIKE WE WILL GET A
TASTE OF MORE TYPICAL DECEMBER TEMPERATURES FOR A FEW DAYS LATER
THIS WEEK INTO THE WEEKEND WITH HIGHS NOT GETTING OUT OF THE 30S. IN
FACT...IF THE ECMWF VERIFIES FRIDAY/SATURDAY MAY NOT EVEN REACH 30F
FOR HIGHS WHICH WILL FEEL VERY COLD AFTER THIS WEEKEND`S NEAR RECORD
WARMTH BUT IN REALITY WILL ONLY BE A FEW DEGREES COLDER THAN NORMAL.
MEDIUM RANGE MODELS SUGGEST THAT THE LONGWAVE TROUGH RESPONSIBLE FOR
THE TASTE OF WINTER WILL BE PROGRESSIVE WITH A MODELS AND CPC BOTH
SUGGESTING A RETURN TO ABOVE AVERAGE TEMPERATURES CHRISTMAS WEEK.
IZZI
&&
.CLIMATE...
NEAR RECORD TEMPERATURES ARE FORECAST FOR THE AREA THROUGH
SUNDAY. HERE ARE THE CURRENT RECORD HIGH TEMPERATURES AND WARMEST
LOW TEMPERATURES ON RECORD FOR CHICAGO AND ROCKFORD.
CHICAGO:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 61 (1877) 48 (1968)
DEC 13 67 (1975) 46 (1920)
---------------------------------
ROCKFORD:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 60 (1991) 43 (1968)
DEC 13 57 (1975) 40 (1920)
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* IFR CIGS LIKELY PREVAILING THROUGH MID AFTERNOON WITH SOME MVFR
BREAKS POSSIBLE. IFR/MVFR VSBY THROUGH MID AFTERNOON.
* WINDS SHIFT NORTHEAST LATE THIS AFTERNOON BRINGING DENSE FOG
INLAND. VSBY OF 1/2SM OR LESS EXPECTED WITH TIMING STILL THE
MAIN QUESTION.
* VSBY IMPROVES AS WINDS TURN SOUTHERLY OVERNIGHT. GUSTY SOUTHWEST
WINDS AND SHOWERS EXPECTED SUNDAY WITH IFR CIGS POTENTIALLY
CONTINUING.
MDB
//DISCUSSION...UPDATED 18Z...
VSBY/CIGS CONTINUE TO SLOWLY IMPROVE LATE THIS MORNING AS WARM
FRONTAL BOUNDARY GRADUALLY SHIFTS NORTHWARD. EXPECT MAINLY IFR
CIGS THROUGH MID AFTERNOON WITH VSBY LOOKING TO PEAK AT MVFR
LEVELS WITH SOME IFR LIKELY LINGERING. A LAKE BOUNDARY WILL PUSH
INLAND LATE THIS AFTERNOON TURNING WINDS NORTHEAST AT ORD/MDW/GYY
WITH DPA/RFD ALSO SEEING A SHIFT TO EAST OR NORTHEAST AS THE WARM
FRONT RE-POSITIONS SOUTHWARD THIS EVENING. THE MAIN CONCERN IS
DENSE FOG MOVING INLAND AS COLD LAKE AIR ENCOUNTERS DEWPOINTS IN
THE MID AND UPPER 50S. EXPECT VSBY TO FAIRLY QUICKLY DROP BELOW
1SM BEHIND THE WIND SHIFT AND ULTIMATELY END UP IN THE 1/4 TO 1/2
SM RANGE BY EARLY EVENING WITH LOWER VSBY POSSIBLE AT TIMES.
TIMING ADJUSTMENTS MAY STILL BE NEEDED WITH LATER TAF UPDATES.
THE FRONT WILL LIFT NORTHWARD AGAIN LATE TONIGHT TURNING WIND
SOUTHERLY AND BRINGING IMPROVEMENT TO VSBY. CIGS MAY REMAIN IFR AS
WELL. SHOWER CHANCES INCREASE WEST AND CANNOT RULE OUT SOME
THUNDER TOO. IFR CIGS MAY CONTINUE THROUGH SUNDAY MORNING WITH
HIGHER SHOWER/THUNDER COVERAGE EXPANDING EASTWARD WITH TIME. SOUTH
WINDS WILL INCREASE MARKEDLY BY AFTERNOON WITH SUSTAINED SPEEDS OF
15-20 KT AND GUSTS OF 25-30 KT POSSIBLE.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN CIG/VSBY TRENDS TIL 22Z. LOW CONFIDENCE IN
ANY MVFR CIG BREAKS OCCURRING. MEDIUM-HIGH CONFIDENCE IN VSBY
BEING MVFR OR LESS TIL 22Z.
* HIGH CONFIDENCE IN TIMING OF WINDS SHIFTING NORTHEAST LATE THIS
AFTERNOON.
* HIGH CONFIDENCE IN VSBY FALLING TO 1/2SM OR LESS LATE THIS
AFTERNOON/EARLY THIS EVENING. MEDIUM-HIGH CONFIDENCE VSBY
REDUCTIONS BEGINNING IN THE 22-00Z TIME FRAME BUT MEDIUM
CONFIDENCE IN HOW MUCH SUB 1SM VSBY OCCURS DURING THIS TIME.
HIGHER CONFIDENCE IN LOWEST VSBY 00Z AND AFTER.
* MEDIUM-HIGH CONFIDENCE IN VSBY IMPROVING LATE TONIGHT BUT LOW-
MEDIUM CONFIDENCE IN TIMING AND MAGNITUDE. MEDIUM CONFIDENCE IN
WIND GUSTS SUNDAY. LOW-MEDIUM CONFIDENCE IN CIG HEIGHTS SUNDAY.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PERIODIC SHRA. IFR LIKELY.
MONDAY...PERIODIC SHRA IN THE MORNING. MVFR CIGS.
TUESDAY...VFR.
WEDNESDAY...SMALL CHANCE OF SHRA/MVFR CIGS.
THURSDAY AND FRIDAY...MVFR CIGS A GOOD BET.
IZZI
&&
.MARINE...
301 AM CST
A DENSE FOG ADVISORY WILL LIKELY BE NEEDED FOR THE SOUTHERN HALF OF
THE LAKE TODAY. HOWEVER...I HAVE LOW CONFIDENCE IN WHEN THE DENSE
FOG WILL DEVELOP AND HOW LONG IT WILL PERSIST INTO THIS AFTERNOON OR
EVENING SO I WILL NOT BE ISSUING A DENSE FOG ADVISORY NOW. BOATERS
SHOULD BE PREPARED FOR DENSE FOG AND SEVERELY REDUCED VISIBILITIES.
A WEAKENING LOW IS OVER IOWA AND THE LOW WILL WEAKEN BEFORE ENTERING
ILLINOIS TODAY. A WARM FRONT LIES JUST SOUTH OF THE THIS MORNING AND
WILL SHIFT NORTH BUT REMAIN OVER THE SOUTHERN END OF THE LAKE
THROUGH SUNDAY. DENSE FOG IS EXPECTED TO FORM BEHIND THE FRONT. A
LAKE BREEZE WILL LIKELY FORM THIS AFTERNOON ALONG THE IL SHORE. THE
NEXT LOW FORMS OVER THE SOUTHERN PLAINS EARLY SUNDAY MORNING WITH
WINDS BECOMING SOUTHEAST ACROSS THE SOUTHERN HALF OF THE LAKE. EAST
WINDS TO 30 KT ARE EXPECTED ACROSS THE NORTHERN HALF OF THE LAKE.
SOUTHEAST WINDS INCREASE TO 30 KT SUNDAY. A SMALL CRAFT ADVISORY
WILL BE NEEDED FOR SUNDAY POTENTIALLY THROUGH MONDAY
EVENING...HOWEVER THERE MAY BE A PERIOD OF GALES MONDAY SO WILL HOLD
OFF ON ISSUING A SMALL CRAFT ADVISORY NOW.
SOUTHEAST WINDS INCREASE TO LOW END GALES SUNDAY NIGHT. THE LOW
SHIFTS NORTH OVER WISCONSIN MONDAY WITH SOUTH TO SOUTHWEST GALES
MAINLY OVER THE SOUTHERN END OF THE LAKE. MAY SEE A FEW GALE FORCE
GUSTS ACROSS THE NORTHERN END. THE LOW PASSES OVER THE NORTHERN END
OF THE LAKE MONDAY EVENING AND NIGHT WITH WINDS BECOMING WEST BEHIND
IT. THE NEXT LOW FORMS OVER THE PLAINS TUESDAY. GUIDANCE SUGGESTS
THIS LOW WILL HAVE A SIMILAR PATH TO THE LOW THIS WEEKEND OR SHIFT
NORTH ACROSS MINNESOTA. EITHER WAY SOUTH TO SOUTHWEST WINDS
INCREASE TO AT LEAST 30 KT WEDNESDAY WITH GALES POSSIBLE ACROSS THE
SOUTHERN HALF OF THE LAKE. ANOTHER SMALL CRAFT ADVISORY MAY BE
NEEDED AS WELL. WEST WINDS 15-25 KT ARE THEN EXPECTED THROUGH LATE
NEXT WEEK.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL NOON
SATURDAY.
DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL MIDNIGHT SUNDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-
LMZ777-LMZ779 UNTIL 9 AM SUNDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
356 PM CST SAT DEC 12 2015
.SYNOPSIS...
ISSUED AT 354 PM CST SAT DEC 12 2015
SFC WARM FRONT BISECTING CWA FROM SW TO NE ROUGHLY NEAR WASHINGTON
IA...TO QUAD CITIES...TO STERLING IL AXIS AT MID AFTN. TO SOUTH
OF THE FRONT NEAR RECORD WARMTH WITH HIGHS IN THE 60S WHILE TO THE
NORTH OF THE FRONT NOT AS WARM BUT STILL WELL ABOVE AVERAGE WITH
TEMPS RANGING FROM THE MID/UPPER 40S PORTIONS OF HWY 20 WHERE
AREAS OF FOG STILL BEING FOUND...TO THE MID/UPPER 50S NEAR HWY 30.
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL LOW SHIFTING EAST FROM
AZ INTO NM... WITH PLENTY OF MOISTURE WITH BOTH GULF AND PACIFIC
FEEDS STREAMING NORTHWARD.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 354 PM CST SAT DEC 12 2015
FRONTAL BOUNDARY TO STALL THIS EVE THEN BEGIN TO LIFT NWD OVRNGT
IN RESPONSE TO SFC LOW EMERGING AND STRENGTHENING IN THE SOUTHERN
PLAINS. MAY SEE SOME DENSE FOG REDEVELOP OR EXPAND NEAR/NORTH
OF THE FRONT THIS EVE AHEAD OF THE RAIN... AND SOMETHING TO WATCH
FOR POSSIBLE ADVISORY. DEEPER MOISTURE HAS BEEN SLOWER TO ARRIVE
THUS TIMING OF POPS DELAYED SOME BUT DO ANTICIPATE ATLEAST
SCATTERED SHOWERS DEVELOPING THIS EVENING INTO THE OVRNGT
NEAR/NORTH OF WARM FRONT WITH WARM ADVECTION... WITH BEST COVERAGE
FAVORED OVER NORTHWEST 1/3RD. WITH SLOWER ARRIVAL OF DEEPER MOISTURE
MEANS A BIT MORE MID LEVEL DRY AIR WHICH ALONG WITH STEEP LAPSE
RATES AND ELEVATED CAPE SUPPORTIVE OF AT LEAST ISOLD STORMS. CANT
RULE OUT SOME HAIL IN STRONGER CELLS WITH WBZ 9-10KFT AGL AND IF
SUFFICIENT MID LEVEL DRY AIR. LATE TONIGHT EXPECT SIGNIFICANT
RAMPING UP OF BOTH COVERAGE AND INTENSITY WITH STRONG CONVERGENCE ON
NOSE OF 60+ KT LOW LEVEL JET. POSSIBLY MORE COVERAGE OF STORMS TO
SCATTERED BASIS WITH CONTINUED POSSIBILITY FOR SOME HAIL IN
STRONGER CELLS AND BANKING ON ENOUGH BL STABILIZATION FOR LIMITED SFC
BASED POTENTIAL.
TEMPS SHOULD DROP A LITTLE INTO EARLY THIS EVE BEFORE STEADYING OUT
THEN EVEN RISING A BIT WITH WARM FRONT.
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 354 PM CST SAT DEC 12 2015
MAIN FORECAST CONCERN FOR THE LONG TERM WILL BE THE ONGOING RAIN AND
ISOLATED THUNDER ACROSS THE AREA AT 12Z TOMORROW. THE BEST CHANCES
FOR HEAVY RAIN APPEAR TO BE IN THE MORNING THEN AGAIN TOMORROW
EVENING AND OVERNIGHT. RAINFALL TOTALS OF 1 TO 3 INCHES APPEARS
POSSIBLE. SOME AREAS MAY SEE LOCALLY HIGHER AMOUNTS.
OVERALL TREND IN THE GUIDANCE IS FOR A SLOWING DOWN SYSTEM. THE NAM
SEEMS TO BE HANDLING THE CURRENT LOCATION OF THE MOISTURE WELL. THE
SPECTRAL MODELS APPEARS TO BE CREATING LARGER AREAS OF PRECIP ALONG
WITH A FASTER MOVEMENT. OVERALL CONSENSUS EXISTS BETWEEN THE
GUIDANCE THAT A STRONG H85 JET TERMINUS WILL BE OVER THE AREA AT 12Z
AND MOVE TO THE EAST THROUGH THE DAY. THIS JET...PAIRED WITH A
SLOWER SYSTEM SUGGESTS THAT A BETTER CHANCE FOR THUNDERSTORMS AND
RAIN EXISTS IN THE MORNING AS THE JET MOVES THROUGH THE AREA. STRONG
LOW LEVEL SHEAR ALONG WITH DEEP LAYER SHEAR WILL LEAD TO STRONGER
UPDRAFTS IN ANY CONVECTIVE ELEMENTS. THE ADDITIONAL FORCING ALONG
THE NOSE OF THE JET SHOULD BE ENOUGH FOR ISOLATED THUNDER AS STRONG
ENOUGH UPDRAFTS SHOULD BRING SUPER COOLED WATER INTO THE MIXED PHASE
REGION OF THE STORMS...LEADING TO CHARGE SEPARATION FOR IC
LIGHTNING. THE THUNDER THREAT SHOULD MIGRATE NORTH AND EAST THROUGH
THE MORNING ALONG THE NOSE OF THE H85 JET.
THE NAM...HIRES MODELS AND GFS 20 KM MODELS SUGGEST A LULL IN THE
ACTIVITY TOMORROW LATE MORNING THROUGH THE AFTERNOON. THEN ANOTHER
SHOT OF RAIN STARTS UP. BETWEEN 21Z SUNDAY AND 06Z MONDAY IT
APPEARS THAT THE HEAVIEST RAIN WILL FALL. THIS GRADUALLY MOVE TO
THE NORTH AS THE CLEAR SLOT WORKS ITS WAY IN. GUIDANCE HAS BEEN
CONSISTENT WITH THE LACK OF COLD AIR ROTATING IN BEHIND THIS SYSTEM.
THIS MEANS THAT RAIN WILL BE THE MAIN PRECIP TYPE. WHEN EVERYTHING
IS SAID AND DONE WE COULD SEE 1 TO 3 INCHES WITH ISOLATED HIGHER
AMOUNTS POSSIBLE. WITH ALL OF THE RAINFALL WE HAVE HAD AND FORECAST
WE MAY START TO SEE HYDRO CONCERNS ON AREA RIVERS.
ONCE THIS SYSTEM MOVES THROUGH...ANOTHER VORT MAX ROTATES THROUGH
THE PLAINS. TEMPERATURES ARE COOLER AND IT LOOKS LIKE WE MAY SEE A
RAIN/SNOW MIX ACROSS THE NORTH TUESDAY NIGHT INTO WEDNESDAY. ON
WEDNESDAY...TEMPS WARM ENOUGH TO CAUSE ANY PRECIP TO BE ALL RAIN.
ONCE THIS SYSTEM MOVES THROUGH. COOLER AIR...MORE SEASONABLE
AIR...MAKES ITS WAY INTO THE AREA FOR LATER THIS WEEK AND NEXT
WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 354 PM CST SAT DEC 12 2015
FRONT TO STALL THIS EVENING THEN LIFT NORTH OVERNIGHT AS WARM
FRONT WITH LOW PRESSURE MOVING INTO THE PLAINS. LIKELY WILL
SEE CONDITIONS IN FOG AND LOW CLOUDS DETERIORATE BACK TO IFR WITH
LIFR/VLIFR ALONG/N OF BOUNDARY IMPACTING MAINLY DBQ AND CID.
ISENTROPIC LIFT OVER BOUNDARY WILL ALSO PROVIDE SOME SCATTERED
SHOWER ACTIVITY THIS EVENING INTO THE OVERNIGHT AND HAVE HANDLED
WITH VCSH. LATE TONIGHT THROUGH MID MORNING SUNDAY... EXPECT
WIDESPREAD SHOWERS AND FEW-SCTD STORMS WITH STRONG CONVERGENCE ON
NOSE OF 60+ KT LOW LEVEL JET... WITH CONDITIONS GENERALLY MVFR TO
IFR. THIS PRECIPITATION SHOULD HELP TO SCOUR OUT ANY DENSE FOG AND
VLIFR CONDITIONS. LATER SHIFTS WILL NEED TO LOOK AT ADDING MENTION
OF LLWS LATE TONIGHT AND EARLY SUNDAY MORNING AS NAM SHOWS 40-45+
KTS FROM THE SOUTHEAST IN 1500-2000FT AGL LAYER. RAP MODEL THOUGH
NOT AS STRONG ONLY AROUND 30 KTS AND MORE MARGINAL CRITERIA WITH
SFC WINDS LIKELY SUSTAINED AROUND 10-15 KTS.
&&
.HYDROLOGY...
ISSUED AT 354 PM CST SAT DEC 12 2015
RAINFALL TONIGHT INTO LATE SUNDAY NIGHT SHOULD TOTAL 1 TO 2 INCHES WITH
LOCAL AMOUNTS NEAR 2.5 INCHES POSSIBLE IN NW SECTIONS OF THE REGION.
THE LONG DURATION SHOULD LIMIT WATER ISSUES INITIALLY TO PONDING IN
LOW LYING AND POORLY DRAINED AREAS. OUR ALREADY WET SOILS WILL RESULT IN
SIGNIFICANT RUNOFF INTO THE LOCAL RIVERS.
AT THIS TIME...AREAS THAT RECEIVE OVER 1.5 INCHES OR MORE OF RAIN MAY
SEE SOME RIVERS REACH BANKFULL. AREA RIVER BASINS THAT RECEIVE AROUND
2 INCHES OR MORE MAY HAVE SOME RIVERS REACH MINOR TO POSSIBLY BRIEFLY
MODERATE RIVER FLOODING EARLY NEXT WEEK. SPECIFIC RIVER LOCATIONS WILL
BE BETTER KNOWN IN THE NEXT 12-24 HOURS AS THE LOCATIONS OF HEAVIEST
RAINFALL ARE CLARIFIED.
&&
.CLIMATE...
ISSUED AT 354 PM CST SAT DEC 12 2015
RECORD WARM LOWS FOR DECEMBER 13...
DUBUQUE........38 IN 1918
MOLINE.........40 IN 1928
RECORD HIGHS FOR DECEMBER 13...
MOLINE.........63 IN 1975
CEDAR RAPIDS...57 IN 1975
DUBUQUE........55 IN 1920
BURLINGTON.....64 IN 1975
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...MCCLURE
SHORT TERM...MCCLURE
LONG TERM...GIBBS
AVIATION...MCCLURE
HYDROLOGY...08/MCCLURE
CLIMATE...MCCLURE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1218 PM CST SAT DEC 12 2015
.UPDATE...
ISSUED AT 1203 PM CST SAT DEC 12 2015
SOME DENSE FOG LINGERS NORTHWEST OF IOWA CITY TO FREEPORT AXIS
BUT MOSTLY PATCHY AND WITH IMPROVING TRENDS NOTED LIFTING FROM
THE SOUTH HAVE ALLOWED THE DENSE FOG ADVISORY TO EXPIRE. WITH
LITTLE CHANGE IN CONDITIONS WE MAY SEE SOME REDEVELOPMENT OF
DENSE FOG THIS EVENING IN THESE SAME AREAS NEAR/NORTH OF STALLED
FRONTAL ZONE.
&&
.SYNOPSIS...
ISSUED AT 250 AM CST SAT DEC 12 2015
06Z SFC DATA HAS A WEAK LOW SOUTH OF KDSM WITH A FRONTAL BOUNDARY
RUNNING EAST INTO ILLINOIS JUST SOUTH OF I-80. A COLD FRONT RAN FROM
THE LOW INTO NORTHERN OKLAHOMA. DEW POINTS WERE IN THE 50S AND 60S
FROM THE SOUTHERN GREAT LAKES TO THE GULF COAST WITH 30S AND 40S
FROM THE UPPER MIDWEST INTO THE PLAINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 250 AM CST SAT DEC 12 2015
RECORD WARM LOWS ARE VERY POSSIBLE TODAY AND SUNDAY. REFER TO THE
CLIMATE SECTION FOR SPECIFIC INFORMATION.
THE DENSE FOG ADVISORY WAS EXPANDED TO ENCOMPASS ROUGHLY THE WESTERN
HALF OF THE AREA THROUGH THE MORNING HOURS. THE POSSIBILITY DOES
EXIST THAT IT MAY NEED TO BE EXPANDED FURTHER EAST WITH THE FRONTAL
BOUNDARY AND WEAK WINDS ACROSS THE AREA. WILL CONTINUE TO MONITOR
FOR THIS POSSIBILITY.
MAINLY DRY CONDITIONS WILL BE SEEN ACROSS THE AREA THIS MORNING.
DURING THE AFTERNOON...ADDITIONAL MOISTURE MOVES INTO THE AREA AND
THE FORCING...ALBEIT WEAK...GETS SLIGHTLY STRONGER. WITH THE
ATMOSPHERE MORE SATURATED...SPRINKLES OR VERY LIGHT RAIN SHOULD
SLOWLY BREAK OUT DURING THE AFTERNOON. TEMPERATURES WILL BE
UNSEASONABLY MILD WITH HIGHS 20 TO 25 DEGREES ABOVE NORMAL.
TONIGHT...MOISTURE/FORCING INCREASES CONSIDERABLY ACROSS THE AREA.
RAIN WILL QUICKLY DEVELOP AND EXPAND IN AREAL COVERAGE DURING THE
EVENING HOURS. STARTING AROUND MIDNIGHT AND CONTINUING THROUGH
SUNRISE FORCING BECOMES VERY STRONG AS ANOTHER SURGE OF MOISTURE
MOVES INTO THE AREA. THIS FORCING/MOISTURE SHOULD BE ENOUGH TO ALLOW
SOME ISOLATED THUNDERSTORMS TO DEVELOP OVER MOST OF THE AREA PRIOR
TO SUNRISE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 250 AM CST SAT DEC 12 2015
SIGNIFICANT RAINS SUNDAY AND SUNDAY NIGHT THE MAIN FORECAST ISSUE.
LONG TERM FORECAST CONFIDENCE ASSESSMENT...GOOD OR ABOVE AVERAGE WITH
LOCATIONS OF HEAVIEST RAIN TOTALS THE BIGGEST ISSUE. NEAR RECORD PRECIPITABLE
WATER VALUES...DEEP SATURATION SUGGEST VERY EFFICIENT RAINFALL PROCESSES
EXPECTED SO AREAS OF 2 INCHES OF RAIN SHOULD OCCUR WITH PROLONGED FORCING
AND PRECIPITABLE WATER VALUES OF 1.2 UP TO NEARLY 1.5 INCHES.
OVERVIEW...INITIALIZATION AND VERIFICATION ARE GOOD WITH NORMAL SLIGHTLY
TOO MOIST BL BIAS IN AMERICAN SOLUTIONS. HI-RES ECMWF ONCE AGAIN MORE
CONSISTENT BOTH IN RUN TO RUN AND IN HANDLING OF LOW LEVEL MOISTURE
FIELDS. PREFER A 60/40 MIX OF HI-RES ECMWF TO GFS. LITTLE SENSIBLE WEATHER
ISSUES ONCE PAST MONDAY AFTERNOON.
SUNDAY AND SUNDAY NIGHT...AREAS OF RAIN...MODERATE AT TIMES TO FALL
INTO THE OVERNIGHT HOURS. RAINFALL RATES SHOULD TEND TO BE IN THE TENTH
TO THREE TENTHS OF AN HOUR WILL RESULT IN PONDING OF WATER INITIALLY.
DESPITE RAINS...HIGHS SHOULD BE NEAR RECORD TO RECORD FOR WARMTH. LOCAL
"LIFT" TOOL DOES SUGGEST A RUMBLE OF THUNDER MAY BE POSSIBLE SUNDAY
AM BUT WILL LEAVE OUT AT THIS TIME. SUNDAY NIGHT...AREAS OF RAIN TO
DIMINISH TOWARD DAYBREAK WITH PASSAGE OF UPPER AND SURFACE LOW. MINS
SHOULD BE AROUND 8 AM...MOSTLY IN THE LOWER TO MIDDLE 40S.
MONDAY...LIGHT RAIN TO SLOWLY DIMINISH WITH BREEZY WESTERLY WINDS AND
TEMPERATURES NEARLY STEADY ALL DAY. ADDITIONAL RAIN TOTALS SHOULD
BE LIGHT AND SPOTTY IN THE ONE TENTH OF AN INCH RANGE OR LESS.
TUESDAY THROUGH FRIDAY...STILL ABOVE NORMAL TEMPERATURES INTO WEDNESDAY
AND THEN NEAR NORMAL. DRY TO MOSTLY DRY CONDITIONS WITH HIGHS MOSTLY
4OS THROUGH WEDNESDAY AND 30S FOR THURSDAY AND FRIDAY. LOWS 30S INTO
WEDNESDAY MORNING AND FALLING INTO THE TEENS AND 20S FOR THURSDAY AND
FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1203 PM CST SAT DEC 12 2015
WARM FRONT LIFTING NORTH WILL BRING SOME IMPROVEMENT IN
CONDITIONS THIS AFTERNOON WITH VFR MAINLY AT BRL AND MLI... AND
IFR TO MVFR AT CID AND DBQ. FRONT LIKELY TO STALL BY THIS EVENING
AS NEXT LOW PRESSURE SYSTEM DEVELOPS AND RIDES ALONG IT. LIKELY
SEE CONDITIONS IN FOG AND LOW CLOUDS DETERIORATE BACK TO IFR WITH
LIFR/VLIFR ALONG/N OF BOUNDARY IMPACTING MAINLY DBQ AND CID.
ISENTROPIC LIFT OVER BOUNDARY WILL ALSO PROVIDE SOME SCATTERED
SHOWER ACTIVITY THIS EVENING INTO THE OVERNIGHT AND HAVE HANDLED
WITH VCSH. LATE TONIGHT THROUGH MID MORNING SUNDAY... EXPECT
WIDESPREAD SHOWERS AND FEW-SCTD STORMS WITH STRONG CONVERGENCE ON
NOSE OF 60+ KT LOW LEVEL JET... WITH CONDITIONS GENERALLY MVFR TO
IFR. THIS PRECIPITATION SHOULD HELP TO SCOUR OUT ANY DENSE FOG AND
VLIFR CONDITIONS. LATER SHIFTS WILL NEED TO LOOK AT ADDING MENTION
OF LLWS LATE TONIGHT AND EARLY SUNDAY MORNING AS NAM SHOWS 40-45+
KTS FROM THE SOUTHEAST IN 1500-2000FT AGL LAYER. RAP MODEL THOUGH
NOT AS STRONG ONLY AROUND 30 KTS AND MORE MARGINAL CRITERIA WITH
SFC WINDS LIKELY SUSTAINED AROUND 10-15 KTS.
&&
.HYDROLOGY...
ISSUED AT 250 AM CST SAT DEC 12 2015
RAIN FALLING OVER A 30 PLUS HOUR TIME SATURDAY NIGHT INTO LATE SUNDAY
NIGHT SHOULD TOTAL 1 TO 2 INCHES WITH LOCAL AMOUNTS NEAR 2.5 INCHES
POSSIBLE IN NW SECTIONS OF THE REGION. THE LONG DURATION SHOULD LIMIT
WATER ISSUES INITIALLY TO PONDING IN LOW LYING AND POORLY DRAINED AREAS.
OUR ALREADY WET SOILS WILL RESULT IN SIGNIFICANT RUNOFF INTO THE LOCAL
RIVERS.
AT THIS TIME...AREAS THAT RECEIVE OVER 1.5 INCHES OR MORE OF RAIN MAY
SEE SOME RIVERS REACH BANKFULL. AREA RIVER BASINS THAT RECEIVE AROUND
2 INCHES OR MORE MAY HAVE SOME RIVERS REACH MINOR TO POSSIBLY BRIEFLY
MODERATE RIVER FLOODING EARLY NEXT WEEK. SPECIFIC RIVER LOCATIONS WILL
BE BETTER KNOWN IN THE NEXT 12-24 HOURS AS THE LOCATIONS OF HEAVIEST
RAINFALL ARE CLARIFIED.
&&
.CLIMATE...
ISSUED AT 250 AM CST SAT DEC 12 2015
RECORD HIGHS FOR DECEMBER 12...
MOLINE.........65 IN 1991
CEDAR RAPIDS...57 IN 1991
DUBUQUE........58 IN 1913
BURLINGTON.....66 IN 1991
RECORD WARM LOWS FOR DECEMBER 13...
DUBUQUE........38 IN 1918
MOLINE.........40 IN 1928
RECORD HIGHS FOR DECEMBER 13...
MOLINE.........63 IN 1975
CEDAR RAPIDS...57 IN 1975
DUBUQUE........55 IN 1920
BURLINGTON.....64 IN 1975
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...05
SYNOPSIS...08
SHORT TERM...08
LONG TERM...NICHOLS
AVIATION...05
HYDROLOGY...NICHOLS
CLIMATE...NICHOLS
AREA FORECAST DISCUSSION
NWS WICHITA KS
1213 PM CST SAT DEC 12 2015
...UPDATED FOR 18Z AVIATION DISCUSSION...
.UPDATE...
ISSUED AT 1027 AM CST SAT DEC 12 2015
FRONTAL BOUNDARY IS A LITTLE FURTHER SOUTH THAN PREVIOUSLY
ANTICIPATED AT THIS TIME. WITH THE BOUNDARY GENERALLY LOCATED FROM
ANTHONY TO KIAB TO EL DORADO NEAR KEMP. THE RICHER GULF MOISTURE
LURKS JUST TO THE SOUTH OF THIS BOUNDARY...WITH LOW 60 DWPTS IN SE
AND SOUTH CENTRAL KS. EVEN SEEING LOW 60 DWPTS NEAR KWLD AND EL
DORADO.
THE QUESTION TODAY IS WHAT WILL HAPPEN TO THIS FRONT AS THE
AFTERNOON PROGRESSES...AS THIS WILL IMPACT LOCATION OF ANY SEVERE
STORM CHANCES FOR THIS EVENING...WITH THE BEST CHANCE FOR ANY SEVERE
STORMS THIS FAR NORTH...BEING IN THE WARM SECTOR. LATEST HI-RES
SHORT TERM HRRR AND RAP SEEM TO HAVE THE BEST HANDLE ON THE CURRENT
FRONTAL POSITION...GRADUALLY SLOSHING THE FRONT BACK TO THE NW AS
THE AFTERNOON PROGRESSES...BACK THROUGH KICT AND JUST NW OF THE KS
TURNPIKE BY LATE THIS AFTERNOON INTO THIS EVENING. THIS WILL PUT
SOME OF OUR SOUTHERN COUNTIES BACK IN THE WARM SECTOR. EVEN WITH THE
HIGHER DEWPOINT AIR IN PLACE...INSTABILITY WILL BE LIMITED...GIVEN
THE WIDESPREAD CLOUD COVER LIMITING THE HEATING/DESTABILIZING OF THE
ATMOSPHERE. BUT SHEAR OF 60-70 KTS WILL HELP OVERCOME THE LOWER
INSTABILITY VALUES FOR A HIGH SHEAR/LOW CAPE SEVERE WEATHER
THREAT...ESPECIALLY FOR COUNTIES JUST TO THE SOUTH OF KICT. THINK
STORMS WILL HOLD OFF UNTIL 22-00Z...TO THE SOUTH OF THE KS/OK
LINE...BUT EXPECT THE STORMS TO RACE RAPIDLY TO NORTH-NORTHEAST INTO
SOUTHERN KS AFTER SUNSET. POTENTIAL STILL EXISTS FOR SOME ELONGATED
FAST MOVING SUPERCELLS...WITH LARGE HAIL AND DAMAGING WINDS THE MAIN
CONCERNS IN THE WARM SECTOR (MAINLY ALONG OR SE OF THE KS TURNPIKE)
AS THE LOW LEVEL JET INCREASES THIS EVENING...COULD EVEN SEE SURFACE
WINDS BACK TO THE SE ALONG THE KS/OK BORDER...WHICH COULD CREATE
ENOUGH DIRECTIONAL SHEAR IN THE LOWEST 1KM FOR AN OUTSIDE SHOT AT
TORNADO OR TWO TO DEVELOP NEAR THE KS/OK BORDER. THINK THE TORNADO
CHANCE IS VERY LOW...BUT STILL WORTH A MENTION. IF A TORNADO CAN GET
GOING IT WILL BE SHORT LIVED.
AS THE THUNDERSTORMS MOVE FURTHER NORTH...INTO KS...HAIL UP TO
QUARTER SIZE IS THE MAIN CONCERN IN THE WARM SECTOR. COULD ALSO SEE
SOME ELEVATED STORMS OVER THE TOP OF THE BOUNDARY INTO CENTRAL
KS...WHICH MAY LEAD TO SOME SMALL HAIL AND GUSTY WINDS.
PLAN ON KEEPING THE WINTER STORM WATCH FOR CENTRAL KS FOR NOW...WITH
THE HEAVIEST SNOW CHANCES STILL MAINLY TO THE WEST OF CENTRAL KS.
BUT GIVEN THE UNCERTAINTY IN THE AXIS OF HEAVY SNOW...WILL KEEP THE
CURRENT WATCH GOING.
KETCHAM
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 220 AM CST SAT DEC 12 2015
A VIGOROUS MID/UPPER TROUGH OVER THE SOUTHWEST IS PROGGED TO MOVE
OVER THE SOUTHERN ROCKIES TODAY AND EMERGE OVER THE SOUTHERN AND
CENTRAL PLAINS ON SUNDAY. AHEAD OF THIS SYSTEM...RICH GULF MOISTURE
WILL ARRIVE SETTING THE STAGE FOR A PERIOD OF STRONG TO PERHAPS
SEVERE STORMS THIS EVENING AND TONIGHT ACROSS SOUTH CENTRAL AND
SOUTHEAST KS. THE BEST CHANCE FOR STORMS SHOULD ARRIVE OVERNIGHT
WHEN THE LLJ NOSES INTO THE CENTRAL PLAINS STATES AND LARGE-SCALE
FORCING FOR ASCENT INCREASES AS THE MID/UPPER TROUGH MOVES OVER THE
SOUTHERN HIGHS PLAINS REGION. PWATS ARE ALSO PROGGED TO CLIMB TO
NEAR RECORD VALUES IN THE 1.25-1.5 INCH RANGE SUPPORTING LOCALLY
HEAVY RAIN AND LOCALIZED FLOODING CONCERNS.
AS THE COLD AIR DEEPENS TOWARD MID DAY OR EARLY AFTERNOON ON
SUNDAY...RAIN WILL RAPIDLY TRANSITION TO SNOW ACROSS CENTRAL KS. THE
NAM IS IN BETTER AGREEMENT WITH THE ECMWF AND GFS WITH THE TRACK OF
THE MID/UPPER TROUGH ACROSS THE REGION ON SUNDAY. THE ECMWF HAS HAD
MUCH BETTER RUN-TO-RUN CONSISTENCY AND REMAINS A BIT SLOWER AND
FURTHER SOUTH COMPARED TO THE NAM/GFS. CONFIDENCE IN A PERIOD OF
HEAVY SNOW IS BEGINNING TO INCREASE ACROSS PORTIONS OF CENTRAL KS ON
SUNDAY AFTERNOON AND SUNDAY EVENING AS THE SOUTHERN PERIPHERY OF THE
TROWAL AIRSTREAM MAY IMPACT THE NORTHWEST CORNER OF OUR FORECAST
AREA LEADING TO HIGHER SNOWFALL ACCUMULATIONS. GOOD LIFT THROUGH THE
DENDRITIC SNOW GROWTH REGION SHOULD RESULT IN HIGH SLRS AND
EFFICIENT SNOWFALL ACCUMULATIONS POSSIBLY EXCEEDING 5-7 INCHES
THROUGH SUNDAY NIGHT AND A WINTER STORM WATCH WILL BE ISSUED FOR
SUNDAY AFTERNOON AND SUNDAY NIGHT ACROSS PORTIONS OF CENTRAL KS.
THE SYSTEM IS EXPECTED TO LIFT FAIRLY RAPIDLY NORTH AND EAST AWAY
FROM THE AREA ON MONDAY WITH CLEARING SKIES AND RISING TEMPERATURES
ANTICIPATED BY AFTERNOON.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 220 AM CST SAT DEC 12 2015
ANOTHER FAST MOVING STORM SYSTEM WILL IMPACT THE CENTRAL ROCKIES
AND NORTHERN PLAINS STATES ON TUESDAY. BREEZY WESTERLY WINDS AND
PERHAPS AN ISOLATED SHOWER OR SNOW FLURRY MAY IMPACT PORTIONS OF
CENTRAL KS...ALTHOUGH LARGE-SCALE FORCING FOR SUBSIDENCE ON THE
SOUTHERN PERIPHERY OF THE MID/UPPER TROUGH SHOULD KEEP MUCH OF THE
AREA DRY. A MEAN MID/UPPER TROUGH IS PROGGED TO REMAIN SITUATED
ACROSS THE CENTRAL CONUS THROUGH THE REMAINDER OF THE PERIOD
RESULTING IN MOSTLY DRY WEATHER CONDITIONS AND SEASONABLY COOL
TEMPERATURES..
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1213 PM CST SAT DEC 12 2015
VERY CHALLENGING AVIATION FORECAST...AS A FRONTAL BOUNDARY IS
SITUATED RIGHT ACROSS THE CENTER OF THE FORECAST AREA....ROUGHLY
FROM KIAB TO NEAR KEMP. RICH BOUNDARY LAYER MOISTURE JUST TO THE
SOUTH OR ALONG THE BOUNDARY HAS LED TO A TRANSIENT AREA OF 1-4SM BR
SLOSHING ACROSS THE KICT AND KHUT TAF SITES. EVEN SEEING SOME OBS
SHOW SOME 1/2SM FG NEARBY...AS THIS RICH MOISTURE COLLIDES WITH THE
COOLER AIR TO THE NORTH OF THE BOUNDARY. THICK STRATUS CLOUDS HAVE
LED TO PREVAILING IFR CIGS AS WELL...WITH EVEN SOME LIFR CIGS NEAR
KICT. NORTH OF THE FRONT IN THE COOLER AIR...THE DEEP MOISTURE IS
ALSO LEADING TO IFR CIGS AS WELL.
EXPECT THE IFR AND POTENTIALLY LIFR CIGS TO CONTINUE ALONG THE
BOUNDARY FOR MOST OF THE DAY AS THE COLD FRONT DRIFTS BACK TO THE
NORTH SOME. AS THE AFTERNOON PROGRESSES INTO THE EVENING...A
VIGOROUS STORM SYSTEM WILL MOVE INTO THE SRN PLAINS...WHICH WILL
LEAD TO SHRA/TSRA DEVELOPING ACROSS THE AREA...ESPECIALLY IN THE
WARM SECTOR EAST OF THE KS TURNPIKE. SO WILL GO WITH A SHRA AND VCTS
MENTION FOR MOST LOCATIONS THIS EVENING.
AS THIS SYSTEM LIFT NORTHEAST ACROSS THE FORECAST AREA...EXPECT THE
SHRA/TSRA TO TRANSITION TO MORE OF A STEADY RAIN. WITH THE STEADY
RAIN...EXPECT WIDESPREAD MVFR/IFR CIGS WITH THE RAIN.
KETCHAM
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 48 47 32 55 / 100 80 40 0
HUTCHINSON 43 44 31 50 / 100 80 60 0
NEWTON 47 47 31 52 / 100 80 40 0
ELDORADO 52 51 32 55 / 100 80 30 0
WINFIELD-KWLD 51 52 33 56 / 100 90 30 0
RUSSELL 36 37 28 46 / 80 80 70 0
GREAT BEND 37 37 29 46 / 80 80 70 0
SALINA 44 43 30 46 / 90 80 70 0
MCPHERSON 44 44 30 48 / 100 80 60 0
COFFEYVILLE 61 60 37 56 / 100 90 30 0
CHANUTE 60 59 36 55 / 100 90 30 10
IOLA 60 59 36 53 / 100 90 30 10
PARSONS-KPPF 60 60 37 56 / 100 90 30 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
NIGHT FOR KSZ032-033-047.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1028 AM CST SAT DEC 12 2015
.UPDATE...
ISSUED AT 1027 AM CST SAT DEC 12 2015
FRONTAL BOUNDARY IS A LITTLE FURTHER SOUTH THAN PREVIOUSLY
ANTICIPATED AT THIS TIME. WITH THE BOUNDARY GENERALLY LOCATED FROM
ANTHONY TO KIAB TO EL DORADO NEAR KEMP. THE RICHER GULF MOISTURE
LURKS JUST TO THE SOUTH OF THIS BOUNDARY...WITH LOW 60 DWPTS IN SE
AND SOUTH CENTRAL KS. EVEN SEEING LOW 60 DWPTS NEAR KWLD AND EL
DORADO.
THE QUESTION TODAY IS WHAT WILL HAPPEN TO THIS FRONT AS THE
AFTERNOON PROGRESSES...AS THIS WILL IMPACT LOCATION OF ANY SEVERE
STORM CHANCES FOR THIS EVENING...WITH THE BEST CHANCE FOR ANY SEVERE
STORMS THIS FAR NORTH...BEING IN THE WARM SECTOR. LATEST HI-RES
SHORT TERM HRRR AND RAP SEEM TO HAVE THE BEST HANDLE ON THE CURRENT
FRONTAL POSITION...GRADUALLY SLOSHING THE FRONT BACK TO THE NW AS
THE AFTERNOON PROGRESSES...BACK THROUGH KICT AND JUST NW OF THE KS
TURNPIKE BY LATE THIS AFTERNOON INTO THIS EVENING. THIS WILL PUT
SOME OF OUR SOUTHERN COUNTIES BACK IN THE WARM SECTOR. EVEN WITH THE
HIGHER DEWPOINT AIR IN PLACE...INSTABILITY WILL BE LIMITED...GIVEN
THE WIDESPREAD CLOUD COVER LIMITING THE HEATING/DESTABILIZING OF THE
ATMOSPHERE. BUT SHEAR OF 60-70 KTS WILL HELP OVERCOME THE LOWER
INSTABILITY VALUES FOR A HIGH SHEAR/LOW CAPE SEVERE WEATHER
THREAT...ESPECIALLY FOR COUNTIES JUST TO THE SOUTH OF KICT. THINK
STORMS WILL HOLD OFF UNTIL 22-00Z...TO THE SOUTH OF THE KS/OK
LINE...BUT EXPECT THE STORMS TO RACE RAPIDLY TO NORTH-NORTHEAST INTO
SOUTHERN KS AFTER SUNSET. POTENTIAL STILL EXISTS FOR SOME ELONGATED
FAST MOVING SUPERCELLS...WITH LARGE HAIL AND DAMAGING WINDS THE MAIN
CONCERNS IN THE WARM SECTOR (MAINLY ALONG OR SE OF THE KS TURNPIKE)
AS THE LOW LEVEL JET INCREASES THIS EVENING...COULD EVEN SEE SURFACE
WINDS BACK TO THE SE ALONG THE KS/OK BORDER...WHICH COULD CREATE
ENOUGH DIRECTIONAL SHEAR IN THE LOWEST 1KM FOR AN OUTSIDE SHOT AT
TORNADO OR TWO TO DEVELOP NEAR THE KS/OK BORDER. THINK THE TORNADO
CHANCE IS VERY LOW...BUT STILL WORTH A MENTION. IF A TORNADO CAN GET
GOING IT WILL BE SHORT LIVED.
AS THE THUNDERSTORMS MOVE FURTHER NORTH...INTO KS...HAIL UP TO
QUARTER SIZE IS THE MAIN CONCERN IN THE WARM SECTOR. COULD ALSO SEE
SOME ELEVATED STORMS OVER THE TOP OF THE BOUNDARY INTO CENTRAL
KS...WHICH MAY LEAD TO SOME SMALL HAIL AND GUSTY WINDS.
PLAN ON KEEPING THE WINTER STORM WATCH FOR CENTRAL KS FOR NOW...WITH
THE HEAVIEST SNOW CHANCES STILL MAINLY TO THE WEST OF CENTRAL KS.
BUT GIVEN THE UNCERTAINTY IN THE AXIS OF HEAVY SNOW...WILL KEEP THE
CURRENT WATCH GOING.
KETCHAM
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 220 AM CST SAT DEC 12 2015
A VIGOROUS MID/UPPER TROUGH OVER THE SOUTHWEST IS PROGGED TO MOVE
OVER THE SOUTHERN ROCKIES TODAY AND EMERGE OVER THE SOUTHERN AND
CENTRAL PLAINS ON SUNDAY. AHEAD OF THIS SYSTEM...RICH GULF MOISTURE
WILL ARRIVE SETTING THE STAGE FOR A PERIOD OF STRONG TO PERHAPS
SEVERE STORMS THIS EVENING AND TONIGHT ACROSS SOUTH CENTRAL AND
SOUTHEAST KS. THE BEST CHANCE FOR STORMS SHOULD ARRIVE OVERNIGHT
WHEN THE LLJ NOSES INTO THE CENTRAL PLAINS STATES AND LARGE-SCALE
FORCING FOR ASCENT INCREASES AS THE MID/UPPER TROUGH MOVES OVER THE
SOUTHERN HIGHS PLAINS REGION. PWATS ARE ALSO PROGGED TO CLIMB TO
NEAR RECORD VALUES IN THE 1.25-1.5 INCH RANGE SUPPORTING LOCALLY
HEAVY RAIN AND LOCALIZED FLOODING CONCERNS.
AS THE COLD AIR DEEPENS TOWARD MID DAY OR EARLY AFTERNOON ON
SUNDAY...RAIN WILL RAPIDLY TRANSITION TO SNOW ACROSS CENTRAL KS. THE
NAM IS IN BETTER AGREEMENT WITH THE ECMWF AND GFS WITH THE TRACK OF
THE MID/UPPER TROUGH ACROSS THE REGION ON SUNDAY. THE ECMWF HAS HAD
MUCH BETTER RUN-TO-RUN CONSISTENCY AND REMAINS A BIT SLOWER AND
FURTHER SOUTH COMPARED TO THE NAM/GFS. CONFIDENCE IN A PERIOD OF
HEAVY SNOW IS BEGINNING TO INCREASE ACROSS PORTIONS OF CENTRAL KS ON
SUNDAY AFTERNOON AND SUNDAY EVENING AS THE SOUTHERN PERIPHERY OF THE
TROWAL AIRSTREAM MAY IMPACT THE NORTHWEST CORNER OF OUR FORECAST
AREA LEADING TO HIGHER SNOWFALL ACCUMULATIONS. GOOD LIFT THROUGH THE
DENDRITIC SNOW GROWTH REGION SHOULD RESULT IN HIGH SLRS AND
EFFICIENT SNOWFALL ACCUMULATIONS POSSIBLY EXCEEDING 5-7 INCHES
THROUGH SUNDAY NIGHT AND A WINTER STORM WATCH WILL BE ISSUED FOR
SUNDAY AFTERNOON AND SUNDAY NIGHT ACROSS PORTIONS OF CENTRAL KS.
THE SYSTEM IS EXPECTED TO LIFT FAIRLY RAPIDLY NORTH AND EAST AWAY
FROM THE AREA ON MONDAY WITH CLEARING SKIES AND RISING TEMPERATURES
ANTICIPATED BY AFTERNOON.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 220 AM CST SAT DEC 12 2015
ANOTHER FAST MOVING STORM SYSTEM WILL IMPACT THE CENTRAL ROCKIES
AND NORTHERN PLAINS STATES ON TUESDAY. BREEZY WESTERLY WINDS AND
PERHAPS AN ISOLATED SHOWER OR SNOW FLURRY MAY IMPACT PORTIONS OF
CENTRAL KS...ALTHOUGH LARGE-SCALE FORCING FOR SUBSIDENCE ON THE
SOUTHERN PERIPHERY OF THE MID/UPPER TROUGH SHOULD KEEP MUCH OF THE
AREA DRY. A MEAN MID/UPPER TROUGH IS PROGGED TO REMAIN SITUATED
ACROSS THE CENTRAL CONUS THROUGH THE REMAINDER OF THE PERIOD
RESULTING IN MOSTLY DRY WEATHER CONDITIONS AND SEASONABLY COOL
TEMPERATURES..
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 600 AM CST SAT DEC 12 2015
INCREASINGLY MOIST LOW LEVEL FLOW MOVING INTO SURFACE FRONT ALONG
I-35 WILL RESULT IN PERSISTENT MVFR/IFR CONDITIONS FOR MUCH OF THE
PERIOD FOR MOST SITES. FRONT WILL WAFFLE IN THE VICINITY OF KICT
THROUGHOUT MUCH OF THE DAY BEFORE MAKING A SLIGHT DRIFT TO THE
NORTHWEST. PRECIPITATION CHANCES WILL INCREASE TONIGHT DUE TO
COMBO OF INCREASING DIFFLUENCE...APPROACHING UPPER ENERGY ANY
DEEPER MOISTURE. MARGINAL INSTABILITY WILL RESULT IN A FEW
EMBEDDED THUNDERSTORMS. -HOWERTON
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 63 47 47 32 / 60 90 80 40
HUTCHINSON 57 43 44 31 / 60 80 80 60
NEWTON 59 46 47 31 / 60 90 80 40
ELDORADO 67 51 51 32 / 50 90 80 30
WINFIELD-KWLD 68 52 52 33 / 50 90 90 30
RUSSELL 49 37 37 28 / 50 70 80 70
GREAT BEND 51 37 37 29 / 50 70 80 70
SALINA 53 43 43 30 / 60 80 80 70
MCPHERSON 55 43 44 30 / 60 80 80 60
COFFEYVILLE 71 60 60 37 / 50 90 90 30
CHANUTE 69 59 59 36 / 50 90 90 30
IOLA 69 59 59 36 / 50 90 90 30
PARSONS-KPPF 70 59 60 37 / 50 90 90 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
NIGHT FOR KSZ032-033-047.
&&
$$
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1255 PM CST SAT DEC 12 2015
.AVIATION...
FOR 12/18Z TAFS...AMPLE MIXING HAS ALLOWED FOR VFR CIGS ACROSS
MOST OF THE REGION. HOWEVER...THIS WILL ONLY LAST UNTIL THE
AFTERNOON HOURS...AS SHOWERS AND THUNDERSTORMS WILL MOVE INTO TO OUR E TX
TERMINALS BY LATE THIS AFTERNOON AND SLOWLY SPREAD EWD DURING THE
LATE EVENING AND OVERNIGHT PERIODS AS AN APPROACHING STORM SYSTEM
MOVES THROUGH THE REGION. SLY WINDS TODAY WILL INCREASE IN SPEED
TO 10-15 KTS WITH HIGHER GUSTS AND REMAIN SO THROUGHOUT MUCH OF
THE PD. /20/
&&
.PREV DISCUSSION... /ISSUED 1148 AM CST SAT DEC 12 2015/
DISCUSSION...
THE STRATUS SHIELD LINGERS ACROSS THE REGION AS OF LATE
MORNING...ALTHOUGH SOME BREAKS HAVE BEEN NOTED ON THE VISIBLE
SATELLITE IMAGERY OVER PORTIONS OF CNTRL AND ERN LA/WRN MS. THIS
STRATUS SHIELD MAY PERSIST THROUGH MUCH OF THE DAY /WITH SOME
SCATTERING POSSIBLE OVER THE ERN ZONES/ AS LOW LEVEL MOISTURE
CONTINUES TO DEEPEN BENEATH THE LOW LEVEL CAPPING INVERSION NOTED
ON THE 12Z KSHV RAOB. THE CIRRUS SHIELD WILL ONLY DEEPEN WITH TIME
AS WELL...AS THE SUBTROPICAL JET SHIFTS FARTHER E ACROSS THE LOWER
MS VALLEY AHEAD OF THE LONGWAVE TROUGH OVER THE DESERT SW. DESPITE
THE CLOUD COVER...SHOULD STILL SEE NEAR RECORD MAX TEMPS THIS
AFTERNOON AS TEMPS APPROACH 80 DEGREES ESPECIALLY OVER N
LA/ADJACENT SECTIONS OF EXTREME ERN TX. HAVE HAD TO RAISE MAX
TEMPS THIS AFTERNOON 1-2 DEGREES GIVEN THE 16-17Z OBS...BUT THE
LACK OF SUN SHOULD TAPER THE DIURNAL SWING IN TEMPS FROM THE WARM
START TO THE MORNING.
MOSAIC RADAR IMAGERY INDICATES AN INCREASING AREAS OF CONVECTION
RAPIDLY DEVELOPING THIS MORNING OVER THE TX HILL COUNTRY...WITH
MORE SCATTERED DEVELOPMENT ONGOING ACROSS SE TX...WHICH WILL
SPREAD NNE INTO PORTIONS OF E TX THIS AFTERNOON IN ASSOCIATION WITH
A WEAK SHORTWAVE/INCREASED PVA EJECTING NE AHEAD OF THE LONGWAVE
TROUGH OVER THE DESERT SW. THE 12Z PROGS AND THE LATEST HRRR RUNS
HAVE INITIALIZED ON THIS WELL...AFFECTING E TX/EXTREME SE OK BY
MID TO LATE AFTERNOON. HAVE INCREASED POPS BACK TO LIKELY ACROSS
THE WRN SECTIONS OF E TX THIS AFTERNOON IN THE LATE MORNING
UPDATE...TAPERING TO HIGH CHANCE ACROSS THE REMAINDER OF E TX/SE
OK. SLIGHT CHANCE POPS SHOULD WORK FOR MUCH OF SW AR/N LA THIS
AFTERNOON AS THE MOISTURE WILL BE LATER TO DEEPEN OVER THESE
AREAS. THE CURRENT LAKE WIND ADVISORY THIS AFTERNOON LOOKS GOOD
OVER THE WRN SECTIONS OF E TX AS THE PRESSURE GRADIENT HAS
TIGHTENED OVER THE SRN PLAINS AHEAD OF DEEPENING SFC LOW PRESSURE
OVER ERN NM. WILL LIKELY HAVE TO EXPAND THE LAKE WIND ADV. FOR
TONIGHT WITH THE AFTERNOON FORECAST PACKAGE AS THE TIGHT PRESSURE
GRADIENT EXPANDS FARTHER E OVER THE REGION.
WILL ALSO RE-ASSESS THE SVR POTENTIAL IN THE AFTERNOON DISCUSSION
AS WELL...ALTHOUGH HAVE HIGHER CONFIDENCE THAT THIS SYSTEM WILL
BE PRIMARILY A HEAVY RAINFALL/FLASH FLOOD THREAT.
ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 80 65 66 45 / 20 90 100 20
MLU 81 68 72 47 / 10 40 100 30
DEQ 76 60 61 40 / 30 100 80 20
TXK 78 62 64 43 / 30 100 100 10
ELD 79 67 70 43 / 20 70 100 30
TYR 78 56 58 43 / 60 100 80 10
GGG 78 60 62 43 / 50 100 80 10
LFK 79 63 64 43 / 50 100 80 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH FROM 6 PM CST THIS EVENING THROUGH SUNDAY
MORNING FOR ARZ050-051-059-060-070-071.
LA...FLASH FLOOD WATCH FROM 6 PM CST THIS EVENING THROUGH SUNDAY
MORNING FOR LAZ001-002-010.
OK...FLASH FLOOD WATCH FROM 6 PM CST THIS EVENING THROUGH SUNDAY
MORNING FOR OKZ077.
TX...FLASH FLOOD WATCH FROM 6 PM CST THIS EVENING THROUGH SUNDAY
MORNING FOR TXZ096-097-108>112-124>126-136>138-149>153-165-
166.
LAKE WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR TXZ096-
108>110-124-125-136-137-149-150.
&&
$$
20
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1148 AM CST SAT DEC 12 2015
.DISCUSSION...
THE STRATUS SHIELD LINGERS ACROSS THE REGION AS OF LATE
MORNING...ALTHOUGH SOME BREAKS HAVE BEEN NOTED ON THE VISIBLE
SATELLITE IMAGERY OVER PORTIONS OF CNTRL AND ERN LA/WRN MS. THIS
STRATUS SHIELD MAY PERSIST THROUGH MUCH OF THE DAY /WITH SOME
SCATTERING POSSIBLE OVER THE ERN ZONES/ AS LOW LEVEL MOISTURE
CONTINUES TO DEEPEN BENEATH THE LOW LEVEL CAPPING INVERSION NOTED
ON THE 12Z KSHV RAOB. THE CIRRUS SHIELD WILL ONLY DEEPEN WITH TIME
AS WELL...AS THE SUBTROPICAL JET SHIFTS FARTHER E ACROSS THE LOWER
MS VALLEY AHEAD OF THE LONGWAVE TROUGH OVER THE DESERT SW. DESPITE
THE CLOUD COVER...SHOULD STILL SEE NEAR RECORD MAX TEMPS THIS
AFTERNOON AS TEMPS APPROACH 80 DEGREES ESPECIALLY OVER N
LA/ADJACENT SECTIONS OF EXTREME ERN TX. HAVE HAD TO RAISE MAX
TEMPS THIS AFTERNOON 1-2 DEGREES GIVEN THE 16-17Z OBS...BUT THE
LACK OF SUN SHOULD TAPER THE DIURNAL SWING IN TEMPS FROM THE WARM
START TO THE MORNING.
MOSAIC RADAR IMAGERY INDICATES AN INCREASING AREAS OF CONVECTION
RAPIDLY DEVELOPING THIS MORNING OVER THE TX HILL COUNTRY...WITH
MORE SCATTERED DEVELOPMENT ONGOING ACROSS SE TX...WHICH WILL
SPREAD NNE INTO PORTIONS OF E TX THIS AFTERNOON IN ASSOCIATION WITH
A WEAK SHORTWAVE/INCREASED PVA EJECTING NE AHEAD OF THE LONGWAVE
TROUGH OVER THE DESERT SW. THE 12Z PROGS AND THE LATEST HRRR RUNS
HAVE INITIALIZED ON THIS WELL...AFFECTING E TX/EXTREME SE OK BY
MID TO LATE AFTERNOON. HAVE INCREASED POPS BACK TO LIKELY ACROSS
THE WRN SECTIONS OF E TX THIS AFTERNOON IN THE LATE MORNING
UPDATE...TAPERING TO HIGH CHANCE ACROSS THE REMAINDER OF E TX/SE
OK. SLIGHT CHANCE POPS SHOULD WORK FOR MUCH OF SW AR/N LA THIS
AFTERNOON AS THE MOISTURE WILL BE LATER TO DEEPEN OVER THESE
AREAS. THE CURRENT LAKE WIND ADVISORY THIS AFTERNOON LOOKS GOOD
OVER THE WRN SECTIONS OF E TX AS THE PRESSURE GRADIENT HAS
TIGHTENED OVER THE SRN PLAINS AHEAD OF DEEPENING SFC LOW PRESSURE
OVER ERN NM. WILL LIKELY HAVE TO EXPAND THE LAKE WIND ADV. FOR
TONIGHT WITH THE AFTERNOON FORECAST PACKAGE AS THE TIGHT PRESSURE
GRADIENT EXPANDS FARTHER E OVER THE REGION.
WILL ALSO RE-ASSESS THE SVR POTENTIAL IN THE AFTERNOON DISCUSSION
AS WELL...ALTHOUGH HAVE HIGHER CONFIDENCE THAT THIS SYSTEM WILL
BE PRIMARILY A HEAVY RAINFALL/FLASH FLOOD THREAT.
ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 80 65 66 45 / 20 90 100 20
MLU 81 68 72 47 / 10 40 100 30
DEQ 76 60 61 40 / 30 100 80 20
TXK 78 62 64 43 / 30 100 100 10
ELD 79 67 70 43 / 20 70 100 30
TYR 78 56 58 43 / 60 100 80 10
GGG 78 60 62 43 / 50 100 80 10
LFK 79 63 64 43 / 50 100 80 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH FROM 6 PM CST THIS EVENING THROUGH SUNDAY
MORNING FOR ARZ050-051-059-060-070-071.
LA...FLASH FLOOD WATCH FROM 6 PM CST THIS EVENING THROUGH SUNDAY
MORNING FOR LAZ001-002-010.
OK...FLASH FLOOD WATCH FROM 6 PM CST THIS EVENING THROUGH SUNDAY
MORNING FOR OKZ077.
TX...FLASH FLOOD WATCH FROM 6 PM CST THIS EVENING THROUGH SUNDAY
MORNING FOR TXZ096-097-108>112-124>126-136>138-149>153-165-
166.
LAKE WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR TXZ096-
108>110-124-125-136-137-149-150.
&&
$$
15
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1224 PM EST SAT DEC 12 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM EST SAT DEC 12 2015
...QUIET WEATHER TODAY BEFORE SIGNIFICANT RAINFALL SUNDAY INTO
MONDAY...
WEAK E-NE UPSLOPE FLOW CONTINUES...ALLOWING FOR SNOW SHOWERS ALONG
NORTH CENTRAL UPPER MICHIGAN AS WELL AS IN THE KEWEENAW. IT IS
ACTUALLY INTERESTING THAT THE PRECIPITATION IS SNOW RATHER THAN
DRIZZLE/FREEZING DRIZZLE AS IT WOULD SEEM HARD TO IMAGINE MUCH ICE
NUCLEI IN THE SHALLOW /2000 FT/ AND RELATIVELY WARM /-4C/ CLOUD.
SHORT TERM NWP DOES NOT SUGGEST ANY SEEDING FROM HIGHER CLOUD IS
POSSIBLE. GIVEN A SIMILAR THERMAL AND MOISTURE PROFILE THIS
MORNING...WILL MAINTAIN SLIGHT CHANCE OF SN/DZ/FZDZ THROUGH NOON.
THEN...THE HRRR SUGGESTS THAT ANY REMAINING DRIZZLE WILL END WITH
SOME SLIGHT LOW LEVEL MIXING.
LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST TONIGHT.
STRONG WARM ADVECTION AND ISENTROPIC LIFT WILL MOVE NORTHWARD INTO
THE UPPER GREAT LAKES BY SUNDAY MORNING. THE 00Z NWP SEEM BE BE IN
EXCELLENT AGREEMENT IN BRINGING RAIN ACROSS MUCH OF THE SOUTHERN
HALF OF THE U.P. AFT 09Z AND TO THE MAJORITY OF UPPER MI EXCEPT THE
KEWEENAW AND THE EASTERN 1/3 BY 12Z. AS SUCH...WILL KEEP POPS
MINIMAL THIS EVENING...THE RAPIDLY RAISE TO LIKELY ACROSS THE WEST
AND CENTRAL BTWN 09-12Z. IN FACT...WILL GO WITH CATEGORICAL POPS
FOR FAR SOUTHERN MENOMINEE COUNTY BY 12Z.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 533 AM EST SAT DEC 12 2015
MODELS ADVERTISE AN ACTIVE PROGRESSIVE PATTERN FOR THE LONG TERM
STARTING OUT WITH A STRONG LOW PRESSURE SYSTEM FROM THE PLAINS
LIFTING NE INTO THE UPPER GREAT LAKES FOR SUNDAY AND MONDAY FOLLOWED
BY ANOTHER PLAINS SYSTEM MOVING IN FOR TUE NIGHT AND WED. THIS
SECOND SYSTEM IS FOLLOWED BY A SERIES OF CLIPPER SHORTWAVES WHICH
WILL BRING IN COLDER AIR FM NW CANADA BY LATE NEXT WEEK. AS A
RESULT...TEMPS WILL START OUT WELL ABOVE NORMAL WITH NEAR RECORD
VALUES INTO MONDAY BUT WILL THEN DROP OFF CLOSER TO NORMAL VALUES BY
THU-FRI.
SUNDAY THROUGH MONDAY...A STRONG SRN STREAM SYSTEM IS EXPECTED TO
LIFT FROM THE SRN PLAINS TO THE WRN LAKES. THE 00Z/12 ECMWF IS
PERHAPS SLIGHTLY SLOWER INITIALLY THAN 00Z GFS AND CANADIAN WITH
ARRIVAL OF OCCLUDING SFC LOW LATE MONDAY BUT OTHERWISE MODELS
GENERALLY IN GOOD AGREEMENT. ALL MODELS SHOW A SIMILAR TRACK ACROSS
THE CENTRAL U.P. ON MONDAY BRINGING PLENTY OF WARM AIR INTO THE CWA
TO SUPPORT MOSTLY RAIN THROUGH MONDAY. VERY STRONG MOISTURE
ADVECTION WILL PUSH PWAT VALUES TO CLIMATOLOGICALLY EXTREME VALUES
NEAR 1.20 INCH OR TO ABOUT A 6.0 SIGMA STANDARDIZED ANOMALY. THIS
STRONG MOISTURE ADVECTION COMBINED WITH STRONG DEEP LAYER Q-VECTOR
CONVERGENCE AND ENHANCED 700 MB FGEN IN RESPONSE TO INCREASED UPPER
DIVERGENCE FROM COUPLED UPPER JET STRUCTURE WILL LIKELY LEAD TO
STORM TOTAL RAINFALL AMOUNTS THROUGH PERIOD IN THE 2 TO 3 INCH RANGE
ACROSS THE CWA WITH THE HEAVIEST AMOUNTS LIKELY OVER THE WEST HALF
SUN NIGHT INTO MONDAY. THE INITIAL BATCH OF RAIN ON SUNDAY WILL
PRIMARILY BE SUPPORTED BY AN AREA OF 290K-300K ISENTROPIC LIFT WITH
RAIN SPREADING TO THE NORTH THROUGH THE CWA.
MON NIGHT-FRI...MODEL THICKNESS/SOUNDINGS AND WET BULB ZERO
CALCULATIONS SUGGEST RAIN WILL FINALLY BEGIN TO CHANGE TO SNOW FROM
WEST TO EAST MON NIGHT INTO TUE...BUT BY THIS TIME MODELS INDICATE
THAT THE HEAVIER PCPN ASSOC WITH THE COMMA HEAD/DEFORMATION AREA OF
SYSTEM WILL HAVE EXITED TO THE EAST. SO ANY SNOW WE GET FROM THIS
SYSTEM LOOKS LIKE IT WILL BE LIGHT (LESS THAN AN INCH) AND CONFINED
TO THE WEST. AFTER LIGHT LES ON TUESDAY IN N-NE FLOW ALONG LAKE
SUPERIOR COUNTIES...MODELS SHOW ANOTHER SHORTWAVE AND ASSOC SFC LOW
APPROACHING FROM THE CENTRAL PLAINS AND UPPER MS VALLEY ON WED. WITH
MODELS TRENDING EVEN FARTHER WEST WITH THIS SYSTEM RAIN IS MORE
LIKELY CENTRAL AND EAST WITH A RAIN/SNOW MIX WEST. A SERIES OF
CLIPPER SHORTWAVES IN THE WAKE OF THE MIDWEEK SYSTEM...WILL BRING IN
COLDER AIR AS 850 MB TEMPS LOWER TO -15C OR COLDER BY FRIDAY. THIS
WILL SUPPORT INCREASING LES CHANCES FOR WESTERLY FLOW FAVORED
LOCATIONS...PARTICULARLY OVER THE KEWEENAW WHERE ADVISORY LES SNOWS
MAY BE POSSIBLE FROM LATE THU INTO FRI.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1224 PM EST SAT DEC 12 2015
EXPECT CONDITIONS TO REMAIN OF THE BORDER BETWEEN IFR AND LOW MVFR
TODAY. DEEPER MOISTURE RETURNS TO THE AREA TONIGHT AHEAD OF THE LOW
PRESSURE SYSTEM. EXPECT IFR TI LIFR CIGS TO SPREAD ACROSS THE ENTIRE
AREA OVERNIGHT WITH RAIN DEVELOPING LATE. THOSE CONDITIONS WILL
PERSIST THROUGH SUNDAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 330 AM EST SAT DEC 12 2015
AS LOW PRESSURE OVER THE CENTRAL PLAINS DEVELOPS AND MOVES NORTHEAST
TODAY...EXPECT EAST-NORTHEAST WINDS TO SLOWLY INCREASE TODAY...WITH
WINDS OF 25KT ACROSS THE WEST HALF BY THIS EVENING. AS THE LOW
CONTINUES TO MOVE NORTHEAST TOWARD THE GREAT LAKES LATER TONIGHT
INTO SUNDAY NIGHT...WINDS WILL CONTINUE TO INCREASE WITH WINDS OF
GALE FORCE ACROSS THE WEST HALF BY SUNDAY AFTERNOON. NE GALES WILL
CONTINUE INTO MONDAY NIGHT ACROSS THE WEST HALF AND MAY ALSO SPREAD
TO THE EAST HALF ON MONDAY AFTERNOON AS THE LOW FINALLY MOVES
NORTHEAST OF THE AREA AND COLDER AIR FILTERS ACROSS THE LAKE ON
NORTHERLY WINDS. WINDS WILL SUBSIDE TO 20 KT BY TUESDAY BEFORE
ANOTHER LOW PRESSURE SYSTEM DEVELOPS AND MOVES INTO THE UPPER GREAT
LAKES FOR WEDNESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SUNDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
LSZ162-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...VOSS
AVIATION...MZ
MARINE...MRD
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
257 PM CST SAT DEC 12 2015
.DISCUSSION...
Issued at 257 PM CST SAT DEC 12 2015
Very well defined temperature boundary draped across the forecast
area this afternoon. This boundary is running roughly from SW to NE
from KPNC to KDBQ. South of this boundary temperatures are in the
upper 60s to lower 70s, with dew points in the upper 50s to lower
60s. North of the boundary, temperatures are in the middle 40s to
lower 50s, with dew points in the 40s. The warm temperatures across
the area exist despite widespread cloud cover, which is in response
to good moisture transport north within the southerly low level
flow. Shameful the warm front likely won`t reach far enough north
for KCI to record the warm air, since today`s record high is 70
degrees, set on December 12, 1889. As it were, expect temperatures
to remain well above seasonal normals across the area, with the warm
sector along and south of I-70 generally remaining about 30 degrees
above normal mid-December values.
Biggest change in this forecast package deals with the timing of the
precipitation into the area. HRRR trends have indicated little in
the way of precipitation moving into the area prior to sunset, and
latest NAM (12z) forecast soundings show pretty poor quality
moisture moving into the area this afternoon. Forecast soundings,
while nicely saturated in the lower levels (stratus) have very dry
air entrapped in the mid levels. This dry air will take some time to
completely saturate. Have bumped back the timing of scattered
precipitation to after 00z, with more widespread rain perhaps
holding off until around 03z to 06z. Once the atmosphere properly
saturates tonight expect widespread rain to overtake the area.
Soundings showing deep saturation all the way to 400 mb as well as
very high PWAT`s (~1.5 to 1.75 inches) indicate very efficient rain
process akin to a tropical type air mass. Forecast anomalies
indicate the moisture quality of the atmosphere are good enough to
represent maximum values observed for mid-December, nearly 5
standard deviations above normal values. Given the impressive
moisture quality rain rates will be high. The progressive nature of
the mid level system will likely make the bulk of the precipitation
fall during a ~12 hour stretch Saturday night through Sunday
morning. By Sunday afternoon/evening the track of the mid level
system will push the mid level dry slot right through the heart of
the forecast area, which will limit rain amounts from KC up through
KIRK. Despite the "limited" amounts, still anticipating over an inch
of rain for the entire area, up to 2 inches, with some areas
reaching 2 to 3 inches. As the mid level trough moves through,
dragging the dry slot through western Missouri a cold front will
dive south/southeast bringing a cooling trend to the first part of
next week. NAM continues to indicate colder air in the lowest levels
in the post frontal deformation band associated with the trowal, and
even hints at accumulating snow for portions of NW Missouri. However
it remains the outlier for temperatures cold enough for snow
production and accumulation. Final forecast lows for Monday morning
in the middle to upper 30s in far NW Missouri put the final nail in
the coffin of any notion of accumulating snow anywhere in Missouri.
That being said, one could certainly infer from the cool air aloft
that some ice crystals could form with perhaps a few making it to
the surface.
As for the mode of rain showers on Saturday night. Forecast models
continue to indicate some very marginal instability, on the order of
a few hundred J/kg of MUCAPE through 09z. Given the marginal
instability it remains conceivable that there could be some embedded
thunderstorms within the stratiform rain. Deep layer shear on the
order of 40 to 50 kts will be enough to help any thunderstorm to
become strong. While widespread severe weather is not anticipated,
there is a chance that one or several of these thunderstorms could
produce some gusty winds and perhaps some small hail. Due to the
prolonged nature of the light to moderate rain it also remains
possible that several area rivers could see some minor/nuisance
flooding.
Expect the rain to linger through the first part of the day on
Monday and be out of the area by Monday afternoon/evening.
Thereafter the pattern goes dry for the foreseeable future, with the
exception of some very low end chances for precipitation (in the form
of very light rain and/or snow for Tuesday night. A much cooler
pattern then develops, much like this area is accustomed to seeing
in mid-December with highs in the 30s and 40s and lows in the 20s
and 30s.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1126 AM CST SAT DEC 12 2015
Still anticipating widespread light to moderate rain to move into the
area later this afternoon. Bumped back the timing a bit for the onset
of said precipitation as the atmosphere will take a bit longer to
saturate. In the meantime expect prevailing stratus, with a few
periods of light freezing rain and drizzle, with borderline MVFR/IFR
conditions. Once the rain sets in, likely between 00z and 03z, it
will be moderate to heavy at times, with perhaps a few embedded
thunderstorms. The lightning threat should wane around 06z, leaving
only prevailing moderate rain through the remainder of the forecast
period.
&&
.EAX Watches/Warnings/Advisories...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Leighton
AVIATION...Leighton
AREA FORECAST DISCUSSION
NWS BISMARCK ND
345 PM CST SAT DEC 12 2015
.UPDATE...
ISSUED AT 341 PM CST SAT DEC 12 2015
GIVEN WEBCAM AND SURFACE OBSERVATION TRENDS ACROSS NORTHWEST AND
PORTIONS OF CENTRAL NORTH DAKOTA THROUGH 2130 UTC...AND THE 18
UTC NAM NEST AND 20 UTC HRRR VISIBILITY FORECASTS SUGGESTING DENSE
FOG WILL CONTINUE THROUGH THE NIGHT FOR THESE LOCATIONS...ISSUED A
DENSE FOG ADVISORY THROUGH 12 UTC SUNDAY FOR THE AFOREMENTIONED
PORTIONS OF THE CWA. FREEZING TEMPERATURES MAY RESULT IN A THIN
LAYER OF ICE FORMING ON ROADS AND SIDEWALKS FROM THE FOG. WILL
MONITOR FOR A POSSIBLE EXPANSION OF THE ADVISORY INTO THE EVENING
WITH STRATUS BUILD DOWN OVER THE PARTIALLY MELTED FRESH SNOW PACK.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 254 PM CST SAT DEC 12 2015
CONCERNS THIS FORECAST INVOLVE FOG. ALSO LOW CLOUDS IMPACTING
TEMPERATURES. FREEZING DRIZZLE CHANCES WERE EXAMINED BUT ENOUGH
UNCERTAINTY SO DID NOT INCLUDE AT THIS TIME.
AT 2 PM CST...A SHALLOW COOL AIRMASS ASSOCIATED WITH HIGH
PRESSURE CENTERED IN CENTRAL MANT/SASK SOUTH THROUGH NORTH DAKOTA.
THE BOUNDARY LAYER IS BEING KEPT COOL AND MOIST FROM THE RECENT
SNOW AND THIS HAS RESULTED IN A PERSISTENT STRATUS AREA EXTENDING
OVER MOST OF CENTRAL AND NORTHERN NORTH DAKOTA SATURDAY AFTERNOON.
TONIGHT THE RAP/HRRR MODEL INDICATES A LOW LEVEL SOUTHEAST WIND
FLOW. SOUTHEAST FLOW IS LESS PREFERABLE THAN EAST OR NORTHEAST
FLOW FOR TERRAIN INDUCED LOW LEVEL VERTICAL MOTION WITHIN THE
NEARLY SATURATED STRATUS ENVIRONMENT OVER WEST AND CENTRAL NORTH
DAKOTA. WHILE THERE SHOULD BE SUFFICIENT MOISTURE FOR FOG
FORMATION...SUFFICIENT UPSLOPE FLOW MAY NOT EXIST TO GENERATE
FREEZING DRIZZLE SO DECIDED TO WAIT.
WILL CONTINUE LITTLE CHANGE IN TEMPERATURES WHERE STRATUS
PERSISTS ACROSS THE NORTH AND CENTRAL WITH THE SOUTHWEST SEEING
SOME DIURNAL RANGE AS THEY ARE LARGELY OUT OF THE LOW LEVEL
STRATUS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 254 PM CST SAT DEC 12 2015
A WEAK SURFACE AND UPPER LEVEL PATTERN HIGHLIGHTS THE BEGINNING OF
THE EXTENDED PERIOD. THEN A BRUSH WITH A MID LATITUDE CYCLONE MID
WEEK FOLLOWED BY MOSTLY DRY AND SEASONABLY COOL WEATHER.
SUNDAY NIGHT A SOUTHERN PLAINS STORM SYSTEM IS FORECAST TO BE
CENTERED OVER KANSAS/OKLAHOMA...WHICH IS FORECAST TO MOVE NORTHEAST
INTO THE GREAT LAKES REGION BY MONDAY EVENING. THE TRACK OF THIS
SYSTEM WOULD LEAVE CENTRAL NORTH DAKOTA IN THE WEAK UPPER LEVEL FLOW
WITH SURFACE STRATUS-TYPE CLOUDS. WITH UPPER LEVEL CLOUDS HAVING
EXITED TO THE EAST...SOME LINGERING STRATUS WITH ISOLATED DRIZZLE
ARE POSSIBLE MONDAY EVENING. SURFACE TEMPERATURES IN THE 20S WOULD
RESULT IN SOME ISOLATED AREAS OF FREEZING DRIZZLE. BUFKIT SOUNDINGS
ALSO SUPPORT THIS...SO KEPT A SLIGHT CHANCE MENTION.
ATTENTION THEN TURNS TO THE NEXT UPPER LEVEL TROUGH SYSTEM WHICH IS
FORECAST TO BE OVER THE WEST COAST SUNDAY EVENING. THE SYSTEM
DEEPENS AND TRACKS EAST OVER THE ROCKIES...WITH THE LEADING EDGE OF
THE ASSOCIATED UPPER LEVEL ENERGY MOVING OVER THE FRONT RANGE ON
MONDAY. THE MODELS DEPICT THE STORM CENTERED OVER COLORADO/KANSAS BY
DAYBREAK TUESDAY...AND MOVING NORTHEAST TO THE SD/MN/NE/IA BORDER BY
DAYBREAK WEDNESDAY...AND NORTH OF LAKE SUPERIOR BY DAYBREAK
THURSDAY. THIS TRACK WOULD KEEP THE BULK OF SNOW FOR THIS SYSTEM TO
THE SOUTH AND EAST OF NORTH DAKOTA.
THIS TRACK SUGGESTS THE BETTER CHANCES OF MODERATE SNOW
ACCUMULATIONS ACROSS THE SOUTHERN HALF OF THE STATE OVER A PERIOD
FROM MONDAY NIGHT THROUGH WEDNESDAY...WITH ONLY LIGHT AMOUNTS
POSSIBLE NORTH. LIGHT SNOW WOULD BEGIN MONDAY NIGHT IN THE WESTERN
COUNTIES...THEN OVER MUCH OF THE STATE ON TUESDAY AND TUESDAY
NIGHT...AND LINGERING MAINLY OVER THE EAST HALF OF THE STATE ON
WEDNESDAY.
COLD AIR GETS PULLED INTO THE REGION BEHIND THE EXITING MID WEEK
SYSTEM...BRINGING TEMPERATURES DOWN TO SEASONABLY COOL READINGS
WITH HIGHS IN THE 20S AND LOWS IN THE SINGLE DIGITS AS WE MOVE TO
THE END OF THE WORK WEEK. LITTLE SIGNIFICANT PRECIPITATION IS
EXPECTED BEYOND THE MONDAY NIGHT - WEDNESDAY SYSTEM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY)
ISSUED AT 341 PM CST SAT DEC 12 2015
SHALLOW COOL AIRMASS OVER A FRESH SNOW PACK WILL RESULT IN
WIDESPREAD IFR TO LOW IFR CONDITIONS DUE TO LOW CEILINGS AND AREAS
OF FOG.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 6 AM CST SUNDAY FOR NDZ001-002-009-010-
017>019-021.
&&
$$
UPDATE...AYD
SHORT TERM...WAA
LONG TERM...JV
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS NORMAN OK
313 PM CST SAT DEC 12 2015
.DISCUSSION...
STRONG TO SEVERE THUNDERSTORMS AS WELL AS HEAVY RAINFALL AND
FLOODING TONIGHT THROUGH SUNDAY MORNING ARE THE MAIN CONCERNS.
ISSUED A FLASH FLOOD WATCH FOR BRYAN AND ATOKA COUNTIES THROUGH
NOON SUNDAY WHERE CONFIDENCE OF WIDESPREAD 2 TO 4 INCHES OF
RAINFALL IN THESE AREAS ARE RATHER HIGH DUE TO ROUNDS OF SHOWERS
AND STORMS.
THROUGH 9 PM TONIGHT...THINK SOME SHOWERS AND THUNDERSTORMS WILL
FORM OVER THE AREA...PARTICULARLY IN BRYAN AND ATOKA COUNTIES.
CAPPING MAY LIMIT STORM FORMATION. SEVERE POTENTIAL REMAINS LOW
DURING THIS TIME FRAME. SOME MODELS INCLUDING THE HRRR SUGGESTED
THAT A FEW STORMS MAY FORM IN WESTERN OKLAHOMA AND WESTERN NORTH
TEXAS DURING THIS TIME FRAME...BUT DOUBT THIS WILL OCCUR DUE TO
SUFFICIENT CAPPING. IF SURFACE BASED STORMS COULD FORM IN WESTERN
OKLAHOMA AND WESTERN NORTH TEXAS...THEY WOULD BE SUPERCELLULAR
WITH SEVERE HAIL UP TO HALF DOLLARS AS THE MAIN HAZARD AND A VERY
LOW CHANCE FOR TORNADOES BASED ON STRONG LOW LEVEL SHEAR. THE
GREATER CHANCES FOR STORMS WILL BE IN WEST TEXAS INCLUDING THE
TEXAS PANHANDLE BEFORE 9 PM WHERE STRONGEST FORCING AND MID LEVEL
TEMPERATURE FALLS WILL ALLOW FOR THE CAP TO BREAK.
THROUGH THIS EVENING...FOG MAY BE RATHER DENSE NEAR AND JUST
NORTH OF THE DEVELOPING FRONT FROM NEAR ARNETT TO CHEROKEE. WITH
RAIN POSSIBLY FORMING IN THE NEXT FEW HOURS WHICH WOULD ALLOW FOR
IMPROVING VISIBILITIES...CHOSE TO HOLD OFF ON A DENSE FOG ADVISORY
FOR THESE AREAS FOR NOW.
AFTER 9 PM TONIGHT...BELIEVE A SQUALL LINE THAT WILL LIKELY FORM
IN WEST TEXAS WILL MOVE EASTWARD THROUGH THE NIGHT. THE TIMING OF
THIS SQUALL LINE REMAINS A BIT UNCERTAIN AND LATEST HRRR RUNS HAVE
BEEN SLOWING THE LINE DOWN. THE LINE PROBABLY WOULD NOT ENTER FAR
WESTERN OKLAHOMA AND FAR WESTERN NORTH TEXAS UNTIL 9 PM...POSSIBLY
APPROACHING THE I-35 CORRIDOR AROUND 2 OR 3 AM...THEN EXITING
SOUTHEASTERN OKLAHOMA BY 9 AM.
THE GREATER POTENTIAL FOR SEVERE STORMS WITH THIS LINE SEEM TO BE
OVER WESTERN NORTH TEXAS AND WESTERN OKLAHOMA SOUTH OF THE SURFACE
FRONT MENTIONED ABOVE. SOME POCKETS OF DAMAGING WINDS UP TO 70
MPH WITH MESOVORTICES WOULD BE THE MAIN HAZARD. MARGINALLY SEVERE
HAIL WOULD BE POSSIBLE AS WELL. TORNADO POTENTIAL REMAINS VERY
LOW DUE TO LIMITED INSTABILITY NEAR THE GROUND...BUT IS NOT ZERO.
CHANCES FOR SEVERE STORMS WILL LIKELY DECREASE AS THE LINE MOVES
EASTWARD THROUGH THE NIGHT INCLUDING THE I-35 CORRIDOR AND POINTS
EAST WHERE MORE STABLE/RAIN COOLED AIR WILL EXIST.
OVERALL...DO NOT THINK THIS WILL BE A WIDESPREAD SEVERE EVENT
WITH GENERALLY A COUPLE OF WIND AND PERHAPS HAIL REPORTS.
ADDITIONAL STORMS WILL LIKELY BE OCCURRING AHEAD OF THE SQUALL
LINE...ESPECIALLY IN SOUTHEASTERN OKLAHOMA...BUT MAINLY SHOULD BE
SUBSEVERE.
SUNDAY AND SUNDAY EVENING...SHOWERS AND STORMS MAY LINGER DURING
THE MORNING HOURS NEAR AND EAST OF I-35. ADDITIONAL SHOWERS WILL
LIKELY FORM NEAR THE MID/UPPER LOW IN NORTHWESTERN OKLAHOMA. KEPT
A RAIN/SNOW MIX NORTH OF AN ARNETT TO MEDFORD LINE DURING THE DAY
WHERE WETBULB ZERO HEIGHTS FALL BELOW 1500 FT AGL. A WET DUSTING
TO AN INCH OF SNOWFALL MAINLY ON GRASSY SURFACES COULD OCCUR IN
HARPER COUNTY...BUT APPEARS THE HEAVIER SNOW ACCUMULATIONS AND
GREATER SNOW IMPACTS WILL BE NORTHWEST OF HARPER COUNTY.
THUS...DID NOT ISSUE A WINTER WEATHER ADVISORY. COOLER
TEMPERATURES WILL OCCUR. SOME SUN AND CLOUDS AS WELL AS BREEZY
CONDITIONS BY AFTERNOON WILL OCCUR IN WESTERN NORTH TEXAS AND
SOUTHERN OKLAHOMA.
LATE SUNDAY NIGHT THROUGH NEXT SATURDAY...A DRY AND QUIETER
WEATHER PATTERN IS FORECAST. TEMPERATURES WILL BE MORE SEASONABLE
DURING THIS TIME FRAME...ESPECIALLY BEYOND TUESDAY ONCE A COLD
FRONT MOVES THROUGH THE AREA.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 50 56 34 61 / 100 60 10 0
HOBART OK 44 53 32 60 / 100 20 10 0
WICHITA FALLS TX 47 59 35 66 / 100 20 10 0
GAGE OK 37 42 27 60 / 100 70 40 0
PONCA CITY OK 52 55 35 58 / 100 90 40 0
DURANT OK 54 62 40 63 / 100 100 10 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR OKZ048-052.
TX...NONE.
&&
$$
25/17
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1149 AM CST SAT DEC 12 2015
.AVIATION...
SITES SHOULD HOLD ONTO MVFR MOST OF THE AFTERNOON WITH PASSING
AREAS OF LIGHT RAIN/SHOWERS. ANY THUNDER SHOULD BE EAST OF THE TAF
SITES THIS AFTERNOON. AS THE SUN SETS THIS EVENING LOOK FOR
CEILINGS TO COME DOWN TO IFR WHILE SOUTHERLY WINDS REMAIN GUSTY
OVER 20 KTS. THE MAIN FORECAST PROBLEM WILL BE THE TIMING OF
POSSIBLE SQUALL LINE. LATEST HRRR MODELS SHOWS THE LINE OF STORMS
TO APPROACH AND MOVE INTO DRT BY AROUND 4Z WITH THE I-35 GETTING
IMPACTED 08-10Z TIME FRAME. THIS TIMING WILL LIKELY GET ADJUSTED
AS LATER MODEL RUNS AND RADAR CAN PINPOINT THE TIMING. LOOKS TO BE
A QUICK MOVING LINE OF STORMS SO WINDS IN EXCESS OF 40KT IS
LIKELY. SEVERE STORMS ARE NOT OUT OF THE QUESTION BUT NOT
CONFIDENT ENOUGH AT THIS POINT TO INPUT ANY SEVERE PARAMETERS.
CLEARING SHOULD TAKE PLACE RAPIDLY BEHIND THE FRONT/SQUALL LINE
WITH VFR CONDITIONS AND WESTERLY GUSTY WINDS AT ALL SITES LIKELY
BY 12Z SUNDAY.
&&
.PREV DISCUSSION... /ISSUED 544 AM CST SAT DEC 12 2015/
UPDATE...12Z AVIATION UPDATE BELOW.
AVIATION...GENERALLY MVFR CEILINGS AROUND 1200-1800 FEET
PREVAIL EARLY THIS MORNING ACROSS SOUTH-CENTRAL TEXAS. COULD SEE
SOME LOCATIONS DROP INTO IFR THROUGH THE MORNING HOURS WITH
PATCHY -DZ AND ISOLATED -SHRA DEVELOPING. MVFR CEILINGS LIKELY
TO CONTINUE AT AUS AND SAT THROUGH THE AFTERNOON HOURS. S TO SE
WINDS GRADUALLY INCREASING AFTER 15Z...BECOMING GUSTY 20-25 KTS
THROUGH THE AFTERNOON. IFR CEILINGS MAY DEVELOP AFTER SUNSET AT
SAT/AUS. A SQUALL LINE IS FORECAST TO MOVE THROUGH DRT 02Z-04Z AND
SAT/AUS 07Z-09Z. STRONG TO SEVERE STRAIGHT-LINE WIND GUSTS MAY
ACCOMPANY THE LINE OF STORMS. A COLD FRONT WILL SWEEP THROUGH THE
AREA BEHIND THE SQUALL LINE...WITH NW WINDS DEVELOPING...PRECIP
ENDING AND CEILINGS BECOMING VFR.
PREV DISCUSSION... /ISSUED 419 AM CST SAT DEC 12 2015/
SHORT TERM (TODAY THROUGH SUNDAY)...
SEVERE WEATHER AND LOCALLY HEAVY RAINFALL IS EXPECTED MAINLY
TONIGHT. RADAR LOOP CONFIRMS THE APPROACH OF A LEAD SHORT-WAVE
DISTURBANCE FROM MEXICO AND AHEAD OF A DEEP UPPER TROUGH
APPROACHING TX FROM THE PACIFIC. MODEL INDICATIONS OF INCREASING
MID LEVEL MOISTURE LEADS TO PWAT VALUES JUMPING UP TO 2 INCHES
OVER THE COASTAL PRAIRIES BY MIDDAY...WITH HIGH RAIN CHANCES
COVERING MUCH OF THE EASTERN HALF OF TX. AS NOTED BY SPC THE HIGH
AMOUNT OF MOISTURE SHOULD LIMIT THE POTENTIAL FOR DAYTIME
SEVERITY...WITH NEAR CONTINUOUS CLOUDINESS LIMITING STORM
STRENGTH. SHOULD BREAKS IN THE CLOUDS OCCUR THERE IS A SMALL
POTENTIAL FOR LOW TOPPED SUPERCELLS GIVEN THE FORECAST
HELICITIES.
INCREASING LOW TO MID LEVEL WINDS IN ADVANCE OF THE APPROACHING
UPPER TROUGH WILL SET UP BEST LOW LEVEL CONVERGENCE OVER THE I-45
CORRIDOR FOR HIGHEST QPF AMOUNTS...BUT SOME OF THE HIGHER RES DATA
DEPICTS AN AREA OF POTENTIAL TRAINING EXTENDING SW INTO OUR FAR
EASTERN COUNTIES. THE FINAL FORECAST HOUR OF THE HRRR SUGGESTS
INCREASED TRAINING POTENTIAL BY 23Z WITH OTHER HIGH-RES SOLUTIONS
CONTINUING A LOCALLY HEAVY RAIN THREAT OVER EASTERN COUNTIES IN
THE EVENING. FAST STORM MOTIONS ARE EXPECTED TO OFFSET THE
TRAINING PROBLEM...BUT THE HIGH PWAT ENVIRONMENT IS STILL LIKELY
TO DUMP ISOLATED DOWNPOURS OF AROUND 2 INCHES BEFORE MIDNIGHT.
BASED ON WHAT DEVELOPS LATE THIS AFTERNOON...LATER SHIFTS MAY NEED
TO MONITOR FOR A POSSIBLE FLASH FLOOD WATCH OVER EASTERN
COUNTIES...AS A MORE WIDESPREAD ROUND OF RAIN ARRIVES LATE
TONIGHT.
MODELS AND THE WPC SHOW A PRETTY CONSISTENT QPF PATTERN WITH
GENERALLY TWO ENHANCED CLUSTERS OF CONVECTION...AND THE LATTER
ROUND OF RAIN IS LIKELY TO PRODUCE A NEAR SOLID LINE OF STRONG TO
SEVERE STORMS WITH VERY HEAVY RAINFALL RATES. AGAIN THE MOTIONS
WILL BE FAST SO WE/RE EXPECTING A QUICK 1 TO 2 INCHES OF RAIN
FALLING IN A SHORT TIME FOLLOWED BY A BRIEF PERIOD OF MODERATE
RAIN. BY THE END OF THE RAIN EVENT SUNDAY MORNING...A FEW SPOTS
WELL TO THE EAST OF AUSTIN COULD RECEIVE 4 INCHES. BOWING SEGMENTS
WITH THE OVERNIGHT ROUND OF RAIN WILL BE DRIVEN BY THE UPPER
TROUGH AND COULD LEAD TO DAMAGING WINDS AND AN ISOLATED TORNADO
THREAT. THE SPC HAS EXPANDED THE SLIGHT RISK AREA FOR ALL BUT THE
COUNTIES ALONG THE RIO GRANDE...AND OUR FORECAST MENTIONS SEVERE
STORMS AS POSSIBLE OVER ALL AREAS.
LIGHTEST RAINFALL AMOUNTS AND STORM POTENTIAL BEING NEAR THE RIO
GRANDE COULD LEAD TO OUR NEXT THREAT CONCERN FOR DAYTIME SUNDAY.
SHOULD AREAS NEAR THE RIO GRANDE FAIL TO RECEIVE SIGNIFICANT
RAINFALL...WINDY AND DRY CONDITIONS BEHIND THE FRONT WOULD PRODUCE
FAVORABLE CONDITIONS FOR THE SPREAD OF FIRES. MODEL RUNS ARE
TRENDING WETTER AND FARTHER WEST WITH HIGHER RAIN CHANCES...SO
THIS CONCERN COULD POSSIBLY DECREASE GOING FORWARD. THE
DOWNSLOPING WESTERLY WINDS WILL LIKELY KEEP HIGH TEMPERATURES
ABOVE SEASONAL NORMS SUNDAY.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
DECREASING WESTERLY WINDS AND THE ADVANCE OF MUCH DRIER AIR INTO
THE AREA WILL TAKE OVERNIGHT TEMPERATURES BACK TO NEAR NORMALS FOR
MONDAY MORNING. WARMING SW WINDS RETURN FOR MONDAY INTO
TUESDAY...AND SOME MOISTURE POOLING OVER THE COASTAL PRAIRIES
COULD LEAD TO A FEW SHOWERS FORMING TUESDAY INTO EARLY WEDNESDAY.
BROAD TROUGHING DEVELOPING OVER THE U.S. BY THIS TIME WILL BRING A
COLD FRONT THROUGH TX AND TAKE TEMPERATURES BELOW SEASONAL NORMALS
FOR THE REST OF THE WORK WEEK. CURRENT MIN FORECAST TEMPERATURES
SHOW FREEZES POSSIBLE MAINLY OVER AREAS THAT ALREADY HAD THEM IN
NOVEMBER.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 76 54 68 47 71 / 70 90 40 - 0
AUSTIN BERGSTROM INTL AIRPORT 77 54 68 41 71 / 70 90 40 - 0
NEW BRAUNFELS MUNI AIRPORT 78 53 70 41 72 / 60 90 30 0 0
BURNET MUNI AIRPORT 74 50 66 42 70 / 50 80 20 0 0
DEL RIO INTL AIRPORT 76 51 70 39 72 / 10 60 0 0 0
GEORGETOWN MUNI AIRPORT 75 52 65 41 70 / 60 90 40 - 0
HONDO MUNI AIRPORT 77 54 72 37 72 / 40 80 20 0 0
SAN MARCOS MUNI AIRPORT 77 53 69 42 71 / 70 90 40 - 0
LA GRANGE - FAYETTE REGIONAL 78 58 66 45 72 / 80 90 60 - 0
SAN ANTONIO INTL AIRPORT 78 55 71 43 73 / 60 80 20 0 0
STINSON MUNI AIRPORT 78 56 72 41 72 / 60 80 20 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...09
SYNOPTIC/GRIDS...05
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1141 AM CST SAT DEC 12 2015
.AVIATION...
LOW CIGS AND VISBYS WILL CONTINUE TO STICK AROUND THE KCDS
TERMINAL THROUGH EARLY AFTERNOON UNDER CONTINUED SOUTHEASTERLY
WINDS. STRONG WINDS WILL DEVELOP AT KPVW/KLBB THIS AFTERNOON WITH
THE APPROACH OF A STRONG UPPER LEVEL STORM SYSTEM. WINDS WILL TURN
TO THE WEST THIS EVENING FOLLOWING THE PASSAGE OF A COLD FRONT AND
WILL BE CAPABLE OF GENERATING WIDESPREAD THUNDERSTORMS. BEST
CHANCES FOR STORMS WILL BE EAST OF KLBB/KPVW AND MAY AFFECT KCDS
THIS EVENING. STORMS WILL RAPIDLY MOVE OUT OF THE KCDS TERMINAL
AFTER MIDNIGHT OR SO. STRONGER WINDS FROM THE NORTHWEST WILL
SPREAD OVER THE REGION BEGINNING LATE SUNDAY MORNING.
&&
PREV DISCUSSION... /ISSUED 232 AM CST SAT DEC 12 2015/
SHORT TERM...
MAIN CONCERN FOR THE SHORT TERM PERIOD WILL BE INCREASING CHANCES
FOR RAIN SHOWERS AND THUNDERSTORMS...WITH A BRIEF WINDOW FOR A FEW
STORMS TO POSSIBLY NEAR STRONG LEVELS.
SFC TEMPS PER 08Z METARS WERE MILD FOR THIS TIME OF YEAR /40S AND
50S/ COURTESY OF S-SW SFC WINDS...WHICH IS A WIND COMPONENT
CONDUCIVE FOR DRY AND WARM CONDITIONS. HOWEVER...DEWPOINTS IN THE
40S EXISTED ACROSS THE LOW ROLLING PLAINS AS THE WIND WAS MORE FROM
THE S-SE THUS AIDING TO FILTER IN GULF MOISTURE. IN FACT...LOW
CLOUDS AND/OR FOG WERE NOTED ACROSS THE BIG COUNTRY REGION...WHICH
MAY HAVE A CHANCE AT SPREADING TOWARDS THE ROLLING PLAINS AOA
SUNRISE. THE HRRR IS MOST AGGRESSIVE IN THE STRATUS DECK/FOG MAKING
IT AS FAR NW TO KLBB...WITH OTHER SOLUTIONS MAINTAINING THE IT TO
THE LOW ROLLING PLAINS AND PERHAPS THE SRN SOUTH PLAINS. HENCE WILL
BE KEEPING AN EYE ON TRENDS FOR THE NEXT SEVERAL HOURS.
THE STORM SYSTEM OF INTEREST IS AN UA TROUGH DRAPED FROM THE GREAT
BASIN TO ACROSS WRN AZ EARLY THIS MORNING. MOST MODEL SOLUTIONS
AGREE THAT THIS SYSTEM WILL BE RATHER PROGRESSIVE...AS IT IS PROGGED
TO BE ACROSS ERN AZ/WRN NM THIS AFTN TO ACROSS CNTRL NM THIS
EVENING...AND FINALLY ACROSS THE PANHANDLE REGION LATE TONIGHT/EARLY
SUN MORNING...ALL THE WHILE EVOLVING TO MORE OF A CLOSED OFF STATE.
THE ECMWF STILL REMAINS THE OUTLIER WITH IT BEING SLIGHTLY SLOWER
AND FARTHER SOUTH VERSUS THE NAM AND GFS SOLUTIONS. THIS AFTN-
EVENING AS THE SYSTEM DRAWS NEAR...ITS SFC COUNTERPART WILL RESPOND
BY DEEPENING AND THEREFORE PROMOTE A TIGHTENED PRESSURE GRADIENT
WHILST TRANSLATING EAST ACROSS THE CWA. MOS GUIDANCE HINTS AT SFC
WIND SPEEDS OF 15-25 MPH OUT OF THE W-SW...WITH THE BREEZIEST
CONDITIONS NOTED ON THE CAPROCK. OFF THE CAPROCK...SFC WINDS WILL BE
OUT OF THE S-SE. PERSISTENT SWRLY FLOW ALOFT AIDING IN TRANSPORTING
HIGH LEVEL CIRRUS CLOUD COVER WILL BE SLOW TO CLEAR OUT FROM WEST TO
EAST...WHERE IF THERE WERE CLEAR SKIES...WIND CONDITIONS COULD BE A
LOT WORSE. CLOUD COVER WILL BE LAST TO CLEAR OUT ACROSS THE ERN
ZONES GIVEN THE FAVORABLE UPSLOPE WIND COMPONENT.
CONCURRENTLY...A 160 KT 250 MB JET MAX WILL MOVE ACROSS THE
CWA...PROVIDING UL SUPPORT AND ENCOURAGE THE DEVELOPMENT OF SHOWERS
AND THUNDERSTORMS MOVING IN FROM WEST TO EAST. MID-LEVEL INSTABILITY
IS NOT VERY IMPRESSIVE /400-600 J/KG/ BUT THE 0-6 KM BULK SHEAR OF
40-70 KTS AND A SLIGHT COOLING IN THE MID-LEVELS /STEEPENING LAPSE
RATES/ DO SUGGEST SOME THUNDERSTORMS APPROACHING STRONG LEVELS
/HAIL AND WIND THE PRIMARY THREATS/ PARTICULARLY ACROSS THE ROLLING
PLAINS...COINCIDING WITH THE BEST MOISTURE AND MID-LEVEL INSTABILITY.
KEEP IN MIND...IF THE CLOUD COVER HANGS AROUND A LITTLE LONGER THAN
ANTICIPATED ACROSS THE ROLLING PLAINS...THE LITTLE BIT OF MID-LEVEL
INSTABILITY MAY NOT BE ENOUGH TO OVERCOME THE CAPPED ATMOSPHERE AND
THUS STRONG THUNDERSTORMS MAY NOT BECOME REALIZED. THE LLJ KICKING
UP INTO THE 40-50 KT RANGE WILL MAINTAIN STORMS ACROSS THE ROLLING
PLAINS THIS EVENING-TONIGHT WHILST THE REMAINDER OF THE CWA BECOMES
ENVELOPED BY DRY-SLOTTING /W-SW WINDS/. SOUNDING PROFILES INDICATE
THIS SCENARIO RATHER WELL WITH TOP-DOWN MOISTENING OCCURRING THIS
AFTN-EVENING...AND DRYING ENSUING IN THE MID AND UPPER LEVELS BY
TONIGHT. LCL/S ARE A BIT LOW ACROSS THE FAR ROLLING PLAINS WHICH
RAISES CONCERNS FOR A TORNADO RISK. HOWEVER...THE AMOUNT OF 0-6 KM
BULK SHEAR MIGHT BE TOO MUCH OF A GOOD THING...AS IT COULD PREVENT
STORMS FROM MAINTAINING GOOD STRUCTURE.
500 MB HEIGHT FALLS WILL LEAD TO A COOLER ALBEIT STILL UNSEASONABLY
WARM SATURDAY...WITH HIGHS IN THE 60S AND 70S...FOLLOWED BY LOWS IN
THE 30S AND 40S.
LONG TERM...
COULD SEE A FEW LIGHT RAIN OR SNOW SHOWERS SUNDAY MORNING ACROSS THE
FAR SRN PANHANDLE AS THE CLOSED LOW SLOWLY EJECTS TO THE ENE ACROSS
THE PANHANDLE TO NWRN OKLAHOMA. HOWEVER...MAIN STORY TURNING OUT TO
BE WIND AS TIGHT LOW TO MID LEVEL HEIGHT GRADIENT ON THE S/SW FLANKS
OF THE UPPER LOW WILL LIKELY TRANSLATE INTO AT LEAST 20-30 MPH RANGE
ACROSS MUCH OF THE FCST AREA IN LINE WITH MOS VALUES AS COLD
ADVECTION WILL LIMIT THE POTENTIAL FOR 50 KT MID LEVEL WINDS TO MIX
TO THE SFC.
AFTER SHORT WAVE RIDGING BRINGS A WARMER AND LESS WINDY DAY
MONDAY...ANOTHER UPPER LOW PROGGED TO MOVE ACROSS THE COLORADO
ROCKIES MONDAY NIGHT AND ONTO THE CNTL HIGH PLAINS DURING THE DAY
TUESDAY. MODELS CURRENTLY PROGGING RAPID CYCLOGENESIS SERN COLO/SWRN
KANSAS EARLY TUESDAY WITH A MID LEVEL JET STREAK ON THE ORDER OF 50
TO 70 KTS ROTATING OVER THE SRN HIGH PLAINS DURING THE DAY TUESDAY.
DEEP COLD ADVECTION WILL AGAIN LIMIT POTENTIAL FOR MIXING TO THE
SFC...BUT AGAIN POTENTIAL EXISTS FOR AT LEAST 20-30 MPH TO BE
REALIZED.
BEYOND TUESDAY...A BROAD LONG WAVE UPPER TROUGH OVER THE WRN CONUS
WILL SHIFT EWD TO THE PLAINS WEDNESDAY LEAVING DRY AND UNEVENTFUL
NWLY FLOW OVER THE FCST AREA THROUGH THE END OF THE WEEK. COLD FRONT
OF CANADIAN ORIGIN BEHIND TUESDAYS UPPER LOW WILL BRING COLDER AIR
INTO THE REGION WITH TEMPS FINALLY REVERTING TO BELOW NORMAL
WEDNESDAY AND THURSDAY BEFORE MODERATING TO END THE WEEK.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
220 PM MST SAT DEC 12 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 220 PM MST SAT DEC 12 2015
LATEST INFRARED SATELLITE IMAGERY SHOWING WARMING CLOUD TOPS OUT
WEST ACROSS CARBON AND ALBANY COUNTIES THIS AFTERNOON. THE EASTERN
BAND OF LIFT CONTINUES TO SHOW COOLING CLOUD TOPS THAT CORRESPOND
PRETTY WELL WITH THE BANDED SNOW BEING OBSERVED ON RADAR IMAGERY.
LATEST HRRR GUIDANCE SHOWING BAND SHIFTING EAST AND NORTHEAST AS
THE EVENING PROGRESSES.
WENT AHEAD AND CANCELLED WINTER HEADLINES FROM THE LARAMIE RANGE
WEST. ROADS LOOK PRETTY GOOD OUT THAT WAY...THOUGH WITH LATE DAY
EARLY EVENING COOL DOWN...COULD SEE THESE ROADS BECOMING SLICK
WITH BLACK ICE. AS FOR THE ADVISORIES FROM CHEYENNE EAST...KEPT
THEM GOING AS SCHEDULED...WITH NO CHANGES EXPECTED.
700MB WINDS BEGIN PICKING UP SUNDAY AFTERNOON AS THE UPPER RIDGE
AXIS MOVES INTO EASTERN WYOMING. GFS WINDS NOT AS STRONG AS THEY
WERE PREVIOUS FOR SUNDAY...BUT STILL REACHING 45KTS SUNDAY NIGHT
INTO MONDAY MORNING. CONTINUED SOME BLOWING SNOW OUT WEST FOR THE
WIND PRONE AREAS. DEPENDING ON HOW STRONG THESE WINDS GET...MAY
NEED A BLOWING SNOW ADVISORY FOR THE ARLINGTON AREA SUNDAY NIGHT
INTO MONDAY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 220 PM MST SAT DEC 12 2015
THE UPPER RIDGE IN THE WAKE OF THE WEEKEND STORM SYSTEM MOVES
QUICKLY EAST ACROSS OUR AREA MONDAY AS A VIGOROUS AMPLIFYING UPPER
TROUGH MOVES EAST ACROSS NEVADA. BOTH THE GFS AND THE ECMWF CLOSE
OFF AND DEEPEN THE UPPER LOW AS IT MOVES ACROSS COLORADO TUESDAY
INTO WEDNESDAY. AS HAS BEEN TYPICAL OF THIS WINTER SEASON SO
FAR...THE GFS IS THE STRONGEST DYNAMICALLY WITH THE NEXT STORM
SYSTEM...BUT THE CONCENSUS AMONGST THE MODELS IS THAT THE NEXT
SYSTEM WILL COME OUT FARTHER NORTH THAN THE SYSTEM WE ARE WORKING
TODAY. ALSO GIVEN THAT LOW IS PROJECTED TO BE DEEPENING JUST TO
OUR SOUTH...IT IS ALSO ADVERTISED TO SLOW DOWN AS IT MOVES ACROSS
EASTERN INTO WESTERN KANSAS. THE MAIN SNOW EVENT LOOKS TO BE FROM
MONDAY NIGHT THROUGH WEDNESDAY MORNING WITH ENOUGH DURATION TO
EXPECT HIGHER TOTALS IN THE SOUTH LARAMIE RANGE AND JUST TO THE
EAST. IT IS TOO EARLY RIGHT NOW TO GET SPECIFIC WITH SNOWFALL
AMOUNTS WITH ANY PRECISION...HOWEVER IF THE MODEL TRENDS HOLD WE
COULD EXPECT HIGHER IMPACTS TO TRAVEL ACROSS SOUTHEASTERN WYOMING
AND THE WESTERN NEBRASKA PANHANDLE. LATER FORECASTS WILL REFINE
POTENTIAL IMPACTS AND TIMING ON THIS NEXT SNOW EVENT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1053 AM MST SAT DEC 12 2015
IFR FLIGHT CATEGORY BECOMING MORE WIDESPREAD IN LIGHT TO MODERATE
SNOW FROM CHEYENNE EAST ACROSS THE WESTERN NEBRASKA PANHANDLE AT
THIS HOUR. WILL KEEP CHEYENNE...SCOTTSBLUFF...ALLIANCE AND CHADRON
IN IFR FORECAST CATEGORY THROUGH MID EVENING AND THEN TREND
VISIBILITY UP TOWARDS LATE EVENING INTO THE EARLY MORNING HOURS.
DIDNT CARRY SNOW AT LARAMIE EVEN THOUGH A BRIEF SHOW SHOWER IS
POSSIBLE THIS AFTERNOON...BUT VFR SHOULD PREVAIL THERE AND RAWLINS
THROUGH MUCH OF THE FORECAST PERIOD WITH THE EXCEPTION OF A BRIEF
PERIOD OF MVFR CEILINGS AT LARAMIE THIS AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 220 PM MST SAT DEC 12 2015
MINIMAL FIRE WEATHER CONCERNS AS AREAS ACROSS EXTREME SOUTHERN
WYOMING HAVE SEEN ACCUMULATING SNOW FROM THIS PAST LOW PRESSURE
SYSTEM. STRONG WINDS STILL POSSIBLE SUNDAY LATE AFTERNOON THROUGH
THE EVENING HOURS...BUT TEMPERATURES WILL BE COLD AND WILL KEEP
HUMIDITIES IN CHECK. ANOTHER WINTER STORM SYSTEM POSSIBLE MONDAY
NIGHT INTO TUESDAY THAT COULD BRING WIDESPREAD MODERATE SNOW
ACCUMULATIONS ACROSS MUCH OF SOUTHEAST WYOMING AND NEBRASKA
PANHANDLE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR WYZ107-
108-118-119.
NE...WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR NEZ002-
003-019>021-054-055-095-096.
&&
$$
SHORT TERM...GCC
LONG TERM...JG
AVIATION...JG
FIRE WEATHER...GCC