Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/26/14
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1032 AM MDT THU APR 24 2014
.UPDATE...
ISSUED AT 1031 AM MDT THU APR 24 2014
CURRENT FORECASTS LOOK IN GOOD SHAPE. FLOW ALOFT BECOMING
NORTHWEST AS UPPER RIDGE BUILDS OVER THE GREAT BASIN. AIRMASS TO
BE DRY...STABLE AND SLIGHTLY COOLER WITH SOME MID AND HIGH LEVEL
MOISTURE DURING THE AFTERNOON. SURFACE HIGH OVER WESTERN COLORADO
ALONG WITH LOWERING PRESSURE OVER KANSAS CREATING GUSTY WINDS
ACROSS THE MOUNTAINS...FOOTHILLS AND NORTHEAST CORNER. WEAK
ANTICYCLONE BEGINNING TO DEVELOP NEAR DIA...CREATING WEAKER WINDS
ALONG THE FRONT RANGE AND NEARBY PLAINS WITH MORE OF A SOUTHERLY
COMPONENT. LATEST MODELS SHOW THIS PATTERN PERSISTING THROUGH THE
DAY...WITH GUSTY WEST TO NORTHWEST WINDS MOST LOCATIONS EXPECT IN
THE DENVER AREA WHERE LIGHT SOUTHERLY WINDS WILL PREVAIL.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 351 AM MDT THU APR 24 2014
NORTHWEST FLOW ALOFT WILL PREVAIL BEHIND THE EXITING TROUGH AND THE
APPROACHING RIDGE TODAY. THIS WILL BRING DRY CONDITIONS AND MOSTLY
SUNNY SKIES. SOME HIGH CLOUDS WILL PASS OVER THE TOP OF THE RIDGE
LATER IN THE DAY. AIRMASS WILL BE SLIGHTLY COOLER TODAY WHICH WILL
PUT MOST LOCATIONS IN THE 60S FOR HIGHS. SURFACE HIGH PRESSURE OVER
THE GREAT BASIN AND LOWER PRESSURE OVER THE CENTRAL PLAINS WILL
PRODUCE MAINLY WEST TO NORTHWEST WINDS. HOWEVER AN ANTI-CYCLONE MAY
FORM AND CAUSE WINDS TO TURN SOUTHERLY ALONG THE FRONT RANGE AND
PARTS OF THE PLAINS THIS AFTERNOON.
THE UPPER LEVEL RIDGE WILL MOVE ACROSS THE STATE TONIGHT. THIS WILL
CONTINUE TO KEEP THE AREA PRECIPITATION FREE. THERE WILL BE SOME
MOISTURE AT THE MID AND UPPER LEVEL OF THE ATMOSPHERE WHICH WILL
LEAD TO MID AND HIGH CLOUDS AT TIMES. OVERNIGHT LOWS WILL AGAIN BE
MILD WITH READINGS MAINLY IN THE UPPER 30S TO MID 40S OVER NORTHEAST
COLORADO.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 351 AM MDT THU APR 24 2014
ATTENTION OVER THE NEXT FEW DAYS CERTAINLY SURROUNDS DEEP UPPER
LEVEL TROUGH WHICH IS EXPECTED TO DROP INTO THE SOUTHWESTERN
UNITED STATES AND THEN DEEPEN SIGNIFICANTLY SOMEWHERE OVER THE
CENTRAL HIGH PLAINS. MODEL CONSENSUS IS COMING AROUND TO A MORE
CONSISTENT PATH...ALTHOUGH DIFFERENCES ON TIMING AND TRENDS STILL
ABOUND. AT THIS TIME...PER WATER VAPOR LOOP SEEMS LIKE THE ECMWF
HAS A HANDLE ON THE SIGNIFICANT PIECES OF ENERGY IN THE PACIFIC
BETWEEN 140W AND 170E. THIS SHOULD ALLOW AMPLE BUCKLING OF THE
FLOW WITH A RATHER SHARP TROUGH REACHING THE WEST COAST FRIDAY. IF
THE SHARPER TROUGH SOLUTION IS CORRECT...THEN WOULD PREFER THE
SLOWER AND EVER SO SLIGHTLY DEEPER SOLUTION OFFERED BY THE ECMWF.
FOR FRIDAY....DEEP WARM ADVECTION WILL OCCUR WITH LEE TROUGHING
AND WARM/RIDGING SOUTHWEST FLOW ALOFT. THIS SHOULD ALLOW
TEMPERATURES TO WARM 10-15 DEGREES ABOVE NORMAL. INCREASING
SOUTHERLY WINDS ESPECIALLY OVER THE PALMER DIVIDE AREA WILL LEAD
TO INCREASING FIRE DANGER BUT MOST OF THAT AREA SAW LIGHT/MODERATE
PRECIPITATION LAST NIGHT AND GREEN-UP CONTINUES. ONLY MARGINAL
AREA WOULD BE SOUTHERN LINCOLN COUNTY AGAIN.
BY SATURDAY...THE DIGGING TROUGH TO OUR WEST AND CONTINUED WARM
ADVECTION WILL BRING ANOTHER VERY WARM DAY TO THE FORECAST AREA.
HAVE BOOSTED HIGHS SEVERAL DEGREES FOR SATURDAY CONSIDERING THE
WARM ADVECTION...STRONG LEE TROUGHING AND MIXING...AND ONLY SLIGHT
INCREASE IN CLOUDS DURING THE DAY. FIRE DANGER WILL INCREASE AGAIN
OVER THE PLAINS WITH STRONG AND DRY SOUTH/SOUTHWEST WINDS.
WITH REGARD TO SEVERE WEATHER THREAT LATE SATURDAY AFTERNOON/
SATURDAY NIGHT...THE AMOUNT OF DRY AIR AHEAD OF SYSTEM APPEARS TO
BE QUITE SUBSTANTIAL. ALMOST ALL MODELS SUGGEST A DRYLINE PUSHING
WELL EAST INTO THE CENTRAL PLAINS...BUT MODELS USUALLY OVERDO
THIS EASTWARD PUSH OF THE DRYLINE WHEN DEEP PRESSURE FALLS OCCUR
IN EASTERN COLORADO. AT THIS TIME...WHILE WE DONT THINK THE
DRYLINE WILL PUSH AS FAR EAST AS MODELS SUGGEST...IT WOULD BE HARD
TO GET THE DEEPER MOISTURE TO HOLD EVEN OVER THE NORTHEAST CORNER.
WILL STILL MENTION SOME THREAT IN THE HAZARDOUS WEATHER OUTLOOK
AND A COUPLE OF THE SREF PLUMES ARE SHOWING NEAR 1000 J/KG CAPE
OVER THE NORTHEAST CORNER.
Q-G LIFT INCREASES SIGNIFICANTLY AND IS DEEP AND STRONG WITH THE
UPPER LEVEL TROUGH...AGAIN DEPENDING ON ITS EXACT MOVEMENT. THIS
WOULD RESULT IN HIGHER SHOWER AND STORM COVERAGE SATURDAY NIGHT
INTO SUNDAY MORNING ALTHOUGH TIMING IS STILL SOMEWHAT IN QUESTION.
WILL TREND POP FORECAST TOWARD ECMWF SOLUTION FOR NOW GIVEN
PREFERENCE MENTIONED ABOVE. IF SYSTEM CONTINUES TO PULL TO THE
NORTHEAST...THEN STRONGER DOWNSLOPE WOULD BE DEVELOPING BY SUNDAY
WITH DRIER AIR ESPECIALLY ALONG THE FRONT RANGE WHERE DOWNSLOPE IS
MAXIMIZED. MEANWHILE...IN THE MOUNTAINS STRONG OROGRAPHIC FLOW
DEVELOPING ON BACKSIDE OF UPPER TROUGH COMBINED WITH MID LEVEL
INSTABILITY AND LIFT COULD PRODUCE A SIGNIFICANT SNOWFALL FOR THE
HIGH COUNTRY. STILL TOO EARLY TO ISSUE ANY WATCHES BUT POTENTIAL
IS CERTAINLY THERE. WITH REGARD TO FOOTHILL QPF AND POTENTIAL
RUNOFF...IF PERSISTENCE DUE TO ANY SLOWER STORM MOTION OR UPSLOPE
WOULD OCCUR THEN PRECIPITATION WOULD LIKELY CHANGE TO SNOW AT MOST
ELEVATIONS ABOVE 7000-7500 FEET. THAT WOULD EFFECTIVELY LIMIT ANY
RUNOFF EVEN IF STORM IS SLOWER/DEEPER THAN MOST MODEL RUNS
INDICATE.
FOR MONDAY-WEDNESDAY...A DEEP AND CLOSED UPPER TROUGH SEEMS
CONTENT TO SPIN OVER THE MIDWEST. THIS WOULD KEEP TEMPERATURES
ABOUT 10 DEGREES BELOW NORMAL ALONG WITH A LOW CHANCE OF SHOWERS.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z FRIDAY MORNING)
ISSUED AT 1031 AM MDT THU APR 24 2014
CURRENT TAF TRENDS LOOK ON TRACK. WEAK ANTICYCLONE DEVELOPING JUST
NORTHWEST OF DENVER CREATING SOUTHEASTERLY WINDS ACROSS THE AREA
AIRPORTS. BOTH THE RAP AND HRRR MOVE THE ANTICYLONE EAST OF DENVER
AROUND 21Z...WITH WESTERLY WINDS MOVING OFF THE FOOTHILLS ACROSS
THE DENVER AREA. THIS ALREADY NOTED IN THE LAST TAF UPDATE FOR
KDEN AND KBJC. WILL CONTINUE FOR THE UPCOMING ISSUANCE. THERE IS
A SLIGHT CHANCE FOR THE WESTERLY WINDS OCCURRING AT KAPA BUT WILL
HOLD OFF FOR NOW. VFR TO PREVAIL WITH SOME MID AND HIGH LEVEL
MOISTURE.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...D-L
SHORT TERM...MEIER
LONG TERM...BARJENBRUCH
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
626 AM EDT THU APR 24 2014
.SYNOPSIS...
HIGH PRESSURE WILL SHIFT OFF THE COAST TODAY THROUGH FRIDAY.
A WEAK COLD FRONT COULD DRIFT IN FROM THE NORTH THIS WEEKEND
BEFORE HIGH PRESSURE BUILDS OVER THE AREA THROUGH EARLY NEXT WEEK.
A STRONGER COLD FRONT WILL CROSS THE REGION NEXT TUESDAY OR
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
24/06Z GUIDANCE INCLUDING THE 09Z RAP HAVE TRENDED WARMER WITH HIGHS
THIS AFTERNOON ACROSS INTERIOR SOUTHEAST GEORGIA. WILL EXPAND THE
AREA OF MID-80S TO MATCH THIS. NO OTHER MAJOR CHANGES WILL BE
MADE.
AN UPPER LEVEL RIDGE AXIS WILL PASS OVERHEAD THIS AFTERNOON AS
SURFACE HIGH PRESSURE SHIFTS OFF THE COAST. THE SYNOPTIC FLOW WILL
BECOME SOUTHEAST THIS AFTERNOON AND EVENTUALLY TO THE SOUTH
TONIGHT AS THE HIGH SHIFTS FARTHER OFFSHORE AND A COLD FRONT
APPROACHES FROM THE WEST. LOW-LEVEL MOISTURE RETURN WILL GENERALLY
REMAIN FOCUSED ACROSS NORTHERN FLORIDA AND FAR SOUTHERN GEORGIA
THROUGH MUCH OF THE DAY...ALTHOUGH MIXING RATIOS WILL BEGIN TO
INCREASE ACROSS THE FAR SOUTHERN ZONES LATE. A ROBUST SEA BREEZE
CIRCULATION WILL DEVELOP EARLY THIS AFTERNOON ALONG THE BEACHES
AND MOVE STEADILY INLAND...AIDED BY THE INCREASED SOUTHEASTERLY
FLOW. THERE MAY BE JUST ENOUGH LOW-LEVEL MOISTURE FLUX CONVERGENCE
TO SUPPORT AN ISOLATED SHOWER OR TO ACROSS INTERIOR SOUTHEAST
GEORGIA...MAINLY SOUTH OF I-16...BUT PROBABILITIES LOOK TOO LOW TO
MENTION SLIGHT CHANCE POPS ATTM. HIGHS WILL RANGE FROM THE UPPER
70S/NEAR 80 ACROSS THE CHARLESTON TRI-COUNTY AREA TO THE LOWER-MID
80S ACROSS ELSEWHERE...WARMEST FAR INTERIOR SOUTHEAST GEORGIA.
BEACH LOCATIONS WILL REMAIN CONSIDERABLY COOLER WITH THE SHELF
WATERS STILL RATHER COOL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
TONIGHT...RETURN FLOW WILL BE IN FULL SWING AS A COLD FRONT
APPROACHES FROM THE WEST AND HIGH PRESSURE SLIPS FARTHER OFFSHORE.
MODELS SHOW SOME WEAK ISENTROPIC ASSENT DEVELOPING FROM SOUTH-
NORTH AS THE NIGHT PROGRESSES...BUT NONE OF THE VARIOUS MEMBERS
ARE OVERLY AGGRESSIVE IN THE DEVELOPMENT OF NOCTURNAL SHOWER
ACTIVITY AS MOST OF THE LIFT WILL GO TOWARDS CLOUD FORMATION GIVEN
THE HIGH CONDENSATION PRESSURE DEFICITS. WILL KEEP THE FORECAST
DRY WITH THE EXCEPTION OF THE CHARLESTON COUNTY COAST WHERE SOME
MARINE BASED CONVECTION COULD BRUSH AREAS FROM ROUGHLY FOLLY BEACH
TO MCCLELLANVILLE VERY EARLY THURSDAY. IT WILL BE A WARM NIGHT
WITH NOCTURNAL JETTING LIKELY KEEPING THE BOUNDARY LAYER FROM
FULLY DECOUPLING. LOWS WILL RANGE FROM THE UPPER 50S FAR INTERIOR
SOUTHEAST SOUTH CAROLINA TO THE LOWER-MID 60S ELSEWHERE. THIS IS
SLIGHTLY ABOVE THE 00Z GUIDANCE CONSENSUS.
FRIDAY...WE SHOULD SEE A FAIR AMOUNT OF CLOUDS TO START OFF THE DAY
AS MODEST ISENTROPIC ASCENT OCCURS AHEAD OF AN EASTWARD ADVANCING H5
SHORTWAVE JUST TO OUR NORTH. WE COULD SEE A FEW SHOWERS DURING
MORNING HOURS AS A RESULT...MAINLY ALONG THE COAST IN SOUTHEAST
SOUTH CAROLINA. A SLIGHT CHANCE OF SHOWERS AND/OR THUNDERSTORMS WILL
THEN BE POSSIBLE BY FRIDAY AFTERNOON AS INSTABILITY INCREASES DURING
PEAK HEATING WITH SBCAPES APPROACHING 700-1200 J/KG AND LIFTED INDEX
VALUES BETWEEN -1 TO -3C. THUNDERSTORM CHANCES APPEAR HIGHEST OVER
INLAND AREAS IN SOUTHEAST SOUTH CAROLINA WHERE FORCING FROM THE H5
SHORTWAVE AND A ARRIVING COLD FRONT ARE GREATEST. ALTHOUGH A CAPPING
INVERSION WILL SUPPRESS MOST DEEP CONVECTION...WE CAN NOT RULE OUT A
STRONGER THUNDERSTORM OR TWO BY FRIDAY EVENING. ACTIVITY WILL LIKELY
DIMINISH WITH COLD FROPA AND DIURNAL HEAT LOSS EARLY FRIDAY NIGHT.
1000-850 MB THICKNESS VALUES ALONG WITH SOME COMPRESSIONAL HEATING
SUPPORT OVERALL HIGH TEMPS IN THE LOW/MID 80S AWAY FROM THE COAST.
OVERNIGHT LOWS WILL RANGE IN UPPER 50S INLAND TO LOWER 60S ALONG THE
COAST BEHIND THE FRONT.
SATURDAY...HIGH PRESSURE WILL HOLD OVER THE AREA UNDER A BUILDING
RIDGE ALOFT. A DOWNSLOPING WIND COMPONENT WILL LIKELY SUPPORT ANOTHER
DAY OF WARM TEMPS WITH AFTERNOON HIGHS IN THE MID 80S OVER MOST
LOCATIONS AWAY FROM THE IMMEDIATE COAST. A WEAK AND DRY COLD FRONT
SHOULD STALL OR DISSIPATE NORTH OF THE FORECAST AREA SATURDAY
NIGHT...WITH LITTLE TO NO INFLUENCE OVER THE SOUTHEAST. THUS A
RAIN-FREE DAY IS EXPECTED. STRONG RADIATIONAL COOLING WILL ALLOW
OVERNIGHT TEMPS TO REACH THE UPPER 50S INLAND TO LOWER 60S ALONG THE
COAST.
SUNDAY...CONDITIONS LOOK FAIRLY DRY TO START OFF THE WEEK AS
ATLANTIC HIGH PRESSURE LINGERS OVER THE AREA WELL AHEAD OF A STRONG
LOW PRESSURE SYSTEM TRACKING EAST OVER THE CENTRAL UNITED STATES.
LIGHT SOUTHERLY FLOW ALONG WITH MID LVL RIDGING SHOULD RESULT IN
EVEN WARMER TEMPS THAN THE PREVIOUS DAY. LATEST 1000-850 MB
THICKNESSES FAVOR OVERALL HIGH TEMPS IN THE MID/UPPER 80S AWAY FROM
THE COAST...WARMEST IN SOUTHEAST GEORGIA.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
LIGHT SOUTHERLY FLOW ALONG WITH MID LVL RIDGING OVER THE SOUTHEAST
WILL LIKELY KEEP WARMER TEMPS OVER THE SOUTHEAST INTO EARLY NEXT
WEEK AHEAD OF THE APPROACHING LOW PRESSURE SYSTEM. IN GENERAL...HIGH
TEMPS WILL BE IN THE LOW/MID 80S MONDAY AND TUESDAY BEFORE COOLING A
FEW DEGREES ON WEDNESDAY AS CLOUD COVER INCREASES WITH THE LOW
PRESSURE SYSTEM SHIFTING OVER THE EASTERN CONUS. A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS WILL REMAIN IN THE FORECAST ON MONDAY AS
SOUTHERLY FLOW DEEPENS MOISTURE OVER THE AREA WHILE AN H5 SHORTWAVE
PASSES OVERHEAD. PRECIP CHANCES SHOULD THEN INCREASE TUESDAY AND
WEDNESDAY AHEAD OF AN EASTWARD MOVING COLD FRONT ASSOCIATED WITH THE
LOW PRESSURE SYSTEM. THERE ARE INDICATIONS THAT WE COULD SEE AN
ENHANCED PERIOD OF SHOWERS AND/OR THUNDERSTORMS LATE TUESDAY INTO
WEDNESDAY AS STRONGER INSTABILITY AND WIND FIELDS SET UP OVER THE
SOUTHEAST AHEAD OF THE FRONT. A FEW THUNDERSTORMS COULD BE
STRONG...ESPECIALLY ON WEDNESDAY DURING PEAK HEATING. SHOWERS AND/OR
THUNDERSTORMS COULD PERSIST INTO MUCH OF THURSDAY AS THE COLD FRONT
SHIFTS OFFSHORE EARLY WHILE THE LARGE MID/UPPER LVL TROUGH REMAINS
POSITIONED OVER THE EASTERN CONUS. OVERALL TEMPS SHOULD COOL OFF
POST FROPA...WITH HIGHS ONLY IN THE MID/UPPER 70S ON THURSDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
VFR...ALTHOUGH THE RISK FOR SUB-VFR CIGS WILL INCREASE AT KSAV
TOWARDS THE END OF THE 12Z TAF PERIOD.
EXTENDED AVIATION OUTLOOK...LOW CHANCES OF MVFR CIGS/VSBYS LATE
MONDAY AND TUESDAY WITH SHOWERS AND/OR THUNDERSTORMS.
&&
.MARINE...
TODAY...EAST TO NORTHEAST WINDS WILL GRADUALLY VEER MORE SOUTHERLY
THIS AFTERNOON AS HIGH PRESSURE SHIFTS OFF THE COAST AND A ROBUST
SEA BREEZE CIRCULATION TAKES HOLD. WINDS WILL GENERALLY BE 10-15
KT WITH SEAS 1-3 FT.
TONIGHT...SOUTHERLY WINDS WILL DOMINATE AS HIGH PRESSURE SHIFTS
EVEN FARTHER OFFSHORE WINDS. WINDS WILL BE 10-15 KT WITH SEAS 2-3
FT.
FRIDAY THROUGH TUESDAY...A WEAK COLD FRONT WILL QUICKLY ADVANCE OVER
THE WATERS FRIDAY NIGHT...LEADING TO A MARGINAL SURGE OF WINDS
BETWEEN 15-20 KTS LATE. HIGH PRESSURE WILL THEN BUILD OVER THE
WATERS SATURDAY AND PERSIST INTO EARLY NEXT WEEK AHEAD OF A LOW
PRESSURE SYSTEM ADVANCING TO THE EASTERN CONUS. WINDS/SEAS ARE
EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH EARLY
TUESDAY...BUT SHOULD APPROACH SMALL CRAFT ADVISORY LEVELS BY TUESDAY
NIGHT AS THE PRESSURE GRADIENT ENHANCES AHEAD OF A COLD FRONT
ADVANCING TO THE SOUTHEASTERN UNITED STATES BY MIDWEEK. IN
GENERAL...SOUTH/SOUTHEAST WINDS WILL REMAIN AT OR BELOW 15 KTS
THROUGH EARLY TUESDAY WHILE SEAS ARE NO HIGHER THAN 3-4 FT. BY
TUESDAY NIGHT...WINDS/SEAS SHOULD INCREASE/BUILD TO 20-25 KTS AND
4-6 FT...HIGHEST BEYOND 10 NM FROM THE COAST.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST/DPB
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
228 PM CDT THU APR 24 2014
.DISCUSSION...
351 AM CDT
MAIN FOCUS THIS MORNING IS WITH SLOWER PROGRESSION OF SURFACE LOW
AND COLD FRONT AND ASSOCIATED RAIN ESPECIALLY LATE TODAY/TONIGHT.
BREEZY/MILD DAY FRIDAY...BEFORE SECOND COLD FRONT PASSES FRIDAY
EVENING AND SETS STAGE FOR PROLONGED PERIOD OF COOL/WET WEATHER
ESPECIALLY SATURDAY NIGHT-WEDNESDAY.
BAND OF SHOWERS/GRAUPEL WITH LEAD SHORT WAVE TROUGH CONTINUES TO
LIFT NORTHEAST ACROSS NORTH/NORTHEAST PARTS OF THE CWA AT 0830Z.
DRYING EVIDENT UPSTREAM INTO WESTERN IL/MO...WITH NEAR TERM GUIDANCE
IN GOOD AGREEMENT IN SUGGESTING MOST OF FORECAST AREA WILL SEE DRY
WEATHER FOR MUCH OF THE MORNING/EARLY AFTERNOON HOURS AS INITIAL
ELEVATED WARM FRONTAL PRECIP LIFTS NORTH OF THE AREA. TREND IN MODEL
GUIDANCE OVER THE PAST 24 HOURS HAS BEEN TO SLOW EASTWARD
PROGRESSION OF COLD FRONT...WITH DEEPER SOUTHERN STREAM SHORT WAVE
ALSO RESULTING IN SURFACE LOW REFLECTION TRACKING FARTHER SOUTH
ACROSS CENTRAL IL. OVERALL...ONLY REAL CHANGE TO GOING FORECAST WAS
TO SLOW ARRIVAL AND DEPARTURE OF HIGHER POPS WITH THE FRONT THROUGH
TONIGHT. WITH STEADIER RAINFALL TONIGHT...STILL LOOKS TO BE ABOUT A
HALF INCH AREA WIDE. FORECAST SOUNDINGS INDICATE LAPSE RATES NOT
PARTICULARLY IMPRESSIVE...AND HAVE ONLY INDICATED ISOLATED THUNDER
MAINLY WITH APPROACH OF COLD LATE TODAY/TONIGHT. FRONT CLEARS
EASTERN CWA AROUND SUNRISE FRIDAY MORNING...WITH WEAK FLAT SURFACE
RIDGE DEVELOPING ACROSS THE AREA DURING THE DAY. DEEPER MIXING AND
SUBSIDENCE INDICATE FRIDAY MAY BE THE MILDEST DAY OF THE STRETCH
WITH MID 60S-LOW 70S EXPECTED FROM FAR NORTH TO FAR SOUTH.
AS INDICATED OVER THE PAST FEW DAYS...ANOTHER COLD FRONT ASSOCIATED
WITH NORTHERN STREAM DISTURBANCE DOES SETTLE SOUTH ACROSS THE
FORECAST AREA FRIDAY EVENING. MODELS CONTINUE TO HAVE SOME
DIFFICULTY PINNING DOWN EXACT TIMING/PLACEMENT OF THE FRONT AS IT
SLOWS UP OVER CENTRAL IL/IN FRIDAY NIGHT...THOUGH MOST GUIDANCE DOES
INDICATE POTENTIAL FOR SOME SPOTTY LIGHT PRECIP AS FRONT UNDERCUTS
WEST-SOUTHWEST FLOW ALOFT. WITH CONFIDENCE IN TIMING/PLACEMENT OF
ANY LIGHT SHOWERS RATHER LOW...HAVE BROAD-BRUSHED SLIGHT CHANCE
OVERNIGHT THOUGH NOT EXPECTING RAIN TO AMOUNT TO MUCH.
BRIEF INTRUSION OF HIGH PRESSURE RIDGING FROM THE NORTH ON SATURDAY
EXPECTED TO YIELD DRY BUT COOLER WEATHER...BEFORE STATIONARY FRONTAL
BOUNDARY TO OUR SOUTH BECOMES FOCUS FOR PRECIP DEVELOPMENT SATURDAY
NIGHT THROUGH THE EXTENDED PORTION OF THE FORECAST AS CLOSED UPPER
LOW AND ITS ASSOCIATED SURFACE CIRCULATION SLOWLY WOBBLES FROM THE
PLAINS TO THE GREAT LAKES REGION THROUGH THE MIDDLE OF NEXT WEEK.
COOL AND GENERALLY WET WEATHER TO PREDOMINATE...WITH EAST-NORTHEAST
LOW LEVEL WINDS AND PERSISTENT MOIST ASCENT FROM THE SOUTH ABOVE THE
STATIONARY BAROCLINIC ZONE TO OUR SOUTH. GUIDANCE HAS TRENDED
GENERALLY WARMER ALOFT SUNDAY-TUESDAY...THOUGH AFOREMENTIONED LOW
LEVEL WINDS OFF LAKE MICHIGAN WILL LIKELY MAKE FOR A FAIRLY LARGE
GRADIENT FROM NORTH TO SOUTH FOR MUCH OF THE PERIOD...WITH HIGHS
ALONG THE LAKE IN THE 40S...WHILE 60S ARE MORE PREVALENT SOUTH OF
THE I-80 CORRIDOR.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* GUSTY SOUTHEAST WINDS THIS AFTERNOON AND EVENING...DIMINISHING
MID EVENING...THEN TURNING TO THE NORTHWEST OVERNIGHT INTO EARLY
FRIDAY.
* CHANCES FOR SHOWERS THIS EVENING/TONIGHT RESULTING IN MVFR
CONDITIONS.
BMD
//DISCUSSION...UPDATED 18Z...
A BROAD AREA OF LOW PRESSURE LIES OVER THE PLAINS THIS AFTERNOON.
AHEAD OF THE LOW THIS AFTERNOON AND EVENING...EXPECT GUSTY SOUTHEAST
WINDS TO CONTINUE ACROSS NORTHERN ILLINOIS...WITH GUSTS PUSHING 30
KT AT TIMES. THIS LOW WILL CONSOLIDATE AS IT MOVES EAST ACROSS
CENTRAL ILLINOIS LATE THIS EVENING/TONIGHT. SHOWERS ALONG WITH
LOWERING CIGS WILL ACCOMPANY THE LOW THIS EVENING. CIGS ARE EXPECTED
TO LOWER TO MVFR...AND CANNOT COMPLETELY RULE OUT IFR AT THIS
TIME...THOUGH THERE ARE BETTER CHANCES FOR CIGS BOTTOMING OUT IN THE
010-015 RANGE. WINDS MAY GO VARIABLE FOR A BRIEF PERIOD AS AN
INVERTED TROUGH PUSHES ACROSS THE AREA...THEN EXPECT WINDS TO BECOME
NNW TO NW BEHIND THE TROUGH WITH CONDITIONS QUICKLY RETURNING TO VFR.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM-HIGH CONFIDENCE IN PRECIP TIMING/IMPACTS TO VSBY THIS
EVENING.
* HIGH CONFIDENCE IN MVFR CIGS...LOW CONFIDENCE IN IFR.
* HIGH CONFIDENCE IN WIND DIRECTION/SPEED THIS AFTERNOON AND EVENING.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...SLIGHT CHANCE OF SHOWERS...OTHERWISE VFR.
SATURDAY...CHANCE OF SHOWERS LATE...OTHERWISE VFR.
SUNDAY...CHANCE OF SHOWERS...OTHERWISE VFR.
MONDAY...CHANCE OF SHOWERS...OTHERWISE VFR.
TUESDAY...CHANCE OF SHOWERS...OTHERWISE VFR.
WEDNESDAY...CHANCE OF SHOWERS...OTHERWISE VFR.
RODRIGUEZ
&&
.MARINE...
158 PM CDT
TWO WEAK LOW PRESSURE CENTERS WERE LOCATED WEST OF LAKE MICHIGAN.
ONE WAS STEADILY WEAKENING OVER CENTRAL IOWA...WHILE A SECOND WAS
BEGINNING TO STRENGTHEN ACROSS CENTRAL MISSOURI. THE TWO LOW
PRESSURES ARE EXPECTED TO CONSOLIDATE THIS EVENING...THEN STEADILY
LIFT NORTHEAST/EAST ACROSS CENTRAL ILLINOIS OVERNIGHT. IN THE
MEANTIME...WINDS WILL GENERALLY REMAIN EASTERLY TO SOUTHEASTERLY.
A TIGHT GRADIENT DOES EXIST...WHICH HAS RESULTED IN WINDS AT TIMES
GUSTING TO 30KT THIS AFTN. GUIDANCE HAS BEEN CONSISTENT IN
DEPICTING WINDS DIMINISHING TONIGHT...THEN WINDS WILL TURN
WEST/NORTHWEST. THIS WILL ALLOW THE WAVES TO SUBSIDE ACROSS THE
NORTH/NORTHWEST PORTIONS OF THE LAKE...WHILE WAVES BEGIN TO BUILD
ONCE AGAIN FOR THE INDIANA NEARSHORE WATERS FRIDAY MIDDAY THROUGH
FRIDAY NIGHT.
HIGH PRESSURE WILL SLIDE EAST ACROSS MANITOBA TO NORTH OF LAKE
SUPERIOR EARLY SATURDAY. THIS WILL ALLOW WINDS TO TURN NORTHERLY
EARLY SATURDAY THEN NORTHEAST TO EASTERLY ACROSS THE LAKE BY
SATURDAY AFTERNOON. THEN A PROLONGED PERIOD OF GENERALLY EASTERLY
WINDS IS EXPECTED ACROSS THE LAKE SUNDAY THROUGH TUESDAY.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM THURSDAY.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1259 PM CDT Thu Apr 24 2014
.DISCUSSION...
ISSUED 1046 AM CDT Thu Apr 24 2014
Area of low pressure currently located near Kansas City will track
slowly E/NE into west-central Illinois by this evening. While
showers and thunderstorms are prevalent ahead of this feature
across central and western Missouri, the airmass further east over
Illinois remains rather dry. 15z/10am surface dewpoints are only
in the middle to upper 30s, while the 12z KILX upper air sounding
showed a large amount of dry air below 700mb. With a southeasterly
low-level flow ahead of the system, am not expecting much moisture
advection before the low and its associated front arrive. High-res
models such as the HRRR and the NAM12 are suggesting that the
eastward progression of the precip will be slower than previously
expected and this seems reasonable given the current conditions.
Have therefore trimmed POPs back today. Will keep the entire KILX
CWA dry through midday, then will slowly advance precip eastward
this afternoon. Will continue with a dry forecast east of the
I-57 corridor through the entire afternoon, with POPs gradually
ramping up to categorical further west across the Illinois River
Valley. Also made adjustments to sky cover to feature more
sunshine across the E/SE. Zone update will be issued shortly.
Barnes
&&
.AVIATION...
ISSUED 1259 PM CDT Thu Apr 24 2014
Showers are beginning to spread into the Illinois River Valley and
may impact KPIA over the next couple of hours. However, overall
trend has been for precip to diminish as it moves eastward into the
dry airmass over Illinois. As atmosphere slowly moistens and upper
wave and its associated cold front approach from the west, showers
will gradually become more prevalent across west-central Illinois
late this afternoon, then will spread eastward across the
remainder of the area during the evening. Most model guidance
suggests KCMI will remain dry until mid-evening at the earliest.
Time-height cross-sections generally reveal MVFR ceilings with
skies clearing from west to east after midnight. Will end the
showers and clear skies at KPIA at 08z, then further east to KCMI
by around 12z. Winds will initially be gusty from the southeast
this afternoon, then will become northwesterly after FROPA later
this evening.
Barnes
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT Thu Apr 24 2014
SHORT TERM...Today through Sunday
00Z models continue to be slower with cold frontal passage and
associated convection and that is the biggest change in the
forecast package. Most areas will be dry this morning with showers
and thunderstorms affecting areas from I-55 west this afternoon
and possibly getting as far east as I-57 late this afternoon. SPC
keeps slight risk of severe storms in southern IL south of our
CWA. Though there is a 5% risk of damaging wind gusts in far sw CWA
from Springfield to Lawrenceville south late this afternoon and
evening. Upper level trof over CO/NM with embedded short wave to
move into IL overnight while a cold front moves east across IL
during tonight. Have increased pops this evening due to slower
movement of front and then decreasing pops from west to east
behind cold front during overnight. Highs today in the upper 60s
nw over IL river valley to mid 70s se of I-70. Lows tonight 45-50F
over central IL and 50-55F in southeast IL. Rainfall amounts this
afternoon and tonight of a half to three quarter inch with locally
three quarter to 1 inch west of I-55.
Storm system to pass east of IL across IN/OH Friday morning with
more sunshine returning and mild highs in the low to mid 70s and
warmest over sw counties. Even a few degrees warmer on Saturday as
models have 850 mb temps of 12-14C. Still appears dry Friday
through the day on Saturday with partly to mostly sunny skies Sat.
Rather mild again on Sunday with highs in the upper 60s to mid 70s.
Models have trended warmer this weekend ahead of next storm system
over the Rockies. Continue chances of showers and isolated
thunderstorms Saturday night and Sunday as warm air advection
regime sets up again.
LONG TERM...Sunday night through Thursday
Extended models like GFS, ECMWF and GEM develop a strong/large cutoff
upper level low near CO Sunday morning and then move it into the MO
valley Tue and mid MS river valley during middle of next week.
This to bring an unsettled weather pattern with daily chance of
showers and isolated thunderstorms from Sunday through Thursday
with highest chances Sunday night through Tuesday. Mild temps
early in the week to cool by middle of next week as upper level
low moves near IL. Widespread rainfall amounts of 1-2 inches
expected during this time with heaviest amounts southern areas.
Seasonable highs in the upper 60s and lower 70s Monday cool into
the low to mid 50s Wed/Thu.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1111 AM CDT THU APR 24 2014
.DISCUSSION...
351 AM CDT
MAIN FOCUS THIS MORNING IS WITH SLOWER PROGRESSION OF SURFACE LOW
AND COLD FRONT AND ASSOCIATED RAIN ESPECIALLY LATE TODAY/TONIGHT.
BREEZY/MILD DAY FRIDAY...BEFORE SECOND COLD FRONT PASSES FRIDAY
EVENING AND SETS STAGE FOR PROLONGED PERIOD OF COOL/WET WEATHER
ESPECIALLY SATURDAY NIGHT-WEDNESDAY.
BAND OF SHOWERS/GRAUPEL WITH LEAD SHORT WAVE TROUGH CONTINUES TO
LIFT NORTHEAST ACROSS NORTH/NORTHEAST PARTS OF THE CWA AT 0830Z.
DRYING EVIDENT UPSTREAM INTO WESTERN IL/MO...WITH NEAR TERM GUIDANCE
IN GOOD AGREEMENT IN SUGGESTING MOST OF FORECAST AREA WILL SEE DRY
WEATHER FOR MUCH OF THE MORNING/EARLY AFTERNOON HOURS AS INITIAL
ELEVATED WARM FRONTAL PRECIP LIFTS NORTH OF THE AREA. TREND IN MODEL
GUIDANCE OVER THE PAST 24 HOURS HAS BEEN TO SLOW EASTWARD
PROGRESSION OF COLD FRONT...WITH DEEPER SOUTHERN STREAM SHORT WAVE
ALSO RESULTING IN SURFACE LOW REFLECTION TRACKING FARTHER SOUTH
ACROSS CENTRAL IL. OVERALL...ONLY REAL CHANGE TO GOING FORECAST WAS
TO SLOW ARRIVAL AND DEPARTURE OF HIGHER POPS WITH THE FRONT THROUGH
TONIGHT. WITH STEADIER RAINFALL TONIGHT...STILL LOOKS TO BE ABOUT A
HALF INCH AREA WIDE. FORECAST SOUNDINGS INDICATE LAPSE RATES NOT
PARTICULARLY IMPRESSIVE...AND HAVE ONLY INDICATED ISOLATED THUNDER
MAINLY WITH APPROACH OF COLD LATE TODAY/TONIGHT. FRONT CLEARS
EASTERN CWA AROUND SUNRISE FRIDAY MORNING...WITH WEAK FLAT SURFACE
RIDGE DEVELOPING ACROSS THE AREA DURING THE DAY. DEEPER MIXING AND
SUBSIDENCE INDICATE FRIDAY MAY BE THE MILDEST DAY OF THE STRETCH
WITH MID 60S-LOW 70S EXPECTED FROM FAR NORTH TO FAR SOUTH.
AS INDICATED OVER THE PAST FEW DAYS...ANOTHER COLD FRONT ASSOCIATED
WITH NORTHERN STREAM DISTURBANCE DOES SETTLE SOUTH ACROSS THE
FORECAST AREA FRIDAY EVENING. MODELS CONTINUE TO HAVE SOME
DIFFICULTY PINNING DOWN EXACT TIMING/PLACEMENT OF THE FRONT AS IT
SLOWS UP OVER CENTRAL IL/IN FRIDAY NIGHT...THOUGH MOST GUIDANCE DOES
INDICATE POTENTIAL FOR SOME SPOTTY LIGHT PRECIP AS FRONT UNDERCUTS
WEST-SOUTHWEST FLOW ALOFT. WITH CONFIDENCE IN TIMING/PLACEMENT OF
ANY LIGHT SHOWERS RATHER LOW...HAVE BROAD-BRUSHED SLIGHT CHANCE
OVERNIGHT THOUGH NOT EXPECTING RAIN TO AMOUNT TO MUCH.
BRIEF INTRUSION OF HIGH PRESSURE RIDGING FROM THE NORTH ON SATURDAY
EXPECTED TO YIELD DRY BUT COOLER WEATHER...BEFORE STATIONARY FRONTAL
BOUNDARY TO OUR SOUTH BECOMES FOCUS FOR PRECIP DEVELOPMENT SATURDAY
NIGHT THROUGH THE EXTENDED PORTION OF THE FORECAST AS CLOSED UPPER
LOW AND ITS ASSOCIATED SURFACE CIRCULATION SLOWLY WOBBLES FROM THE
PLAINS TO THE GREAT LAKES REGION THROUGH THE MIDDLE OF NEXT WEEK.
COOL AND GENERALLY WET WEATHER TO PREDOMINATE...WITH EAST-NORTHEAST
LOW LEVEL WINDS AND PERSISTENT MOIST ASCENT FROM THE SOUTH ABOVE THE
STATIONARY BAROCLINIC ZONE TO OUR SOUTH. GUIDANCE HAS TRENDED
GENERALLY WARMER ALOFT SUNDAY-TUESDAY...THOUGH AFOREMENTIONED LOW
LEVEL WINDS OFF LAKE MICHIGAN WILL LIKELY MAKE FOR A FAIRLY LARGE
GRADIENT FROM NORTH TO SOUTH FOR MUCH OF THE PERIOD...WITH HIGHS
ALONG THE LAKE IN THE 40S...WHILE 60S ARE MORE PREVALENT SOUTH OF
THE I-80 CORRIDOR.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* STRONG/GUSTY SOUTHEAST WINDS TODAY.
* SHOWERS LATER TONIGHT INTO EARLY FRIDAY MORNING.
* LOW END MVFR CEILINGS LIKELY TONIGHT INTO EARLY FRIDAY
MORNING...WITH A POSSIBILITY FOR IFR CEILINGS.
RODRIGUEZ/DEUBELBEISS
//DISCUSSION...UPDATED 12Z...
VFR CEILINGS IN PLACE THIS MORNING WITH ANY LINGERING SHOWERS WELL
NORTH/NORTHEAST OF THE TERMINALS AT THIS TIME. EXPECT DRY
CONDITIONS FOR MOST OF TODAY AND EVENING WITH ONLY MID/HIGH HIGH
LEVEL CLOUD COVER LIKELY FOR MOST OF TODAY. A SLOWER EVOLUTION OF
THE APPROACHING SYSTEM TODAY IS APPEARING LIKELY AND HAVE PUSHED
BACK TIMING OF SHOWERS TO LATER TONIGHT WHEN THIS TROUGH OF LOW
PRESSURE FINALLY ARRIVES. ALTHOUGH THERE DOES STILL APPEAR TO BE
SOME POSSIBLE ISOLATED LIGHT SHOWERS BEFORE THEN...EXPECT ANY
SHOWERS TO BRIEF AND LIGHT AND SO HAVE REMOVED THE VCSH MENTION
FOR EARLIER THIS EVENING. NOT EXPECTED THUNDER WITH THE SHOWERS
TONIGHT AS BEST INSTABILITY/MOISTURE WILL REMAIN WELL SOUTH OF ALL
THE TERMINALS. VFR CEILINGS THIS EVENING WILL LIKELY FALL TO LOW
END MVFR FOR A TIME TONIGHT INTO EARLY FRIDAY MORNING...WITH A
POSSIBILITY FOR SOME PERIODS OF IFR. CONFIDENCE IS LOW WITH
REGARDS TO THE IFR AND SO HAVE LEFT OUT ANY MENTION IN THE TAFS.
EAST SOUTHEAST WINDS ARE IN PLACE THIS MORNING AND ARE STEADILY
INCREASING AT THIS HOUR. WITH THE SURFACE GRADIENT BECOMING
ORGANIZED THIS MORNING...EXPECT WINDS/GUSTS TO RAPIDLY INCREASE
OVER THE NEXT COUPLE OF HOURS AND REMAIN HIGH THROUGH THE
AFTERNOON. GUSTS OF AROUND 30KT ARE POSSIBLE FOR A TIME
TODAY...BEFORE WINDS/GUSTS DIMINISH LATE IN THE AFTERNOON AND
EARLY EVENING. PERSISTENT SOUTHEAST WINDS WILL LIKELY BECOME MORE
VARIABLE WITHIN THE TROUGH/PRECIP AXIS LATER TONIGHT BEFORE
TURNING TO THE NORTHWEST ON THE BACKSIDE OF THIS SYSTEM...STAYING
THIS DIRECTION INTO FRIDAY.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE WITH WIND SPEED/DIRECTION.
* MEDIUM HIGH CONFIDENCE WITH SHOWERS AND TIMING TONIGHT.
* MEDIUM HIGH CONFIDENCE WITH MVFR CEILINGS...WITH LOW CONFIDENCE
FOR POSSIBLE IFR CEILINGS.
RODRIGUEZ/DEUBELBEISS
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...SLIGHT CHANCE OF SHOWERS...OTHERWISE VFR.
SATURDAY...CHANCE OF SHOWERS LATE...OTHERWISE VFR.
SUNDAY...CHANCE OF SHOWERS...OTHERWISE VFR.
MONDAY...CHANCE OF SHOWERS...OTHERWISE VFR.
TUESDAY...CHANCE OF SHOWERS...OTHERWISE VFR.
WEDNESDAY...CHANCE OF SHOWERS...OTHERWISE VFR.
RODRIGUEZ
&&
.MARINE...
443 AM CDT
LIGHTER FLOW REMAINING OVER THE LAKE EARLY THIS MORNING WITH
WEAKER SURFACE PATTERN STILL IN PLACE. ALTHOUGH...EXPECT EAST TO
SOUTHEAST WINDS TO RAPIDLY INCREASE THROUGH MID MORNING AND THEN
ESPECIALLY INTO THE AFTERNOON WHEN TO 30 KT WINDS WILL BE
OBSERVED...IN RESPONSE TO AN APPROACHING TROUGH OF LOW PRESSURE.
EAST TO SOUTHEAST WINDS WILL STILL REMAIN TO 30 KT THIS EVENING
BUT SLOWLY DIMINISH AS THIS TROUGH OF LOW PRESSURE MOVES THROUGH
THE REGION. WINDS WILL BEGIN TURNING TO THE WEST/NORTHEAST ON THE
BACKSIDE OF THIS SYSTEM LATE TONIGHT INTO FRIDAY BEFORE TURNING
MORE NORTHERLY FRIDAY NIGHT INTO SATURDAY.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM THURSDAY.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1046 AM CDT Thu Apr 24 2014
.DISCUSSION...
ISSUED 1046 AM CDT Thu Apr 24 2014
Area of low pressure currently located near Kansas City will track
slowly E/NE into west-central Illinois by this evening. While
showers and thunderstorms are prevalent ahead of this feature
across central and western Missouri, the airmass further east over
Illinois remains rather dry. 15z/10am surface dewpoints are only
in the middle to upper 30s, while the 12z KILX upper air sounding
showed a large amount of dry air below 700mb. With a southeasterly
low-level flow ahead of the system, am not expecting much moisture
advection before the low and its associated front arrive. High-res
models such as the HRRR and the NAM12 are suggesting that the
eastward progression of the precip will be slower than previously
expected and this seems reasonable given the current conditions.
Have therefore trimmed POPs back today. Will keep the entire KILX
CWA dry through midday, then will slowly advance precip eastward
this afternoon. Will continue with a dry forecast east of the
I-57 corridor through the entire afternoon, with POPs gradually
ramping up to categorical further west across the Illinois River
Valley. Also made adjustments to sky cover to feature more
sunshine across the E/SE. Zone update will be issued shortly.
Barnes
&&
.AVIATION...
ISSUED 625 AM CDT Thu Apr 24 2014
Several forecast concerns this period include surface wind gusts
later this morning into this afternoon and a deterioration in
cigs this evening as showers and scattered TSRA affect the TAF
sites. Band of showers was located over east central Iowa, tracking
mainly to the northeast and not expected to affect our TAF
locations this morning. However, as a frontal boundary out to our
west make progress to the east later today, the threat for showers
and storms will increase from west to east in the 20z-01z time
frame. Widespread rain and isold TSRA will be the story this
evening with the cigs gradually lowering to MVFR with some brief
IFR cigs possible where some of the heavier showers/storms move
through. Steadier light rains will follow later this evening
before the system shifts off to our east late tonight. Surface
winds will be out of the southeast at 15 to 25 kts today with
a few gusts around 30 kts at times. FROPA is not expected until
or just after 03z at PIA with CMI the last to see the wind shift
by 08z.
Smith
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT Thu Apr 24 2014
SHORT TERM...Today through Sunday
00Z models continue to be slower with cold frontal passage and
associated convection and that is the biggest change in the
forecast package. Most areas will be dry this morning with showers
and thunderstorms affecting areas from I-55 west this afternoon
and possibly getting as far east as I-57 late this afternoon. SPC
keeps slight risk of severe storms in southern IL south of our
CWA. Though there is a 5% risk of damaging wind gusts in far sw CWA
from Springfield to Lawrenceville south late this afternoon and
evening. Upper level trof over CO/NM with embedded short wave to
move into IL overnight while a cold front moves east across IL
during tonight. Have increased pops this evening due to slower
movement of front and then decreasing pops from west to east
behind cold front during overnight. Highs today in the upper 60s
nw over IL river valley to mid 70s se of I-70. Lows tonight 45-50F
over central IL and 50-55F in southeast IL. Rainfall amounts this
afternoon and tonight of a half to three quarter inch with locally
three quarter to 1 inch west of I-55.
Storm system to pass east of IL across IN/OH Friday morning with
more sunshine returning and mild highs in the low to mid 70s and
warmest over sw counties. Even a few degrees warmer on Saturday as
models have 850 mb temps of 12-14C. Still appears dry Friday
through the day on Saturday with partly to mostly sunny skies Sat.
Rather mild again on Sunday with highs in the upper 60s to mid 70s.
Models have trended warmer this weekend ahead of next storm system
over the Rockies. Continue chances of showers and isolated
thunderstorms Saturday night and Sunday as warm air advection
regime sets up again.
LONG TERM...Sunday night through Thursday
Extended models like GFS, ECMWF and GEM develop a strong/large cutoff
upper level low near CO Sunday morning and then move it into the MO
valley Tue and mid MS river valley during middle of next week.
This to bring an unsettled weather pattern with daily chance of
showers and isolated thunderstorms from Sunday through Thursday
with highest chances Sunday night through Tuesday. Mild temps
early in the week to cool by middle of next week as upper level
low moves near IL. Widespread rainfall amounts of 1-2 inches
expected during this time with heaviest amounts southern areas.
Seasonable highs in the upper 60s and lower 70s Monday cool into
the low to mid 50s Wed/Thu.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1249 AM CDT THU APR 24 2014
.DISCUSSION...
931 PM CDT
SHOWERS CONTINUE TO MOVE/DEVELOP EASTWARD ACROSS NORTHERN ILLINOIS
EARLY THIS EVENING WITHIN A ZONE OF INCREASING ISENTROPIC ASCENT
ALONG THE WESTERN PERIPHERY OF A SURFACE RIDGE OF HIGH PRESSURE. THIS
ACTIVITY IS EXPECTED TO CONTINUE MOVING EASTWARD ACROSS NORTHERN
ILLINOIS LATE THIS EVENING...AND LIKELY ENDING PRIOR TO DAYBREAK
THURSDAY AS THE BETTER FORCING AND MOISTENING SHIFTS TO THE NORTH
AND EAST OF THE REGION. THEREFORE...NO BIG CHANGES ARE NEEDED TO THE
GOING FORECAST FOR TONIGHT.
THURSDAY IS SHAPING UP TO BE A BREEZY AND A MILDER DAY ACROSS THE
AREA AS SOUTHEASTERLY FLOW RAMPS UP IN RESPONSE TO AN AREA OF LOW
PRESSURE APPROACHING WESTERN ILLINOIS DURING THE AFTERNOON. IT
APPEARS THAT IN SPITE OF THE SOUTH-SOUTHEASTERLY WIND
COMPONENT...THAT WINDS COULD BE VERY GUSTY...UP IN THE 30 TO 35 KT
RANGE...DURING THE AFTERNOON. ALSO...IT APPEARS THAT THESE
SOUTHEASTERLY WINDS WILL TRANSPORT A DRIER LOWER LEVEL AIR MASS IN
ACROSS THE AREA DURING THE DAY...AND THIS COULD LEAD TO LOWER
SURFACE DEW POINTS THAN CURRENTLY FORECAST...ESPECIALLY ACROSS THE
EASTERN HALF OF THE AREA. WITH THIS IN MIND...I HAVE BACKED OFF ON
POPS DURING THE AFTERNOON THURSDAY...WITH A LIKELY SLOWER EVOLUTION
OF THE PRECIPITATION. IT APPEARS THE MAIN FORCING AND MOISTURE WILL
NOT ARRIVE ACROSS THE AREA UNTIL THURSDAY EVENING. AT THIS TIME I
HAVE LEFT SOME LOW END POPS IN DURING THE AFTERNOON...BUT IF THESE
TRENDS CONTINUE...WE MAY BE ABLE TO GO DRY ALL AFTERNOON ON
THURSDAY...ESPECIALLY ACROSS THE EASTERN HALF OF THE AREA. PERIODS
OF RAIN STILL APPEAR TO BE A GOOD BET THURSDAY NIGHT.
KJB
//PREV DISCUSSION...
310 PM CDT
SYNOPSIS...ANOTHER PLEASANT DAY TODAY...BUT SHOWERS MOVE IN FROM THE
WEST THIS EVENING. SHOWERS AND STORMS ARE EXPECTED TOMORROW
AFTERNOON AND EVENING WITH A DRY AND WARM END TO THE WORK WEEK.
THIS WEEKEND LOOKS TO HAVE BELOW NORMAL TEMPERATURES WITH SHOWERS
AND PERHAPS SOME THUNDERSTORMS ALONG AND SOUTH OF I-80 FOR THE FIRST
HALF OF NEXT WEEK.
REST OF TODAY AND TONIGHT...
A LARGE UPPER LEVEL RIDGE IS OVER THE CENTRAL PLAINS WHILE A SURFACE
HIGH IS CENTERED OVER LAKE MICHIGAN. THE RIDGE PASSES OVERHEAD
TONIGHT WHILE THE SURFACE HIGH PUSHES EAST TO THE NORTHERN OHIO
VALLEY THROUGH EASTERN QUEBEC.
A WEAK SHORTWAVE IS OVER EASTERN NEBRASKA AND WESTERN IOWA WITH
SHOWERS OVER WESTERN IOWA. THE SHOWERS WILL CONTINUE TO PUSH
EAST...BUT WITH DEWPOINT DEPRESSIONS AT 20+ DEGREES...THINKING THE
SHOWERS WILL DISSIPATE A BIT BEFORE MOVING INTO CENTRAL IL. AS SUCH
THINKING THE FIRST SHOWERS WILL ENTER THE FAR EASTERN CWA AFTER 5PM
CST. USED THE LOCAL ARW...RAP...AND HRRR TO CREATE THE POPS FOR THE
REST OF TODAY AND TONIGHT. THINKING A BAND OF SCATTERED SHOWERS WILL
SLOWLY CROSS NORTHERN IL THIS EVENING IN ASSOCIATION WITH AN UPPER
LEVEL VORTICITY STREAMER. THE BEST COVERAGE WILL BE BETWEEN MIDNIGHT
AND 4 AM CST WITH A CHANCE OF LIGHT RAIN SHOWERS NORTH OF I-80. THE
BAND THEN LIFTS NORTH EARLY THURSDAY MORNING AS THE RIDGE MOVES
DIRECTLY OVERHEAD. NOT EXPECTING ANY SIGNIFICANT PRECIP
ACCUMULATIONS.
CLOUD COVER WILL INCREASE THROUGH THIS AFTERNOON AND LOOKING AT MIN
TEMPS IN THE UPPER 30S TO MID 40S ACROSS THE CWA.
TOMORROW AND TOMORROW NIGHT...
AN UPPER LEVEL TROUGH MOVES OVER THE PLAINS TOMORROW MORNING AND THE
TROUGH PASSES OVER THE REGION TOMORROW NIGHT. THE UPPER LEVEL LOW
ASSOCIATED WITH THE TROUGH PASSES FARTHER NORTH...ALONG THE
US/CANADA BORDER. THE SURFACE LOW ALSO BEGINS OVER THE PLAINS
THURSDAY MORNING AND THEN MOVES OVER IL THURSDAY EVENING. GUIDANCE
HAS THE LOW PROGRESSING A BIT SLOWER AND MADE THE NECESSARY
ADJUSTMENTS.
RAIN AND SOME STORMS MOVE IN FROM THE WEST THROUGH THE MORNING AND
EARLY AFTERNOON. INSTABILITY IS NOT EXTREMELY IMPRESSIVE WITH THE
SYSTEM SO KEPT ONLY A CHANCE OF THUNDER. QPF AMOUNTS ON THE OTHER
HAND COULD BE IMPRESSIVE WITH TOTALS AROUND A HALF INCH OF RAIN.
WINDS WILL ALSO BE SHIFTING FROM SOUTHEAST IN THE MORNING TO OUT OF
THE WEST OVERNIGHT BEHIND THE LOW. LOOKING AT A BREEZY AFTERNOON
WITH SOUTH WINDS GUSTING TO 35 MPH. THE AMPLE WAA WILL LEAD TO MAX
TEMPS FROM AROUND 60 ALONG THE IL/WI BORDER TO THE UPPER 60S IF NOT
70 IN THE SOUTHERN CWA.
FRIDAY AND SATURDAY...
THE UPPER LEVEL LOW CONTINUES TO SHIFT EAST REACHING NEW ENGLAND BY
SATURDAY AFTERNOON/EVENING. THE SURFACE LOW SHIFTS EAST AND
EXPECTING PRECIP TO COME TO AN END EARLY FRIDAY MORNING. WEST WINDS
WILL BE GUSTING TO ARND 30 MPH FRIDAY AND AM THINKING THERE COULD BE
SOME DRY AIR MIXING DOWN TO THE SURFACE SO LOWERED DEWPOINTS A BIT.
THE AIR BEHIND THE COLD FRONT IS NOT REALLY ALL THAT COLD SINCE MAX
TEMPS ON FRIDAY LOOK TO BE AROUND 70 DEGREES. A BACK DOOR COLD
FRONT SLIDES DOWN FROM THE NORTH IN THE EVENING. SOME GUIDANCE
MEMBERS FEATURE A BAND OF PRECIP FORMING AHEAD OF THE FRONT OVER FAR
NORTHERN IL AND NW INDIANA. PUT IN A CHANCE OF PRECIP SINCE FORCING
LOOKS GOOD...BUT HAVE LOW CONFIDENCE IN THE BAND OF PRECIP ACTUALLY
FORMING. AS SUCH KEPT POPS IN THE CHANCE RANGE. WINDS TURN
NORTHEAST BEHIND THE FRONT AND OVERNIGHT LOWS WILL BE IN THE UPPER
30S TO MID 40S.
SOME GUIDANCE MEMBERS KEEP A BAND OF PRECIP OVER THE REGION SATURDAY
MORNING...BUT WITH HIGH PRESSURE MOVING OVER THE REGION HAVE LOW
CONFIDENCE AND WENT WITH A DRY FORECAST SATURDAY. SKIES WILL CLEAR
BUT THE COOLER AIR OFF THE LAKE WILL RESULT IN HIGHS IN THE UPPER
40S TO MID 50S ALONG THE LAKE...AND THEN IN THE LOW TO MID 60S IN
THE OUTLYING AREAS.
GUIDANCE FEATURES PRECIP MOVING IN AHEAD OF THE NEXT LOW SATURDAY
NIGHT. HAVE LOW CONFIDENCE IN THIS ROUND OF PRECIP AS WELL...BUT
LEFT A CHANCE OF RAIN IN THE FORECAST. OVERNIGHT LOWS WILL RANGE
FROM THE UPPER 30S TO THE MID 40S.
EXTENDED...SUNDAY THROUGH TUESDAY...
AN UPPER LEVEL CLOSED LOW SHIFTS OVER THE GREAT PLAINS SUNDAY
EVENING/NIGHT. GUIDANCE DIFFERS ON ITS EXACT PATH EARLY NEXT WEEK
BUT DOES HAVE THE UPPER LEVEL LOW OVER THE REGION THROUGH AT LEAST
MID WEEK. ITS ASSOCIATED SURFACE LOW MOVES OVER THE PLAINS LATE
SUNDAY NIGHT/MONDAY MORNING AND SLIDES SOUTH OF THE CWA MONDAY
NIGHT. THE 12Z GUIDANCE AGREED A BIT MORE ABOUT THE SURFACE LOWS
PATH...AND HAVE IT MOVING THROUGH SOUTHERN IL TUESDAY.
IN TWO WORDS EARLY NEXT WEEK LOOKS CHILLY AND WET. A BOUNDARY OVER
NORTHERN IL BRINGS THE LIFT FOR THE FIRST WAVE OF PRECIP EARLY ON
SUNDAY...BUT THEN MULTIPLE VORTICITY STREAMERS PASS THROUGH THE
REGION AS THE LOW SLOWLY SHIFTS EAST. THIS WILL RESULT IN A CHANCE
OF PRECIP THROUGHOUT THE EXTENDED. WILL INCLUDE A SLIGHT CHANCE OF
THUNDER ALONG AND SOUTH OF I-80 WHERE THERE WILL BE LIMITED ELEVATED
INSTABILITY BUT ENOUGH TO PERHAPS SUPPORT A COUPLE OF THUNDERSTORMS
SUNDAY NIGHT AND MONDAY. THE UPPER LEVEL JET DIPS FAR SOUTH THROUGH
TEXAS ALLOWING COOL AIR TO SPREAD ACROSS THE REGION. AS SUCH HIGHS
WILL VARY BETWEEN THE LOW 50S NORTH TO MID 60S SOUTH WITH A COOLING
TREND THROUGH TUESDAY. LUCKILY OVERNIGHT LOWS LOOK LIKE THEY WILL
REMAIN ABOVE FREEZING.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* PERIODS OF LIGHT RAIN THROUGH EARLY THIS MORNING.
* STRONG/GUSTY SOUTHEAST WINDS TODAY.
* SHRA LATER THIS EVENING W/ ISOL TSRA.
* POSSIBLE LOW END MVFR CEILINGS LATE IN THE FORECAST PERIOD.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
TERMINALS REMAIN ON EASTERN FRINGE OF PERSISTENT SHOWER
DEVELOPMENT AT THIS HOUR...AND NOW EXPECT THIS TO CONTINUE OVER
THE NEXT COUPLE OF HOURS BEFORE THIS PRECIP SHIELD ALL LIFTS TO
THE NORTH OF THE TERMINALS LATER THIS MORNING. ALTHOUGH...STILL
CONFIDENT THIS WILL REMAIN LIGHT WITH VFR CONDITIONS CONTINUING.
A LULL IN THE ACTIVITY AS WELL AS CLOUD COVER WILL LIKELY OCCUR
FOR THE REMAINDER OF THE DAY BEFORE THE NEXT SYSTEM CURRENTLY WELL
WEST OF THE TERMINALS SLOWLY APPROACHES. VFR CEILINGS WILL RETURN
LATE THIS AFTERNOON INTO THE EVENING AS WELL AS
SHOWER/THUNDERSTORM CHANCES. MAINTAINED JUST SHOWERS IN THE TAFS
WITH LOW CONFIDENCE OF TSRA AT THIS TIME...WITH EVEN SOME
POSSIBILITY OF DELAYING THE ONSET OF VCSH/-SHAR WITH LATER
FORECASTS. SOUTHEAST WINDS WILL RAMP UP RATHER QUICKLY LATER THIS
MORNING WITH STRONG GUSTS TO AROUND 30 KT LIKELY BEFORE A SLOW
DOWNWARD TREND OCCURS LATER THIS AFTERNOON. WITH CONFIDENCE LOWER
WITH REGARDS TO OVERALL TIMING OF THIS SYSTEM...HAVE LEFT OUT ANY
MENTION OF WIND SHIFT TO THE NORTHWEST AND POSSIBLE LOW END MVFR
CEILINGS VERY LATE IN THE FORECAST PERIOD FOR ORD.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE WITH RAIN AND VFR CONDITIONS.
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED/DIRECTION.
* HIGH CONFIDENCE WITH SHOWERS LATER THIS EVENING...WITH LOW
MEDIUM CONFIDENCE ON EXACT TIMING AND TSRA.
* LOW CONFIDENCE WITH LOW END MVFR CEILING CHANCES.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY AND SATURDAY...DRY/VFR.
* SUNDAY THROUGH TUESDAY...CHANCE OF SHRA. MVFR POSSIBLE.
&&
.MARINE...
219 PM CDT
PROGRESSIVE FLOW WILL CONTINUE THROUGH FRIDAY BEFORE A MUCH MORE
AMPLIFIED AND LOCKED PATTERN WILL SET UP FOR THE WEEKEND THROUGH THE
MIDDLE OF NEXT WEEK. THE HIGH PRESSURE PRESENTLY OVER THE LAKE WILL
BE SCOOTED EASTWARD EARLY FRIDAY AS LOW PRESSURE FROM THE CENTRAL
PLAINS BOOKS EASTWARD INTO NORTHERN INDIANA. DURING THURSDAY THIS
WILL PROVIDE STRONG SOUTHERLY FLOW. A FAIRLY STOUT INVERSION SHOULD
BE PRESENT OVER THE LAKE...BUT STRONG OFFSHORE WINDS IN NEARSHORE
AREAS SHOULD LEAD TO 25 TO POSSIBLE 30 KT GUSTS. AS A DEEP TROUGH
SETS UP ACROSS THE WESTERN U.S. AND SLOWLY MOVES EAST THROUGH THE
WEEKEND AND EARLY NEXT WEEK...SURFACE HIGH PRESSURE WILL GET
LOCKED OVER THE CENTRAL GREAT LAKES. A TIGHTENING PRESSURE
GRADIENT ON ITS SOUTHERN AND WESTERN SIDES WILL PROVIDE CONTINUOUS
EAST TO NORTHEAST SURFACE WINDS. THIS LOOKS LIKE A POTENTIAL
PROLONGED PERIOD OF SMALL CRAFT ADVISORY CRITERIA.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...10 AM THURSDAY TO 10 PM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
631 PM CDT FRI APR 25 2014
.SYNOPSIS...
ISSUED AT 238 PM CDT FRI APR 25 2014
BEAUTIFUL DAY TODAY WITH PLENTIFUL SUNSHINE AND TEMPERATURES AS
OF 2 PM ALREADY IN THE UPPER 60S/LOW 70S AREA WIDE. DEWPOINTS HAVE
MANAGED TO STAY IN THE 40S THROUGH MUCH OF THE MORNING AND ARE
ONLY NOW DROPPING INTO THE 30S.
UPPER AIR ANALYSIS THIS MORNING DEPICTED CUTOFF UPPER LOW SPINNING
OVER NORTHEAST MINNESOTA AND LAKE SUPERIOR WITH BROAD RIDGING
TAKING PLACE FROM WESTERN KANSAS INTO ALBERTA CANADA. AT THE
SURFACE...WEAK RIDGING THAT WAS OVER THE CWA HAS NOW PUSHED EAST
INTO INDIANA. A WEAK COLD FRONT WAS SEEN SLOWLY PUSHING SOUTH OVER
MINNESOTA WITH MAINLY MID-HIGH LEVEL CLOUDS SEEN BEHIND THE FRONT.
LATEST WV IMAGERY SHOWS STRONG SYSTEM JUST OFF THE WEST COAST. THIS
SYSTEM WILL BRING UNSETTLED WEATHER TO THE REGION THIS WEEKEND AND
BEYOND.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 238 PM CDT FRI APR 25 2014
FORECAST FOCUS ON SMALL CHANCE OF PCPN THIS EVENING...OTHERWISE
QUIET AND DRY CONDITIONS EXPECTED.
WEAK COLD FRONT OVER MINNESOTA WILL DROP SOUTH ACROSS THE CWA
TONIGHT AND STALL AS IT REACHES THE IOWA-MISSOURI BORDER. HI-RES
MODELS AND THE LATEST RAP TRENDS ALL SHOW LOW LEVEL CONVERGENCE...
OMEGAS...AND MOISTURE IN THE 850-700MB LAYER ALONG AND BEHIND THE
FRONT INCREASING TONIGHT AND SHOULD BE SUFFICIENT ENOUGH TO
PRODUCE VERY LIGHT SHOWERS OR SPRINKLES MAINLY NORTH AND EAST OF A
LINE FROM THE QUAD CITIES TO PRINCETON ILLINOIS. HAVE MAINTAINED SLIGHT
CHANCE POPS IN THIS AREA FOR THIS POSSIBILITY. I AM CONCERNED THAT
THE SURFACE TO 850MB LAYER MAY BE TOO DRY FOR ANY PCPN TO REACH
THE GROUND AND WILL PASS THIS ON TO THE NIGHT SHIFT. WINDS TO
GRADUALLY SHIFT TO THE NORTHEAST AS FRONT TRACKS THROUGH THE CWA.
OVERNIGHT LOW TEMPERATURES WILL DEPEND ON HOW FAST THE FRONT MOVES
THROUGH AND ITS POSITION EARLY SATURDAY. LOWS SHOULD RANGE FROM
THE UPPER 30S/LOW 40S ON THE COOL SIDE OF THE BOUNDARY TO THE
LOWER 50S IN THE FAR SOUTH.
SATURDAY...ANOTHER PLEASANT DAY IN STORE AS UPPER LEVEL RIDGING
MOVES ACROSS THE AREA. A FRONTAL BOUNDARY WILL BE SITUATED ACROSS
THE SOUTHERN PORTIONS OF THE CWA WITH WINDS MAINLY FROM THE EAST
DURING THE DAY. THIS WILL RESULT IN A LARGE TEMPERATURE GRADIENT
SETTING UP ACROSS THE AREA BY THE AFTERNOON. DEEP MIXING TO 900MB
AND PARTLY SUNNY SKIES THROUGH AT LEAST THE EARLY AFTERNOON WILL
ALLOW HIGHS TO REACH THE LOWER 60S IN THE NORTHEAST TO THE UPPER
70S IN THE FAR SOUTH. AN ACTIVE PATTERN BEGINS ACROSS THE MIDWEST
STARTING SATURDAY NIGHT...SEE LONG TERM DISCUSSION FOR MORE DETAILS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 248 PM CDT FRI APR 25 2014
MODELS CONTINUE TO SHOW A HIGHLY AMPLIFIED...BLOCKED...PATTERN
EVOLVING OVER THE CONSUS DURING THE WEEKEND. THIS WILL RESULT IN A
LARGE OCCLUDED SYSTEM BECOMING NEARLY STATIONARY OVER THE UPPER
MIDWEST FOR MUCH OF THE COMING WEEK. THIS PATTERN CONTINUES TO
SUPPORT A PROLONGED RAINFALL EVENT OVER THE MID MISSISSIPPI VALLEY
WITH SIGNIFICANT RAINFALL...RESULTING IN FLOODING ON AREA
TRIBUTARIES AND THE MISSISSIPPI RIVER.
SATURDAY NIGHT SURFACE CYCLOGENESIS WILL TAKE PLACE OVER THE WESTERN
PLAINS...AHEAD OF A DEEP UPPER TROF MOVING THROUGH THE WESTERN U.S.
AS THE SURFACE LOW FORMS A WARM FRONT WILL DEVELOP FROM THE CENTRAL
PLAINS THROUGH NORTHERN MISSOURI. DEEP SOUTHERN FLOW AHEAD OF THE
WESTERN TROF WILL BRING ABUNDANT GULF MOISTURE NORTH ACROSS THE WARM
FRONT. THE LOW LEVEL JET BY LATE SATURDAY EVENING SHOULD BE POINTED
AT EASTERN NE AND WESTERN IA PROVIDING FORCING FOR MCS DEVELOPMENT.
THE MCS SHOULD TRACK EAST OVERNIGHT REACHING EASTERN IA DURING THE
EARLY MORNING HOURS. WHILE THE THREAT OF SEVERE STORMS WITH THIS
MCS WILL BE THE GREATEST OVER WESTERN IA AND EASTERN NE...SOME
ISOLATED SEVERE STORMS COULD REACH PARTS OF EASTERN IOWA AFTER
MIDNIGHT WITH HAIL BEING THE GREATEST THREAT. SUNDAY AND SUNDAY
NIGHT THE SEVERE THREAT WILL INCREASE FOR THE MID MISSISSIPPI VALLEY
AS THE WARM FRONT MOVES INTO NORTHERN MO OR SOUTHERN IA AND CENTRAL
IL AND STRONG MID LEVEL FLOW AHEAD OF THE UPPER LOW MOVES NORTH
THROUGH THE REGION. THE GREATEST THREAT OF SEVERE STORMS SHOULD BE
SUNDAY AFTERNOON AND EVENING ALONG AND SOUTH OF INTERSTATE 80. HAIL
SHOULD BE THE PRIMARY THREAT WITH MODELS SHOWING SOME MID LEVEL
DRYING. HOWEVER NEAR AND SOUTH OF THE WARM FRONT DAMAGING WINDS AND
TORNADIC STORMS CAN/T BE RULED OUT.
HEAVY RAIN POTENTIAL WILL EXIST OVER MUCH OF THE AREA FROM LATE
SATURDAY NIGHT THROUGH SUNDAY NIGHT AND POSSIBLY INTO MONDAY AS THE
SYSTEM MOVES TOWARD THE REGION. THIS MORNINGS WPC 3 DAY TOTAL QPF
ENDING MONDAY MORNING SHOWED A LARGE AREA OF 1 TO 3 INCHES OVER MUCH
OF THE FORECAST AREA...ROUGHLY CENTERED ALONG I80. THIS LOOKS
REASONABLE GIVEN PW/S OF 1 TO 1.5 INCHES OVER THE AREA MUCH OF THE
WEEKEND AND THE SLOW MOVEMENT OF THE OCCLUDED SYSTEM.
AFTER MONDAY MOST MODELS SHOW THE UPPER LOW OVER THE MISSISSIPPI
VALLEY AND MOVING SLOWLY EAST MID TO LATE WEEK. THIS SHOULD KEEP
MORE SHOWERY TYPE PRECIPITATION OVER THE AREA AT LEAST THROUGH
THURSDAY AND POSSIBLY INTO FRIDAY. ISOLATED THUNDERSTORMS WILL BE
POSSIBLE DURING THE AFTERNOON AND EVENING HOURS MONDAY AND TUESDAY
WITH SURFACE DEWPOINTS STILL IN THE 50S AND THE COLD POOL ASSOCIATED
WITH UPPER LOW STILL OVER HEAD. BY MID TO LATE WEEK DRY SURFACE AIR
MOVING IN SHOULD END THE THUNDERSTORM THREAT.
TEMPERATURES SHOULD BE NEAR NORMAL FOR THE WEEKEND THEN TREND BELOW
NORMAL...ESPECIALLY THE HIGHS...FOR MUCH OF THE UPCOMING WEEK WITH
ABUNDANT CLOUDS EXPECTED TO BE OVER THE AREA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 621 PM CDT FRI APR 25 2014
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF CYCLE. SCATTERED HIGH BASED
SHOWERS ARE POSSIBLE LATE THIS EVENING AND OVERNIGHT AS A FRONT
SAGS THROUGH THE REGION. WITH UNCERTAINTY ON COVERAGE AND LIKELIHOOD
OF REMAINING VFR IN SHOWERS... I HAVE LEFT OUT ANY MENTION IN TAFS
ATTIM. WINDS WILL BECOME EASTERLY BY SAT AM... AND INCREASE AT OR ABOVE
10 KTS AND LOCALLY GUSTY LATE AM THROUGH PM.
&&
.HYDROLOGY...
ISSUED AT 248 PM CDT FRI APR 25 2014
THREAT OF FLOODING ON AREA TRIBUTARIES AND THE MISSISSIPPI RIVER
WILL INCREASE BY EARLY NEXT WEEK AS A WIDESPREAD SIGNIFICANT
RAINFALL EVENT OCCURS OVER THE REGION. CURRENT FORECASTS SUGGEST A
WIDESPREAD AREA OF 1 TO 4 INCHES OF RAIN ARE POSSIBLE OVER MUCH OF
THE FORECAST AREA BY WEDNESDAY. LOCALLY HEAVY RAINS WILL BE POSSIBLE FROM
LATE SATURDAY NIGHT THROUGH SUNDAY NIGHT WITH SCATTERED SHOWERS
EXPECTED OVER THE AREA EARLY TO MIDWEEK. SINCE THE PRECIPITATION IS
GOING TO OCCUR OVER AN EXTENDED PERIOD OF TIME THE THREAT OF FLASH
FLOODING WILL BE LOW. HOWEVER RIVER FLOODING IS EXPECTED WITH MANY
OF THE AREA TRIBUTARIES AND THE MISSISSIPPI RIVER SEEING AT LEAST
MINOR TO MODERATE FLOODING BY THE MIDDLE OF NEXT WEEK.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...GROSS
SHORT TERM...GROSS
LONG TERM...DLF
AVIATION...05
HYDROLOGY...DLF
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1245 PM CDT THU APR 24 2014
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TODAY/...
ISSUED AT 343 AM CDT THU APR 24 2014
PRIMARY CONCERNS TODAY WILL BE INTERRELATED PRECIP AND TEMP TRENDS
WITH NOT THE GREATEST CONFIDENCE IN EITHER...ESPECIALLY TEMPS. LONG
WAVE TROUGH IS STILL WELL TO THE WEST JUST EXITING THE ROCKIES AND
ASSOCIATED KINEMATIC FORCING SEEMS TO BE THE MAIN MECHANISM DRIVING
CURRENT KS/NE PRECIP BEHIND THE INVERTED TROUGH. THERMODYNAMIC
FORCING SEEMS TO BE MAINLY RESPONSIBLE FOR IA/MN PRECIP AND LOOKS TO
GRADUALLY BECOME THE DOMINATE FORCING LATER IN THE DAY. EXPECT THE
NE/KS PRECIP TO WANE AND BE REPLACED BY WEAK CONVECTION NOW
INCREASING SOMEWHAT ALONG THE I35 CORRIDOR AND MOISTURE TRANSPORT
AXIS. LATEST HIGH RES MODELS SEEM TO HAVE A DECENT HANDLE ON THIS
PROGRESSION AS WELL...WHICH EVENTUALLY ENDS UP WITH LINGERING POPS
IN THE EAST 21Z-00Z. INSTABILITY IS FAIRLY WEAK AT THE MOMENT WITH
MUCAPES JUST A FEW HUNDRED. MAX AXIS...STILL ONLY AROUND 500
J/KG...IS STILL OFF TO THE WEST HOWEVER SO THERE MAY BE A MINOR
UPTICK IN INTENSITY THROUGH THE MORNING WITH SOME SMALL HAIL
POSSIBLE...STILL BELOW SEVERE LIMITS. THE ERN THIRD OF THE FORECAST
AREA MAY SEE ANOTHER HALF INCH PLUS OF BENEFICIAL RAINS.
TEMP GUIDANCE IS QUITE VARIED WITH A DECENT SPREAD IN BOTH RAW AND
MOS VALUES. 8F DIFFERENCE IN DSM MOS FOR INSTANCE. SOME
MODELS...ESPECIALLY RECENT RAP RUNS...WERE MORE AGGRESSIVE MIXING
TODAY WHILE OTHERS KEEP MORE LOW LEVEL MOISTURE IN PLACE. DO NOT
REALLY HAVE A GOOD FEELING WHICH WAY TO LEAN HERE SO FOLLOWED MORE
OF A BLEND...WHICH IS JUST SLIGHTLY LOWER THAN PERSISTENCE.
.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 343 AM CDT THU APR 24 2014
SYSTEM SHOULD QUICKLY EXIT THE STATE THIS EVENING...WITH SOME
LINGERING LIGHT SHOWERS/ISOLATED THUNDERSTORMS POSSIBLE ACROSS THE
FAR SOUTHEASTERN CWA EARLY IN THE EVENING. OTHERWISE UPPER LEVEL
RIDGING TO BUILD INTO THE CENTRAL US FRIDAY INTO SATURDAY...WITH WAA
AND DRY CONDITIONS EXPECTED. HIGHLY AMPLIFIED LONGWAVE UPPER LEVEL
TROUGH STILL EXPECTED TO DIG INTO THE DESERT SOUTHWEST
SATURDAY...WITH SOUTHWEST FLOW ALOFT DEVELOPING ACROSS THE CENTRAL
US LATE SATURDAY NIGHT INTO SUNDAY. ALL MODELS EJECTING THIS SYSTEM
INTO THE WESTERN HIGH PLAINS BY SUNDAY AND SLOWLY MOVE IT EAST
NORTHEASTWARD INTO EARLY NEXT WEEK. THIS WILL SET UP A WET ACTIVE
PATTERN ACROSS THE REGION/STATE BY LATE SATURDAY NIGHT INTO EARLY
NEXT WEEK.
FINER DETAILS STILL TO BE DETERMINED WITH SOME UNCERTAINTY IN HOW
FAR THE SFC FRONT WILL PUSH NORTHWARD SUNDAY INTO MONDAY. FOR NOW
MODELS JUST BRING THE SFC FRONT INTO EXTREME SOUTHERN IOWA LATE
SUNDAY INTO MONDAY. INSTABILITY INCREASES ACROSS THE AREA WITH
STRONG PUSH OF MOISTURE NORTHWARD FROM THE GULF AND WAA ALOFT SHOULD
SEE DECENT CHANCE FOR THUNDER ACROSS THE ENTIRE CWA. AS SYSTEM
BECOMES MORE WRAPPED UP AND SLOWLY TRANSLATES EAST INTO LATE MONDAY
THROUGH WEDNESDAY...THREAT OF THUNDER DECREASES WITH MORE STRATIFORM
RAIN EXPECTED. AS THE UPPER LEVEL SYSTEM PUSHES EVER SLOW SLOWLY
EASTWARD...REGION SHOULD REMAIN UNDER THE INFLUENCE OF UPPER LEVEL
CYCLONIC FLOW THROUGH MUCH OF NEXT WEEK WITH A WET AND COOLER
PATTERN EXPECTED.
&&
.AVIATION...24/18Z
ISSUED AT 1240 PM CDT THU APR 24 2014
MVFR/IFR CIGS AND INTERMITTENT VIS WILL CONTINUE THROUGH 19-20Z
AS THE LOW PRESSURE MOVES NORTHEAST AND LIGHT PRECIP TAPERS OFF.
ANOTHER BATCH OF RAIN/TSTMS MOVING NORTHEAST FROM MISSOURI LOOKS
TO MAINLY AFFECT OTM AND POSSIBLY DSM FOR A SHORT TIME. CAA
DEVELOPS THIS AFTERNOON BEHIND THE LOW AND KEPT MVFR CIGS INTO
TONIGHT FOR MUCH OF THE TAF SITES.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...BEERENDS
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
343 AM CDT THU APR 24 2014
.SHORT TERM /TODAY/...
ISSUED AT 343 AM CDT THU APR 24 2014
PRIMARY CONCERNS TODAY WILL BE INTERRELATED PRECIP AND TEMP TRENDS
WITH NOT THE GREATEST CONFIDENCE IN EITHER...ESPECIALLY TEMPS. LONG
WAVE TROUGH IS STILL WELL TO THE WEST JUST EXITING THE ROCKIES AND
ASSOCIATED KINEMATIC FORCING SEEMS TO BE THE MAIN MECHANISM DRIVING
CURRENT KS/NE PRECIP BEHIND THE INVERTED TROUGH. THERMODYNAMIC
FORCING SEEMS TO BE MAINLY RESPONSIBLE FOR IA/MN PRECIP AND LOOKS TO
GRADUALLY BECOME THE DOMINATE FORCING LATER IN THE DAY. EXPECT THE
NE/KS PRECIP TO WANE AND BE REPLACED BY WEAK CONVECTION NOW
INCREASING SOMEWHAT ALONG THE I35 CORRIDOR AND MOISTURE TRANSPORT
AXIS. LATEST HIGH RES MODELS SEEM TO HAVE A DECENT HANDLE ON THIS
PROGRESSION AS WELL...WHICH EVENTUALLY ENDS UP WITH LINGERING POPS
IN THE EAST 21Z-00Z. INSTABILITY IS FAIRLY WEAK AT THE MOMENT WITH
MUCAPES JUST A FEW HUNDRED. MAX AXIS...STILL ONLY AROUND 500
J/KG...IS STILL OFF TO THE WEST HOWEVER SO THERE MAY BE A MINOR
UPTICK IN INTENSITY THROUGH THE MORNING WITH SOME SMALL HAIL
POSSIBLE...STILL BELOW SEVERE LIMITS. THE ERN THIRD OF THE FORECAST
AREA MAY SEE ANOTHER HALF INCH PLUS OF BENEFICIAL RAINS.
TEMP GUIDANCE IS QUITE VARIED WITH A DECENT SPREAD IN BOTH RAW AND
MOS VALUES. 8F DIFFERENCE IN DSM MOS FOR INSTANCE. SOME
MODELS...ESPECIALLY RECENT RAP RUNS...WERE MORE AGGRESSIVE MIXING
TODAY WHILE OTHERS KEEP MORE LOW LEVEL MOISTURE IN PLACE. DO NOT
REALLY HAVE A GOOD FEELING WHICH WAY TO LEAN HERE SO FOLLOWED MORE
OF A BLEND...WHICH IS JUST SLIGHTLY LOWER THAN PERSISTENCE.
.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 343 AM CDT THU APR 24 2014
SYSTEM SHOULD QUICKLY EXIT THE STATE THIS EVENING...WITH SOME
LINGERING LIGHT SHOWERS/ISOLATED THUNDERSTORMS POSSIBLE ACROSS THE
FAR SOUTHEASTERN CWA EARLY IN THE EVENING. OTHERWISE UPPER LEVEL
RIDGING TO BUILD INTO THE CENTRAL US FRIDAY INTO SATURDAY...WITH WAA
AND DRY CONDITIONS EXPECTED. HIGHLY AMPLIFIED LONGWAVE UPPER LEVEL
TROUGH STILL EXPECTED TO DIG INTO THE DESERT SOUTHWEST
SATURDAY...WITH SOUTHWEST FLOW ALOFT DEVELOPING ACROSS THE CENTRAL
US LATE SATURDAY NIGHT INTO SUNDAY. ALL MODELS EJECTING THIS SYSTEM
INTO THE WESTERN HIGH PLAINS BY SUNDAY AND SLOWLY MOVE IT EAST
NORTHEASTWARD INTO EARLY NEXT WEEK. THIS WILL SET UP A WET ACTIVE
PATTERN ACROSS THE REGION/STATE BY LATE SATURDAY NIGHT INTO EARLY
NEXT WEEK.
FINER DETAILS STILL TO BE DETERMINED WITH SOME UNCERTAINTY IN HOW
FAR THE SFC FRONT WILL PUSH NORTHWARD SUNDAY INTO MONDAY. FOR NOW
MODELS JUST BRING THE SFC FRONT INTO EXTREME SOUTHERN IOWA LATE
SUNDAY INTO MONDAY. INSTABILITY INCREASES ACROSS THE AREA WITH
STRONG PUSH OF MOISTURE NORTHWARD FROM THE GULF AND WAA ALOFT SHOULD
SEE DECENT CHANCE FOR THUNDER ACROSS THE ENTIRE CWA. AS SYSTEM
BECOMES MORE WRAPPED UP AND SLOWLY TRANSLATES EAST INTO LATE MONDAY
THROUGH WEDNESDAY...THREAT OF THUNDER DECREASES WITH MORE STRATIFORM
RAIN EXPECTED. AS THE UPPER LEVEL SYSTEM PUSHES EVER SLOW SLOWLY
EASTWARD...REGION SHOULD REMAIN UNDER THE INFLUENCE OF UPPER LEVEL
CYCLONIC FLOW THROUGH MUCH OF NEXT WEEK WITH A WET AND COOLER
PATTERN EXPECTED.
&&
.AVIATION...24/06Z
ISSUED AT 1203 AM CDT THU APR 24 2014
LOW PRESSURE OVER CENTRAL KS WITH COLD FRONT FROM ERN SD THROUGH
THE LOW INTO THE TX PANHANDLE WILL MOVE EAST TO CENTRAL IA BY
EARLY THU AFTERNOON...AND EAST OF THE TAF SITES BY EVENING.
DETERIORATING CONDITIONS TONIGHT AS MOISTURE AND THUNDERSTORMS
INCREASE AHEAD OF THE FRONT. SEVERAL HOURS OF MVFR CIGS AROUND THE
FRONT. CONDITIONS WILL IMPROVE QUICKLY OVER WRN IA THU
AFTERNOON...AND IN THE EAST BY EVENING.
OUTLOOK...WEAK HIGH PRESSURE WILL MOVE OVER THE STATE ON FRIDAY
WITH GOOD VFR CONDITIONS AND LIGHT WINDS. VFR INTO SATURDAY BEFORE
NEXT WEATHER SYSTEM MOVES IN ABOUT SAT NIGHT.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...BEERENDS
AVIATION...MS APR 14
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1245 AM CDT Thu Apr 24 2014
...Updated Aviation Section...
.SHORT TERM...(This evening through Thursday)
ISSUED AT 142 PM CDT WED APR 23 2014
RAP, HRRR, and NAM all suggesting dryline will be located near
Garden City and Liberal between 21Z Wednesday and 00z Thursday.
Convective initiation along this boundary however somewhat more
uncertain given the warm 700mb temperatures and cloud
cover/precipitation currently over portions of southwest Kansas.
At this time based on the ARW,NMM, and HRRR still suggests there
will be some widely scattered convection developing late day/early
this evening. Will therefore follow the general trend of the non
hydrostatic models for for late today/early tonight but keep
precipitation chances more widely scattered. Mid level instability
and shear continues to support that if storms do develop they will
be capable of becoming severe. Main hazard early tonight still
appears to be hail and strong winds given shear, mid level
instability, high cloud bases, downdraft capes, and model
soundings at 00z Thursday.
A cold front crossing northwest Kansas earlier this afternoon is
forecast to cross southwest Kansas between 00z and 09z Thursday.
Convection along this cold front is expected to develop late day
and increase in areal coverage early tonight as an upper level
trough, which was located near the four corners region as 12z
Thursday, moves east across the Central High Plains. This cold
front will provide the better opportunity for precipitation,
especially along and east of a Dighton to Liberal line based on
where the better low level moisture is forecast to be early tonight
by the NAM. Precipitation chances will begin to taper off from
northwest to southeast, mainly after midnight as this cold front
surges south.
Behind this cold front very windy conditions are expected to
develop given the pressure tendencies and 925 to 850mb winds. Wind
speeds of 30 to 35 mph will be likely for several hours behind
this front, especially west of highway 283 between 03z and 09z.
After 09z Thursday the winds will begin to decrease and are
expected to continue to decrease during the day on Thursday as a
surface high/ridge axis crosses western Kansas. NAM and GFS 850mb
mixdown temperatures and guidance was with 2-4 degrees of each
other for highs on Thursday so given this and the expected
sunshine Thursday afternoon will stay close to what they suggest.
.LONG TERM...(Thursday night through Wednesday)
ISSUED AT 255 PM CDT WED APR 23 2014
Medium range models indicate weak upper level ridging transitioning
eastward across the Western High Plains Friday and into the Central
Plains Saturday. Meanwhile, a strong upper level trough of low
pressure will begin to push ashore into southern California Saturday
setting up a southwest flow across the Western High Plains by
Saturday afternoon. As a lack of significant low/mid level moisture
prevails during this time frame, dry conditions will persist through
Saturday afternoon. The potential for thunderstorms returns Saturday
evening as the upper level trough begins to lift northeast out of
the Desert Southwest into the Western High Plains. As the shortwave
approaches, a prevailing low level southeasterly flow will continue
to draw moisture northward into Kansas ahead of a sharpening dryline.
Although where the dryline sets up is uncertain this far out, the
likelihood for thunderstorm development is good ahead of it as upper
level dynamic support becomes more favorable. Severe weather is
possible late Saturday into early Sunday morning. Precip potential
shifts north and east Sunday as the upper level trough lifts
northeast across the Western High Plains increasing the potential
for dryslotting across southwest Kansas.
Temperatures will be above normal Friday as weak upper level ridging
moves eastward out of the Rockies across the Western High Plains. A
south to southeasterly flow will return to western Kansas as lee
side troughing redevelops across eastern Colorado. This will draw
warmer air north into the area with H85 temperatures ranging from
around 20C across central Kansas to near 25C in far southwest
Kansas. Look for highs well up into the 80s(F) Friday afternoon.
The warming trend continues into Saturday as enhanced warm air
advection raises H85 temperatures into the mid to upper 20s(C)
across southwest Kansas. Mid to upper 80s(F) are likely Saturday
afternoon with the lower 90s(F) possible behind a dryline across
extreme southwest Kansas. Much cooler temperatures will arrive
early next week as a cold front sweeps through western Kansas.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1244 AM CDT THU APR 24 2014
A strong cold front will continue surging southward over western
and central Kansas into the overnight hours. Behind this boundary
a band of thunderstorms will move through the HYS and DDC terminals
through the mid overnight hours. MVFR ceilings and wind gusts up
to 50-60 mph will be possible within these thunderstorms. Further,
strong north to northwest winds of 25-35 mph along with higher
gusts will also be possible behind the front through the remainder
of tonight. High pressure will then build into the region later
this afternoon with winds easing quickly while an unlimited
ceiling develops.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 45 84 54 88 / 0 0 0 20
GCK 43 84 50 86 / 0 0 0 10
EHA 46 85 52 89 / 0 0 0 10
LBL 44 86 53 90 / 0 0 0 10
HYS 43 81 51 82 / 0 0 0 20
P28 46 85 58 90 / 0 0 0 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 2 AM CDT /1 AM MDT/ early this morning FOR
KSZ043-044-061>063-074>076-084>086.
&&
$$
SHORT TERM...Burgert
LONG TERM...JJohnson
AVIATION...AJohnson
AREA FORECAST DISCUSSION
NWS PADUCAH KY
320 PM CDT Thu Apr 24 2014
.SHORT TERM...(Tonight through Saturday night)
Issued at 320 PM CDT THU APR 24 2014
Finally have some lower 50s surface dewpoints spreading into
southeast Missouri as of 19Z. It has taken most of the day, but
mid to upper 50 dewpoints seem reasonable for much of the area
ahead of the storms late this afternoon and this evening.
Instability is still meager at best, and the forcing associated
with the mid/upper-level trough will be the main instigating
factor for this event.
The HRRR has been fairly consistent through the day at bringing
the first of the showers and storms into Ripley and Carter
counties around 22Z, and to the Mississippi River by 00Z. It
appears as though the convection will become more organized as it
moves east over the remainder of the region through 06Z.
Model soundings indicate impressive 0-3KM SRH values, certainly
enough to support rotating updrafts, but the forcing is likely to
result in a linear event. So, would expect wind damage to be the
main concern with some minor potential for a brief tornado or two
with mesovortices or embedded supercell structures. Not sure just
how much severe weather there will be, given the struggling
moisture and instability. This may result in a better severe
threat across southeast Missouri and west Kentucky, where the
better low-level moisture will be located.
The 12Z models are in reasonable agreement that there will be some
wrap-around showers late tonight across the northeast half of the
area, as the main mid/upper trough moves through the region. The
showers may last through sunrise, especially in the Owensboro
area. Increased Pops to likely levels for this activity.
The 12Z models leave little to debate for Friday through Saturday,
but they do diverge a bit in the location of the weak frontal
boundary by 12Z Sunday. The GFS brings the boundary into the Tri
State area, while the NAM keeps it northeast of the area. It
basically stalls out, and takes on the look of a warm front, and
the models are dry through 12Z Sunday, so it will not make much
difference.
As for temperatures, will lean to the warm side of guidance for
lows tonight through Saturday night, and for highs on Saturday.
Guidance has cooled things down a few degrees for highs Friday, so
decided to blend the consensus of 12Z guidance with the previous
forecast.
.LONG TERM...(Sunday through Thursday)
Issued at 320 PM CDT THU APR 24 2014
During the day Sun, a large scale, deep low pressure system will
approach the PAH forecast area from the west, as agreed on by the
GFS/ECMWF ensemble means. Individual deterministic runs of the med
range models began to differ with the details after Mon (Day 6), but
agreement on the mid level and sfc features was not bad for that
time frame.
Some time on Sun morning, a warm front ahead of the system will
begin its trek nwd across the region. This, combined with divergence
aloft, deep moisture advection and instability, will result in
plentiful tstm activity west of the MS River, and scattered tstms
east of the MS River. Sun night/Mon/Mon night, showers will be
nearly a sure thing, with the best chance of tstms during the day
time hours. Due to multiple rounds of deep moist convection, and the
slower movement of the overall system, heavy rainfall amounts are
possible. Wind shear increases aloft Mon, and with available
instability, severe weather is possible into the evening.
From Tue through Wed night, pcpn chances are forecast to gradually
wane as the nearly stacked low pressure system wobbles through the
Midwest. The last signal for instability tstms appeared to be Tue.
There could be a resurgence of showers Thu as energy wraps around
the back side of the vast mid/upper low, as it possibly begins to
depart.
&&
.AVIATION...
Issued at 1252 PM CDT THU APR 24 2014
VFR conditions are expected this afternoon with just a few cu
around 5kft expected around KCGI late this afternoon. Used a 2 to 3
hour TEMPO group to time the main line of thunderstorms through
the area this evening and tonight. As the line gets more organized
with time this evening, the thunder potential may linger awhile
longer at KEVV and KOWB. Also the models are indicating more in
the way of wrap-around showers lingering potentially past 12Z at
KEVV and KOWB. Not sure if visibilities will drop to MVFR levels,
but ceilings will certainly be there through daybreak, and IFR
ceilings are likely at least for part of that time.
Scattering/clearing is expected in the east by late morning.
Winds will increase and become gusty from the south or south
southeast this afternoon and evening, and then veer to southwest
behind the main line of convection. Gusts into the mid 20kts can
be expected in the western half of the area this afternoon. They
will eventually veer to the west northwest Friday morning, as the
whole storm system moves east of our area. Some gusts into the
teens will be possible Friday morning.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...DRS
LONG TERM...DB
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
320 PM EDT Thu Apr 24 2014
.SHORT TERM (Now through Friday Night)...
Issued at 310 PM EDT Thu Apr 24 2014
In the near term, afternoon visible satellite imagery shows high
level cirrus clouds progressing northeast across central KY and
southern IN, in advance of a shortwave to our west, with surface
temperatures warming steadily to near 70 east and lower and mid 70s
west. Temperatures will continue to rise a couple/few more degrees
through late afternoon before falling back this evening.
Pronounced shortwave over KS/OK at this time will move steadily east
tonight accompanied by an increase in low-level moisture and
southerly winds, which will effectively limit/end our evening fall
in surface temperatures overnight. Surface winds should become gusty
overnight. Currently, this system is causing widespread convective
development from western MO to eastern OK and AR. Models are in good
agreement bringing these storms in a band into central KY and
southern IN late this evening and overnight. The 15z HRRR and 12z
in-house mesoscale models bring the leading edge of the convection
to our western forecast area border around 04 UTC.
Looking at model soundings, boundary layer cools this evening but
steep lapse rates and elevated instability remain if lifting a
parcel from about 900-950 mb. This will support continuation of
convection as axis of precipitation moves across our area,
especially western part of forecast area. With increasing winds at
925 and 850 mb, there is a chance that greater momentum air could
mix down to surface and create a few strong wind gusts with the
strongest cells (again, more likely in western sections), but
presence of weak-to-moderate nocturnal boundary layer inversion
should keep strongest winds aloft, unable to penetrate to surface.
After this band passes, there could be a brief lull in precip, but
models bring another area of moisture through from early to mid
morning (from west to east) associated with the actual mid-level
trough axis and surface front. As a result, additional scattered
showers and thunderstorms are expected during that time, with models
again indicating presence of some instability.
Front passes through the area first half of Friday. Winds behind the
boundary will become quite gusty from the west-northwest around 30
mph. Morning clouds and lingering showers will move off to the east
followed quickly by a clearing trend. Highs Friday afternoon should
be in the upper 60s and lower 70s, depending on how rapdily skies
clear. Friday night will be mainly clear with lows again down in the
40s in most locations.
.LONG TERM (Saturday through Thursday)...
Issued at 318 PM EDT Thu Apr 24 2014
Saturday - Sunday...
Heights will rise through the weekend as a progressive upper ridge
axis approaches and then slides through. Meanwhile, a cold front
will sag southward across southern Ohio and into central IN,
stalling by Saturday evening as it becomes parallel to the upper
level flow. Technically, it would be a back door cold front if it
were to make progress through the area, but it looks to stall just
to our north. Either way, the boundary will be moisture starved and
we should stay on the warm side of it. This will lead to a dry and
warm weekend. Expect highs on Saturday in the upper 70s north to low
80s south. Lows Saturday night should dip into the lower 50s. Should
start to see an gradual increase in mid and upper level clouds on
Sunday as the ridge axis starts to slide east, however 1000-850
thicknesses and 850 mb temps will support a 2-3 degree increase from
Saturday. Therefore, have gone with mostly lower 80s on Sunday. A
few Bluegrass or southern IN counties may stay confined to upper 70s.
Will continue to leave the slightest of chances for a shower or
storm in our far western tier or two of counties late Sunday
afternoon, however bulk of precip will not arrive until Sunday night
onward.
Sunday Night - Tuesday...
By Sunday night, blocking upper ridge axis will be off to our east
with an impressive closed upper low over the central Plains.
Southwesterly flow through a deep layer will overspread the Ohio
Valley, including a 40 knot low level jet nosing in. The quasi-
stationary frontal boundary will be just off to our northeast with
expansive mid level deformation aloft. By dawn on Monday, expect
scattered to numerous showers and a few t-storms mainly along and
west of I-65. These likely shower and t-storm chances will then
encompass the entire CWA on Monday. Tough to tell how well we
destabilize in this environment, but it appears that a stronger to
possibly severe storm threat will be conditional upon
destabilization, especially along and west of I-65.
Another threat of stronger to severe storms may move in later Monday
night into early Tuesday as the exit region of another impulse
rotating around the upper low ejects out of the southern Plains.
Again, strength of storms would be conditional upon destabilization.
Scattered to numerous showers and storms could then plague the area
again later Tuesday afternoon/evening.
Will continue to monitor threat for stronger storms to start the new
work week, but will also keep an eye on the threat for periods of
heavy rain and flooding. With repeated rounds of t-storms possible
and PWATs jumping up around 2 standard deviations above normal
for this time of year, flooding could become a concern. Tough to
judge temperatures during this time, solid reading in the 70s seem
reasonable each day on the warm side of the boundary and warm
advective flow. Obviously, convection will be the deciding factor.
Lows will be mild during this time, at least in the low 60s in
most spots.
Tuesday Night - Thursday...
We begin to transition to a cooler period by the middle and end of
the week as the wobbling upper low and its associated surface
reflection slide into the Midwest. Precipitation chances look to
become more scattered in nature during this time with thunder
chances becoming less likely. These days will likely not be
wash-outs, but will be mostly cloudy and considerably cooler. Look
for highs Wednesday and Thursday in the 50s and lows in the low and
mid 40s by Wednesday night.
&&
.AVIATION (18Z TAF Update)...
Issued at 130 PM EDT Thu Apr 24 2014
In the near term through this evening, VFR conditions will prevail
at all 3 TAF sites, with a southeast surface wind becoming south at
5 to 15 mph. Tonight, a strong shortwave trough will progress
eastward across the Ohio Valley, accompanied by a band or 2 of
showers and thunderstorms. Low-level wind fields will increase from
the south with surface gusts over 20 kts at times late tonight.
Winds at 850 mb may increase to around 50 kts, but winds will
increase steadily from the surface to 850 mb with no abrupt change
in wind direction, i.e., strong low-level/sudden wind shear should
not be a significant concern.
A band of convection should reach SDF and BWG in the 04-06z time
frame or so, and then just thereafter at LEX. Convective cells would
be more likely at BWG and SDF, and then more scattered within a band
of showers at LEX as the line moves east. This should take vsbys
and/or ceilings into MVFR category as predominant. After this axis
of rain moves through, there may be a break of precipitation with a
return mainly to VFR. But then scattered thunderstorms are again
possible a couple/few hours either side of 12z as the surface front
and mid-level trough pass through the TAF sites. Have accounted for
this with VCTS in the grids.
After frontal passage Friday morning, winds will become west to
northwest and gust from 20-30 kts at times. Low clouds will also
clear during the day.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Short Term........TWF
Long Term.........BJS
Aviation..........TWF
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1206 AM CDT THU APR 24 2014
.DISCUSSION...
24/06Z TAF ISSUANCE.
&&
.AVIATION...
SATELLITE IMAGERY LATE THIS EVENING SHOWS A FEW LOW CLOUDS
BEGINNING TO STREAM IN OFF THE GULF WHILE VEIL OF CIRRUS MOVES IN
FM THE WEST. OBS SITES CONTINUE TO SHOW P6SM VISBYS. ADJUSTED
VISBY FCST FOR TONIGHT AS STRENGTHENING LOW LVL JET AND INCREASING
CLOUDS ACRS SE TX WILL LIMIT FOG DEVELOPMENT AT BPT AND LCH.
FURTHER EAST...FOG STILL COULD BE AN ISSUE DUE TO LIGHTER WIND
FIELD/LESS CLOUD COVER AND LATEST HRRR VISBY PROGS ALSO REFLECT
THIS. WITH THIS IN MIND...KEPT VFR CONDITIONS AT BPT...PREVAILING
VFR/TEMPO MVFR AT LCH WITH PREVAILING MVFR/TEMPO IFR AT ERN SITES.
FOG EXPECTED TO LIFT TO MVFR CIGS BY 14Z-15Z...THEN BECOMING VFR
BY 18Z WITH SLY WINDS 10-15 KT GUSTING TO 20-25 KT DURING THE
AFTN. WINDS WILL DIMINISH SLIGHTLY DURING THE EVENING AS A WEAK
FRONT APPROACHES THE AREA...WITH LOW CIGS RETURNING. 24
&&
.PREV DISCUSSION... /ISSUED 953 PM CDT WED APR 23 2014/
UPDATE...
HIGH PRESSURE OVER THE NORTHERN GULF IS ALLOWING FOR MOISTURE TO
MOVE INLAND OVER SOUTHEAST TEXAS AND SOUTHERN LOUISIANA THIS
EVENING. ANOTHER BEAUTIFUL DAY TODAY SAW TEMPERATURES CLIMB INTO
THE 80S UNDER SUNNY SKIES AFTER THE FOG BURNED OFF THIS MORNING.
THE FRONT THAT WAS TO OUR SOUTH HAS MOVED BACK NORTHWARD AND
EXTENDS FROM SOUTHEAST OKLAHOMA INTO SOUTH-CENTRAL MISSISSIPPI
THIS EVENING.
MODELS ARE HINTING AT MORE FOG ON TAP TONIGHT WITH SOME AREAS
FALLING BELOW ONE MILE TOWARDS SUNRISE. TEMPS EXPECTED TO RANGE
FROM THE MID TO UPPER 60S AT THE COAST TO NEAR 60 ACROSS THE LAKES
REGION OF SOUTHWEST TEXAS AND CENTRAL LOUISIANA. ANOTHER FRONT
LOOKS TO APPROACH FROM THE NORTHWEST BY EARLY FRIDAY MORNING
BEFORE STALLING OVER THE COASTAL WATERS. NOT LOOKING FOR ANY REAL
CHANCE AT PRECIP AND TEMPS WILL NOT SHOW MUCH VARIATION...BUT
DRIER AIR WILL SET IN FOR FRIDAY. THE HIGH PRESSURE WILL MOVE
QUICKLY OFF TO THE EAST WITH RETURN FLOW ON SATURDAY MORNING.
RETURN MOISTURE WILL MOVE UP FROM DEEP SOUTH TEXAS AND INTO
EASTERN TEXAS BY EARLY SUNDAY MORNING. THIS WILL ESTABLISH A
DEEPER MOISTURE PROFILE WITH THE CHANCE FOR SOME SHOWERS SUNDAY
AFTERNOON/EVENING TIME-FRAME. CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL CONTINUE INTO MONDAY AS ANOTHER FRONT THIS TIME
STRONGER WILL PUSH THROUGH THE REGION. TEMPERATURES WILL COOL ON
TUESDAY WITH WEDNESDAY MORNING SEEING TEMPS STARING OUT IN THE LOW
50S CENTRAL LOUISIANA WITH MID 50S DOWN ALONG THE I-10 CORRIDOR.
19
PREV DISCUSSION... /ISSUED 645 PM CDT WED APR 23 2014/
DISCUSSION...
23/00Z TAF ISSUANCE.
AVIATION...
AFTN CU FIELD BEGINNING TO DISSIPATE WITH THE LOSS OF DAYTIME
HEATING...WITH VFR CONDITIONS EXPECTED FOR THE REMAINDER OF THE
EVENING. SLY WINDS CONTINUE TO USHER PLENTY OF LOW LVL MOISTURE
INTO THE REGION. WINDS WILL LIGHTEN DURING THE EVENING WITH FOG
EXPECTED TO DEVELOP BY MIDNIGHT. THE ONSET OF FOG LOOKS MORE
LIKELY AT THE ERN TERMINALS TONIGHT WITH LOW LVL WINDS
STRENGTHENING TO THE WEST RESULTING IN MORE OF A LOW CIG AT KBPT
ALTHOUGH OCCASIONAL PERIODS OF FOG CANNOT BE RULED OUT.
OTHERWISE...FEW CHANGES TO REMAINDER OF FCST WITH FOG/CIGS LIFTING
THU MORNING AND SLY WINDS STRENGTHENING...BECOMING GUSTY DURING
THE AFTN AS THE NEXT WEAK FRONT APPROACHES THE AREA. 24
PREV DISCUSSION... /ISSUED 421 PM CDT WED APR 23 2014/
DISCUSSION...PLEASANT AFTERNOON ACROSS THE FORECAST AREA.
TEMPERATURES GENERALLY RUNNING IN THE LOW 80S AND HUMIDITY LEVELS
ON THE LOW SIDE WITH DEWPOINTS RANGING FROM THE MID 50S INTO THE
LOWER 60S. SATELLITE IMAGERY DEPICTING SCATTERED CU ACROSS THE
REGION. SOME ENHANCEMENT OF THE CU NOTED FROM LOWER ACADIANA WEST
NORTHWEST INTO INTERIOR SOUTHEAST TEXAS. THIS MARKING THE
RETREATING FRONTAL BOUNDARY.
A FAIRLY QUIET WEATHER PATTERN AHEAD FOR THE REMAINDER OF THE
WEEK. TEMPERATURES ANTICIPATED TO GENERALLY REMAIN A FEW DEGREES
ABOVE THE NORM AS A DEEPENING SOUTHERLY FLOW BECOMES ESTABLISHED.
STEADY ONSHORE FLOW WILL PROVIDE A DAILY CHANCE OF NIGHT-TIME
ADVECTION FOG DEVELOPMENT. BOUNDARY LAYER WINDS MAY JUST BE HIGH
ENOUGH FOR STRATUS RATHER THAN FOG BUT TOO CLOSE OF A CALL AT
THIS TIME. CARRYING PATCHY FOG TONIGHT.
NEXT MID/UPPER LEVEL TROF ADVANCING THROUGH THE CENTRAL CONUS WILL
SWING AN ACCOMPANYING WEAK SURFACE TROF ACROSS THE FORECAST AREA
LATE THURSDAY NIGHT. HAVE MAINTAINED LOW END POPS FOR THURSDAY
AFTERNOON AND EVENING WITH FEATURES OVER CENTRAL LOUISIANA INTO
INTERIOR SOUTHEAST TEXAS. MOISTURE/LIFT AT THIS TIME APPEARS TO
LIMITED FOR MENTIONABLE POPS FURTHER SOUTH. PASSAGE WILL BRING
NORTHING MORE THAN A VERY BRIEF AND LIMITED LOWERING OF DEWPOINTS.
VIGOROUS SYSTEM DEVELOPING AND ADVANCING THROUGH THE PLAINS WILL
SWING ANOTHER COLD FRONT THROUGH THE AREA MONDAY. RAIN CHANCES
INCREASE SUNDAY AND MONDAY.
MARINE...AN ONSHORE FLOW WILL RETURN TODAY AS HIGH PRESSURE BECOMES
REESTABLISHED IN THE WAKE OF A WARM FRONT ADVANCING INLAND FROM
THE NORTHWEST GULF. WINDS WILL STRENGTHEN AND SEAS BUILD THROUGH
THE WEEKEND IN ADVANCE OF OUR NEXT FRONTAL PASSAGE EXPECTED LATE
MONDAY. 23
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 62 81 64 82 / 0 10 20 10
KBPT 64 80 65 81 / 0 10 10 10
KAEX 60 84 63 83 / 0 20 20 10
KLFT 64 81 65 82 / 0 10 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
939 PM EDT FRI APR 25 2014
.SYNOPSIS...
LOW PRESSURE TRACKS ACROSS THE NORTHERN MID ATLANTIC THIS
AFTERNOON AND EVENING AND EXITS THE DELMARVA COAST AROUND MIDNIGHT.
A COLD FRONT DROPS ACROSS THE REGION SATURDAY NIGHT...WITH HIGH
PRESSURE BUILDING IN FROM THE GREAT LAKES SUNDAY. PERIODS OF
UNSETTLED WEATHER ARE EXPECTED NEXT WEEK AS A COMPLEX AREA OF LOW
PRESSURE TRACKS FROM THE CENTRAL TO THE EASTERN UNITED STATES.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE LATEST WV IMAGERY INDICATES A POTENT SHORTWAVE TROUGH TRACKING
ACROSS THE CENTRAL APPALACHIANS. AT THE SURFACE...A 1004MB
SURFACE LOW IS NEAR LAKE ERIE...WITH A ~4MB/3HR PRESSURE FALLS
OCCURRING ACROSS CENTRAL VA/NC. A COLD FRONT (PRIMARILY A DEWPOINT
BOUNDARY) EXTENDS SOUTHWARD THROUGH THE SRN APPALACHIANS. THE
WARM FRONTAL STRUCTURE REMAINS RATHER COMPLEX WITH DEWPOINTS
RANGING FROM THE UPPER 20S OVER THE LOWER MD ERN SHORE TO THE
UPPER 50S/LOW 60S OVER S-CENTRAL VA AND NE NC.
THE MID-LEVEL TROUGH IS PROGGED TO LIFT NE THROUGH THE EASTERN
GREAT LAKES DURING THE LATE AFTERNOON AND EVENING. THIS WILL
CONTINUE TO DRAW MOISTURE N OVER THE MID ATLANTIC REGION. WV
IMAGERY SHOWS A DRY CONVEYOR PUNCHING INTO WRN NC THIS AFTERNOON.
THIS HAS CREATED AN UNSTABLE THERMODYNAMIC PROFILE AS IT
OVERSPREADS RICHER LOW-LEVEL MOISTURE. HEIGHT FALLS AHEAD OF THE
TROUGH WILL CONTRIBUTE TO MID-LEVEL COOLING AND WILL ALSO RESULT
IN RATHER ROBUST VERTICAL MOTION. THE 25/17Z HRRR TRACKS
CONVECTION ACROSS THE LOCAL AREA THROUGH THE LATE AFTERNOON AND
LARGELY OFF THE COAST BY 03Z...WITH LINGERING SHOWERS OVER THE
EASTERN SHORE THROUGH 06Z...BEFORE THE DRY BOUNDARY OVERSPREADS
THE AREA.
AS FOR THE SEVERE POTENTIAL...THE GREATEST THREAT REMAINS ACROSS
SE VA/NE NC WHERE THE BEST COMBINATION OF DYNAMICAL AND
THERMODYNAMIC FORCING OCCURS. 0-6KM DEEP LAYER SHEAR PER SPC
ANALYSIS IS 40-50KT AND THIS SHOULD BE SUFFICIENT TO PRODUCE
ORGANIZED CLUSTERS OF STORMS. WIND WILL BE THE GREATEST
THREAT...BUT THE COMBINATION OF DEEP LIFT AND WBZ HEIGHTS AROUND
10 KFT WILL MAKE LARGE HAIL POSSIBLE. THERE IS A THREAT FOR
ISOLATED TORNADOES WITH LOW-LEVEL DIRECTIONAL SHEAR RESULTING FROM
A SURFACE LOW DEVELOPING OVER W-CENTRAL NC. THE SEVERE THREAT
SHOULD END W-E THROUGH 01Z.
THE SKY WILL QUICKLY CLEAR FROM W-E DURING THE LATE EVENING AND
OVERNIGHT HOURS. LOWS SHOULD RANGE FROM THE UPPER 40S NW...TO THE
UPPER 50S SE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY SHOULD BEGIN MOSTLY SUNNY...BEFORE CLOUDS INCREASE
(ESPECIALLY N) AHEAD OF A COLD FRONT APPROACHING FROM THE NW. THIS
FRONTAL PASSAGE SHOULD MAINLY BE DRY. HOWEVER...A SLIGHT CHC POP
WILL BE INCLUDED FOR THE LOWER MD EASTERN SHORE. HIGHS SHOULD
RANGE FROM THE LOW/MID 70S NE (LOCALLY COOLER ALONG THE IMMEDIATE
COAST)...TO AROUND 80 ALONG AND W OF I-95.
THE COLD FRONT DROPS THROUGH THE AREA SATURDAY NIGHT...WITH HIGH
PRESSURE BUILDING IN FROM THE GREAT LAKES SUNDAY. LOWS SHOULD RANGE
FROM THE MID 40S TO LOW 50S SATURDAY NIGHT...WITH HIGHS SUNDAY
AFTERNOON IN THE LOW/MID 60S NE TO LOW/MID 70S SW UNDER A MOSTLY
SUNNY/CLEAR SKY.
HIGH PRESSURE SHIFTS TO THE NE SUNDAY NIGHT AND MONDAY ALLOWING A
WARM FRONT TO SLOWLY LIFT N. CLOUDS SHOULD INCREASE LATE SUNDAY
NIGHT INTO MONDAY...WITH SLIGHT CHC/LOW-END CHC POPS INTO WESTERN
PORTIONS BY MONDAY AFTERNOON. LOWS SUNDAY NIGHT SHOULD RANGE FROM
THE MID 40S TO LOW 50S...FOLLOWED BY HIGHS MONDAY IN THE LOW 60S
NE...TO AROUND 70 SW.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS CONTINUE THE TREND FOR AN EXTENDED PERIOD OF UNSETTLED
WX MOST OF NEXT WEEK DUE TO A HIGHLY AMPLIFIED/BLOCKY PATTERN.
TODAYS MODELS TAKE MAIN UPR LEVEL LOW FARTHER NORTH & WEST OF
THE MTS TUE / WED THAN PREVIOUS RUNS DID. FORECAST BECOMES RATHER
PROBLEMATIC DUE TO THE INITIAL COOL WEDGE THAT SETS UP TUES WITH
A SECONDARY EAST COAST SHOOTER DEVELOPS ALLOWING A TRIPLE POINT TO
MOVE ACROSS SERN VA/NE NC ERLY WED. WHAT THIS CHANGE DOES IS ALLOW
THE WARM FRONT TO LIFT FARTHER NORTH INTO VA PULLING WARMER & MORE
HUMID AIR NORTH (BUT HOW FAR GIVEN PTNTL PIEDMONT WEDGE???). WILL
BE ADDING CHANCE OF TSTORMS ACROSS SERN SECTIONS WED AFTRN.
THIS COASTAL LOW PROGGED TO BECOME THE MORE DOMINANT LOW AS IT MOVES
NE ALONG THE COAST THURSDAY NIGHT AND FRIDAY. TRAILING COLD FRONT
PROGGED TO CROSS THE RGN THURSDAY TAPPING SOME OF THE GULF MOISTURE
TO THE SOUTH. UPSHOT...A RATHER WET PERIOD TUES THROUGH THUSRDAY
WITH LIKELY POPS. BEST CHCS FOR THUNDER APPEARS TO AHEAD AND ALONG
THE COLD FRNT WED NIGHT AND THURS. DRYING OUT FRI.
HIGHS TUE L-M60S NORTH...U60S-L70S SOUTH. HIGHS WED/THU/FRI U60S-M70S.
LOWS MON NITE U40S-M50S. OTW...GNRLY 50-60.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
STRONG TO SEVERE THUNDERSTORMS CONTINUE TO MOVE ACROSS SE VA AND NE
NC. EXPECT THE STRONGEST STORMS TO PERSIST THROUGH 02Z SAT WITH
SHOWERS AND LOWERED CIGS LASTING THROUGH 06Z SAT. THE LOW PRESSURE
SYSTEM AND ASSOCIATED COLD FRONT WILL PUSH OFF THE COAST OVERNIGHT.
THIS WILL USHER IN DRIER AIR HELPING TO CLEAR ANY REMAINING PRECIP
AND LOW CLOUDS. FOG WILL MOST LIKELY NOT BE AN ISSUE OVERNIGHT DUE
TO WINDS OVER 12KT OVERNIGHT KEEPING THE BOUNDARY LAYER MIXED.
EXPECT GUSTY WINDS TOMORROW AS THE LOW DEEPENS OFF THE ATLANTIC
COAST.
A BACKDOOR COLD FRONT AND WIND SHIFT TO THE NORTH ARE EXPECTED SAT
NIGHT. A SLOW MOVING LOW PRES SYSTEM WILL SPREAD UNSETTLED WEATHER
WITH PERIODS OF RAIN NEXT WEEK...BEGINNING TUESDAY.
&&
.MARINE...
FRONT APPRCHG WATERS LATE THIS EVE WITH THE ASSOCIATED CONVECTION
MOVG OFFSHORE. ADJUSTED WIND GRIDS TO REFLECT SUB SCA WINDS NEXT
FEW HRS PER CRNT OBS. MODELS SHOWING A DECENT SURGE BEHIND THE
COLD FRONTAL PASSAGE LATER TONIGHT INTO SAT MORNING ACROSS THE
BAY...SO HEADLINES WILL CONTINUE THERE. EXPT ABT A 2-4 HR PRD OF
GUSTINESS (UP TO 30 KTS) ACROSS NRN COASTAL WATERS SAT AFTRN WHICH
WILL LIKELY RESULT IN SOME 5 FOOT SEAS OUT NR 20 NM SO SCA REMAINS
IN EFFECT THERE. OTW...HIGH PRS BUILDS ACROSS WTRS SAT AFTRN
ALLOWING CONDITIONS ACROSS THE ENTIRE MARINE AREA TO DMNSH THRU
SAT EVENING.
NEXT FRNT CROSSES THE AREA SAT NIGHT PRODUCING A 3-6 HR SURGE OF CAA
SEEN DOWN THE BAY LATE SAT NIGHT...STRNGST OVR THE MIDDLE CHES BAY.
HIGH PRESSURE TO THE NORTH RESULTS IN WNDS BCMG NE SUNDAY THEN E BY
MONDAY. HIGH PROB FOR A PROLONGED PERIOD OF ONSHORE WNDS BEGINNING
SUNDAY THROUGH WED. THIS WILL LIKELY CREATE LONG PERIOD SWELLS ALONG
WITH SEAS AOA 5 FT.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR ANZ630>632-
634.
SMALL CRAFT ADVISORY FROM 5 AM TO NOON EDT SATURDAY FOR ANZ650-
652.
&&
$$
SYNOPSIS...AJZ/BMD
NEAR TERM...AJZ
SHORT TERM...AJZ/BMD
LONG TERM...MPR
AVIATION...DAP
MARINE...MPR
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
734 PM EDT FRI APR 25 2014
.SYNOPSIS...
LOW PRESSURE TRACKS ACROSS THE NORTHERN MID ATLANTIC THIS
AFTERNOON AND EVENING AND EXITS THE DELMARVA COAST AROUND MIDNIGHT.
A COLD FRONT DROPS ACROSS THE REGION SATURDAY NIGHT...WITH HIGH
PRESSURE BUILDING IN FROM THE GREAT LAKES SUNDAY. PERIODS OF
UNSETTLED WEATHER ARE EXPECTED NEXT WEEK AS A COMPLEX AREA OF LOW
PRESSURE TRACKS FROM THE CENTRAL TO THE EASTERN UNITED STATES.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE LATEST WV IMAGERY INDICATES A POTENT SHORTWAVE TROUGH TRACKING
ACROSS THE CENTRAL APPALACHIANS. AT THE SURFACE...A 1004MB
SURFACE LOW IS NEAR LAKE ERIE...WITH A ~4MB/3HR PRESSURE FALLS
OCCURRING ACROSS CENTRAL VA/NC. A COLD FRONT (PRIMARILY A DEWPOINT
BOUNDARY) EXTENDS SOUTHWARD THROUGH THE SRN APPALACHIANS. THE
WARM FRONTAL STRUCTURE REMAINS RATHER COMPLEX WITH DEWPOINTS
RANGING FROM THE UPPER 20S OVER THE LOWER MD ERN SHORE TO THE
UPPER 50S/LOW 60S OVER S-CENTRAL VA AND NE NC.
THE MID-LEVEL TROUGH IS PROGGED TO LIFT NE THROUGH THE EASTERN
GREAT LAKES DURING THE LATE AFTERNOON AND EVENING. THIS WILL
CONTINUE TO DRAW MOISTURE N OVER THE MID ATLANTIC REGION. WV
IMAGERY SHOWS A DRY CONVEYOR PUNCHING INTO WRN NC THIS AFTERNOON.
THIS HAS CREATED AN UNSTABLE THERMODYNAMIC PROFILE AS IT
OVERSPREADS RICHER LOW-LEVEL MOISTURE. HEIGHT FALLS AHEAD OF THE
TROUGH WILL CONTRIBUTE TO MID-LEVEL COOLING AND WILL ALSO RESULT
IN RATHER ROBUST VERTICAL MOTION. THE 25/17Z HRRR TRACKS
CONVECTION ACROSS THE LOCAL AREA THROUGH THE LATE AFTERNOON AND
LARGELY OFF THE COAST BY 03Z...WITH LINGERING SHOWERS OVER THE
EASTERN SHORE THROUGH 06Z...BEFORE THE DRY BOUNDARY OVERSPREADS
THE AREA.
AS FOR THE SEVERE POTENTIAL...THE GREATEST THREAT REMAINS ACROSS
SE VA/NE NC WHERE THE BEST COMBINATION OF DYNAMICAL AND
THERMODYNAMIC FORCING OCCURS. 0-6KM DEEP LAYER SHEAR PER SPC
ANALYSIS IS 40-50KT AND THIS SHOULD BE SUFFICIENT TO PRODUCE
ORGANIZED CLUSTERS OF STORMS. WIND WILL BE THE GREATEST
THREAT...BUT THE COMBINATION OF DEEP LIFT AND WBZ HEIGHTS AROUND
10 KFT WILL MAKE LARGE HAIL POSSIBLE. THERE IS A THREAT FOR
ISOLATED TORNADOES WITH LOW-LEVEL DIRECTIONAL SHEAR RESULTING FROM
A SURFACE LOW DEVELOPING OVER W-CENTRAL NC. THE SEVERE THREAT
SHOULD END W-E THROUGH 01Z.
THE SKY WILL QUICKLY CLEAR FROM W-E DURING THE LATE EVENING AND
OVERNIGHT HOURS. LOWS SHOULD RANGE FROM THE UPPER 40S NW...TO THE
UPPER 50S SE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY SHOULD BEGIN MOSTLY SUNNY...BEFORE CLOUDS INCREASE
(ESPECIALLY N) AHEAD OF A COLD FRONT APPROACHING FROM THE NW. THIS
FRONTAL PASSAGE SHOULD MAINLY BE DRY. HOWEVER...A SLIGHT CHC POP
WILL BE INCLUDED FOR THE LOWER MD EASTERN SHORE. HIGHS SHOULD
RANGE FROM THE LOW/MID 70S NE (LOCALLY COOLER ALONG THE IMMEDIATE
COAST)...TO AROUND 80 ALONG AND W OF I-95.
THE COLD FRONT DROPS THROUGH THE AREA SATURDAY NIGHT...WITH HIGH
PRESSURE BUILDING IN FROM THE GREAT LAKES SUNDAY. LOWS SHOULD RANGE
FROM THE MID 40S TO LOW 50S SATURDAY NIGHT...WITH HIGHS SUNDAY
AFTERNOON IN THE LOW/MID 60S NE TO LOW/MID 70S SW UNDER A MOSTLY
SUNNY/CLEAR SKY.
HIGH PRESSURE SHIFTS TO THE NE SUNDAY NIGHT AND MONDAY ALLOWING A
WARM FRONT TO SLOWLY LIFT N. CLOUDS SHOULD INCREASE LATE SUNDAY
NIGHT INTO MONDAY...WITH SLIGHT CHC/LOW-END CHC POPS INTO WESTERN
PORTIONS BY MONDAY AFTERNOON. LOWS SUNDAY NIGHT SHOULD RANGE FROM
THE MID 40S TO LOW 50S...FOLLOWED BY HIGHS MONDAY IN THE LOW 60S
NE...TO AROUND 70 SW.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS CONTINUE THE TREND FOR AN EXTENDED PERIOD OF UNSETTLED
WX MOST OF NEXT WEEK DUE TO A HIGHLY AMPLIFIED/BLOCKY PATTERN.
TODAYS MODELS TAKE MAIN UPR LEVEL LOW FARTHER NORTH & WEST OF
THE MTS TUE / WED THAN PREVIOUS RUNS DID. FORECAST BECOMES RATHER
PROBLEMATIC DUE TO THE INITIAL COOL WEDGE THAT SETS UP TUES WITH
A SECONDARY EAST COAST SHOOTER DEVELOPS ALLOWING A TRIPLE POINT TO
MOVE ACROSS SERN VA/NE NC ERLY WED. WHAT THIS CHANGE DOES IS ALLOW
THE WARM FRONT TO LIFT FARTHER NORTH INTO VA PULLING WARMER & MORE
HUMID AIR NORTH (BUT HOW FAR GIVEN PTNTL PIEDMONT WEDGE???). WILL
BE ADDING CHANCE OF TSTORMS ACROSS SERN SECTIONS WED AFTRN.
THIS COASTAL LOW PROGGED TO BECOME THE MORE DOMINANT LOW AS IT MOVES
NE ALONG THE COAST THURSDAY NIGHT AND FRIDAY. TRAILING COLD FRONT
PROGGED TO CROSS THE RGN THURSDAY TAPPING SOME OF THE GULF MOISTURE
TO THE SOUTH. UPSHOT...A RATHER WET PERIOD TUES THROUGH THUSRDAY
WITH LIKELY POPS. BEST CHCS FOR THUNDER APPEARS TO AHEAD AND ALONG
THE COLD FRNT WED NIGHT AND THURS. DRYING OUT FRI.
HIGHS TUE L-M60S NORTH...U60S-L70S SOUTH. HIGHS WED/THU/FRI U60S-M70S.
LOWS MON NITE U40S-M50S. OTW...GNRLY 50-60.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
STRONG TO SEVERE THUNDERSTORMS CONTINUE TO MOVE ACROSS SE VA AND NE
NC. EXPECT THE STRONGEST STORMS TO PERSIST THROUGH 02Z SAT WITH
SHOWERS AND LOWERED CIGS LASTING THROUGH 06Z SAT. THE LOW PRESSURE
SYSTEM AND ASSOCIATED COLD FRONT WILL PUSH OFF THE COAST OVERNIGHT.
THIS WILL USHER IN DRIER AIR HELPING TO CLEAR ANY REMAINING PRECIP
AND LOW CLOUDS. FOG WILL MOST LIKELY NOT BE AN ISSUE OVERNIGHT DUE
TO WINDS OVER 12KT OVERNIGHT KEEPING THE BOUNDARY LAYER MIXED.
EXPECT GUSTY WINDS TOMORROW AS THE LOW DEEPENS OFF THE ATLANTIC
COAST.
A BACKDOOR COLD FRONT AND WIND SHIFT TO THE NORTH ARE EXPECTED SAT
NIGHT. A SLOW MOVING LOW PRES SYSTEM WILL SPREAD UNSETTLED WEATHER
WITH PERIODS OF RAIN NEXT WEEK...BEGINNING TUESDAY.
&&
.MARINE...
GUSTY WINDS AHEAD OF APRCHG COLD FRONT WILL CONT THE SCA HEADLINES
FOR THE BAY / RIVERS / CURRITUCK NEXT FEW HOURS. MODELS SHOWING A
DECENT SURGE BEHIND THE COLD FRONTAL PASSAGE LATER TONIGHT INTO SAT
MORNING ACROSS THE BAY...SO HEADLINES WILL CONTINUE THERE. EXPT ABT
A 2-4 HR PRD OF GUSTINESS (UP TO 30 KTS) ACROSS NRN COASTAL WATERS
SAT AFTRN WHICH WILL LIKELY RESULT IN SOME 5 FOOT SEAS OUT NR 20 NM
SO SCA REMAINS IN EFFECT THERE. OTW...HIGH PRS BUILDS ACROSS WTRS
SAT AFTRN ALLOWING CONDITIONS ACROSS THE ENTIRE MARINE AREA TO DMNSH
THRU SAT EVENING.
NEXT FRNT CROSSES THE AREA SAT NIGHT PRODUCING A 3-6 HR SURGE OF CAA
SEEN DOWN THE BAY LATE SAT NIGHT...STRNGST OVR THE MIDDLE CHES BAY.
HIGH PRESSURE TO THE NORTH RESULTS IN WNDS BCMG NE SUNDAY THEN E BY
MONDAY. HIGH PROB FOR A PROLONGED PERIOD OF ONSHORE WNDS BEGINNING
SUNDAY THROUGH WED. THIS WILL LIKELY CREATE LONG PERIOD SWELLS ALONG
WITH SEAS AOA 5 FT.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ633-
635-636-638.
SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR ANZ630>632-
634.
SMALL CRAFT ADVISORY FROM 5 AM TO NOON EDT SATURDAY FOR ANZ650-
652.
&&
$$
SYNOPSIS...AJZ/BMD
NEAR TERM...AJZ
SHORT TERM...AJZ/BMD
LONG TERM...MPR
AVIATION...DAP
MARINE...MPR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
421 AM EDT THU APR 24 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 507 PM EDT WED APR 23 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF SWEEPING ACROSS THE
WRN CONUS WITH AXIS OVER THE ROCKIES THEN CURVING NW AND OFF THE
COAST OF BRITISH COLUMBIA. DOWNSTREAM RIDGE EXTENDS ACROSS THE
MISSISSIPPI VALLEY AND IS SUPPORTING SFC HIGH PRES RIDGE EXTENDING
FROM NRN ONTARIO ACROSS THE WRN GREAT LAKES AND DOWN TO THE GULF
COAST. VERY DRY AIR MASS IS ASSOCIATED WITH THE RIDGE PER REGIONAL
12Z RAOBS. END RESULT HAS BEEN PLENTY OF SUNSHINE TO START THE
DAY...BUT HIGH CLOUDS ARE FANNING E INTO THE AREA AHEAD OF THE WRN
CONUS TROF. DRY AIR HAS ALLOWED DEEP MIXING IN THE INTERIOR WHERE
TEMPS HAVE RISEN SIGNIFICANTLY FROM THE EARLY MORNING CHILL. TEMPS
ARE INTO THE LOW AND MID 50S AWAY FROM MARINE COOLING. ALONG LAKE
SUPERIOR...TEMPS ARE IN THE MID 30S TO LWR 40S. DEEP MIXING INTO THE
DRY AIR ALOFT HAS ALSO CAUSED SFC DWPTS TO FALL AS LOW AS THE MID
TEENS AT SOME LOCATIONS.
SHORT TERM WILL BEGIN QUIET WITH VERY DRY AIR MASS LINGERING OVER
THE AREA IN ASSOCIATION WITH SFC HIGH PRES RIDGE DRIFTING E FROM THE
WRN GREAT LAKES. HIGH AND THEN MID CLOUDS WILL CONTINUE TO ADVANCE
INTO THE UPPER LAKES TONIGHT AS WAA/ISENTROPIC ASCENT REGIME SPREADS
E AHEAD OF THE TROF MOVING INTO THE WRN PLAINS. WITH WAA/ISENTROPIC
NOT PARTICULARLY STRONG TONIGHT AND WITH SUBSTANTIAL ANTECEDANT
LOW-LEVEL DRY AIR IN PLACE (NOTE THE VERY DRY AIR SAMPLED ON
REGIONAL 12Z RAOBS)...IT MAY BE TOUGH TO GET PCPN INTO WRN UPPER MI
LATE TONIGHT. WILL NEED TO WATCH THE INITIAL NNW-SSE ORIENTED PCPN
BAND CURRENTLY OVER MN TO SEE HOW AGGRESSIVELY IT BATTLES THE DRY
AIR THIS EVENING. FOR NOW...WILL UTILIZE MOSTLY SCHC POPS OVER FAR
WRN UPPER MI OVERNIGHT WITH CHC NEAR KIWD. PTYPE WILL PROBABLY BE
RAIN...BUT WITH DRY AIR/EVAPORATIVE COOLING AND LIMITED DEPTH OF
ABOVE 0C WETBULB TEMPS...THERE COULD BE SOME WET SNOW.
AT 12Z THU...MID/UPPER LEVEL TROF AXIS WILL BE OVER THE WRN PLAINS.
WITHIN THE TROF...STRONGER SHORTWAVE WILL BE OVER ERN MT/WRN ND WITH
SRN SHORTWAVE OVER THE SRN PLAINS. THRU THE DAY...THE NRN WAVE WILL
DEEPEN AS IT TRACKS A LITTLE S OF E WHILE THE SRN PLAINS WAVE TRACKS
SLIGHTLY N OF E. AS THE TROF SHARPENS UP/DEEPENS WHILE SHIFTING
E...RIBBON OF STRONGER ISENTROPIC ASCENT TRANSLATES TO THE UPPER
LAKES ALONG WITH INCREASING DEEP LAYER FORCING. WITH SUBSTANTIAL
MOISTURE AVBL (MIXING RATIOS 4-5G/KG ADVECTING INTO UPPER MI AROUND
750MB)...DECENT PCPN AMOUNTS ARE LIKELY. FOR MANY DAYS...MODELS HAVE
SHOWN THERMAL PROFILES ON THE BORDER FOR RAIN/SNOW...AND THAT HASN`T
CHANGED MUCH. GIVEN THE HIGH SUN ANGLE THIS TIME OF YEAR...BOUNDARY
LAYER WARMTH IS A PROBLEM...BUT IT APPEARS PCPN RATES WILL PROBABLY
BE SUFFICIENT FOR PCPN TO CHANGE TO MOSTLY SNOW OVER HIGHER TERRAIN
FROM DICKINSON/MARQUETTE COUNTIES WESTWARD. IN ADDITION...NEAR SFC E
TO SE WINDS WILL CONTINUE TO ADVECT LOW-LEVEL DRIER AIR INTO THE
FCST AREA...AIDING EVAPORATIVE COOLING. THUS...GRIDS WILL SHOW AN
EXPANSION OF SNOW PTYPE AS HEAVIER PCPN SPREADS NE THU AFTN ALONG
WITH SFC TEMPS FALLING TO AROUND 33/34F. DETERMINING SNOW
ACCUMULATIONS THIS LATE IN THE SEASON WITH HIGHER SUN ANGLE IS A
CHALLENGE. SNOW MAY NOT ACCUMULATE MUCH IF AT ALL ON ROADWAYS UNLESS
HEAVY SNOW IS FALLING. ON GROUND SURFACES...SNOW ACCUMULATIONS OF AN
INCH OR TWO MAY OCCUR WITH AS MUCH AS 3 POSSIBLE FROM WRN DICKINSON
INTO GOGEBIC COUNTIES WHERE HEAVIEST PCPN ARRIVES IN THE AFTN.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 417 AM EDT THU APR 24 2014
MAIN FCST CONCERNS IN THE LONG TERM ARE FOCUSED ON POPS/PTYPE/
ADDITIONAL SN AMOUNTS ON FRI/FRI NGT. HUDSON BAY HI PRES SHOULD
BRING A DRY BUT COOL PERIOD OF WX THIS WEEKEND INTO EARLY NEXT WEEK.
FRI...WARM CONVEYOR BELT RIBBON OF MSTR WITH H7 SPECIFIC HUMIDITY AS
HI AS 4G/KG AND DEEP LYR QVECTOR CNVGC UNDER DIFFLUENT UPR FLOW
AHEAD OF STRONG SHRTWV MOVING THRU WRN LK SUP ARE FCST TO STILL BE
INFLUENCING THE KEWEENAW AND MUCH OF THE E HALF OF THE CWA AT
12Z ON FRI...WITH MID LVL DRY SLOTTING ON THE SRN FLANK OF THE
SHRTWV IMPACTING AREAS NEAR THE WI BORDER. EXACTLY HOW FAR N OR S
THIS SHRTWV TRACKS W-E THRU UPR MI WL INFLUENCE HOW LONG HEAVIER
PCPN UNDER THE WARM CONVEYOR BELT CAN LINGER AT ANY GIVEN
POINT...WITH LOCATIONS TO THE S OF THE H7 LO TRACK UNDER MORE
AGGRESSIVE MID LVL DRY SLOTTING SEEING A QUICKER END TO THE HEAVIER
PCPN. THE 00Z NAM/GFS/HIER RES CNDN MODEL/LOCAL WRF ARW/ECMWF HAVE
ALL TRENDED FARTHER TO THE N WITH THE SHRTWV/H7 LO TRACK AND SHOW
AGGRESSIVE MID LVL DRYING MOVING W-E THRU UPR MI AND QUICKLY
DIMINISHING THE PCPN BY EARLY AFTN EXCEPT PERHAPS FOR SOME SCT RA/SN
SHOWERS OVER THE N AND ESPECIALLY THE KEWEENAW CLOSER TO THE PATH OF
THESE FEATURES. WITH MORE AGGRESSIVE MID LVL DRYING AND LESS
PCPN...BUMPED UP FCST HI TEMPS FOR ALL BUT THE NRN CWA EVEN THOUGH
LINGERING LLVL MSTR WL ALLOW FOR A GOOD DEAL OF SC TO LINGER UNDER
STRENGTHENING MID LVL INVRN. THE WARMEST AREA WL BE OVER THE
SCENTRAL...WHERE DOWNSLOPING WNW FLOW WL ALLOW FOR MORE BREAKS IN
THE CLDS/WARMING. INCREASED HI TEMPS INTO THE 50S IN THIS AREA.
FRI NGT...STEADY HGT RISES/DNVA/DEEP LYR QVECTOR DVGC IN THE WAKE OF
THE DEPARTING SHRTWV TO THE E WL BE INFLUENCING UPR MI...BUT SOME
MODELS INCLUDING THE 00Z GFS SHOW ANOTHER SHRTWV SLIDING SEWD THRU
THE UPR LKS IN THE WAKE OF THE LEAD DISTURBANCE BRINGING MORE DEEPER
MSTR/SOME HEAVIER PCPN TO THE AREA. GIVEN THE STRENGTH OF THE LEAD
SHRTWV AND FAIRLY AGGRESSIVE DEEP LYR QVECTOR DVGC IN ITS WAKE...
PREFER THE 12Z ECWMF/00Z NAM THAT SUPPRESS THIS SECOND DISTURBANCE
AND MAINTAIN MORE MID LVL DRYING. HOWEVER...LINGERING CYC LLVL NE
FLOW IN THE PRESENCE OF LINGERING LLVL MSTR MAY ALLOW FOR SOME LGT
RA/SN SHOWERS TO PERSIST IN THE UPSLOPE AREAS NEAR LK SUP FOR A GOOD
PORTION OF THE NGT.
SAT...SFC HI PRES IS FCST TO BUILD OVER HUDSON BAY...WITH SFC RDG
AXIS EXTENDING S INTO THE UPR LKS UNDER STEADILY RISING HGTS...IN
LINE WITH GOING DRY FCST. ALTHOUGH THERE MAY BE SOME LINGERING LO
CLDS MAINLY NEAR LK SUP IN LLVL NNE FLOW WITHIN SHALLOW COOL LYR
UNDER LOWERING/STRENGTHENING INVRN...THESE CLDS SHOULD BURN OFF WITH
DAYTIME HEATING. DESPITE THE RETURN OF SOME AFTN SUNSHINE...
LOCATIONS NEAR LK SUP WL BE QUITE CHILLY WITH H85 TEMPS RISING NO
HIER THAN -3C AND THE LLVL NNE FLOW OFF THE WATER STILL COVERED WITH
A GOOD DEAL OF ICE. HELD FCST HI TEMPS IN THE WELL BLO NORMAL
MID-UPR 30S NEAR LK SUP.
SAT NGT/SUN...LONGER RANGE MODELS ARE VERY CONSISTENT SHOWING UPR
RDG BLDG OVER SCENTRAL CANADA INTO THE GREAT LKS TO THE NE OF POTENT
SHRTWV EMERGING OUT OF THE DESERT SW INTO THE CENTRAL PLAINS. BUT A
GOOD NUMBER OF THE EXTENDED MODELS SHOW DEEPER MSTR RETURNING TO THE
UPR GRT LKS WELL TO THE NE OF THE CLOSED LO. GIVEN THE TREND TOWARD
BLDG RDG AND PRESENCE OF HUDSON BAY HI PRES WITH DRY ENE LLVL FLOW/
SPRING CLIMATOLOGY FOR HUDSON BAY HI PRES...SUSPECT THE 00Z ECWMF IS
ON THE RIGHT TRACK WITH A DRY FCST FOR UPR MI. SINCE OTHER MODELS
ARE MORE AGGRESSIVE WITH RETURNING MSTR...TENDED TOWARD THE LO END
OF GUIDANCE/ECMWF FCST TEMPS FOR SAT NGT...WHICH COULD BE QUITE
CHILLY WITH MIN TEMPS FALLING TOWARD THE LO 20S.
EXTENDED...AS THE CLOSED LO/ACCOMPANYING SFC LO/LARGER SCALE CYC
FLOW TO THE SW SLOWLY MOVE NEWD...MAINTAINED GRADUAL INCRS IN POPS
SHOWN BY MODEL CONSENSUS IN THE MON THRU WED TIME. TIGHTENING PRES
GRADIENT BTWN THE SLOWLY RETREATING HUDSON BAY HI PRES AND APRCHG
DEEP LO PRES WL RESULT IN STEADY/GUSTY E WINDS. FCST THERMAL FIELDS
THAT SUPPORT WELL BLO NORMAL TEMPS ALSO INDICATE SOME OF THE PCPN
MAY BE AT LEAST MIXED WITH SN AT TIMES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1206 AM EDT THU APR 24 2014
VFR CONDITIONS CONTINUE OVER THE REGION AS DRY AIR LINGERS. PCPN
FROM APPROACHING SYSTEM MOVING THROUGH THE PLAINS STRUGGLING TO
OVERCOME THE DRIER AT AT KIWD EARLY THIS MORNING...HOWEVER THE
LATEST BUFKIT NAM DATA HAS LIGHT RAIN REACHING THAT AREA A LITTLE
EARLIER THAN PREVIOUS RUNS AND THUS HAVE MOVED TIMING OF LIGHT RAIN
UP A BIT THERE. OTHERWISE PCPN TO HOLD OFF AT KCMX AND KSAW UNTIL
AFTER 18Z. CONCERNS ON TIMING OF PHASE CHANGE AT ALL THREE SITES AS
NAM TRENDING A BIT WARMER...THUS AT THIS TIME HAVE TRENDED SLIGHTLY
SLOWER WITH THE CHANGEOVER FROM RAIN TO SNOW. CIGS TO DROP FROM VFR
TO MVFR AT 18Z AT KIWD AND THEN THE OTHER SITES LATER IN THE
AFTERNOON AS PCPN PICKS UP IN INTENSITY. INTRODUCED IFR CIGS AFTER
0Z AT KSAW AND KCMX DUE TO UPSLOPE WINDS...BUT SE DIRECTION IS
DOWNSLOPE AT KIWD AND THUS HAVE LEFT CIGS AT THE LOW END OF MVFR
THERE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 350 AM EDT THU APR 24 2014
AS THE HIGH PRESSURE RIDGE OVER LAKE HURON EARLY THIS MORNING DRIFTS
OFF THE EAST COAST FRIDAY MORNING...A LOW OVER THE CENTRAL PLAINS
WILL SHIFT TO THE LOWER GREAT LAKES. SE GUSTS WILL NEAR 30-35KTS
LATE THIS EVENING OVER MAINLY CENTRAL LAKE SUPERIOR. THE LOW WILL
CONTINUE NE INTO NEW ENGLAND ON SATURDAY. A LARGE CANADIAN HIGH
PRESSURE RIDGE WILL THEN BUILD ACROSS THE UPPER GREAT LAKES SATURDAY
INTO MONDAY. ANOTHER ROUND OF STRONGER E WINDS NEARING 25-30KTS WILL
BE POSSIBLE MONDAY...IN BETWEEN THE EXITING RIDGE OF HIGH PRESSURE
AND NEARING LOW PRESSURE FROM THE PLAINS STATES.
&&
.HYDROLOGY...
ISSUED AT 417 AM EDT THU APR 24 2014
RUNOFF FROM RECENT ABOVE NORMAL TEMPS AND SNOWMELT CONTINUES TO FLOW
THRU THE GROUND...SO SOME AREA STREAMS AND RIVERS ARE STILL RUNNING
HIGH AND EVEN RISING SLOWLY...DESPITE THE COOLER TEMPERATURES THAT
WERE SEEN RECENTLY. LOCATIONS THAT STILL ARE STILL NEAR OR ABOVE
BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR CHASSELL AND
THE PAINT RIVER NEAR CRYSTAL FALLS. WHILE THE PAINT RIVER NEAR
CRYSTAL FALLS IS NOT EXPECTED TO REACH FLOOD STAGE IN THE SHORT
TERM...THE STURGEON RIVER NEAR CHASSELL WILL BE CLOSE AND WILL
CONTINUE TO BE MONITORED.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
MORE PRECIPITATION WILL RETURN TODAY INTO FRIDAY AS ANOTHER LOW
PRESSURE SYSTEM MOVES FROM THE PLAINS TOWARD THE GREAT LAKES...
POTENTIALLY ADDING TO RUNOFF. AT THIS POINT THE BEST CHANCE OF
SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE WEST HALF OF UPPER
MI...AND SPECIFICALLY THE KEWEENAW PENINSULA...WHERE 0.50-1.25 INCH
OF LIQUID WILL BE POSSIBLE BY FRIDAY AFTERNOON. THERE IS SOME
UNCERTAINTY ON HOW MUCH WILL FALL AS RAIN AND HOW MUCH WILL FALL AS
SNOW...BUT THE BEST CHANCE OF SNOW WILL BE OVER THE KEWEENAW
PENINSULA. IF MORE OF THE PRECIPITATION FALLS AS SNOW...RUNOFF WILL
BE DELAYED UNTIL WARMER WEATHER RETURNS NEXT WEEK.
OVERALL...WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. THOSE
LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER
LEVELS OVER THE NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 11 AM EDT
FRIDAY FOR MIZ001-003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KC
AVIATION...RJT
MARINE...KF
HYDROLOGY...KC/KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
351 AM EDT THU APR 24 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 507 PM EDT WED APR 23 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF SWEEPING ACROSS THE
WRN CONUS WITH AXIS OVER THE ROCKIES THEN CURVING NW AND OFF THE
COAST OF BRITISH COLUMBIA. DOWNSTREAM RIDGE EXTENDS ACROSS THE
MISSISSIPPI VALLEY AND IS SUPPORTING SFC HIGH PRES RIDGE EXTENDING
FROM NRN ONTARIO ACROSS THE WRN GREAT LAKES AND DOWN TO THE GULF
COAST. VERY DRY AIR MASS IS ASSOCIATED WITH THE RIDGE PER REGIONAL
12Z RAOBS. END RESULT HAS BEEN PLENTY OF SUNSHINE TO START THE
DAY...BUT HIGH CLOUDS ARE FANNING E INTO THE AREA AHEAD OF THE WRN
CONUS TROF. DRY AIR HAS ALLOWED DEEP MIXING IN THE INTERIOR WHERE
TEMPS HAVE RISEN SIGNIFICANTLY FROM THE EARLY MORNING CHILL. TEMPS
ARE INTO THE LOW AND MID 50S AWAY FROM MARINE COOLING. ALONG LAKE
SUPERIOR...TEMPS ARE IN THE MID 30S TO LWR 40S. DEEP MIXING INTO THE
DRY AIR ALOFT HAS ALSO CAUSED SFC DWPTS TO FALL AS LOW AS THE MID
TEENS AT SOME LOCATIONS.
SHORT TERM WILL BEGIN QUIET WITH VERY DRY AIR MASS LINGERING OVER
THE AREA IN ASSOCIATION WITH SFC HIGH PRES RIDGE DRIFTING E FROM THE
WRN GREAT LAKES. HIGH AND THEN MID CLOUDS WILL CONTINUE TO ADVANCE
INTO THE UPPER LAKES TONIGHT AS WAA/ISENTROPIC ASCENT REGIME SPREADS
E AHEAD OF THE TROF MOVING INTO THE WRN PLAINS. WITH WAA/ISENTROPIC
NOT PARTICULARLY STRONG TONIGHT AND WITH SUBSTANTIAL ANTECEDANT
LOW-LEVEL DRY AIR IN PLACE (NOTE THE VERY DRY AIR SAMPLED ON
REGIONAL 12Z RAOBS)...IT MAY BE TOUGH TO GET PCPN INTO WRN UPPER MI
LATE TONIGHT. WILL NEED TO WATCH THE INITIAL NNW-SSE ORIENTED PCPN
BAND CURRENTLY OVER MN TO SEE HOW AGGRESSIVELY IT BATTLES THE DRY
AIR THIS EVENING. FOR NOW...WILL UTILIZE MOSTLY SCHC POPS OVER FAR
WRN UPPER MI OVERNIGHT WITH CHC NEAR KIWD. PTYPE WILL PROBABLY BE
RAIN...BUT WITH DRY AIR/EVAPORATIVE COOLING AND LIMITED DEPTH OF
ABOVE 0C WETBULB TEMPS...THERE COULD BE SOME WET SNOW.
AT 12Z THU...MID/UPPER LEVEL TROF AXIS WILL BE OVER THE WRN PLAINS.
WITHIN THE TROF...STRONGER SHORTWAVE WILL BE OVER ERN MT/WRN ND WITH
SRN SHORTWAVE OVER THE SRN PLAINS. THRU THE DAY...THE NRN WAVE WILL
DEEPEN AS IT TRACKS A LITTLE S OF E WHILE THE SRN PLAINS WAVE TRACKS
SLIGHTLY N OF E. AS THE TROF SHARPENS UP/DEEPENS WHILE SHIFTING
E...RIBBON OF STRONGER ISENTROPIC ASCENT TRANSLATES TO THE UPPER
LAKES ALONG WITH INCREASING DEEP LAYER FORCING. WITH SUBSTANTIAL
MOISTURE AVBL (MIXING RATIOS 4-5G/KG ADVECTING INTO UPPER MI AROUND
750MB)...DECENT PCPN AMOUNTS ARE LIKELY. FOR MANY DAYS...MODELS HAVE
SHOWN THERMAL PROFILES ON THE BORDER FOR RAIN/SNOW...AND THAT HASN`T
CHANGED MUCH. GIVEN THE HIGH SUN ANGLE THIS TIME OF YEAR...BOUNDARY
LAYER WARMTH IS A PROBLEM...BUT IT APPEARS PCPN RATES WILL PROBABLY
BE SUFFICIENT FOR PCPN TO CHANGE TO MOSTLY SNOW OVER HIGHER TERRAIN
FROM DICKINSON/MARQUETTE COUNTIES WESTWARD. IN ADDITION...NEAR SFC E
TO SE WINDS WILL CONTINUE TO ADVECT LOW-LEVEL DRIER AIR INTO THE
FCST AREA...AIDING EVAPORATIVE COOLING. THUS...GRIDS WILL SHOW AN
EXPANSION OF SNOW PTYPE AS HEAVIER PCPN SPREADS NE THU AFTN ALONG
WITH SFC TEMPS FALLING TO AROUND 33/34F. DETERMINING SNOW
ACCUMULATIONS THIS LATE IN THE SEASON WITH HIGHER SUN ANGLE IS A
CHALLENGE. SNOW MAY NOT ACCUMULATE MUCH IF AT ALL ON ROADWAYS UNLESS
HEAVY SNOW IS FALLING. ON GROUND SURFACES...SNOW ACCUMULATIONS OF AN
INCH OR TWO MAY OCCUR WITH AS MUCH AS 3 POSSIBLE FROM WRN DICKINSON
INTO GOGEBIC COUNTIES WHERE HEAVIEST PCPN ARRIVES IN THE AFTN.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 503 PM EDT WED APR 23 2014
WET SNOW POSSIBLE FOR PORTIONS OF NORTHWEST UPR MICHIGAN LATE
THURSDAY INTO THURSDAY NIGHT. SNOW AMOUNTS ARE THE MAIN ISSUE WITH
THE SYSTEM...AS THAT DICTATES THE NEED FOR ANY HEADLINES.
SHORTWAVE TROUGH CROSSING THE ROCKIES THIS AFTN IS THE MAIN FOCUS
FOR THE THURSDAY INTO FRIDAY TIME FRAME. TROUGH IS FORECAST ARRIVE
OVER THE NORTHERN PLAINS TO THE MIDDLE MISSISSIPPI VALLEY THURSDAY
EVENING. AT THE SFC...ONE LOW IS OVER NORTH DAKOTA WITH ANOTHER LOW
CROSSING SOUTHERN PORTIONS OF THE UPPER GREAT LAKES. SFC TROUGH IS
IN BTWN THE TWO LOWS. MODELS DIFFER ON WHICH SFC LOW IS STRONGER.
TREND WAS EMERGING IN RECENT RUNS OF THE GFS/ECMWF/GEM-NH AND UKMET
THAT NORTHERN PORTION OF THE SHORTWAVE TROUGH AT H85/H7/H5 WOULD BE
THE STRONGER SECTION AND THAT TROUGH WOULD REMAIN MORE PROGRESSIVE
WHICH RESULTED IN LESS PRECIP LATER THURSDAY NIGHT AND CERTAINLY
INTO FRIDAY. RECENT NAM RUNS HAVE BEEN SHOWING MORE OF CLOSED OFF
IDEA WITH MID LEVEL TROUGH AND IS MORE WRAPPED UP WITH THE UPPER LOW
ON FRIDAY... SHOWING CLOSED OFF H5 LOW OVER SCNTRL LK SUPERIOR AT
18Z ON FRIDAY WITH CLOSED OFF H7/H85 AND SFC LOWS OVER CNTRL CWA AT
THE SAME TIME...RESULTING IN DEFORMATION AXIS OF PRECIP LINGERING
OVER NW CWA LATER THURSDAY NIGHT INTO FRIDAY. 12Z NAM CONTINUES TO
SHOW THE SAME THING...BUT IS NOW JOINED BY GFS AND GEM-NH...
REPRESENTING A SHIFT BACK TO WHAT THE GFS WAS SHOWING WITH THE 12Z
RUN ON TUESDAY. SWITCH SHOWS UP IN GFS RUN TOTAL QPF WITH AREAS OF
WESTERN CWA NOW SEEING WELL OVER AN INCH WHERAS PAST RUNS WERE MORE
IN THE 0.50-1.00 RANGE. OVERALL THE THEME OFFERED UP BY THE 12Z
MODELS IS THAT THE POTENTIAL FOR MORE SNOW FOR A LONGER DURATION IS
INCREASING...ESPECIALLY OVER THE WESTERN THIRD OF THE
CWA...INCLUDING THE KEWEENAW PENINSULA.
DIVING INTO THE SPECIFICS...INITIAL SURGE OF PRECIP LATE THURSDAY
AND THURSDAY EVENING IS SUPPORTED IN UPPER LEVELS BY H85-H5 Q-VECTOR
CONVERGENCE AND H3-H25 DIVERGENCE ALOFT DUE TO DIFFLUENT FLOW AS JET
STREAK LIFTS ACROSS UPPER GREAT LAKES FM MID MISSISSIPPI VALLEY TO
NORTHERN ONTARIO. ADDITIONAL LOW-MID LEVEL FORCING IS DUE MAINLY TO
H925-H85 THETA-E ADVECTION AHEAD OF SFC-H85 TROUGH ALONG WITH
290-295K ISENTROPIC ASCENT LIFTING ACROSS UPR MICHIGAN. MOISTURE
INFLUX INTO SYSTEM MORE THAN SUFFICIENT FOR HEAVIER PRECIP WITH
MIXING RATIOS OF 4-6G/KG ON THE 290K SFC /H8-H75/ AND AT LEAST 4G/KG
ON THE 300K SFC /NEAR H7/. AS THE UPPER LOW BECOMES MORE NEGATIVELY
TILTED LATER THURSDAY NIGHT...MAIN FORCING FOR PRECIP WILL COME VIA
PERSISTENT ISENTROPIC ASCENT AND DEFORMATION ALONG AND NORTHWEST OF
MAINLY THE H85 LOW. NAM WOULD SUGGEST TROWAL PRECIP ENHANCEMENT
COULD IMPACT KEWEENAW BASED ON THE THETA-E AT THE H65-H6 LAYER. FOR
THE FORECAST...WILL TREND TOWARD NEGATIVE TILTED SYSTEM...BUT KEEP
HEAVIER QPF ANCHORED IN THE 00Z-06Z FRIDAY PERIOD WHEN H7 MIXING
RATIOS TOWARD 4G/KG ARE PRESENT. AFTER THAT WILL HEAD TOWARD MORE
TONED DOWN QPF FM THE UKMET/ECMWF AND SOMEWHAT THE NAM /SUGGESTING
AROUND 0.30 TO PERHAPS AS MUCH AS NEAR 0.50 INCH IN THE 06Z-12Z TIME
PERIOD WITHIN AXIS OF HEAVIER PRECIP...VERSUS THE WETTER GFS AND
GEM-NH.
PTYPE AND ULTIMATELY SNOW AMOUNTS...REMAINS AN ISSUE. HOWEVER TREND
MAY BE SIGNALING MOSTLY SNOW FOR AT LEAST THE WEST HALF OF THE
CWA...ROUGHLY WEST OF IMT TO MQT. FORECAST SOUNDINGS FM NAM ARE
NEARLY ISOTHERMAL AND NEAR 0C THROUGH H8 AT IMT AND IWD...BUT ARE
SUFFICIENTLY COLD ENOUGH IN THIS LAYER AT CMX AND MQT FOR SNOW.
FARTHER EAST...AT MNM/ESC/P53 THE WARM LAYER IS TO H95/1000FT AGL OR
HIGHER THROUGH THE OVERNIGHT...BUT COULD LOWER ENOUGH BLO 1000FT AGL
TO RESULT IN AT LEAST A MIX OF SNOW OR PERHAPS A TURNOVER TO ONLY
SNOW BTWN 06Z AND 12Z. AT ERY...COULD STAY COLD ENOUGH TO KEEP PTYPE
MAINLY SNOW LIKELY DEPENDING LARGELY ON SFC TEMPS. THOUGH THE
INSOLATION AND BLYR WARMING MAY MAKE IT TOUGH TO ACCUMULATE SNOW
INITIALLY LATER THURSDAY AFTN WOULD EXPECT BY EARLY THURSDAY
EVENING...INCREASING SNOW RATES AND LOSS OF INSOLATION WILL RESULT
IN ACCUMULATIONS INCREASING. SREF OUTPUT BASED ON EXPECTED MODEL
SKIN TEMPS INDICATES THAT BY EARLY THURSDAY EVENING...MAJORITY OF
ENSEMBLE MEMBERS SUGGEST SNOW WOULD START ACCUMLATING ON ROADS AS
WELL...ESPECIALLY IF SNOWFALL RATES PUSH OVER 1 INCH PER HOUR.
EXPECT SNOW ACCUMULATIONS OVER MUCH OF INTERIOR CNTRL CWA TO EXCEED
6 INCHES LATE THURSDAY AFTERNOON INTO FRIDAY...WITH POTENTIAL FOR 8
TO 10 INCHES OVER NORTHWEST CWA. BASED ON THE TRENDS FROM THE 12Z
MODELS AND AFTER COORDINATION WITH SHORT TERM FORECASTER...WILL BE
GOING FOR A WINTER STORM WATCH FOR THE KEWEENAW PENINSULA. IN
ADDITION TO HEAVY SNOW...WILL ALSO SEE POTENTIAL FOR BLOWING SNOW AS
EAST WINDS GUST 20-30 MPH ON THURSDAY NIGHT INTO EARLY FRIDAY
MORNING.
IT WILL BE CLOSE FOR SEEING ENOUGH SNOWFALL FOR A WARNING FOR AREAS
FROM IRON TO MARQUETTE COUNTIES /CURRENTLY HAVE 4-7 INCHES FALLING
MAINLY FROM LATE THURSDAY AFTN THROUGH MIDDAY FRIDAY/...AND POSSIBLY
OVER WESTERN UPR MICHIGAN...BUT WILL KEEP WITH SPECIAL WEATHER
STATEMENT FOR THESE AREAS ATTM. MID SHIFT CAN ASSESS AGAIN AND
DETERMINE WHETHER A WARNING OR ADVISORY IS NEEDED.
SLOWER/MORE CLOSED OFF SYSTEM RESULTS IN HIGHER POPS LINGERING
INTO FRIDAY AFTN...ESPECIALLY NEAR LK SUPERIOR OVER THE NORTHWEST.
SOUNDINGS INDICATE DEEPER MOISTURE BEGINS TO SCOUR OUT FRIDAY
EVENING BUT ENOUGH LOW-LEVEL MOISTURE TO H8 WITH TEMPS WITHIN H85
THERMAL TROUGH TOWARD -10C TO KEEP SMALL CHANCES GOING. BY LATE
FRIDAY NIGHT...H85 MOISTURE LEAVES THE REGION AND HIGH PRESSURE
BECOMES THE BIGGER FACTOR. SHOULD BE GENERALLY CLEAR SKIES ON
SATURDAY AS THE HIGH DOMINATES...BUT ENE-NE WINDS OUT OF THE HIGH
KEEPS THE COOL AIR LOCKED IN. MIXING TO H9 ALONG THE BORDER SUPPORTS
HIGHS INTO THE MID 40S. READINGS ALONG LK SUPERIOR AND OVER MOST OF
THE NORTHERN CWA WILL REMAIN IN THE MID-UPR 30S...15-20 DEGREES
BELOW NORMAL AND FAIRLY CLOSE TO RECORD LOW MAX TEMPS FOR THIS
WEEKEND.
REST OF THE EXTENDED...HUDSON BAY HIGH PRESSURE WITH A LOT OF DRY
AIR AT H85 HOLDS ITS OWN INTO EARLY NEXT WEEK. COULD BE A PERIOD IN
THERE EARLY NEXT WEEK WHERE INCREASE OF MID LEVEL MOISTURE MAY
OCCUR. GIVEN THE STRENGTH OF THE HIGH THOUGH...THINKING THAT PRECIP
CHANCES WILL BE MINIMAL EARLY THIS WEEK. MODELS ARE TRENDING THAT
WAY NOW IT APPEARS. CUTOFF LOW COULD MAKE RUN ACROSS UPPER LAKES BY
MIDDLE OF NEXT WEEK...SO THAT IS WHEN CHANCE POPS RETURN TO THE
FORECAST. STAYING COOL...ESPECIALLY NEAR LK SUPERIOR WHEN THERE ARE
ONSHORE NORTHEAST WINDS. LEANED ON BIAS CORRECTED GUIDANCE FOR MAX
TEMPS THROUGH THE EXTENDED. CONSENSUS WAS USED FOR THE REST OF THE
FORECAST ELEMENTS INCLUDING POPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1206 AM EDT THU APR 24 2014
VFR CONDITIONS CONTINUE OVER THE REGION AS DRY AIR LINGERS. PCPN
FROM APPROACHING SYSTEM MOVING THROUGH THE PLAINS STRUGGLING TO
OVERCOME THE DRIER AT AT KIWD EARLY THIS MORNING...HOWEVER THE
LATEST BUFKIT NAM DATA HAS LIGHT RAIN REACHING THAT AREA A LITTLE
EARLIER THAN PREVIOUS RUNS AND THUS HAVE MOVED TIMING OF LIGHT RAIN
UP A BIT THERE. OTHERWISE PCPN TO HOLD OFF AT KCMX AND KSAW UNTIL
AFTER 18Z. CONCERNS ON TIMING OF PHASE CHANGE AT ALL THREE SITES AS
NAM TRENDING A BIT WARMER...THUS AT THIS TIME HAVE TRENDED SLIGHTLY
SLOWER WITH THE CHANGEOVER FROM RAIN TO SNOW. CIGS TO DROP FROM VFR
TO MVFR AT 18Z AT KIWD AND THEN THE OTHER SITES LATER IN THE
AFTERNOON AS PCPN PICKS UP IN INTENSITY. INTRODUCED IFR CIGS AFTER
0Z AT KSAW AND KCMX DUE TO UPSLOPE WINDS...BUT SE DIRECTION IS
DOWNSLOPE AT KIWD AND THUS HAVE LEFT CIGS AT THE LOW END OF MVFR
THERE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 350 AM EDT THU APR 24 2014
AS THE HIGH PRESSURE RIDGE OVER LAKE HURON EARLY THIS MORNING DRIFTS
OFF THE EAST COAST FRIDAY MORNING...A LOW OVER THE CENTRAL PLAINS
WILL SHIFT TO THE LOWER GREAT LAKES. SE GUSTS WILL NEAR 30-35KTS
LATE THIS EVENING OVER MAINLY CENTRAL LAKE SUPERIOR. THE LOW WILL
CONTINUE NE INTO NEW ENGLAND ON SATURDAY. A LARGE CANADIAN HIGH
PRESSURE RIDGE WILL THEN BUILD ACROSS THE UPPER GREAT LAKES SATURDAY
INTO MONDAY. ANOTHER ROUND OF STRONGER E WINDS NEARING 25-30KTS WILL
BE POSSIBLE MONDAY...IN BETWEEN THE EXITING RIDGE OF HIGH PRESSURE
AND NEARING LOW PRESSURE FROM THE PLAINS STATES.
&&
.HYDROLOGY...
ISSUED AT 503 PM EDT WED APR 23 2014
RUNOFF FROM RECENT ABOVE NORMAL TEMPS AND SNOWMELT CONTINUES TO
FLOW THRU THE GROUND...SO SOME AREA STREAMS AND RIVERS ARE STILL
RISING SLOWLY...DESPITE THE COOLER TEMPERATURES THAN WERE SEEN
RECENTLY. LOCATIONS THAT STILL ARE ABOVE BANKFUL AT THIS TIME
INCLUDE THE STURGEON RIVER NEAR CHASSELL AND THE PAINT RIVER NEAR
CRYSTAL FALLS. NEITHER OF THESE RIVERS IS EXPECTED TO REACH FLOOD
STAGE IN THE SHORT TERM.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
UNSETTLED WEATHER WILL RETURN THURSDAY INTO FRIDAY AS ANOTHER LOW
PRESSURE SYSTEM MOVES FROM THE PLAINS TOWARD THE GREAT LAKES...
POTENTIALLY ADDING TO RUNOFF. AT THIS POINT THE BEST CHANCE OF
SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE WEST HALF OF UPPER
MI...AND SPECIFICALLY THE KEWEENAW PENINSULA...WHERE 0.70-1.25 INCH
OF LIQUID WILL BE POSSIBLE BY FRIDAY AFTERNOON. THERE IS SOME
UNCERTAINTY ON HOW MUCH WILL FALL AS RAIN AND HOW MUCH WILL FALL AS
SNOW...BUT THE BEST CHANCE OF SNOW WILL BE OVER THE KEWEENAW
PENINSULA. IF MORE OF THE PRECIPITATION FALLS AS SNOW...RUNOFF WILL
BE DELAYED UNTIL WARMER WEATHER RETURNS NEXT WEEK.
OVERALL...WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. THOSE
LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER
LEVELS OVER THE NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 11 AM EDT
FRIDAY FOR MIZ001-003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...RJT
MARINE...KF
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1206 AM EDT THU APR 24 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 507 PM EDT WED APR 23 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF SWEEPING ACROSS THE
WRN CONUS WITH AXIS OVER THE ROCKIES THEN CURVING NW AND OFF THE
COAST OF BRITISH COLUMBIA. DOWNSTREAM RIDGE EXTENDS ACROSS THE
MISSISSIPPI VALLEY AND IS SUPPORTING SFC HIGH PRES RIDGE EXTENDING
FROM NRN ONTARIO ACROSS THE WRN GREAT LAKES AND DOWN TO THE GULF
COAST. VERY DRY AIR MASS IS ASSOCIATED WITH THE RIDGE PER REGIONAL
12Z RAOBS. END RESULT HAS BEEN PLENTY OF SUNSHINE TO START THE
DAY...BUT HIGH CLOUDS ARE FANNING E INTO THE AREA AHEAD OF THE WRN
CONUS TROF. DRY AIR HAS ALLOWED DEEP MIXING IN THE INTERIOR WHERE
TEMPS HAVE RISEN SIGNIFICANTLY FROM THE EARLY MORNING CHILL. TEMPS
ARE INTO THE LOW AND MID 50S AWAY FROM MARINE COOLING. ALONG LAKE
SUPERIOR...TEMPS ARE IN THE MID 30S TO LWR 40S. DEEP MIXING INTO THE
DRY AIR ALOFT HAS ALSO CAUSED SFC DWPTS TO FALL AS LOW AS THE MID
TEENS AT SOME LOCATIONS.
SHORT TERM WILL BEGIN QUIET WITH VERY DRY AIR MASS LINGERING OVER
THE AREA IN ASSOCIATION WITH SFC HIGH PRES RIDGE DRIFTING E FROM THE
WRN GREAT LAKES. HIGH AND THEN MID CLOUDS WILL CONTINUE TO ADVANCE
INTO THE UPPER LAKES TONIGHT AS WAA/ISENTROPIC ASCENT REGIME SPREADS
E AHEAD OF THE TROF MOVING INTO THE WRN PLAINS. WITH WAA/ISENTROPIC
NOT PARTICULARLY STRONG TONIGHT AND WITH SUBSTANTIAL ANTECEDANT
LOW-LEVEL DRY AIR IN PLACE (NOTE THE VERY DRY AIR SAMPLED ON
REGIONAL 12Z RAOBS)...IT MAY BE TOUGH TO GET PCPN INTO WRN UPPER MI
LATE TONIGHT. WILL NEED TO WATCH THE INITIAL NNW-SSE ORIENTED PCPN
BAND CURRENTLY OVER MN TO SEE HOW AGGRESSIVELY IT BATTLES THE DRY
AIR THIS EVENING. FOR NOW...WILL UTILIZE MOSTLY SCHC POPS OVER FAR
WRN UPPER MI OVERNIGHT WITH CHC NEAR KIWD. PTYPE WILL PROBABLY BE
RAIN...BUT WITH DRY AIR/EVAPORATIVE COOLING AND LIMITED DEPTH OF
ABOVE 0C WETBULB TEMPS...THERE COULD BE SOME WET SNOW.
AT 12Z THU...MID/UPPER LEVEL TROF AXIS WILL BE OVER THE WRN PLAINS.
WITHIN THE TROF...STRONGER SHORTWAVE WILL BE OVER ERN MT/WRN ND WITH
SRN SHORTWAVE OVER THE SRN PLAINS. THRU THE DAY...THE NRN WAVE WILL
DEEPEN AS IT TRACKS A LITTLE S OF E WHILE THE SRN PLAINS WAVE TRACKS
SLIGHTLY N OF E. AS THE TROF SHARPENS UP/DEEPENS WHILE SHIFTING
E...RIBBON OF STRONGER ISENTROPIC ASCENT TRANSLATES TO THE UPPER
LAKES ALONG WITH INCREASING DEEP LAYER FORCING. WITH SUBSTANTIAL
MOISTURE AVBL (MIXING RATIOS 4-5G/KG ADVECTING INTO UPPER MI AROUND
750MB)...DECENT PCPN AMOUNTS ARE LIKELY. FOR MANY DAYS...MODELS HAVE
SHOWN THERMAL PROFILES ON THE BORDER FOR RAIN/SNOW...AND THAT HASN`T
CHANGED MUCH. GIVEN THE HIGH SUN ANGLE THIS TIME OF YEAR...BOUNDARY
LAYER WARMTH IS A PROBLEM...BUT IT APPEARS PCPN RATES WILL PROBABLY
BE SUFFICIENT FOR PCPN TO CHANGE TO MOSTLY SNOW OVER HIGHER TERRAIN
FROM DICKINSON/MARQUETTE COUNTIES WESTWARD. IN ADDITION...NEAR SFC E
TO SE WINDS WILL CONTINUE TO ADVECT LOW-LEVEL DRIER AIR INTO THE
FCST AREA...AIDING EVAPORATIVE COOLING. THUS...GRIDS WILL SHOW AN
EXPANSION OF SNOW PTYPE AS HEAVIER PCPN SPREADS NE THU AFTN ALONG
WITH SFC TEMPS FALLING TO AROUND 33/34F. DETERMINING SNOW
ACCUMULATIONS THIS LATE IN THE SEASON WITH HIGHER SUN ANGLE IS A
CHALLENGE. SNOW MAY NOT ACCUMULATE MUCH IF AT ALL ON ROADWAYS UNLESS
HEAVY SNOW IS FALLING. ON GROUND SURFACES...SNOW ACCUMULATIONS OF AN
INCH OR TWO MAY OCCUR WITH AS MUCH AS 3 POSSIBLE FROM WRN DICKINSON
INTO GOGEBIC COUNTIES WHERE HEAVIEST PCPN ARRIVES IN THE AFTN.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 503 PM EDT WED APR 23 2014
WET SNOW POSSIBLE FOR PORTIONS OF NORTHWEST UPR MICHIGAN LATE
THURSDAY INTO THURSDAY NIGHT. SNOW AMOUNTS ARE THE MAIN ISSUE WITH
THE SYSTEM...AS THAT DICTATES THE NEED FOR ANY HEADLINES.
SHORTWAVE TROUGH CROSSING THE ROCKIES THIS AFTN IS THE MAIN FOCUS
FOR THE THURSDAY INTO FRIDAY TIME FRAME. TROUGH IS FORECAST ARRIVE
OVER THE NORTHERN PLAINS TO THE MIDDLE MISSISSIPPI VALLEY THURSDAY
EVENING. AT THE SFC...ONE LOW IS OVER NORTH DAKOTA WITH ANOTHER LOW
CROSSING SOUTHERN PORTIONS OF THE UPPER GREAT LAKES. SFC TROUGH IS
IN BTWN THE TWO LOWS. MODELS DIFFER ON WHICH SFC LOW IS STRONGER.
TREND WAS EMERGING IN RECENT RUNS OF THE GFS/ECMWF/GEM-NH AND UKMET
THAT NORTHERN PORTION OF THE SHORTWAVE TROUGH AT H85/H7/H5 WOULD BE
THE STRONGER SECTION AND THAT TROUGH WOULD REMAIN MORE PROGRESSIVE
WHICH RESULTED IN LESS PRECIP LATER THURSDAY NIGHT AND CERTAINLY
INTO FRIDAY. RECENT NAM RUNS HAVE BEEN SHOWING MORE OF CLOSED OFF
IDEA WITH MID LEVEL TROUGH AND IS MORE WRAPPED UP WITH THE UPPER LOW
ON FRIDAY... SHOWING CLOSED OFF H5 LOW OVER SCNTRL LK SUPERIOR AT
18Z ON FRIDAY WITH CLOSED OFF H7/H85 AND SFC LOWS OVER CNTRL CWA AT
THE SAME TIME...RESULTING IN DEFORMATION AXIS OF PRECIP LINGERING
OVER NW CWA LATER THURSDAY NIGHT INTO FRIDAY. 12Z NAM CONTINUES TO
SHOW THE SAME THING...BUT IS NOW JOINED BY GFS AND GEM-NH...
REPRESENTING A SHIFT BACK TO WHAT THE GFS WAS SHOWING WITH THE 12Z
RUN ON TUESDAY. SWITCH SHOWS UP IN GFS RUN TOTAL QPF WITH AREAS OF
WESTERN CWA NOW SEEING WELL OVER AN INCH WHERAS PAST RUNS WERE MORE
IN THE 0.50-1.00 RANGE. OVERALL THE THEME OFFERED UP BY THE 12Z
MODELS IS THAT THE POTENTIAL FOR MORE SNOW FOR A LONGER DURATION IS
INCREASING...ESPECIALLY OVER THE WESTERN THIRD OF THE
CWA...INCLUDING THE KEWEENAW PENINSULA.
DIVING INTO THE SPECIFICS...INITIAL SURGE OF PRECIP LATE THURSDAY
AND THURSDAY EVENING IS SUPPORTED IN UPPER LEVELS BY H85-H5 Q-VECTOR
CONVERGENCE AND H3-H25 DIVERGENCE ALOFT DUE TO DIFFLUENT FLOW AS JET
STREAK LIFTS ACROSS UPPER GREAT LAKES FM MID MISSISSIPPI VALLEY TO
NORTHERN ONTARIO. ADDITIONAL LOW-MID LEVEL FORCING IS DUE MAINLY TO
H925-H85 THETA-E ADVECTION AHEAD OF SFC-H85 TROUGH ALONG WITH
290-295K ISENTROPIC ASCENT LIFTING ACROSS UPR MICHIGAN. MOISTURE
INFLUX INTO SYSTEM MORE THAN SUFFICIENT FOR HEAVIER PRECIP WITH
MIXING RATIOS OF 4-6G/KG ON THE 290K SFC /H8-H75/ AND AT LEAST 4G/KG
ON THE 300K SFC /NEAR H7/. AS THE UPPER LOW BECOMES MORE NEGATIVELY
TILTED LATER THURSDAY NIGHT...MAIN FORCING FOR PRECIP WILL COME VIA
PERSISTENT ISENTROPIC ASCENT AND DEFORMATION ALONG AND NORTHWEST OF
MAINLY THE H85 LOW. NAM WOULD SUGGEST TROWAL PRECIP ENHANCEMENT
COULD IMPACT KEWEENAW BASED ON THE THETA-E AT THE H65-H6 LAYER. FOR
THE FORECAST...WILL TREND TOWARD NEGATIVE TILTED SYSTEM...BUT KEEP
HEAVIER QPF ANCHORED IN THE 00Z-06Z FRIDAY PERIOD WHEN H7 MIXING
RATIOS TOWARD 4G/KG ARE PRESENT. AFTER THAT WILL HEAD TOWARD MORE
TONED DOWN QPF FM THE UKMET/ECMWF AND SOMEWHAT THE NAM /SUGGESTING
AROUND 0.30 TO PERHAPS AS MUCH AS NEAR 0.50 INCH IN THE 06Z-12Z TIME
PERIOD WITHIN AXIS OF HEAVIER PRECIP...VERSUS THE WETTER GFS AND
GEM-NH.
PTYPE AND ULTIMATELY SNOW AMOUNTS...REMAINS AN ISSUE. HOWEVER TREND
MAY BE SIGNALING MOSTLY SNOW FOR AT LEAST THE WEST HALF OF THE
CWA...ROUGHLY WEST OF IMT TO MQT. FORECAST SOUNDINGS FM NAM ARE
NEARLY ISOTHERMAL AND NEAR 0C THROUGH H8 AT IMT AND IWD...BUT ARE
SUFFICIENTLY COLD ENOUGH IN THIS LAYER AT CMX AND MQT FOR SNOW.
FARTHER EAST...AT MNM/ESC/P53 THE WARM LAYER IS TO H95/1000FT AGL OR
HIGHER THROUGH THE OVERNIGHT...BUT COULD LOWER ENOUGH BLO 1000FT AGL
TO RESULT IN AT LEAST A MIX OF SNOW OR PERHAPS A TURNOVER TO ONLY
SNOW BTWN 06Z AND 12Z. AT ERY...COULD STAY COLD ENOUGH TO KEEP PTYPE
MAINLY SNOW LIKELY DEPENDING LARGELY ON SFC TEMPS. THOUGH THE
INSOLATION AND BLYR WARMING MAY MAKE IT TOUGH TO ACCUMULATE SNOW
INITIALLY LATER THURSDAY AFTN WOULD EXPECT BY EARLY THURSDAY
EVENING...INCREASING SNOW RATES AND LOSS OF INSOLATION WILL RESULT
IN ACCUMULATIONS INCREASING. SREF OUTPUT BASED ON EXPECTED MODEL
SKIN TEMPS INDICATES THAT BY EARLY THURSDAY EVENING...MAJORITY OF
ENSEMBLE MEMBERS SUGGEST SNOW WOULD START ACCUMLATING ON ROADS AS
WELL...ESPECIALLY IF SNOWFALL RATES PUSH OVER 1 INCH PER HOUR.
EXPECT SNOW ACCUMULATIONS OVER MUCH OF INTERIOR CNTRL CWA TO EXCEED
6 INCHES LATE THURSDAY AFTERNOON INTO FRIDAY...WITH POTENTIAL FOR 8
TO 10 INCHES OVER NORTHWEST CWA. BASED ON THE TRENDS FROM THE 12Z
MODELS AND AFTER COORDINATION WITH SHORT TERM FORECASTER...WILL BE
GOING FOR A WINTER STORM WATCH FOR THE KEWEENAW PENINSULA. IN
ADDITION TO HEAVY SNOW...WILL ALSO SEE POTENTIAL FOR BLOWING SNOW AS
EAST WINDS GUST 20-30 MPH ON THURSDAY NIGHT INTO EARLY FRIDAY
MORNING.
IT WILL BE CLOSE FOR SEEING ENOUGH SNOWFALL FOR A WARNING FOR AREAS
FROM IRON TO MARQUETTE COUNTIES /CURRENTLY HAVE 4-7 INCHES FALLING
MAINLY FROM LATE THURSDAY AFTN THROUGH MIDDAY FRIDAY/...AND POSSIBLY
OVER WESTERN UPR MICHIGAN...BUT WILL KEEP WITH SPECIAL WEATHER
STATEMENT FOR THESE AREAS ATTM. MID SHIFT CAN ASSESS AGAIN AND
DETERMINE WHETHER A WARNING OR ADVISORY IS NEEDED.
SLOWER/MORE CLOSED OFF SYSTEM RESULTS IN HIGHER POPS LINGERING
INTO FRIDAY AFTN...ESPECIALLY NEAR LK SUPERIOR OVER THE NORTHWEST.
SOUNDINGS INDICATE DEEPER MOISTURE BEGINS TO SCOUR OUT FRIDAY
EVENING BUT ENOUGH LOW-LEVEL MOISTURE TO H8 WITH TEMPS WITHIN H85
THERMAL TROUGH TOWARD -10C TO KEEP SMALL CHANCES GOING. BY LATE
FRIDAY NIGHT...H85 MOISTURE LEAVES THE REGION AND HIGH PRESSURE
BECOMES THE BIGGER FACTOR. SHOULD BE GENERALLY CLEAR SKIES ON
SATURDAY AS THE HIGH DOMINATES...BUT ENE-NE WINDS OUT OF THE HIGH
KEEPS THE COOL AIR LOCKED IN. MIXING TO H9 ALONG THE BORDER SUPPORTS
HIGHS INTO THE MID 40S. READINGS ALONG LK SUPERIOR AND OVER MOST OF
THE NORTHERN CWA WILL REMAIN IN THE MID-UPR 30S...15-20 DEGREES
BELOW NORMAL AND FAIRLY CLOSE TO RECORD LOW MAX TEMPS FOR THIS
WEEKEND.
REST OF THE EXTENDED...HUDSON BAY HIGH PRESSURE WITH A LOT OF DRY
AIR AT H85 HOLDS ITS OWN INTO EARLY NEXT WEEK. COULD BE A PERIOD IN
THERE EARLY NEXT WEEK WHERE INCREASE OF MID LEVEL MOISTURE MAY
OCCUR. GIVEN THE STRENGTH OF THE HIGH THOUGH...THINKING THAT PRECIP
CHANCES WILL BE MINIMAL EARLY THIS WEEK. MODELS ARE TRENDING THAT
WAY NOW IT APPEARS. CUTOFF LOW COULD MAKE RUN ACROSS UPPER LAKES BY
MIDDLE OF NEXT WEEK...SO THAT IS WHEN CHANCE POPS RETURN TO THE
FORECAST. STAYING COOL...ESPECIALLY NEAR LK SUPERIOR WHEN THERE ARE
ONSHORE NORTHEAST WINDS. LEANED ON BIAS CORRECTED GUIDANCE FOR MAX
TEMPS THROUGH THE EXTENDED. CONSENSUS WAS USED FOR THE REST OF THE
FORECAST ELEMENTS INCLUDING POPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1206 AM EDT THU APR 24 2014
VFR CONDITIONS CONTINUE OVER THE REGION AS DRY AIR LINGERS. PCPN
FROM APPROACHING SYSTEM MOVING THROUGH THE PLAINS STRUGGLING TO
OVERCOME THE DRIER AT AT KIWD EARLY THIS MORNING...HOWEVER THE
LATEST BUFKIT NAM DATA HAS LIGHT RAIN REACHING THAT AREA A LITTLE
EARLIER THAN PREVIOUS RUNS AND THUS HAVE MOVED TIMING OF LIGHT RAIN
UP A BIT THERE. OTHERWISE PCPN TO HOLD OFF AT KCMX AND KSAW UNTIL
AFTER 18Z. CONCERNS ON TIMING OF PHASE CHANGE AT ALL THREE SITES AS
NAM TRENDING A BIT WARMER...THUS AT THIS TIME HAVE TRENDED SLIGHTLY
SLOWER WITH THE CHANGEOVER FROM RAIN TO SNOW. CIGS TO DROP FROM VFR
TO MVFR AT 18Z AT KIWD AND THEN THE OTHER SITES LATER IN THE
AFTERNOON AS PCPN PICKS UP IN INTENSITY. INTRODUCED IFR CIGS AFTER
0Z AT KSAW AND KCMX DUE TO UPSLOPE WINDS...BUT SE DIRECTION IS
DOWNSLOPE AT KIWD AND THUS HAVE LEFT CIGS AT THE LOW END OF MVFR
THERE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 PM EDT WED APR 23 2014
LOW PRESSURE MOVES INTO THE REGION THURSDAY NIGHT INTO FRIDAY. LOW
IS TRENDING STRONGER...SO EAST WINDS MAY REACH 30 KTS THURSDAY NIGHT
THEN SHIFT TO THE NORTH-NORTHWEST UP TO 30 KTS BY FRIDAY AFTN AFTER
THE LOW MOVES TO THE EAST OF LK SUPERIOR. POSSIBLE THAT SOME GALE
GUSTS TO 35 KTS MAY OCCUR LATE FRIDAY AFTN INTO FRIDAY EVENING.
WINDS DIMINISH BLO 20 KTS FOR THE WEEKEND AS HIGH PRESSURE SETTLES
ACROSS ONTARIO AND THE GREAT LAKES. NEXT CHANCE OF STRONGER EAST
WINDS WOULD BE ON MONDAY AS THE HIGH SLOWLY MOVES EAST AND LOW
PRESSURE DEVELOPS OVER THE PLAINS.
&&
.HYDROLOGY...
ISSUED AT 503 PM EDT WED APR 23 2014
RUNOFF FROM RECENT ABOVE NORMAL TEMPS AND SNOWMELT CONTINUES TO
FLOW THRU THE GROUND...SO SOME AREA STREAMS AND RIVERS ARE STILL
RISING SLOWLY...DESPITE THE COOLER TEMPERATURES THAN WERE SEEN
RECENTLY. LOCATIONS THAT STILL ARE ABOVE BANKFUL AT THIS TIME
INCLUDE THE STURGEON RIVER NEAR CHASSELL AND THE PAINT RIVER NEAR
CRYSTAL FALLS. NEITHER OF THESE RIVERS IS EXPECTED TO REACH FLOOD
STAGE IN THE SHORT TERM.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
UNSETTLED WEATHER WILL RETURN THURSDAY INTO FRIDAY AS ANOTHER LOW
PRESSURE SYSTEM MOVES FROM THE PLAINS TOWARD THE GREAT LAKES...
POTENTIALLY ADDING TO RUNOFF. AT THIS POINT THE BEST CHANCE OF
SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE WEST HALF OF UPPER
MI...AND SPECIFICALLY THE KEWEENAW PENINSULA...WHERE 0.70-1.25 INCH
OF LIQUID WILL BE POSSIBLE BY FRIDAY AFTERNOON. THERE IS SOME
UNCERTAINTY ON HOW MUCH WILL FALL AS RAIN AND HOW MUCH WILL FALL AS
SNOW...BUT THE BEST CHANCE OF SNOW WILL BE OVER THE KEWEENAW
PENINSULA. IF MORE OF THE PRECIPITATION FALLS AS SNOW...RUNOFF WILL
BE DELAYED UNTIL WARMER WEATHER RETURNS NEXT WEEK.
OVERALL...WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. THOSE
LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER
LEVELS OVER THE NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER STORM WATCH FROM THIS EVENING THROUGH FRIDAY AFTERNOON
FOR MIZ001-003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...RJT
MARINE...JLA
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS JACKSON MS
314 PM CDT THU APR 24 2014
.DISCUSSION...
TODAY THROUGH SATURDAY
STRONG TO SEVERE STORMS WILL BE POSSIBLE THIS AFTERNOON AND EVENING
ACROSS THE DELTA REGION AND EASTWARD ALONG THE HIGHWAY 82 CORRIDOR.
ONCE THE BOUNDARY MOVES THROUGH FRIDAY MORNING, EXPECT A DRYING AND
WARMING TREND INTO THE FIRST HALF OF THE WEEKEND. PLEASE SEE LONG
TERM AS CONFIDENCE CONTINUES TO GROW ON A SIGNIFICANT SEVERE WEATHER
EPISODE WITH MULTIPLE ROUNDS OF SEVERE WEATHER SUNDAY AFTN THROUGH
TUESDAY.
STRONG TO SEVERE STORMS HAVE ALREADY BEGUN TO FIRE THIS AFTERNOON IN
LA AND AR IN ASSOCIATION WITH A SHARP S/WV TROUGH AND ALONG A
PREFRONTAL PRESSURE TROUGH WHERE SBCAPE VALUES HAVE BUILT INTO THE
1500-2000 J/KG RANGE. THIS INSTABILITY IN COMBINATION WITH 40-50 KT
DEEP LAYER SHEAR AND NEAR 8 C/KM H7-H5 LAPSE RATES WILL FURTHER
SUPPORT A SEVERE WEATHER RISK GOING INTO THE ARKLAMISS DELTA
COUNTIES LATE THIS AFTN AND EVENING. DAMAGING WINDS OF 60 MPH AND
HAIL TO SIZE OF HALF DOLLARS LOOK TO MAIN HAZARDS AT THIS TIME. SPC
MESOANALYSIS CURRENTLY DEPICTS LESS THEN 100 M2/S2 0-1KM SRH WITHIN
SURFACE BASED CONVECTIVE AREA. THIS, IN CONJUNCTION WITH HIGHER
LCL/LFCS ALONG AND EAST OF THE DELTA SHOULD LIMIT TORNADO POTENTIAL.
HOWEVER, IT SHOULD BE NOTED THAT HRRR CONTINUES TO SHOW 0-1KM
HELICITY VALUES INCREASING TOWARDS 150-200 M2/S2 OVER THE DELTA AND
NORTH CENTRAL MS THROUGH THE EARLY EVENING AND THUS A NON-ZERO RISK
OF A TORNADO EXISTS. THE GOING GRAPHICS HANDLE THE OVERALL SITUATION
WELL.
INSTABILITY WILL DECREASE THROUGH THE NIGHT AFTER 1AM AS THE BROKEN
LINE SHIFTS EAST INTO LESS SUPPORTIVE THERMO ENVIRONMENT AND OVERALL
WEAKENING TREND SHOULD OCCUR AS A WEAK COOL FRONT MOVES THROUGH THE
REGION BY FRIDAY MORNING. A DRYING TREND WILL START FRIDAY AND GO
INTO SATURDAY WITH A WARMING TREND INTO THE EARLY WEEKEND. AFTER A
SLIGHTLY COOLER START TOMORROW MORNING HIGHS WILL REBOUND INTO THE
MID TO UPPER 70S FRI AFTN UNDER FULL SUN. HIGHS SATURDAY WILL REACH
INTO THE LOW TO MID 80S WITH SOME AREAS APPROACHING UPPER 80S.
A VOLATILE EPISODE OF SEVERE STORMS AND HEAVY RAIN CONTINUES TO LOOK
PROBABLE LATE WEEKEND INTO EARLY NEXT WEEK. PLEASE STAY UP TO DATE
ON THIS SITUATION. /ALLEN/
SUNDAY THROUGH NEXT WEDNESDAY...
FORECAST THINKING IS GENERALLY THE SAME REGARDING THE POTENT SET-
UP FOR SEVERE WEATHER AND HEAVY RAIN INDICATED BY GLOBAL MODEL
GUIDANCE FOR EARLY NEXT WEEK...PARTICULARLY FROM LATE SUNDAY THROUGH
MONDAY NIGHT...AND PERHAPS THROUGH TUESDAY INTO TUESDAY NIGHT. ALL
MODES OF SEVERE WEATHER INCLUDING THE POTENTIAL FOR STRONG TORNADOES
WILL BE POSSIBLE. SIGNIFICANT FLOODING COULD DEVELOP IF MULTIPLE
ROUNDS OF STORMS MATERIALIZE.
DRY WEATHER WILL CONTINUE THROUGH SATURDAY NIGHT OVER THE ARKLAMISS...
BUT DRAMATIC CHANGES ARE EXPECTED STARTING SUNDAY AFTERNOON AND GOING
THROUGH SUNDAY NIGHT AS A POWERFUL DEEPENING CYCLONE TRAVERSES THE
PLAINS STATES AND BRINGS RAPID PRESSURE FALLS TO THE LOWER MS VALLEY
REGION. A STRENGTHENING LOW LEVEL JET JUXTAPOSED BY STEEP MID LEVEL
LAPSE RATES WILL DRAW RICH GULF MOISTURE NORTHWARD (SFC DEWPOINTS
APPROACHING 70 F) AND INCREASE LOW LEVEL SHEAR AND TORNADO POTENTIAL
BY SUNDAY EVENING OVER THE DELTA REGION AS SFC- BASED THUNDERSTORMS
BREAK OUT. THE FIRST ROUND OF STORMS MAY ORGANIZE INTO A MESOSCALE
CONVECTIVE SYSTEM TAPPING INTO VERY MOIST AIR WITH PRECIPITABLE WATER
~ 1.75 INCHES. THIS MCS COULD PUSH ACROSS MUCH OF THE ARKLAMISS
OVERNIGHT BEFORE WEAKENING SOME AS IT OUTRUNS BETTER UPPER LEVEL
SUPPORT. HOWEVER...EXPECT RE-NEWED SEVERE THUNDERSTORM ACTIVITY
MONDAY AS THE NOSE OF POWERFUL PACIFIC JET ENERGY ROUNDS THE BASE OF
THE DEEP CENTRAL CONUS TROUGH AND ENHANCES WIND SHEAR/LIFT AND THE
SEVERE WEATHER RISK OVER THE FORECAST AREA. MIXED LAYER CAPE > 3000
J/KG COULD HELP MAY FOR A VOLATILE SET-UP WITH THIS SYNOPTIC PATTERN.
CIPS ANALOGS ARE SHOWING VERY SIGNIFICANT EVENTS FOR COMPARISON TO
THIS SET-UP ADDING MORE CONFIDENCE THAT SIGNIFICANT SEVERE WEATHER
AND FLOODING WILL BE POSSIBLE...ESPECIALLY IF A SLOW-MOVING
CONVECTIVE SYSTEM SETS UP MONDAY NIGHT AS GUIDANCE SUGGESTS. ANOTHER
CONCERN IS THE POSSIBILITY FOR THE CYCLONIC REGIME TO STALL OVER THE
CENTRAL CONUS FOR A LONGER PERIOD INTO TUESDAY...ALLOWING ANOTHER LOBE
OF SHORTWAVE ENERGY TO MOVE ACROSS THE AREA AND BACK FLOW
SUFFICIENTLY FOR REGENERATION OF STORMS. BEYOND TUESDAY NIGHT...
EXPECT DRIER AND COOLER AIR TO FINALLY MOVE INTO THE REGION. /EC/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 59 81 52 87 / 17 5 0 5
MERIDIAN 60 82 48 86 / 22 5 0 5
VICKSBURG 57 81 53 86 / 23 5 0 5
HATTIESBURG 63 84 56 87 / 18 5 0 5
NATCHEZ 60 81 55 85 / 15 5 0 5
GREENVILLE 56 79 52 85 / 71 5 0 5
GREENWOOD 57 78 49 85 / 62 5 0 5
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
ALLEN/EC/BK
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1223 PM CDT Thu Apr 24 2014
.UPDATE:
Issued at 1029 AM CDT Thu Apr 24 2014
Based on latest radar/satellite data...adjusted temperatures
upwards a few degrees across the eastern half of the CWA while
trimming highs over portions of central and northeastern Missouri
where pre-frontal cloudiness and shra with embedded thunder is
moving in late this morning.
For this afternoon...not sure how unstable we will
get...especially for the northern half to two-thirds of the CWFA.
Aforementioned pre-frontal clouds/precipitation could really hamper
instability from rising later on this afternoon. HRRR/RAP really
suffering from warming warm sector way too much as hourly
temperatures even over central Missouri per these near-term models
would climb into the upper 70s and low 80s.
Consequently...developing way too much sfc-based instability. In
addition...stronger shear this afternoon/evening will be over
southeastern Missouri just to south of area so not sure degree of
strong/severe storms this far north. Regardless...very strong
forcing for ascent via strong DCPVA and jet coupling aloft should
produce a widespread shield of rain with embedded thunderstorms
along the front. Will montior situation throughout today and make
additional adjustments/changes to the forecast as necessary.
Gosselin
&&
.SHORT TERM: (Today through Friday
Issued at 329 AM CDT Thu Apr 24 2014
Strong upper level trof is moving east through the Great Plains
this morning. The surface reflection of this trof extends from
eastern Nebraska/Kansas southwest into western Texas. Looks like
good moisture surging ahead of the trof with upper 50s to mid 60s
dewpoints all the way up into eastern Kansas. All short-range
guidance has slowed the eastward progression of this system today,
and thereby also slowing down the precipitation associated with
it. This should allow for a warmer day than previously forecast.
Have bumped up temperatures toward warmer MAV guidance for today.
Should see little but spotty showers across most of the area this
morning, but with increasing chances of precipitation by 18-20Z.
Additional heating of course mean more instability than previously
forecast as well, and the NAM is forecasting a narrow corridor of
1200+ J/Kg MUCAPE ahead of the front this afternoon along and
south of the I-70 corridor. With deep layer shear in excess of 40
kts it does look like some severe storms will be possible.
Convective mode is somewhat indeterminate with shear strong enough
for supercells, but instability probably lacking a bit. I kind of
like the latest run of the HRRR which as a broken line of storms
moving across the area this afternoon, tho with a bit more
instability the convection could easily be more discrete
initially. Front now looks to be into central Missouri by around
00Z, along the Mississippi River by 03-04Z, and through Salem
Illinois by about 06Z. Have adjusted PoPs for this slower
progression through tonight.
Temperatures on Friday are still somewhat in question. A relatively
mild Pacific airmass will build in behind the front on Friday.
850mb temps don`t really fall off that much and are 10-12C by 00Z
Saturday. This would suggest mid to upper 70s which makes MOS
numbers a bit too cool across most of the area. Bumped up a bit
over MOS to compensate.
Carney
.LONG TERM: (Saturday through Wednesday)
Issued at 403 AM CDT Thu Apr 24 2014
Guidance continues to come into better agreement for the weekend.
The secondary front which was forecast to sweep all the way
through Missouri into Arkansas earlier in the week is now only
going to get to southern Iowa according to the model collective.
Still showing a good low level baroclinic zone stretching from
southwest Missouri up into Iowa Saturday through Sunday with a
southwest low level jet ramping up to 40-50kts flowing
perpendicular to the thermal gradient. All models print out some
light precip in response to this on Saturday, primarily over
central and western Missouri but I wouldn`t be surprised to see it
a bit further north/northeast as well if this verifies.
Temperatures will be highly dependent on how much sunshine we end
up getting, but I leaned heavily on the warmer MAV numbers.
Strong warm advection continues ahead of the ginormous trof which
will be moving over the Rockies Saturday night, and it looks like
there could be some nocturnal convection as a a result...mostly
across northern sections of the CWFA. The trof moves into the Great
Plains on Sunday and closes off while also becoming negatively
tilted. The resulting wound up, slow moving storm system will draw
abundant moisture into the Mid-Mississippi Valley from the Gulf
producing at least a couple of rounds of showers and thunderstorms
Sunday into Monday night before the associated cold front comes
through and drier air works into the area. Temperatures should stay
seasonably mild through the Monday with highs near normal.
Tuesday and Wednesday the storm system moves slowly overhead and
then on into the Ohio Valley. Models print out widespread precip
over the area as cold air aloft moves in with the cut off low.
Heaviest amounts look to be across northern Missouri and southern
Iowa associated with the deformation zone. While this makes sense
conceptually, still not sure I totally believe the medium range
models as this is a highly anomalous pattern for late April/early.
Stuck relatively close to guidance though as the mass fields on the
GFS and ECMWF are in very good agreement considering strength of
this system and its anomalous nature.
Carney
&&
.AVIATION: (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1216 PM CDT Thu Apr 24 2014
Round of pre-frontal precpitation beginning to affect KCOU and
should also affect KUIN with shra/embedded thunder possible.
Ceilings/visibilities may dip down into MVFR category early this
afternoon. Frontal timing a bit slower than earlier
forecast...around 2100 UTC at KCOU...2300 UTC at KUIN...and
0000-0200 UTC at metro TAF sites. More instability as you head
south...but round of thunderstorms expected at terminals with
brief periods of IFR visbys in heavy rain possible. Showers are
expected to linger behind front for a few hours. Winds will shift
to the northwest behind front with brief gusts along/just behind
front from 25-30 knots. Skies will quickly clear out overnight
tonight with winds backing to the west/southwest Friday.
Specifics for KSTL:
Round of pre-frontal is expected to weaken as it heads east toward
terminal so uncertain whether or not some light rain showers will
affect the site. Frontal timing a bit slower than earlier
forecast...around 0100 UTC. More instability as you head
south...but round of thunderstorms expected at terminal with
brief periods of IFR visbys in heavy rain possible. Showers are
expected to linger behind front for a few hours. Winds will shift
to the northwest behind front with brief gusts along/just behind
front from 25-30 knots. Skies will quickly clear out overnight
tonight with winds backing to the west/southwest Friday afternoon.
Gosselin
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1036 AM CDT Thu Apr 24 2014
.UPDATE:
Issued at 1029 AM CDT Thu Apr 24 2014
Based on latest radar/satellite data...adjusted temperatures
upwards a few degrees across the eastern half of the CWA while
trimming highs over portions of central and northeastern Missouri
where pre-frontal cloudiness and shra with embedded thunder is
moving in late this morning.
For this afternoon...not sure how unstable we will
get...especially for the northern half to two-thirds of the CWFA.
Aforementioned pre-frontal clouds/precipitation could really hamper
instability from rising later on this afternoon. HRRR/RAP really
suffering from warming warm sector way too much as hourly
temperatures even over central Missouri per these near-term models
would climb into the upper 70s and low 80s.
Consequently...developing way too much sfc-based instability. In
addition...stronger shear this afternoon/evening will be over
southeastern Missouri just to south of area so not sure degree of
strong/severe storms this far north. Regardless...very strong
forcing for ascent via strong DCPVA and jet coupling aloft should
produce a widespread shield of rain with embedded thunderstorms
along the front. Will montior situation throughout today and make
additional adjustments/changes to the forecast as necessary.
Gosselin
&&
.SHORT TERM: (Today through Friday
Issued at 329 AM CDT Thu Apr 24 2014
Strong upper level trof is moving east through the Great Plains
this morning. The surface reflection of this trof extends from
eastern Nebraska/Kansas southwest into western Texas. Looks like
good moisture surging ahead of the trof with upper 50s to mid 60s
dewpoints all the way up into eastern Kansas. All short-range
guidance has slowed the eastward progression of this system today,
and thereby also slowing down the precipitation associated with
it. This should allow for a warmer day than previously forecast.
Have bumped up temperatures toward warmer MAV guidance for today.
Should see little but spotty showers across most of the area this
morning, but with increasing chances of precipitation by 18-20Z.
Additional heating of course mean more instability than previously
forecast as well, and the NAM is forecasting a narrow corridor of
1200+ J/Kg MUCAPE ahead of the front this afternoon along and
south of the I-70 corridor. With deep layer shear in excess of 40
kts it does look like some severe storms will be possible.
Convective mode is somewhat indeterminate with shear strong enough
for supercells, but instability probably lacking a bit. I kind of
like the latest run of the HRRR which as a broken line of storms
moving across the area this afternoon, tho with a bit more
instability the convection could easily be more discrete
initially. Front now looks to be into central Missouri by around
00Z, along the Mississippi River by 03-04Z, and through Salem
Illinois by about 06Z. Have adjusted PoPs for this slower
progression through tonight.
Temperatures on Friday are still somewhat in question. A relatively
mild Pacific airmass will build in behind the front on Friday.
850mb temps don`t really fall off that much and are 10-12C by 00Z
Saturday. This would suggest mid to upper 70s which makes MOS
numbers a bit too cool across most of the area. Bumped up a bit
over MOS to compensate.
Carney
.LONG TERM: (Saturday through Wednesday)
Issued at 403 AM CDT Thu Apr 24 2014
Guidance continues to come into better agreement for the weekend.
The secondary front which was forecast to sweep all the way
through Missouri into Arkansas earlier in the week is now only
going to get to southern Iowa according to the model collective.
Still showing a good low level baroclinic zone stretching from
southwest Missouri up into Iowa Saturday through Sunday with a
southwest low level jet ramping up to 40-50kts flowing
perpendicular to the thermal gradient. All models print out some
light precip in response to this on Saturday, primarily over
central and western Missouri but I wouldn`t be surprised to see it
a bit further north/northeast as well if this verifies.
Temperatures will be highly dependent on how much sunshine we end
up getting, but I leaned heavily on the warmer MAV numbers.
Strong warm advection continues ahead of the ginormous trof which
will be moving over the Rockies Saturday night, and it looks like
there could be some nocturnal convection as a a result...mostly
across northern sections of the CWFA. The trof moves into the Great
Plains on Sunday and closes off while also becoming negatively
tilted. The resulting wound up, slow moving storm system will draw
abundant moisture into the Mid-Mississippi Valley from the Gulf
producing at least a couple of rounds of showers and thunderstorms
Sunday into Monday night before the associated cold front comes
through and drier air works into the area. Temperatures should stay
seasonably mild through the Monday with highs near normal.
Tuesday and Wednesday the storm system moves slowly overhead and
then on into the Ohio Valley. Models print out widespread precip
over the area as cold air aloft moves in with the cut off low.
Heaviest amounts look to be across northern Missouri and southern
Iowa associated with the deformation zone. While this makes sense
conceptually, still not sure I totally believe the medium range
models as this is a highly anomalous pattern for late April/early.
Stuck relatively close to guidance though as the mass fields on the
GFS and ECMWF are in very good agreement considering strength of
this system and its anomalous nature.
Carney
&&
.AVIATION: (For the 12z TAFs through 12z Friday Morning)
Issued at 633 AM CDT Thu Apr 24 2014
Needless to say, a complex forecast for this period for area TAF
sites. Showers/thunderstorms currently ongoing over western
Missouri will continue to move ENE this morning, largely fueled by
warm advection and a strong southwesterly low level jet. The HRRR
has maintained a good handle on the evolution of the precipitation
overnight, thus have taken it into consideration regarding future
trends today. Thinking is for SHRA/TSRA from western Missouri to
impact KCOU by around 15Z-16Z and KUIN by 16Z-17Z. This
precipitation should remain northwest of metro TAF sites, thus
have not included precipitation mention for metro sites until late
this afternoon when SHRA/TSRA associated with the cold front are
expected to impact the area. Expect KCOU and KUIN to see a few
rounds of SHRA/TSRA this afternoon, prior to the passage of a cold
front through the terminals by around 00Z (KCOU) and 02Z (KUIN).
For metro TAF sites, expect SHRA/TSRA activity to increase by
ahead of the front, and continue until the front passes between
03Z-04Z, with lingering showers for perhaps another 2 hours
affecting area TAF sites.
Prior to the onset of precipitation, expect continued
gusty southerly/southeasterly winds and VFR flight conditions
along with increasing midlevel clouds. Flight conditions will
decrease to MVFR during SHRA/TSRA, and slowly improve late tonight
post- FROPA. Winds will quickly veer to the west in the wake of
the front, and remain between 10-15KT overnight.
Specifics for KSTL:
VFR flight conditions expected to prevail through the first part
of the forecast period. An area of showers and thunderstorms over
western Missouri continues to move ENE this morning, and is
expected to remain just northwest of the terminal given latest
HRRR guidance. Expect SHRA/TSRA activity to ramp up late this
afternoon ahead of an advancing cold front, and persist until the
front passes through the terminal around 03Z-04Z. Flight
conditions will decrease to MVFR in areas of precipitation, with
ceilings slowly improving overnight after SHRA has ended and
drier air begins to filter into the region in the wake of the cold
front. Winds will remain southerly/southeasterly today, gusting to
20-25KT, and veer quickly to the west behind the front tonight,
remaining between 12-15KT sustained. Clouds are expected to
scatter out by daybreak, providing VFR conditions through the end
of the period on Friday.
JP
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
654 AM CDT Thu Apr 24 2014
.SHORT TERM: (Today through Friday
Issued at 329 AM CDT Thu Apr 24 2014
Strong upper level trof is moving east through the Great Plains
this morning. The surface reflection of this trof extends from
eastern Nebraska/Kansas southwest into western Texas. Looks like
good moisture surging ahead of the trof with upper 50s to mid 60s
dewpoints all the way up into eastern Kansas. All short-range
guidance has slowed the eastward progression of this system today,
and thereby also slowing down the precipitation associated with
it. This should allow for a warmer day than previously forecast.
Have bumped up temperatures toward warmer MAV guidance for today.
Should see little but spotty showers across most of the area this
morning, but with increasing chances of precipitation by 18-20Z.
Additional heating of course mean more instability than previously
forecast as well, and the NAM is forecasting a narrow corridor of
1200+ J/Kg MUCAPE ahead of the front this afternoon along and
south of the I-70 corridor. With deep layer shear in excess of 40
kts it does look like some severe storms will be possible.
Convective mode is somewhat indeterminate with shear strong enough
for supercells, but instability probably lacking a bit. I kind of
like the latest run of the HRRR which as a broken line of storms
moving across the area this afternoon, tho with a bit more
instability the convection could easily be more discrete
initially. Front now looks to be into central Missouri by around
00Z, along the Mississippi River by 03-04Z, and through Salem
Illinois by about 06Z. Have adjusted PoPs for this slower
progression through tonight.
Temperatures on Friday are still somewhat in question. A relatively
mild Pacific airmass will build in behind the front on Friday.
850mb temps don`t really fall off that much and are 10-12C by 00Z
Saturday. This would suggest mid to upper 70s which makes MOS
numbers a bit too cool across most of the area. Bumped up a bit
over MOS to compensate.
Carney
.LONG TERM: (Saturday through Wednesday)
Issued at 403 AM CDT Thu Apr 24 2014
Guidance continues to come into better agreement for the weekend.
The secondary front which was forecast to sweep all the way
through Missouri into Arkansas earlier in the week is now only
going to get to southern Iowa according to the model collective.
Still showing a good low level baroclinic zone stretching from
southwest Missouri up into Iowa Saturday through Sunday with a
southwest low level jet ramping up to 40-50kts flowing
perpendicular to the thermal gradient. All models print out some
light precip in response to this on Saturday, primarily over
central and western Missouri but I wouldn`t be surprised to see it
a bit further north/northeast as well if this verifies.
Temperatures will be highly dependent on how much sunshine we end
up getting, but I leaned heavily on the warmer MAV numbers.
Strong warm advection continues ahead of the ginormous trof which
will be moving over the Rockies Saturday night, and it looks like
there could be some nocturnal convection as a a result...mostly
across northern sections of the CWFA. The trof moves into the Great
Plains on Sunday and closes off while also becoming negatively
tilted. The resulting wound up, slow moving storm system will draw
abundant moisture into the Mid-Mississippi Valley from the Gulf
producing at least a couple of rounds of showers and thunderstorms
Sunday into Monday night before the associated cold front comes
through and drier air works into the area. Temperatures should stay
seasonably mild through the Monday with highs near normal.
Tuesday and Wednesday the storm system moves slowly overhead and
then on into the Ohio Valley. Models print out widespread precip
over the area as cold air aloft moves in with the cut off low.
Heaviest amounts look to be across northern Missouri and southern
Iowa associated with the deformation zone. While this makes sense
conceptually, still not sure I totally believe the medium range
models as this is a highly anomalous pattern for late April/early.
Stuck relatively close to guidance though as the mass fields on the
GFS and ECMWF are in very good agreement considering strength of
this system and its anomalous nature.
Carney
&&
.AVIATION: (For the 12z TAFs through 12z Friday Morning)
Issued at 633 AM CDT Thu Apr 24 2014
Needless to say, a complex forecast for this period for area TAF
sites. Showers/thunderstorms currently ongoing over western
Missouri will continue to move ENE this morning, largely fueled by
warm advection and a strong southwesterly low level jet. The HRRR
has maintained a good handle on the evolution of the precipitation
overnight, thus have taken it into consideration regarding future
trends today. Thinking is for SHRA/TSRA from western Missouri to
impact KCOU by around 15Z-16Z and KUIN by 16Z-17Z. This
precipitation should remain northwest of metro TAF sites, thus
have not included precipitation mention for metro sites until late
this afternoon when SHRA/TSRA associated with the cold front are
expected to impact the area. Expect KCOU and KUIN to see a few
rounds of SHRA/TSRA this afternoon, prior to the passage of a cold
front through the terminals by around 00Z (KCOU) and 02Z (KUIN).
For metro TAF sites, expect SHRA/TSRA activity to increase by
ahead of the front, and continue until the front passes between
03Z-04Z, with lingering showers for perhaps another 2 hours
affecting area TAF sites.
Prior to the onset of precipitation, expect continued
gusty southerly/southeasterly winds and VFR flight conditions
along with increasing midlevel clouds. Flight conditions will
decrease to MVFR during SHRA/TSRA, and slowly improve late tonight
post- FROPA. Winds will quickly veer to the west in the wake of
the front, and remain between 10-15KT overnight.
Specifics for KSTL:
VFR flight conditions expected to prevail through the first part
of the forecast period. An area of showers and thunderstorms over
western Missouri continues to move ENE this morning, and is
expected to remain just northwest of the terminal given latest
HRRR guidance. Expect SHRA/TSRA activity to ramp up late this
afternoon ahead of an advancing cold front, and persist until the
front passes through the terminal around 03Z-04Z. Flight
conditions will decrease to MVFR in areas of precipitation, with
ceilings slowly improving overnight after SHRA has ended and
drier air begins to filter into the region in the wake of the cold
front. Winds will remain southerly/southeasterly today, gusting to
20-25KT, and veer quickly to the west behind the front tonight,
remaining between 12-15KT sustained. Clouds are expected to
scatter out by daybreak, providing VFR conditions through the end
of the period on Friday.
JP
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 73 50 78 55 / 80 80 0 10
Quincy 68 47 76 51 / 80 80 0 10
Columbia 71 46 78 51 / 80 70 0 10
Jefferson City 72 48 79 50 / 80 80 0 10
Salem 74 49 76 51 / 70 80 0 10
Farmington 75 49 77 49 / 80 80 0 10
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
403 AM CDT Thu Apr 24 2014
.SHORT TERM: (Today through Friday
Issued at 329 AM CDT Thu Apr 24 2014
Strong upper level trof is moving east through the Great Plains
this morning. The surface reflection of this trof extends from
eastern Nebraska/Kansas southwest into western Texas. Looks like
good moisture surging ahead of the trof with upper 50s to mid 60s
dewpoints all the way up into eastern Kansas. All short-range
guidance has slowed the eastward progression of this system today,
and thereby also slowing down the precipitation associated with
it. This should allow for a warmer day than previously forecast.
Have bumped up temperatures toward warmer MAV guidance for today.
Should see little but spotty showers across most of the area this
morning, but with increasing chances of precipitation by 18-20Z.
Additional heating of course mean more instability than previously
forecast as well, and the NAM is forecasting a narrow corridor of
1200+ J/Kg MUCAPE ahead of the front this afternoon along and
south of the I-70 corridor. With deep layer shear in excess of 40
kts it does look like some severe storms will be possible.
Convective mode is somewhat indeterminate with shear strong enough
for supercells, but instability probably lacking a bit. I kind of
like the latest run of the HRRR which as a broken line of storms
moving across the area this afternoon, tho with a bit more
instability the convection could easily be more discrete
initially. Front now looks to be into central Missouri by around
00Z, along the Mississippi River by 03-04Z, and through Salem
Illinois by about 06Z. Have adjusted PoPs for this slower
progression through tonight.
Temperatures on Friday are still somewhat in question. A relatively
mild Pacific airmass will build in behind the front on Friday.
850mb temps don`t really fall off that much and are 10-12C by 00Z
Saturday. This would suggest mid to upper 70s which makes MOS
numbers a bit too cool across most of the area. Bumped up a bit
over MOS to compensate.
Carney
.LONG TERM: (Saturday through Wednesday)
Issued at 403 AM CDT Thu Apr 24 2014
Guidance continues to come into better agreement for the weekend.
The secondary front which was forecast to sweep all the way
through Missouri into Arkansas earlier in the week is now only
going to get to southern Iowa according to the model collective.
Still showing a good low level baroclinic zone stretching from
southwest Missouri up into Iowa Saturday through Sunday with a
southwest low level jet ramping up to 40-50kts flowing
perpendicular to the thermal gradient. All models print out some
light precip in response to this on Saturday, primarily over
central and western Missouri but I wouldn`t be surprised to see it
a bit further north/northeast as well if this verifies.
Temperatures will be highly dependent on how much sunshine we end
up getting, but I leaned heavily on the warmer MAV numbers.
Strong warm advection continues ahead of the ginormous trof which
will be moving over the Rockies Saturday night, and it looks like
there could be some nocturnal convection as a a result...mostly
across northern sections of the CWFA. The trof moves into the Great
Plains on Sunday and closes off while also becoming negatively
tilted. The resulting wound up, slow moving storm system will draw
abundant moisture into the Mid-Mississippi Valley from the Gulf
producing at least a couple of rounds of showers and thunderstorms
Sunday into Monday night before the associated cold front comes
through and drier air works into the area. Temperatures should stay
seasonably mild through the Monday with highs near normal.
Tuesday and Wednesday the storm system moves slowly overhead and
then on into the Ohio Valley. Models print out widespread precip
over the area as cold air aloft moves in with the cut off low.
Heaviest amounts look to be across northern Missouri and southern
Iowa associated with the deformation zone. While this makes sense
conceptually, still not sure I totally believe the medium range
models as this is a highly anomalous pattern for late April/early.
Stuck relatively close to guidance though as the mass fields on the
GFS and ECMWF are in very good agreement considering strength of
this system and its anomalous nature.
Carney
&&
.AVIATION: (For the 06z TAFs through 06z Thursday Night)
Issued at 1155 PM CDT Wed Apr 23 2014
VFR flight conditions/mid-high clouds will persist overnight with modest
southeast surface winds. A southerly LLJ has developed and is broader
than originally anticipated, and now have marginal LLWS conditions
at all TAF sites. Precipitation timing is still a tough call on
Thursday, but overall the trend and timing is slower than previous
forecasts. Expecting shra and possibly a few rumbles of thunder to
impact KCOU-KUIN in the 16-18z time frame with this activity
weakening as it moves east. Better potential for organized showers
and thunderstorms at all TAFS sites will be on Thursday afternoon/evening
along and ahead of a cold front where I have conditions lowering
to MVFR.
Specifics for KSTL:
VFR flight conditions/mid-high clouds will persist overnight with modest
southeast surface winds. A southerly LLJ has developed and is broader
than originally anticipated, and local radar VWPs suggest marginal LLWS
conditions through 14-15z. Best potential for organized showers
and thunderstorms at KSTL will be between 22-02z on Thursday
afternoon/evening along and ahead of a cold front where I have
conditions lowering to MVFR.
Glass
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 73 50 78 55 / 80 80 0 10
Quincy 68 47 76 51 / 80 80 0 10
Columbia 71 46 78 51 / 80 70 0 10
Jefferson City 72 48 79 50 / 80 80 0 10
Salem 74 49 76 51 / 70 80 0 10
Farmington 75 49 77 49 / 80 80 0 10
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
330 AM CDT Thu Apr 24 2014
.SHORT TERM: (Today through Friday
Issued at 329 AM CDT Thu Apr 24 2014
Strong upper level trof is moving east through the Great Plains
this morning. The surface reflection of this trof extends from
eastern Nebraska/Kansas southwest into western Texas. Looks like
good moisture surging ahead of the trof with upper 50s to mid 60s
dewpoints all the way up into eastern Kansas. All short-range
guidance has slowed the eastward progression of this system today,
and thereby also slowing down the precipitation associated with
it. This should allow for a warmer day than previously forecast.
Have bumped up temperatures toward warmer MAV guidance for today.
Should see little but spotty showers across most of the area this
morning, but with increasing chances of precipitation by 18-20Z.
Additional heating of course mean more instability than previously
forecast as well, and the NAM is forecasting a narrow corridor of
1200+ J/Kg MUCAPE ahead of the front this afternoon along and
south of the I-70 corridor. With deep layer shear in excess of 40
kts it does look like some severe storms will be possible.
Convective mode is somewhat indeterminate with shear strong enough
for supercells, but instability probably lacking a bit. I kind of
like the latest run of the HRRR which as a broken line of storms
moving across the area this afternoon, tho with a bit more
instability the convection could easily be more discrete
initially. Front now looks to be into central Missouri by around
00Z, along the Mississippi River by 03-04Z, and through Salem
Illinois by about 06Z. Have adjusted PoPs for this slower
progression through tonight.
Temperatures on Friday are still somewhat in question. A relatively
mild Pacific airmass will build in behind the front on Friday.
850mb temps don`t really fall off that much and are 10-12C by 00Z
Saturday. This would suggest mid to upper 70s which makes MOS
numbers a bit too cool across most of the area. Bumped up a bit
over MOS to compensate.
Carney
.LONG TERM: (Thursday through Next Wednesday)
Issued at 329 PM CDT Wed Apr 23 2014
(Thursday through Saturday)
Main focus for Thurs will be precip chances. Not much change from
the prev forecast other than slowing timing down a bit. Some
questions remain regarding exactly how precip on Thurs will play
out. Believe that the morning hours will be similar to what is
occurring now. Expect precip to intensify during the afternoon and
into the evening along and just ahead of the cdfnt, if enuf heating
can occur. Am becoming more concerned of an isod TSRA becoming
strong to severe, mainly across portions of central MO. However,
this is highly conditional on the amount of heating that can occur
during the day. Will therefore not mention for now and allow the
night shift to reevaluate.
Beyond Thurs, the remainder of the period shud be dry. Did keep low
chance POPs for Sat as a wrmfnt lifts thru the region due to
uncertainty. However, with height rises over the area and better
forcing across KS and wrn MO, believe bulk of precip will remain W
of the CWA.
The focus quickly turns to temps for Fri and Sat. Differences among
mdls leads to a lot of uncertainty for these days. Given the past
couple of warm up events, will trend twd the GFS/local WRF solns.
These solns strong SW to W flow at the sfc with the thermal ridge
pushing into the region. This, coupled with deep mixing, shud allow
temps to reach the 80s for Fri. Sat shud be a little cooler as a
weak cdfnt drops swd across the region, but still a warm day.
(Sunday through Wednesday)
While specifics may differ among mdl solns, general trends are in
fairly good agreement thru the extd period. Mdls suggest an initial
surge of TSRA will push thru the region on Sun thru Mon as a large
low system approaches the area. This system has a threat of severe
weather for much of the CWA. As this system is still 5 plus days
out, time will not be spent discussing details that are likely to
change many times by the end of this weekend.
By Mon night, a S/W associated with the upper low progd to be over
the nrn Atlantic, will approach the upper low over the MO region.
After a brief Fujiwhara interaction, these two low centers are progd
to combine forming one large low system. Mdls differ regarding
placement of this interaction, which will be vital to determining
where precip will occur associated with this low. If the interaction
is further E, the low shud eject precip ewd out of the region, per
the GFS soln. If it is further W, per the ECMWF, precip shud linger
for at least a while.
Regardless, both solns suggest much colder temps will remain locked
in place thru the remainder of next week. Will take a closer look at
temps for Wed and beyond tomorrow, but going forecast of mid 50s may
have too much of an influence on climo and need to be lowered with
future updates.
Tilly
&&
.AVIATION: (For the 06z TAFs through 06z Thursday Night)
Issued at 1155 PM CDT Wed Apr 23 2014
VFR flight conditions/mid-high clouds will persist overnight with modest
southeast surface winds. A southerly LLJ has developed and is broader
than originally anticipated, and now have marginal LLWS conditions
at all TAF sites. Precipitation timing is still a tough call on
Thursday, but overall the trend and timing is slower than previous
forecasts. Expecting shra and possibly a few rumbles of thunder to
impact KCOU-KUIN in the 16-18z time frame with this activity
weakening as it moves east. Better potential for organized showers
and thunderstorms at all TAFS sites will be on Thursday afternoon/evening
along and ahead of a cold front where I have conditions lowering
to MVFR.
Specifics for KSTL:
VFR flight conditions/mid-high clouds will persist overnight with modest
southeast surface winds. A southerly LLJ has developed and is broader
than originally anticipated, and local radar VWPs suggest marginal LLWS
conditions through 14-15z. Best potential for organized showers
and thunderstorms at KSTL will be between 22-02z on Thursday
afternoon/evening along and ahead of a cold front where I have
conditions lowering to MVFR.
Glass
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 73 50 78 55 / 80 80 0 10
Quincy 68 47 76 51 / 80 80 0 10
Columbia 71 46 78 51 / 80 70 0 10
Jefferson City 72 48 79 50 / 80 80 0 10
Salem 74 49 76 51 / 70 80 0 10
Farmington 75 49 77 49 / 80 80 0 10
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1200 PM CDT THU APR 24 2014
.UPDATE...
ISSUED AT 936 AM CDT THU APR 24 2014
UPDATED FORECAST FOR MAINLY FIRE WEATHER ELEMENTS. BASED ON RAPID
CITYS UPPER AIR SOUNDING AND THE LATEST RAP MODEL...LOWERED
RELATIVE HUMIDITIES ACROSS MUCH OF THE AREA FOR TODAY. THE WINDS
LOOK TO BE ON TRACK FOR THE RED FLAG WARNING ALSO. HOWEVER...WINDS
MAY DROP OFF BY LATE AFTERNOON. UPDATED OTHER FIRE WEATHER
ELEMENTS BASED ON LATEST MODEL DATA INCLUDING HAINES...MIXING
HEIGHT...TRANSPORT WINDS...AND VENTILATION RATE/SMOKE DISPERSAL.
PUBLIC FORECAST WAS LARGELY UNCHANGED WITH THIS UPDATE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 311 AM CDT THU APR 24 2014
POST FRONTAL SHOWERS CONTINUE OVER A SMALL PORTION OF SOUTHWEST
NEBRASKA AND NORTH CENTRAL NEBRASKA EARLY THIS MORNING. LAST
LIGHTNING WAS AROUND 05Z. FAIRLY STRONG NORTHWEST FLOW CONTINUING
OVER THE FORECAST AREA EARLY THIS MORNING. ALL SHOWERS SHOULD HAVE
CLEARED FORECAST AREA BY 12Z. BIG WINNERS TONIGHT WERE GARFIELD
AND WHEELER COUNTIES WITH LESS THAN A QUARTER OF AN INCH. THIS
WILL HAVE IMPLICATIONS WITH FIRE WEATHER...SEE DISCUSSION BELOW.
MODELS IN FAIR AGREEMENT THIS MORNING FOR THE NEAR TERM.
TEMPERATURES ABOUT 10F DEGREES COOLER TODAY ACROSS THE FORECAST
AREA. STRONG NORTHWEST FLOW TO CONTINUE OVER THE AREA AGAIN TODAY
WITH GOOD MIXING AND SKIES CLEARING OUT FROM THE PANHANDLE
EASTWARD THROUGH THE MORNING. MODELS HAVE CLOUDS CLEARING OUT
PRETTY QUICKLY BUT CURRENT TRENDS ON SATELLITE NOT SUPPORTIVE OF
THIS. FULL SUN EXPECTED BY THIS AFTERNOON...AND WITH GUSTY
NORTHWEST FLOW HAVE GONE A COUPLE OF DEGREES ABOVE GUIDANCE FOR
HIGHS. TONIGHT WITH CLEAR SKIES TEMPERATURES WILL FALL INTO THE
MID 30S TO AROUND 40. FRIDAY...AS WEAK RIDGE CONTINUES TO MOVE
EAST INTO THE NORTHERN PLAINS...EXPECT CONTINUED DRY AND WEAK
SOUTHWEST FLOW AS A WEAK SURFACE TROUGH TRANSITIONS TO THE EAST
ACROSS WESTERN NEBRASKA WITH A VERY DRY AIRMASS IN PLACE.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 311 AM CDT THU APR 24 2014
A POTENT UPPER LEVEL TROUGH OF LOW PRESSURE WILL MOVE ONSHORE THE
PACIFIC COAST FRIDAY EVENING...AND PROGRESS EASTWARD INTO THE
CENTRAL PLAINS DURING THE WEEKEND. THE 24/00Z MODEL RUNS HAVE ALL
SHIFTED THE TRACK OF THE STORM NORTH...WITH A NEARLY STACKED H5/H7
CIRCULATION CENTER LOCATED INVOF NORTHEAST COLORADO OR WESTERN
NEBRASKA AT 00Z MONDAY 28TH APRIL. GEFS ALSO CLUSTERING A AN H5
CIRCULATION CENTER IN THE SAME AREA. OPERATIONAL MODELS AND THE GEFS
ALL INDICATE A VERY DEEP SURFACE LOW /NEAR 983MB/ IN THE SAME
GENERAL AREA. THIS WILL BE A VERY DYNAMIC SYSTEM...WITH UNMODIFIED
RICH GULF MOISTURE STREAMING NORTHWARD INTO THE PLAINS. THIS
SPELLS SEVERE THUNDERSTORMS AND HEAVY RAINFALL IN AREAS. THE
CAVEAT TO ALL OF THIS WILL BE A PRONOUNCED DRY SLOT...THAT WILL
IMPACT SOME PORTION OF THE CENTRAL PLAINS. WITH TONIGHTS NORTHWARD
SHIFT IN THE MODELS...THIS DRY SLOT WOULD IMPACT PART OR ALL OF
THE NWS NORTH PLATTE FORECAST AREA SOMETIME DURING THE WEEKEND. AT
THIS POINT HOWEVER...THE SYSTEM IS STILL WELL OFFSHORE AND NOT
BEING SAMPLED BY UPPER AIR OBSERVING NETWORK. THEREFORE AM
HESITANT TO MAKE MAJOR CHANGES TO THE CURRENT FORECAST. IF THE
MODELS CONTINUE TO FAVOR A NORTHWARD TRACK IN FUTURE RUNS...THEN
WILL HAVE TO WARM HIGHS AND CUT PRECIPITATION CHANCES FOR PART OF
THE WEEKEND.
EARLY NEXT WEEK...THE AREA WILL CONTINUE TO BE IMPACTED FROM THIS
LARGE SLOW MOVING STORM SYSTEM. HOW THIS WHOLE SYSTEM EVOLVES COULD
BE QUITE INTERESTING. FOR EXAMPLE...THE LATEST 24/00Z ECMWF DUMBBELLS
A SECOND UPPER LOW WESTWARD FROM EASTERN CANADA...EVENTUALLY MERGING
THE TWO SYSTEM TOGETHER LATE MONDAY INTO TUESDAY...SENDING A LARGE
SHIELD OF RAIN WEST ACROSS THE AREA. THIS IS JUST ONE POSSIBLE
SCENARIO. FOR NOW...HAVE LOW CONFIDENCE ON HOW THIS WILL ALL PAN
OUT...AND WILL KEEP A CHANCE FOR RAIN AND COOL TEMPERATURES GOING
THROUGH AT LEAST TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1200 PM CDT THU APR 24 2014
VFR CONDITIONS ARE EXPECTED AT THE TAF SITES FOR THE NEXT 24
HOURS. GUSTY NORTHWEST WINDS WILL DIMINISH LATE THIS AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 311 AM CDT THU APR 24 2014
HAVE ISSUED A RED FLAG WARNING FOR ALL OF WESTERN NEBRASKA THIS
AFTERNOON FOR LOW RELATIVE HUMIDITY AND WINDS. GARFIELD...WHEELER
AND SOUTHERN HOLT COUNTIES RECEIVED LESS THAN A QUARTER OF AN INCH
OF PRECIPITATION OVER NIGHT IN FIRE ZONE 209 BUT THE MAJORITY OF
THAT ZONE WAS TRACE AMOUNTS OR A HUNDREDTH OF AN INCH AT BEST. THE
REMAINDER OF WESTERN NEBRASKA SAW A HUNDREDTH OR LESS OF
PRECIPITATION. MINIMUM RELATIVE HUMIDITIES FELL INTO THE SINGLE
DIGITS AND TEENS YESTERDAY OVER MOST OF THE FORECAST AREA. THINGS
ARE STARTING TO GREEN UP BUT FUELS ARE STILL FAVORABLE. LOOKING TO
THE WEST ACROSS THE BORDER IN WYOMING VERY DRY AIR MASS UNDER THE
HIGH PRESSURE SYSTEM...WITH DEW POINTS IN THE SINGLE DIGITS AND
TEENS. STRONG NORTHWEST FLOW WILL DIMINISH ACROSS WESTERN AND
NORTH CENTRAL NEBRASKA LATE THIS AFTERNOON. WINDS SHOULD REMAIN
GUSTY TROUGH AT LEAST EARLY AFTERNOON HOWEVER. MINIMUM RH WILL
FALL INTO THE TEENS OVER THE ENTIRE FORECAST AREA AND MAY FALL
INTO THE SINGLE DIGITS OVER SOUTHWEST NEBRASKA AND THE SOUTHEAST
NEBRASKA PANHANDLE. ALL OF WESTERN NEBRASKA IN THE DAY 1 STORM
PREDICTION CENTER FIRE WEATHER OUTLOOK. FIRE WEATHER MAY BE A
CONCERN AGAIN ON FRIDAY WITH LOW RH BUT LIGHTER WINDS WILL BE
LIMITING FACTOR.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR
NEZ204-206-208>210-219.
&&
$$
UPDATE...KNUTSVIG
SHORT TERM...POWER
LONG TERM...TAYLOR
AVIATION...KNUTSVIG
FIRE WEATHER...POWER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
942 AM CDT THU APR 24 2014
.UPDATE...
ISSUED AT 936 AM CDT THU APR 24 2014
UPDATED FORECAST FOR MAINLY FIRE WEATHER ELEMENTS. BASED ON RAPID
CITYS UPPER AIR SOUNDING AND THE LATEST RAP MODEL...LOWERED
RELATIVE HUMIDITIES ACROSS MUCH OF THE AREA FOR TODAY. THE WINDS
LOOK TO BE ON TRACK FOR THE RED FLAG WARNING ALSO. HOWEVER...WINDS
MAY DROP OFF BY LATE AFTERNOON. UPDATED OTHER FIRE WEATHER
ELEMENTS BASED ON LATEST MODEL DATA INCLUDING HAINES...MIXING
HEIGHT...TRANSPORT WINDS...AND VENTILATION RATE/SMOKE DISPERSAL.
PUBLIC FORECAST WAS LARGELY UNCHANGED WITH THIS UPDATE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 311 AM CDT THU APR 24 2014
POST FRONTAL SHOWERS CONTINUE OVER A SMALL PORTION OF SOUTHWEST
NEBRASKA AND NORTH CENTRAL NEBRASKA EARLY THIS MORNING. LAST
LIGHTNING WAS AROUND 05Z. FAIRLY STRONG NORTHWEST FLOW CONTINUING
OVER THE FORECAST AREA EARLY THIS MORNING. ALL SHOWERS SHOULD HAVE
CLEARED FORECAST AREA BY 12Z. BIG WINNERS TONIGHT WERE GARFIELD
AND WHEELER COUNTIES WITH LESS THAN A QUARTER OF AN INCH. THIS
WILL HAVE IMPLICATIONS WITH FIRE WEATHER...SEE DISCUSSION BELOW.
MODELS IN FAIR AGREEMENT THIS MORNING FOR THE NEAR TERM.
TEMPERATURES ABOUT 10F DEGREES COOLER TODAY ACROSS THE FORECAST
AREA. STRONG NORTHWEST FLOW TO CONTINUE OVER THE AREA AGAIN TODAY
WITH GOOD MIXING AND SKIES CLEARING OUT FROM THE PANHANDLE
EASTWARD THROUGH THE MORNING. MODELS HAVE CLOUDS CLEARING OUT
PRETTY QUICKLY BUT CURRENT TRENDS ON SATELLITE NOT SUPPORTIVE OF
THIS. FULL SUN EXPECTED BY THIS AFTERNOON...AND WITH GUSTY
NORTHWEST FLOW HAVE GONE A COUPLE OF DEGREES ABOVE GUIDANCE FOR
HIGHS. TONIGHT WITH CLEAR SKIES TEMPERATURES WILL FALL INTO THE
MID 30S TO AROUND 40. FRIDAY...AS WEAK RIDGE CONTINUES TO MOVE
EAST INTO THE NORTHERN PLAINS...EXPECT CONTINUED DRY AND WEAK
SOUTHWEST FLOW AS A WEAK SURFACE TROUGH TRANSITIONS TO THE EAST
ACROSS WESTERN NEBRASKA WITH A VERY DRY AIRMASS IN PLACE.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 311 AM CDT THU APR 24 2014
A POTENT UPPER LEVEL TROUGH OF LOW PRESSURE WILL MOVE ONSHORE THE
PACIFIC COAST FRIDAY EVENING...AND PROGRESS EASTWARD INTO THE
CENTRAL PLAINS DURING THE WEEKEND. THE 24/00Z MODEL RUNS HAVE ALL
SHIFTED THE TRACK OF THE STORM NORTH...WITH A NEARLY STACKED H5/H7
CIRCULATION CENTER LOCATED INVOF NORTHEAST COLORADO OR WESTERN
NEBRASKA AT 00Z MONDAY 28TH APRIL. GEFS ALSO CLUSTERING A AN H5
CIRCULATION CENTER IN THE SAME AREA. OPERATIONAL MODELS AND THE GEFS
ALL INDICATE A VERY DEEP SURFACE LOW /NEAR 983MB/ IN THE SAME
GENERAL AREA. THIS WILL BE A VERY DYNAMIC SYSTEM...WITH UNMODIFIED
RICH GULF MOISTURE STREAMING NORTHWARD INTO THE PLAINS. THIS
SPELLS SEVERE THUNDERSTORMS AND HEAVY RAINFALL IN AREAS. THE
CAVEAT TO ALL OF THIS WILL BE A PRONOUNCED DRY SLOT...THAT WILL
IMPACT SOME PORTION OF THE CENTRAL PLAINS. WITH TONIGHTS NORTHWARD
SHIFT IN THE MODELS...THIS DRY SLOT WOULD IMPACT PART OR ALL OF
THE NWS NORTH PLATTE FORECAST AREA SOMETIME DURING THE WEEKEND. AT
THIS POINT HOWEVER...THE SYSTEM IS STILL WELL OFFSHORE AND NOT
BEING SAMPLED BY UPPER AIR OBSERVING NETWORK. THEREFORE AM
HESITANT TO MAKE MAJOR CHANGES TO THE CURRENT FORECAST. IF THE
MODELS CONTINUE TO FAVOR A NORTHWARD TRACK IN FUTURE RUNS...THEN
WILL HAVE TO WARM HIGHS AND CUT PRECIPITATION CHANCES FOR PART OF
THE WEEKEND.
EARLY NEXT WEEK...THE AREA WILL CONTINUE TO BE IMPACTED FROM THIS
LARGE SLOW MOVING STORM SYSTEM. HOW THIS WHOLE SYSTEM EVOLVES COULD
BE QUITE INTERESTING. FOR EXAMPLE...THE LATEST 24/00Z ECMWF DUMBBELLS
A SECOND UPPER LOW WESTWARD FROM EASTERN CANADA...EVENTUALLY MERGING
THE TWO SYSTEM TOGETHER LATE MONDAY INTO TUESDAY...SENDING A LARGE
SHIELD OF RAIN WEST ACROSS THE AREA. THIS IS JUST ONE POSSIBLE
SCENARIO. FOR NOW...HAVE LOW CONFIDENCE ON HOW THIS WILL ALL PAN
OUT...AND WILL KEEP A CHANCE FOR RAIN AND COOL TEMPERATURES GOING
THROUGH AT LEAST TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 626 AM CDT THU APR 24 2014
MID AND HIGH CLOUDS CLEARING OUT OVER WESTERN NEBRASKA THIS
MORNING WEST OF A LINE FROM KVTN TO KOGA P6SM SKC. SKIES WILL
CLEAR WEST OF A LINE FROM KONL TO KBBW THROUGH NOON CDT. WEST TO
NORTHWEST WINDS WILL INCREASE THROUGH THE MORNING TO 10 TO 20 MPH
WITH HIGHER GUSTS.
&&
.FIRE WEATHER...
ISSUED AT 311 AM CDT THU APR 24 2014
HAVE ISSUED A RED FLAG WARNING FOR ALL OF WESTERN NEBRASKA THIS
AFTERNOON FOR LOW RELATIVE HUMIDITY AND WINDS. GARFIELD...WHEELER
AND SOUTHERN HOLT COUNTIES RECEIVED LESS THAN A QUARTER OF AN INCH
OF PRECIPITATION OVER NIGHT IN FIRE ZONE 209 BUT THE MAJORITY OF
THAT ZONE WAS TRACE AMOUNTS OR A HUNDREDTH OF AN INCH AT BEST. THE
REMAINDER OF WESTERN NEBRASKA SAW A HUNDREDTH OR LESS OF
PRECIPITATION. MINIMUM RELATIVE HUMIDITIES FELL INTO THE SINGLE
DIGITS AND TEENS YESTERDAY OVER MOST OF THE FORECAST AREA. THINGS
ARE STARTING TO GREEN UP BUT FUELS ARE STILL FAVORABLE. LOOKING TO
THE WEST ACROSS THE BORDER IN WYOMING VERY DRY AIR MASS UNDER THE
HIGH PRESSURE SYSTEM...WITH DEW POINTS IN THE SINGLE DIGITS AND
TEENS. STRONG NORTHWEST FLOW WILL DIMINISH ACROSS WESTERN AND
NORTH CENTRAL NEBRASKA LATE THIS AFTERNOON. WINDS SHOULD REMAIN
GUSTY TROUGH AT LEAST EARLY AFTERNOON HOWEVER. MINIMUM RH WILL
FALL INTO THE TEENS OVER THE ENTIRE FORECAST AREA AND MAY FALL
INTO THE SINGLE DIGITS OVER SOUTHWEST NEBRASKA AND THE SOUTHEAST
NEBRASKA PANHANDLE. ALL OF WESTERN NEBRASKA IN THE DAY 1 STORM
PREDICTION CENTER FIRE WEATHER OUTLOOK. FIRE WEATHER MAY BE A
CONCERN AGAIN ON FRIDAY WITH LOW RH BUT LIGHTER WINDS WILL BE
LIMITING FACTOR.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR
NEZ204-206-208>210-219.
&&
$$
UPDATE...KNUTSVIG
SHORT TERM...POWER
LONG TERM...TAYLOR
AVIATION...POWER
FIRE WEATHER...POWER
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
812 PM EDT FRI APR 25 2014
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL TRACK EAST ACROSS THE AREA TONIGHT
BRINGING SOME SHOWERS. A FEW SHOWERS WILL LINGER SATURDAY AND
SATURDAY NIGHT AS UPPER LEVEL LOW PRESSURE MOVES ACROSS THE AREA.
HIGH PRESSURE OVER EASTERN CANADA WILL BRING A RETURN TO MAINLY
DRY WEATHER SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
810 PM UPDATE...
NUMEROUS LOPRES CNTRS ON SFC ANALYSIS THIS EVNG, ONE OVR UP OF
MICHIGAN, ANOTHER OVR WRN NY AND YET ANOTHER DOWN OVR THE PIEDMONT
OF NC. TWO AREAS OF SHOWERS AFFECTING CWA AT THIS TIME, WITH FIRST
BATCH HVG MVD UP FM PA IN AREA OF ISENTROPIC LIFT. AREA OF SHOWERS
MVG IN FM WRN NY ASSOC WITH FRONTAL BNDRY PUSHING EWRD. BACK EDGE
OF RAIN SHIELD IS HANDLED BEAUTIFULLY BY LATEST HRRR AND EXPECT
THIS TO BE ALONG THE I-81 CORRIDOR BY 07Z. CURRENT GRIDS REFLECT
THIS WELL AND THE ONLY CHG NEEDED WAS TO RMV THUNDER MENTION THRU
THE OVRNGT. NEAREST IN-CLOUD LIGHTNING STRIKES ARE DOWN ACRS THE
VA CAPES WITH LATEST GUIDANCE KEEPING SHOWALTERS WELL ABV ZERO
TONIGHT.
EXPECT LO CLDS TO LINGER THRU THE MRNG HRS WITH A BRIEF POTENTIAL
FOR PCLDY SKIES DRG THE MRNG HRS UNTIL PARENT H5 LOW DROPS ACRS NY
STATE DRG THE DAY. WITH LOW-LVL MOISTURE RMNG, ESPECIALLY IN CNTR
NY, SKIES WL CLD BACK UP BY NOON WITH POSSIBLE SHOWERS DVLPNG DRG
THE DAY.
PREV DISCUSSION BLO...
MID TO HI CLOUDS ARE RAPIDLY INCREASING OVER CENTRAL NY AND
NORTHEAST PA AS PER VISIBLE SATELLITE IMAGERY AS MOISTURE
STREAMS EASTWARD ALOFT AHEAD OF NEXT UPPER LEVEL WAVE AND
ASSOCIATED SURFACE SYSTEM. THIS UPPER LEVEL WAVE WAS SEEN WELL ON
THE WATER VAPOR IMAGERY OVER OHIO AND WAS MOVG EAST/NORTHEAST.
THERE WAS SIGNIFICANT MID TO HIGH LEVEL ISENTROPIC LIFT OR
ALTERNATELY WARM AIR ADVECTION FOR THOSE WHO LIKE PRESSURE
COORDINATES! WITH THIS, WAS ALSO SIGNIFICANT MOISTURE ADVECTION.
THE END RESULT WAS INCREASING MID TO HI CLDS THAT WILL CONTINUE
FOR THE REST OF THE AFTERNOON INTO THE EARLY EVENING HOURS. BY
00Z, THE POTENTIAL VORTICITY MAXIMUM WITH THE UPPER LEVEL WAVE
WILL REACH WRN PA TO WRN NY AND PROVIDE SIGNIFICANT MID LEVEL
LIFTG OF AIR THAT IS ALREADY RISING UP THE MOIST AND SATURATED
ADIABATS. THIS WILL USHER IN A STEADY RAIN FROM SW TO NE ACRS C
NY/NE PA BTWN ABT 22Z FROM SW STEUBEN CO TO WILKES BARRE TO 02Z IN
THE RME AREA. THIS UPPER LEVEL POTENTIAL VORTICITY MAX WILL BECOME
MORE STRETCHED AND ELONGATED IN TIME AS IT PASSES BY C NY/NE PA
BY 6Z-10Z TONIGHT. THE RAIN WILL TAPER OFF AT THIS TIME. MODELS
INDICATE SOME ELEVATED INSTABILITY LATER THIS EVENING WITH
SHOWALTER INDICES DROPPING TO NEAR OR BELOW 0C. SO I HAVE ADDED A
SLGHT CHC TO CHC OF THUNDER IN NE PA AND SC NY LATER IN THE
EVENING. PRECIP WINDS DOWN LATE TONIGHT.
FOR SATURDAY AM, THERE WILL BE PLENTY OF LOW CLOUDS AROUND AS WE
ARE IN BETWEEN THE FIRST UPPER WAVE HEADING TO OUR NORTHEAST AND
THE NEXT SIGNIFICANT UPPER LEVEL WAVE AND SIGNIFICANT SHOT OF COLD
AIR ADVECTION COMING FROM THE GREAT LAKES REGION. HENCE I SEE LOTS
OF LEFT OVER CLOUDS AROUND SAT AM. SHRA WILL DEVELOP BY SAT
PM, AS BNDRY LAYER HEATING COMBINES WITH COOLING ALOFT ARRIVING
WITH THIS NEXT SHOT OF COLD AIR ADVECTION AND LIFTG. HENCE I SEE
PLENTY OF SHRA DEVELOP BY AFTERNOON. SAT WILL BE COOL AND BREEZY
AS WELL.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
OPERATIONAL MODELS ARE IN GOOD AGREEMENT WITH THE FORECAST
SCENARIO THROUGH THIS PERIOD. UPPER LEVEL LOW PRESSURE WILL DIG
SOUTHEAST FROM THE NORTHERN GREAT LAKES TO SOUTHERN NEW ENGLAND
SATURDAY NIGHT ACCOMPANIED BY SCATTERED SHOWERS ESPECIALLY NORTH
OF THE NY/PA BORDER. A FEW SNOW FLAKES COULD MIX WITH THE RAIN
LATER SATURDAY NIGHT ESPECIALLY OVER HIGHER ELEVATIONS AS
TEMPERATURES WILL BECOME MARGINAL FOR SOME MIXED PRECIPITATION...
BUT NO ACCUMULATIONS ARE EXPECTED. PRECIPITATION AMOUNTS SATURDAY
NIGHT WILL BE LIGHT. LOW TEMPERATURES WILL BE IN THE 30S.
SCATTERED SHOWERS... SPRINKLES OF MORNING FLURRIES MAY LINGER FOR
AWHILE ON SUNDAY IN MOIST NNW FLOW PATTERN... ESPECIALLY OVER NY
STATE. 850 MB TEMPERATURES DOWN AROUND -4 C WILL NOT BE COLD
ENOUGH FOR ANY REAL LAKE ENHANCEMENT WITH LAKE ONTARIO TEMP STILL
AROUND +2... SO MAIN CONCENTRATION OF SHOWERS MAY BE INLAND FROM
THE FINGER LAKES TO THE SOUTHERN TIER OF NY... AS OPPOSED TO
FARTHER NORTH NEAR LAKE ONTARIO. DRY AIR ASSOCIATED WITH HIGH
PRESSURE OVER EASTERN CANADA WILL EVENTUALLY BREAK UP THE CLOUD
COVER ACROSS THE AREA DURING THE AFTERNOON OR EVENING HOURS.
TEMPERATURES SUNDAY WILL BE BELOW NORMAL WITH READINGS MAINLY IN
THE 50S.
AFTER A CLEAR CHILLY NIGHT SUNDAY NIGHT MONDAY WILL BE DRY WITH
NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES UNDER HIGH PRESSURE AT
THE SURFACE AND ALOFT. THE NEXT CHC OF RAIN WILL BE LATER MONDAY
NIGHT OR TUESDAY AS SURFACE THROUGH UPPER LEVEL LOW PRESSURE
APPROACHES FROM THE SOUTHWEST AND ISENTROPIC LIFT DEVELOPS WITH
INCREASING SW FLOW ALOFT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
A STRONG HIGH PRESSURE RIDGE DEVELOPING OVER CENTRAL CANADA WILL
FAVOR UPPER LEVEL LOW PRESSURE TO THE SOUTH-SOUTHEAST OVER THE
CENTRAL AND EASTERN U.S. THROUGH THIS PERIOD. GFS/ECMWF HAVE BEEN
ADVERTISING THIS PATTERN FOR QUITE SOME TIME NOW AND THERE IS HIGH
CONFIDENCE FOR A GENERALLY UNSETTLED PERIOD OF WEATHER DURING THE
MIDDLE AND LATE PART OF NEXT WEEK... ALTHOUGH THE DETAILS OF
COURSE REMAIN VERY UNCLEAR AT THIS TIME RANGE. CURRENT FORECAST
INDICATING AT LEAST A CHC OF SHOWERS EACH DAY FROM TUESDAY THROUGH
FRIDAY APPEARS REASONABLE. TEMPERATURES LOOK TO BE AT LEAST A
LITTLE BELOW NORMAL THROUGH THIS PERIOD... ALTHOUGH HOW FAR BELOW
NORMAL WILL DEVELOP ON EXACTLY WHERE THE UPPER LOW DEVELOPS.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AREAS OF RAIN WILL BE OVER THE FCST AREA THIS EVNG AS LOW PRES
OVER WRN NY LIFTS NEWD AND DRAGS A CDFNT THRU THE FCST AREA. BACKEDGE
OF THE STEADIER RAIN...WHICH HAS ENTERED WRN NY/PA...WILL PASS
THRU THE CWA IN THE 04-08Z TIME FRAME. CIGS WILL FALL INTO THE
MVFR RNG THIS EVNG AS THE RAIN MOVS IN. IFR CONDITIONS ARE ALSO PSBL
LATE...BEST CHC AT RME AND PSBLY AT HIER ELEVATION SITES ITH/BGM
AFTER FROPA. CONDITIONS WILL IMPRV TMRW MRNG AFTER MVFR CIGS
LIFT/SCATTER OUT (MVFR CIGS LIKELY TO PERSIST LONGER AT SYR/RME
TMRW MRNG). POTNL FOR A FEW -SHRA AT SYR/RME TMRW AFTN AS ANOTHER
S/WV APRCHS.
WINDS THIS EVNG GNRLY FROM THE S AT 10-15 KTS WITH G20...BECMG
WRLY AFTER FROPA TNGT ARND 10 KTS...THEN WNW ON SAT INCRSNG TO
15-25 KTS.
OUTLOOK...
SUN-MON...VFR.
TUE AND WED...RESTRICTIONS POSSIBLE IN RAIN SHOWERS.
&&
.FIRE WEATHER...
RAINFALL HAS MOVED INTO NORTHEAST PENNSYLVANIA THIS EVENING WITH
AMOUNTS RANGING FROM A FEW HUNDREDTHS OF AN INCH TO A TENTH OF AN
INCH. WITH SHOWERS EXPECTED TONIGHT AND AGAIN SATURDAY, NO THREAT
FOR FIRE WEATHER CONDITIONS EXIST THROUGH THE WEEKEND.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE/TAC
NEAR TERM...DJN/PVN
SHORT TERM...MSE
LONG TERM...MSE
AVIATION...
FIRE WEATHER...PN
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
337 PM EDT THU APR 24 2014
.SYNOPSIS...
HIGH PRESSURE OVER THE NORTH COUNTRY TONIGHT WILL RESULT IN
MAINLY CLEAR SKIES AND COOL TEMPERATURES. FRIDAY WILL START WITH
PLENTY OF SUNSHINE BUT CLOUDS WILL DEVELOP DURING THE AFTERNOON
HOURS WITH SHOWERS ARRIVING FOR FRIDAY NIGHT INTO SATURDAY.
TEMPERATURES WILL BE NEAR NORMAL FOR FRIDAY...BUT BELOW NORMAL
WITH CLOUDS AND SHOWERS ON SATURDAY INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 320 PM EDT THURSDAY...SFC HIGH PRES LOCATED OVER THE EASTERN GREAT
LAKES WL SHIFT INTO THE NORTH COUNTRY TONIGHT WITH CLRING SKIES
AND LIGHT TRRN DRIVEN WINDS DEVELOPING. RAP SOUNDINGS STILL SHOW
SOME ENHANCED RH AROUND 800MB...BUT THINKING ANY CLOUDS ASSOCIATED
WITH UPSLOPE FLW AND THIS MOISTURE WL QUICKLY DISSIPATE BY SUNSET.
GUIDANCE IS VERY COLD WITH SLK MAV/MET SHOWING READINGS OF
17/18...AND AROUND 29F FOR BTV. WL TREND A COUPLE DEGREES
HIGHER...BUT GIVEN VERY LOW SFC DWPTS AND LIGHT WINDS...THINKING
VALUES WL RANGE FROM THE UPPER 10S COLDER MTN VALLEYS/NEK TO M/U
20S ELSEWHERE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 320 PM EDT THURSDAY...MID/UPPER LVL RIDGE ACRS THE NE CONUS WL QUICKLY
SHIFT INTO EASTERN NEW ENGLAND BY 00Z SATURDAY...AS PROGRESSIVE
WESTERLY FLW ALOFT CONTS ACRS THE NORTHERN TIER OF THE UNITED
STATES. DEEP DRY LAYER AND STRONG SUBSIDENCE PER LATEST WATER
VAPOR TRENDS WL RESULT IN MOSTLY SUNNY SKIES ON FRIDAY
MORNING...BUT MID/UPPER LVL RH INCREASES AFT 18Z FROM SW TO NE.
BEST 850 TO 700MB OMEGA FIELDS AND ASSOCIATED RIBBON OF 850 TO
500MB RH >80% ARRIVES AFT 00Z SAT...SO WL KEEP FRIDAY DRY ATTM.
PROGGED 85H TEMPS RANGE FROM 0C NEK TO 4C SOUTHWEST
SLV...RESULTING IN TEMPS RANGING FROM THE L/M 50S NEK/MTNS TO L60S
SLV AND WARMER/UHI AREAS OF THE CPV.
FRIDAY NIGHT INTO SATURDAY...850 TO 500MB RH QUICKLY OVERSPREADS THE
FA WITH MODEST UVVS ASSOCIATED WITH 5H VORT AND DEVELOPMENT OF
MID/UPPER LVL TROF. STILL FEEL INITIAL 5H VORT AND MOISTURE WL
DISSIPATE ACRS OUR CWA ON FRIDAY NIGHT...WITH LEADING EDGE OF PRECIP
FALLING AS MOSTLY VIRGA...ESPECIALLY GIVEN VERY DRY LVLLS. BETTER
DYNAMICS AND DEEPER RH ARRIVES ASSOCIATED WITH CLOSED 5H/7H
CIRCULATION BTWN 06Z-12Z SATURDAY...WITH A BAND OF LIGHT TO MODERATE
RAIN ANTICIPATED. HAVE NOTED POCKETS OF COOLER PROGGED 85H TEMPS <0C
ACRS CENTRAL/NORTHERN VT/NEK ON SATURDAY MORNING...WHICH COULD
RESULT IN SOME WET SNOW IN THE MTN SUMMITS. COLD POOL ALOFT
ASSOCIATED WITH CLOSED SYSTEM MOVES DIRECTLY OVERHEAD ON
SATURDAY...WITH COOLING PROFILES ALOFT ANTICIPATED. THIS COMBINED
WITH SOME LIMITED SFC HEATING WL RESULT IN ADDITIONAL INSTABILITY
FOR MORE SCATTERED SHOWERS TO DEVELOP. BOTTOM LINE SAT WL BE COOL
AND DAMP WITH OCCASIONAL RAIN SHOWERS AND HIGH ELEVATION SNOW
SHOWERS LIKELY. TOTAL QPF WL RANGE BTWN 0.10 AND 0.50 OF AN INCH.
TEMPS WL RANGE FROM THE U30S/M40S NEK/MTNS TO M40S/L50S VALLEYS ON
SAT.
SATURDAY NIGHT...CLOSED MID/UPPER LVL CIRCULATION CONTS TO DEEPEN AS
SEVERAL EMBEDDED S/W`S INTERACT WITH THIS LARGE SYNOPTIC SCALE
SYSTEM. THIS WL SLOW OVERALL MOVEMENT OF SYSTEM DOWN WITH IT
BECOMING STATIONARY OFF THE NEW ENGLAND COASTLINE BY SAT NIGHT...AND
NUMEROUS RIBBONS OF MOISTURE ROTATING ACRS OUR CENTRAL/EASTERN CWA.
THIS COMBINED WITH DEVELOPING WEST TO NORTHWEST FLW WL RESULT IN
ADDITIONAL SHOWERS. GIVEN THE DEEPENING COLD POOL ALOFT AND
ASSOCIATED COOLING OF LLVL THERMAL PROFILES...THINKING SNOW LEVELS
WL DROP TO AROUND 2000 FT BY SUNDAY MORNING. HOWEVER...ACCUMULATIONS
SHOULD BE LIGHT. TEMPS WITH CLOUDS/WIND AND PRECIP WL HOLD MAINLY IN
THE 30S TO NEAR 40F...FAIRLY UNIFORMED ACRS OUR REGION.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 336 PM EDT THURSDAY...EXTENDED RANGE FORECAST CONTINUES TO
LOOKS VERY UNCERTAIN AS MUCH OF THE CONUS WILL BE IMPACTED BY A
DEVELOPING OMEGA BLOCK LATE THIS WEEKEND. UPPER LOW LOW WHICH
WILL HAVE BROUGHT RAIN/SNOW SHOWERS TO THE REGION SATURDAY AND
SATURDAY NIGHT WILL SHIFT OFFSHORE SUNDAY WITH A GENERALLY DRY
YET COOL AND BRISK END TO THE WEEKEND. HIGHS WILL RUN ABOUT 5-10
DEGREES BELOW NORMAL IN THE MID 40S TO LOWER 50S. AS THE LOW
SHIFTS FURTHER OFFSHORE SUNDAY NIGHT...OMEGA BLOCK SETUPS UP
ACROSS THE CONUS WITH ANOTHER CLOSED LOW DEVELOPING OVER THE
CENTRAL ROCKIES AND A HIGHLY AMPLIFIED RIDGE ACROSS MUCH OF THE
EASTERN CONUS. THIS PATTERN REMAINS FAIRLY PERSISTENT FOR MONDAY
THROUGH WEDNESDAY WITH A SLOW PROGRESSION EASTWARD AND SOME
SLIGHT MODIFICATION TO THE AMPLITUDE OF THE RIDGE. AT THIS
TIME...THE FORECAST DOES LOOK GENERALLY DRY FOR THE NORTH
COUNTRY...BUT DEPENDING ON THE EXACT TRACK OF ALL THE ABOVE SAID
FEATURES...THINGS COULD CHANGE. TEMPS WILL BE HIGHLY VARIABLE
BASED ON RIDGE/LOW PLACEMENTS...BUT IN GENERAL LOOK TO RUN AT OR
BELOW NORMAL. AS WE GET CLOSER TO THURSDAY...SIGNS ARE THAT THE
RIDGE BEGINS TO BREAK DOWN AND ROCKIES LOW SHIFTS EASTWARD INTO
THE GREAT LAKES RENEWING CHANCES FOR PRECIP ACROSS THE NORTHEAST.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
THROUGH 18Z FRIDAY...VFR CONDITIONS ARE EXPECTED THROUGH THE
PERIOD. AS HIGH PRESSURE BUILDS INTO THE REGION THIS EVENING SCT-
BKN VFR DECK OVER NE VT WILL EVENTUALLY CLEAR OUT TO SKC AND GUSTY
NW WINDS ACROSS THE REGION WILL ABATE. EXPECT A PERIOD OF SKC ACROSS
THE ENTIRE REGION 00-06Z...THEN MID/HIGH CLOUDS AT 10-15KFT MOVE
IN FROM THE WEST IN ADVANCE OF OUR NEXT SYSTEM.
OUTLOOK 12Z FRIDAY THROUGH MONDAY...
18Z FRI THRU 00Z SAT...VFR WITH CIGS SLOWLY LOWERING TO NEAR 5KFT.
00Z SAT THRU 00Z MON...MIX OF MVFR/VFR WITH PERIODS OF SHOWERS
ASSOCIATED WITH UPPER LOW PASSAGE.
00Z MON THRU 00Z TUE...MVFR TRENDING TO VFR AS UPPER LOW PULLS
AWAY FROM THE REGION.
00Z TUE THRU 00Z WED...VFR UNDER HIGH PRESSURE.
&&
.FIRE WEATHER...
AS OF 930 AM EDT THURSDAY...RED FLAG WARNING CONTINUES UNTIL 7 PM
THIS EVENING FOR PARTS OF CENTRAL/SOUTHERN VT AND EASTERN ESSEX
COUNTY NY.
FIRE WEATHER CONCERNS CONTINUE THIS AFTERNOON FOR ELEVATIONS BELOW
1500 FEET ACROSS THE SOUTHERN CHAMPLAIN VALLEY...AND PORTIONS OF
SOUTHERN VT...DUE TO THE COMBINATION OF THE RECENT DRY
SPELL...EXPECTED GUSTY WINDS...AND LOW MIN RH VALUES.
MOST THE CPV AND SOUTHERN VERMONT HAVE SEEN LESS THAN A QUARTER
INCH OF RAINFALL IN THE PAST FIVE DAYS...THIS HAS RESULTED IN
SIGNIFICANT DRYING OF THE FINE FUELS PER LOCAL FOREST CONTACTS
BELOW 1500 FEET...WHERE GREEN UP HAS NOT OCCURRED.
MEANWHILE...ABOVE 1500 FEET MOST OF THE FINE FUELS AND LEAF
LITTER IS COMPRESSED FROM RECENT SNOW PACK OR STILL WET. MOST OF
CENTRAL/NORTHERN VT MTNS AND NORTHERN NY HAVE RECEIVED MEASURABLE
PRECIP OVER THE PAST 2 TO 5 DAYS OR SNOW PACK IS STILL ON THE
GROUND ABOVE 2000 FEET...RESULTING IN LIMITED THREAT.
BREEZY WEST TO NORTHWEST WINDS OF 15 TO 25 MPH WITH GUSTS TO 35
MPH ARE EXPECTED ACRS THE HIGHER TRRN...PARTS OF THE CT RIVER
VALLEY...AND CHAMPLAIN VALLEY THIS AFTN.
IN ADDITION...MIN AFTN RH VALUES WL DROP BTWN 20% AND 30% ACRS
NRN NY...THE CPV AND SOUTHERN VT.
THESE CONDITIONS COMBINED WITH THE OVERALL DRYING OF
GRASSES...TWIGS...AND DEBRIS SUCH AS DEAD LEAVES FROM LAST FALL
WILL ALLOW ANY FIRES THAT DO OCCUR TO SPREAD QUICKLY...BURN
INTENSELY...AND BE DIFFICULT TO CONTAIN. PAY CLOSE ATTENTION TO
ANY OUTDOOR BURNING YOU MAY BE ATTEMPTING TODAY. MONITOR WEATHER
CONDITIONS...DO NOT LEAVE YOUR BRUSH OR DEBRIS PILE
UNATTENDED...AND HEED ANY ADVICE FROM YOUR LOCAL FIRE WARDEN.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR VTZ009>012.
NY...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR NYZ035.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...LAHIFF
AVIATION...LAHIFF
FIRE WEATHER...TABER/KGM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
321 PM EDT THU APR 24 2014
.SYNOPSIS...
HIGH PRESSURE OVER THE NORTH COUNTRY TONIGHT WILL RESULT IN
MAINLY CLEAR SKIES AND COOL TEMPERATURES. FRIDAY WILL START WITH
PLENTY OF SUNSHINE BUT CLOUDS WILL DEVELOP DURING THE AFTERNOON
HOURS WITH SHOWERS ARRIVING FOR FRIDAY NIGHT INTO SATURDAY.
TEMPERATURES WILL BE NEAR NORMAL FOR FRIDAY...BUT BELOW NORMAL
WITH CLOUDS AND SHOWERS ON SATURDAY INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 320 PM EDT THURSDAY...SFC HIGH PRES LOCATED OVER THE EASTERN GREAT
LAKES WL SHIFT INTO THE NORTH COUNTRY TONIGHT WITH CLRING SKIES
AND LIGHT TRRN DRIVEN WINDS DEVELOPING. RAP SOUNDINGS STILL SHOW
SOME ENHANCED RH AROUND 800MB...BUT THINKING ANY CLOUDS ASSOCIATED
WITH UPSLOPE FLW AND THIS MOISTURE WL QUICKLY DISSIPATE BY SUNSET.
GUIDANCE IS VERY COLD WITH SLK MAV/MET SHOWING READINGS OF
17/18...AND AROUND 29F FOR BTV. WL TREND A COUPLE DEGREES
HIGHER...BUT GIVEN VERY LOW SFC DWPTS AND LIGHT WINDS...THINKING
VALUES WL RANGE FROM THE UPPER 10S COLDER MTN VALLEYS/NEK TO M/U
20S ELSEWHERE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 320 PM EDT THURSDAY...MID/UPPER LVL RIDGE ACRS THE NE CONUS WL QUICKLY
SHIFT INTO EASTERN NEW ENGLAND BY 00Z SATURDAY...AS PROGRESSIVE
WESTERLY FLW ALOFT CONTS ACRS THE NORTHERN TIER OF THE UNITED
STATES. DEEP DRY LAYER AND STRONG SUBSIDENCE PER LATEST WATER
VAPOR TRENDS WL RESULT IN MOSTLY SUNNY SKIES ON FRIDAY
MORNING...BUT MID/UPPER LVL RH INCREASES AFT 18Z FROM SW TO NE.
BEST 850 TO 700MB OMEGA FIELDS AND ASSOCIATED RIBBON OF 850 TO
500MB RH >80% ARRIVES AFT 00Z SAT...SO WL KEEP FRIDAY DRY ATTM.
PROGGED 85H TEMPS RANGE FROM 0C NEK TO 4C SOUTHWEST
SLV...RESULTING IN TEMPS RANGING FROM THE L/M 50S NEK/MTNS TO L60S
SLV AND WARMER/UHI AREAS OF THE CPV.
FRIDAY NIGHT INTO SATURDAY...850 TO 500MB RH QUICKLY OVERSPREADS THE
FA WITH MODEST UVVS ASSOCIATED WITH 5H VORT AND DEVELOPMENT OF
MID/UPPER LVL TROF. STILL FEEL INITIAL 5H VORT AND MOISTURE WL
DISSIPATE ACRS OUR CWA ON FRIDAY NIGHT...WITH LEADING EDGE OF PRECIP
FALLING AS MOSTLY VIRGA...ESPECIALLY GIVEN VERY DRY LVLLS. BETTER
DYNAMICS AND DEEPER RH ARRIVES ASSOCIATED WITH CLOSED 5H/7H
CIRCULATION BTWN 06Z-12Z SATURDAY...WITH A BAND OF LIGHT TO MODERATE
RAIN ANTICIPATED. HAVE NOTED POCKETS OF COOLER PROGGED 85H TEMPS <0C
ACRS CENTRAL/NORTHERN VT/NEK ON SATURDAY MORNING...WHICH COULD
RESULT IN SOME WET SNOW IN THE MTN SUMMITS. COLD POOL ALOFT
ASSOCIATED WITH CLOSED SYSTEM MOVES DIRECTLY OVERHEAD ON
SATURDAY...WITH COOLING PROFILES ALOFT ANTICIPATED. THIS COMBINED
WITH SOME LIMITED SFC HEATING WL RESULT IN ADDITIONAL INSTABILITY
FOR MORE SCATTERED SHOWERS TO DEVELOP. BOTTOM LINE SAT WL BE COOL
AND DAMP WITH OCCASIONAL RAIN SHOWERS AND HIGH ELEVATION SNOW
SHOWERS LIKELY. TOTAL QPF WL RANGE BTWN 0.10 AND 0.50 OF AN INCH.
TEMPS WL RANGE FROM THE U30S/M40S NEK/MTNS TO M40S/L50S VALLEYS ON
SAT.
SATURDAY NIGHT...CLOSED MID/UPPER LVL CIRCULATION CONTS TO DEEPEN AS
SEVERAL EMBEDDED S/W`S INTERACT WITH THIS LARGE SYNOPTIC SCALE
SYSTEM. THIS WL SLOW OVERALL MOVEMENT OF SYSTEM DOWN WITH IT
BECOMING STATIONARY OFF THE NEW ENGLAND COASTLINE BY SAT NIGHT...AND
NUMEROUS RIBBONS OF MOISTURE ROTATING ACRS OUR CENTRAL/EASTERN CWA.
THIS COMBINED WITH DEVELOPING WEST TO NORTHWEST FLW WL RESULT IN
ADDITIONAL SHOWERS. GIVEN THE DEEPENING COLD POOL ALOFT AND
ASSOCIATED COOLING OF LLVL THERMAL PROFILES...THINKING SNOW LEVELS
WL DROP TO AROUND 2000 FT BY SUNDAY MORNING. HOWEVER...ACCUMULATIONS
SHOULD BE LIGHT. TEMPS WITH CLOUDS/WIND AND PRECIP WL HOLD MAINLY IN
THE 30S TO NEAR 40F...FAIRLY UNIFORMED ACRS OUR REGION.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 407 AM EDT THURSDAY...ECMWF AND GFS MODELS SHOW A CLOSED
UPPER LOW WILL BE OVER THE REGION SATURDAY NIGHT...SO WILL
CONTINUE WITH A CHANCE OF SHOWERS. THE CLOSED UPPER LOW WILL MOVE
EAST OF THE REGION BY SUNDAY...BUT THE FORECAST AREA WILL STILL
BE UNDER CYCLONIC FLOW...SO HAVE SLIGHT TO CHANCE POPS FOR
SHOWERS IN THE FORECAST FOR SUNDAY. EXPECTING MAINLY DRY
CONDITIONS SUNDAY NIGHT WITH JUST SOME SLIGHT CHANCE POPS FOR
SHOWERS OVER NORTHEAST VERMONT. A MAINLY DRY DAY ON MONDAY AS A
RIDGE OF HIGH PRESSURE BUILDS SOUTH FROM CANADA AND REMAINS OVER
THE REGION THROUGH MONDAY NIGHT.
ECMWF AND GFS MODELS SHOWING SOME MAJOR DIFFERENCES FOR THE
TUESDAY AND WEDNESDAY FORECAST. THUS...FORECASTER CONFIDENCE IS
LOW. ECMWF MODEL HAS A RIDGE OF HIGH PRESSURE AT THE SURFACE AND
ALOFT OVER THE REGION WITH A DRY FORECAST INDICATED FOR TUESDAY
AND WEDNESDAY... AS ECMWF MODEL SUGGESTING THE REGION WILL BE
UNDER AN OMEGA BLOCK WITH A CLOSED UPPER LOW OVER THE MID
MISSISSIPPI VALLEY WITH ANOTHER CLOSED UPPER LOW OVER THE
ATLANTIC SOUTH OF THE CANADIAN MARITIMES. HOWEVER...GFS MODEL
SHOWS A CLOSED UPPER LOW ALSO OVER THE MID MISSISSIPPI VALLEY
WITH THE OTHER CLOSED UPPER LOW MUCH FURTHER EAST IN THE ATLANTIC
THAN DEPICTED BY THE ECMWF MODEL. GFS MODEL BRINGS MOISTURE
NORTHEAST INTO THE REGION FROM THE SOUTHEASTERN U.S. TUESDAY AND
WEDNESDAY WITH A CHANCE OF SHOWERS. FOR NOW...WILL USE SUPER
BLEND POPS AND KEEP A CHANCE OF SHOWERS IN THE FORECAST FOR
TUESDAY AND WEDNESDAY...BUT GIVEN MODEL DIFFERENCES FORECASTER
CONFIDENCE IS LOW AT THIS TIME.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
THROUGH 18Z FRIDAY...VFR CONDITIONS ARE EXPECTED THROUGH THE
PERIOD. AS HIGH PRESSURE BUILDS INTO THE REGION THIS EVENING SCT-
BKN VFR DECK OVER NE VT WILL EVENTUALLY CLEAR OUT TO SKC AND GUSTY
NW WINDS ACROSS THE REGION WILL ABATE. EXPECT A PERIOD OF SKC ACROSS
THE ENTIRE REGION 00-06Z...THEN MID/HIGH CLOUDS AT 10-15KFT MOVE
IN FROM THE WEST IN ADVANCE OF OUR NEXT SYSTEM.
OUTLOOK 12Z FRIDAY THROUGH MONDAY...
18Z FRI THRU 00Z SAT...VFR WITH CIGS SLOWLY LOWERING TO NEAR 5KFT.
00Z SAT THRU 00Z MON...MIX OF MVFR/VFR WITH PERIODS OF SHOWERS
ASSOCIATED WITH UPPER LOW PASSAGE.
00Z MON THRU 00Z TUE...MVFR TRENDING TO VFR AS UPPER LOW PULLS
AWAY FROM THE REGION.
00Z TUE THRU 00Z WED...VFR UNDER HIGH PRESSURE.
&&
.FIRE WEATHER...
AS OF 930 AM EDT THURSDAY...RED FLAG WARNING CONTINUES UNTIL 7 PM
THIS EVENING FOR PARTS OF CENTRAL/SOUTHERN VT AND EASTERN ESSEX
COUNTY NY.
FIRE WEATHER CONCERNS CONTINUE THIS AFTERNOON FOR ELEVATIONS BELOW
1500 FEET ACROSS THE SOUTHERN CHAMPLAIN VALLEY...AND PORTIONS OF
SOUTHERN VT...DUE TO THE COMBINATION OF THE RECENT DRY
SPELL...EXPECTED GUSTY WINDS...AND LOW MIN RH VALUES.
MOST THE CPV AND SOUTHERN VERMONT HAVE SEEN LESS THAN A QUARTER
INCH OF RAINFALL IN THE PAST FIVE DAYS...THIS HAS RESULTED IN
SIGNIFICANT DRYING OF THE FINE FUELS PER LOCAL FOREST CONTACTS
BELOW 1500 FEET...WHERE GREEN UP HAS NOT OCCURRED.
MEANWHILE...ABOVE 1500 FEET MOST OF THE FINE FUELS AND LEAF
LITTER IS COMPRESSED FROM RECENT SNOW PACK OR STILL WET. MOST OF
CENTRAL/NORTHERN VT MTNS AND NORTHERN NY HAVE RECEIVED MEASURABLE
PRECIP OVER THE PAST 2 TO 5 DAYS OR SNOW PACK IS STILL ON THE
GROUND ABOVE 2000 FEET...RESULTING IN LIMITED THREAT.
BREEZY WEST TO NORTHWEST WINDS OF 15 TO 25 MPH WITH GUSTS TO 35
MPH ARE EXPECTED ACRS THE HIGHER TRRN...PARTS OF THE CT RIVER
VALLEY...AND CHAMPLAIN VALLEY THIS AFTN.
IN ADDITION...MIN AFTN RH VALUES WL DROP BTWN 20% AND 30% ACRS
NRN NY...THE CPV AND SOUTHERN VT.
THESE CONDITIONS COMBINED WITH THE OVERALL DRYING OF
GRASSES...TWIGS...AND DEBRIS SUCH AS DEAD LEAVES FROM LAST FALL
WILL ALLOW ANY FIRES THAT DO OCCUR TO SPREAD QUICKLY...BURN
INTENSELY...AND BE DIFFICULT TO CONTAIN. PAY CLOSE ATTENTION TO
ANY OUTDOOR BURNING YOU MAY BE ATTEMPTING TODAY. MONITOR WEATHER
CONDITIONS...DO NOT LEAVE YOUR BRUSH OR DEBRIS PILE
UNATTENDED...AND HEED ANY ADVICE FROM YOUR LOCAL FIRE WARDEN.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR VTZ009>012.
NY...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR NYZ035.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...WGH
AVIATION...LAHIFF
FIRE WEATHER...TABER/KGM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
556 PM CDT THU APR 24 2014
.UPDATE...
ISSUED AT 549 PM CDT THU APR 24 2014
EARLY EVENING UPDATE FOR MINOR CHANGES TO POPS ACROSS THE EAST AND
TEMPERATURE TRENDS. ISOLATED PEA SIZE HAIL WILL REMAIN POSSIBLE
WITH A FEW STORMS OVER THE NEXT HOUR OR SO BEFORE THE CONVECTION
MOVES EAST AND DISSIPATES. EXPECTING FOG AGAIN OVERNIGHT...MAINLY
ALONG THE EASTERN FRINGE OF THE FORECAST AREA...FROM THE TURTLE
MOUNTAINS THROUGH THE JAMES RIVER VALLEY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 329 PM CDT THU APR 24 2014
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP NORTH
CENTRAL NORTH DAKOTA THIS AFTERNOON. THE CURRENT AREA OF CONVECTION
IS IN AN ENVIRONMENT CHARACTERIZED BY 400 J/KG OF CAPE AND VERY
LITTLE WIND SHEAR. THEREFORE...THESE STORMS SHOULD REMAIN BELOW
SEVERE LIMITS. HOWEVER...SPC`S NON-SUPERCELL TORNADO PARAMETER
INDICATES THE POSSIBILITY OF COLD AIR FUNNELS OVER BOTTINEAU AND
MCHENRY COUNTIES. WOULD NOT BE SURPRISED TO GET FUNNEL CLOUD
REPORTS FROM THOSE AREAS IN THE NEXT HOUR OR SO. SCATTERED
SHOWERS ARE BEGINNING TO DEVELOP OVER NORTHWESTERN AND SOUTH
CENTRAL NORTH DAKOTA AS INSTABILITY INCREASES THIS AFTERNOON.
AFTER SUNSET...THE BOUNDARY LAYER SHOULD BEGIN TO STABILIZE AND
CONVECTIVE ACTIVITY SHOULD BEGIN TO WANE. VERY WEAK GRADIENT FLOW
ACROSS THE STATE SHOULD ALLOW FOR TEMPERATURES TO RADIATE INTO THE
30S. FURTHERMORE...THE LATEST HRRR AND RAP PROG FOG DEVELOPMENT FROM
THE TURTLE MOUNTAINS SOUTH THROUGH THE JAMES RIVER BASIN AFTER
MIDNIGHT. FOR NOW INDICATED PATCHY/AREAS OF FOG FOR SAID REGION
DURING THE 09Z-15Z FRIDAY PERIOD.
WEAK GRADIENT FLOW IS PROGGED TO CONTINUE FRIDAY. ANOTHER ROUND OF
INCREASING INSTABILITY IS FORECAST TO DEVELOP FRIDAY AFTERNOON.
HOWEVER...IT SHOULD NOT BE AS MUCH AS IS BEING OBSERVED THIS
AFTERNOON. WIND SHEAR WILL BE A LITTLE STRONGER FRIDAY AFTERNOON.
THE FAVORED AREA FOR CONVECTIVE DEVELOPMENT WILL BE OVER NORTHERN
NORTH DAKOTA. CONTINUED TO INDICATE A SLIGHT CHANCE OF SHOWERS
THERE FRIDAY AFTERNOON AS A RESULT.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 329 PM CDT THU APR 24 2014
A WET AND MUCH COOLER WEATHER PATTERN EVOLVES THROUGH THE LONG TERM
PERIOD. WATER VAPOR IMAGERY SHOWS A SHORTWAVE LOCATED NEAR 142W/43N
WITH AN UPSTREAM 300MB JET STREAK OF 160KT DIGGING THE SHORTWAVE
TROUGH SOUTHEAST WITH TIME. GOOD AGREEMENT AMONGST THE LONG TERM
MODELS WITH A SPLITTING TROUGH DEVELOPING ALONG THE WEST COAST BY
SATURDAY...AND THE SOUTHERN PORTION OF THE AFOREMENTIONED UPPER JET
AND SHORTWAVE TROUGH DEVELOPING INTO AN UPPER LOW OVER SOUTHWEST
CALIFORNIA. THIS LOW IS FORECAST TO CLOSE OFF OFF NEAR COLORADO
SUNDAY...THEN CIRCULATE INTO THE CENTRAL PLAINS AND UPPER MIDWEST
MONDAY THROUGH THURSDAY. THIS RESULTS IN PLENTY OF MOISTURE THIS
WEEKEND INTO EARLY NEXT WEEK WITH A COOLING TREND.
FOR FRIDAY NIGHT...700MB RIDGE AXIS SHIFTS EAST...STRETCHING FROM
NORTHERN NORTH DAKOTA INTO MINNESOTA. SOUTHWEST FLOW WITH SEVERAL
EMBEDDED SHORTWAVES APPROACH AND MOVE INTO WESTERN AND CENTRAL NORTH
DAKOTA. THIS WILL ALLOW RAIN TO DEVELOP WEST AND WEST CENTRAL NORTH
DAKOTA.
SATURDAY THROUGH TUESDAY...A MORE SOUTHERLY FLOW SETS UP AS THE
AFOREMENTIONED UPPER LOW DEVELOPS AND MOVES INTO THE CENTRAL PLAINS.
MID LEVEL SHORTWAVES WILL CONTINUE TO ALLOW FOR SUFFICIENT LIFT WITH
MOISTURE ALREADY IN PLACE. HAVE MAINTAINED A SLIGHT CHANCE OF
THUNDERSTORMS SATURDAY AFTERNOON. A MUCH WETTER SYSTEM ARRIVES
SUNDAY INTO MONDAY...AS THE MAIN UPPER CLOSED LOW AND ASSOCIATED
SURFACE LOW WITH AN INVERTED TROUGH IMPINGE INTO WESTERN AND CENTRAL
NORTH DAKOTA. THE RESULT WILL BE FOR SEVERAL PERIODS OF WIDESPREAD
RAINFALL. HIGH TEMPERATURES SUNDAY INTO TUESDAY WILL REMAIN IN THE
40S OVER MOST OF WESTERN AND CENTRAL NORTH DAKOTA.
FOR TUESDAY NIGHT THROUGH THURSDAY...AREAL COVERAGE OF SHOWERS WILL
DIMINISH TUESDAY NIGHT/WEDNESDAY...WITH DRY WEATHER FORECAST FOR
THURSDAY. HIGH TEMPERATURES WILL SLOWLY RISE INTO THE 50S BY
THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 549 PM CDT THU APR 24 2014
ISOLATED SHOWERS AND THUNDERSTORMS SHOULD END NEAR KJMS AROUND 01Z
THIS EVENING. EXPECTING MVFR FOG DEVELOPMENT AGAIN OVERNIGHT AT
KJMS...AND POSSIBLY KMOT. OTHERWISE...VFR CONDITIONS THROUGH THE PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE/AVIATION...RP KINNEY
SHORT TERM...TM
LONG TERM...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
329 PM CDT THU APR 24 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 329 PM CDT THU APR 24 2014
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP NORTH
CENTRAL NORTH DAKOTA THIS AFTERNOON. THE CURRENT AREA OF CONVECTION
IS IN AN ENVIRONMENT CHARACTERIZED BY 400 J/KG OF CAPE AND VERY
LITTLE WIND SHEAR. THEREFORE...THESE STORMS SHOULD REMAIN BELOW
SEVERE LIMITS. HOWEVER...SPC`S NON-SUPERCELL TORNADO PARAMETER
INDICATES THE POSSIBILITY OF COLD AIR FUNNELS OVER BOTTINEAU AND
MCHENRY COUNTIES. WOULD NOT BE SURPRISED TO GET FUNNEL CLOUD
REPORTS FROM THOSE AREAS IN THE NEXT HOUR OR SO. SCATTERED
SHOWERS ARE BEGINNING TO DEVELOP OVER NORTHWESTERN AND SOUTH
CENTRAL NORTH DAKOTA AS INSTABILITY INCREASES THIS AFTERNOON.
AFTER SUNSET...THE BOUNDARY LAYER SHOULD BEGIN TO STABILIZE AND
CONVECTIVE ACTIVITY SHOULD BEGIN TO WANE. VERY WEAK GRADIENT FLOW
ACROSS THE STATE SHOULD ALLOW FOR TEMPERATURES TO RADIATE INTO THE
30S. FURTHERMORE...THE LATEST HRRR AND RAP PROG FOG DEVELOPMENT FROM
THE TURTLE MOUNTAINS SOUTH THROUGH THE JAMES RIVER BASIN AFTER
MIDNIGHT. FOR NOW INDICATED PATCHY/AREAS OF FOG FOR SAID REGION
DURING THE 09Z-15Z FRIDAY PERIOD.
WEAK GRADIENT FLOW IS PROGGED TO CONTINUE FRIDAY. ANOTHER ROUND OF
INCREASING INSTABILITY IS FORECAST TO DEVELOP FRIDAY AFTERNOON.
HOWEVER...IT SHOULD NOT BE AS MUCH AS IS BEING OBSERVED THIS
AFTERNOON. WIND SHEAR WILL BE A LITTLE STRONGER FRIDAY AFTERNOON.
THE FAVORED AREA FOR CONVECTIVE DEVELOPMENT WILL BE OVER NORTHERN
NORTH DAKOTA. CONTINUED TO INDICATE A SLIGHT CHANCE OF SHOWERS
THERE FRIDAY AFTERNOON AS A RESULT.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 329 PM CDT THU APR 24 2014
A WET AND MUCH COOLER WEATHER PATTERN EVOLVES THROUGH THE LONG TERM
PERIOD. WATER VAPOR IMAGERY SHOWS A SHORTWAVE LOCATED NEAR 142W/43N
WITH AN UPSTREAM 300MB JET STREAK OF 160KT DIGGING THE SHORTWAVE
TROUGH SOUTHEAST WITH TIME. GOOD AGREEMENT AMONGST THE LONG TERM
MODELS WITH A SPLITTING TROUGH DEVELOPING ALONG THE WEST COAST BY
SATURDAY...AND THE SOUTHERN PORTION OF THE AFOREMENTIONED UPPER JET
AND SHORTWAVE TROUGH DEVELOPING INTO AN UPPER LOW OVER SOUTHWEST
CALIFORNIA. THIS LOW IS FORECAST TO CLOSE OFF OFF NEAR COLORADO
SUNDAY...THEN CIRCULATE INTO THE CENTRAL PLAINS AND UPPER MIDWEST
MONDAY THROUGH THURSDAY. THIS RESULTS IN PLENTY OF MOISTURE THIS
WEEKEND INTO EARLY NEXT WEEK WITH A COOLING TREND.
FOR FRIDAY NIGHT...700MB RIDGE AXIS SHIFTS EAST...STRETCHING FROM
NORTHERN NORTH DAKOTA INTO MINNESOTA. SOUTHWEST FLOW WITH SEVERAL
EMBEDDED SHORTWAVES APPROACH AND MOVE INTO WESTERN AND CENTRAL NORTH
DAKOTA. THIS WILL ALLOW RAIN TO DEVELOP WEST AND WEST CENTRAL NORTH
DAKOTA.
SATURDAY THROUGH TUESDAY...A MORE SOUTHERLY FLOW SETS UP AS THE
AFOREMENTIONED UPPER LOW DEVELOPS AND MOVES INTO THE CENTRAL PLAINS.
MID LEVEL SHORTWAVES WILL CONTINUE TO ALLOW FOR SUFFICIENT LIFT WITH
MOISTURE ALREADY IN PLACE. HAVE MAINTAINED A SLIGHT CHANCE OF
THUNDERSTORMS SATURDAY AFTERNOON. A MUCH WETTER SYSTEM ARRIVES
SUNDAY INTO MONDAY...AS THE MAIN UPPER CLOSED LOW AND ASSOCIATED
SURFACE LOW WITH AN INVERTED TROUGH IMPINGE INTO WESTERN AND CENTRAL
NORTH DAKOTA. THE RESULT WILL BE FOR SEVERAL PERIODS OF WIDESPREAD
RAINFALL. HIGH TEMPERATURES SUNDAY INTO TUESDAY WILL REMAIN IN THE
40S OVER MOST OF WESTERN AND CENTRAL NORTH DAKOTA.
FOR TUESDAY NIGHT THROUGH THURSDAY...AREAL COVERAGE OF SHOWERS WILL
DIMINISH TUESDAY NIGHT/WEDNESDAY...WITH DRY WEATHER FORECAST FOR
THURSDAY. HIGH TEMPERATURES WILL SLOWLY RISE INTO THE 50S BY
THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1251 PM CDT THU APR 24 2014
VFR CONDITIONS WILL PREVAIL OVER WESTERN AND CENTRAL NORTH DAKOTA
THROUGH THE TAF PERIOD. TEMPO MVFR CONDITIONS IN ISOLATED
THUNDERSTORMS WILL BE POSSIBLE OVER KMOT THIS AFTERNOON.
HOWEVER...AVIATION IMPACTS SHOULD BE MINIMAL AND BRIEF.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...TM
LONG TERM...KS
AVIATION...TM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
116 PM CDT THU APR 24 2014
.UPDATE...
ISSUED AT 111 PM CDT THU APR 24 2014
12Z NCEP MODELS AND LATEST RAP/HRRR STILL FOCUS A NARROW RIBBON OF
700 J/KG AND SHOWWALTERS -3C ALONG WITH NON-SUPERCELL TSTM
PARAMETERS OF GREATER THAN 2 IN AN AXIS FROM ROLLA THROUGH DEVILS
LAKE TO BTWN VALLEY CITY-FARGO TO JUST WEST OF WAHPETON. HOWEVER
CURRENT SPC MESO PAGE HAS NR 1000 MOST UNSTABLE CAPE IN SOUTHEAST
SASK AND STORMS ARE IN THAT AREA WITH SOME CAPE INTO FAR NW ND AND
A FEW ECHOES INTO THAT AREA. LATEST HRRR INDICATE STORMS IN THE
TURTLE MOUNTAIN REGION DEVELOPING SOUTHEAST ALONG AXIS MENTIONED
ABOVE IN THAT 21Z-01Z PERIOD. OTHER THAN THAT AREA OF SOLID RAIN
IN MINNESOTA WILL CONTINUE TO MOVE NORTH AND SLOWLY TAPER OFF IN
FAR WRN MN DURING THE AFTN. TIGHT TEMP GRADIENT WITH UPR 30S-LOW
40S EAST AND 50S WEST. REPORT OF WET SNOW MIXED WITH RAIN IN OTTER
TAIL COUNTY MN JUST BEFORE NOON IN POCKET OF HEAVIER PCPN. DONT
THINK THIS WILL LAST LONG UNLIKE LAST EVE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 330 AM CDT THU APR 24 2014
MANY CHALLENGES THROUGH THE SHORT AND INTO THE LONG TERM AS ACTIVE
AND AT TIMES COMPLEX PATTERN CONTINUES. CONSIDERING ACTIVE PATTERN
MODELS IN PRETTY GOOD AGREEMENT.
INTERESTING DAY AHEAD WITH TEMPERATURES...RAIN...THUNDERSTORM AND
ACCUMULATING SNOW POTENTIAL ALL CONTRIBUTING TO CHALLENGING
FORECAST. SUBSIDENCE IN THE WAKE OF SHORTWAVE LIFTING INTO CANADA
HAS DIMINISHED SHOWERS IN THE NEAR TERM. HOWEVER ELEVATED BOUNDARY
OVER THE CENTRAL DAKOTAS WILL PROPAGATE EAST ACROSS FA ALONG WITH
BAND OF FRONTOGENETIC FORCING AND WARM ADVECTION. GLOBAL AND
MESOSCALE MODELS ALL SUPPORT SHOWERS BECOMING MORE ORGANIZED FROM
VALLEY EAST THIS MORNING. PCPN AREA WILL THEN SHIFT EAST MAINLY ACROSS
WESTERN MN. IN THE WAKE OF THIS ELEVATED TROUGH DRYING WILL MOVE
INTO AREAS MAINLY WEST OF THE VALLEY AND COULD SEE SOME SOLAR
THERE WHICH WOULD HELP BOOST TEMPERATURES CLOSE TO AVERAGE WHERE
AREAS IN THE RAIN WILL LIKELY HOLD IN THE 40S. IN THE MEAN TIME
UPPER LOW AND ASSOCIATED COLD POOL WILL PROPAGATE SE REACHING FA
AT PRIME HEATING. WITH COLD POOL WILL SEE SOME PRETTY STEEP LAPSE
RATES ALONG WITH SUFFICIENT INSTABILITY AND AROUND 400J/KG OF
MIXED LAYER CAPE. ASSOCIATED SURFACE LOW WILL ALSO BE OVER FA AT
SAME TIME PROVIDING LOW LEVEL CONVERGENCE. SO EVEN WITH DRYING
ALLOWING PRECIPITABLE H2O VALUES TO DROP TO AROUND A HALF INCH
THERE WILL BE POTENTIAL FOR THUNDERSTORM DEVELOPMENT. WITH UPPER
AND SURFACE LOW OVER FA CANNOT RULE OUT POTENTIAL FOR A FEW SPIN-
UPS UNDER STRONGER STORMS.
TONIGHT COULD CONTINUE TO SEE SOME SPOTTY CONVECTION MAINLY EITHER
SIDE OF THE VALLEY UNTIL LOSS OF HEATING. BEST LIFT TONIGHT WILL
BE ACROSS THE FAR NE AHEAD OF SHARP SHEAR AXIS. WITH COLUMN COLD
ENOUGH WILL NEED TO MONITOR THE LAKE OF THE WOODS REGION FOR SOME
ACCUMULATING SNOW.
FRIDAY SHOULD BE RELATIVELY QUIET WITH ANY PCPN CONFINED TO THE NE
FA CLOSER TO DEPARTING SURFACE BOUNDARY. MODELS IN DISAGREEMENT ON
HOW FAR SOUTH COLDER AIR WILL SPREAD WITH GFS THE COLDEST. AT ANY
RATE LOOKS TO BE A RESPECTABLE NE-SW ORIENTED THERMAL GRADIENT
ACROSS THE FA WHICH WILL MAKE THE TEMPERATURE FORECAST TRICKY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 AM CDT THU APR 24 2014
ON SATURDAY BAND OF WARM ADVECTION LIFTS NORTH THROUGH THE WESTERN
FA AS NEXT AREA OF LOW PRESSURE ORGANIZES OVER THE CENTRAL HIGH
PLAINS. WITH GOOD MODEL AGREEMENT INCREASE POPS ACROSS THE WEST.
SURFACE LOW DEEPENS SATURDAY NIGHT OVER CENTRAL HIGH PLAINS AS
NEXT UPPER LOW CROSSES THE CENTRAL ROCKIES. WILL MAINTAIN CURRENT
POPS AS BROAD AREA OF ISENTROPIC LIFT AND LOWERING CONDENSATION
PRESSURE DEFICITS SETS UP.
SUNDAY-WEDNESDAY...HIGH LATITUDE BLOCKING WILL SET UP OVER EASTERN
CANADA...WITH AN INTENSE UPPER WAVE EXPECTED TO LIFT INTO THE
CENTRAL HIGH PLAINS ON SUNDAY BEFORE SLOWLY MEANDERING INTO THE
UPPER MISSISSIPPI VALLEY/GREAT LAKES FOR MID-WEEK. A MAIN SOURCE OF
UNCERTAINTY IS THE DETAILS OF THE EVOLUTION OF THE UPPER LOW AND
DOWNSTREAM RIDGE. MODELS SUGGEST DEEP RELATIVELY MOIST
SOUTH/SOUTHEAST FLOW UPSTREAM FROM THE RIDGE AXIS INTO THE NORTHERN
PLAINS WILL HELP TO PROMOTE WIDESPREAD PRECIPITATION IN THIS REGION
INTO EARLY NEXT WEEK...WITH DRIER AIR ASSOCIATED WITH SFC HIGH
PRESSURE OVER EASTERN CANADA POTENTIALLY INHIBITING PRECIP FARTHER
EAST FOR AT LEAST SOME TIME PERIOD...ESPECIALLY IF THE AMPLIFIED
UPPER RIDGE ENDS UP DISPLACED SLIGHTLY WEST. THERMAL FIELDS VARY
SOMEWHAT AMONG MODELS...BUT KEPT THE IDEA OF PRIMARILY RAIN DURING
THE DAYTIME HOURS WITH PERHAPS SOME MIXED SNOW AT NIGHT. TEMPS ARE
GENERALLY EXPECTED TO REMAIN ON THE COOL SIDE THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 111 PM CDT THU APR 24 2014
EXPECT LINGERING IFR CIGS AT GFK...BJI AND TVF TO SLOWLY RISE TO
MVFR CIGS THIS EARLY AFTN. EXPECT PREDOMINANT CONDS THROUGH
TOMORROW MORNING TO BE MVFR CIGS WITH SOME FLUCTUATIONS UP OR
DOWN. LOW CONFIDENCE THE CLEARING WE ARE SEEING AT FAR WILL REACH
GFK AND CERTAINLY NOT OUR MN TAF SITES. DVL...WHICH IS
CLEAR...SHOULD CU UP AND SEE A THREAT FOR TSTMS ACTIVITY THIS
AFTN. WITH FAR STILL OVC...DO NOT EXPECT CLEARING WILL ALLOW IT TO
HEAT SUFFICIENTLY FOR TSTMS TO GENERATE ALTHOUGH STORMS COULD
ADVECT IN FROM WEST. WILL NOT MENTION TS AT FAR AT THIS TIME.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...VOELKER
LONG TERM...MAKOWSKI/VOELKER
AVIATION...SPEICHER
SEE BELOW FOR AN UPDATED AVIATION FORECAST DISCUSSION.
THERE IS A COLD FRONT MOVING THROUGH THE CWA. THE LATEST RAPID
REFRESH GUIDANCE SHOWS IT SLOWING SOME OVERNIGHT AS THE NEXT WAVE
OF LOW PRESSURE DEVELOPING OVER SRN NEBRASKA LIFTS NEWD ALONG THE
FRONT. THE RAPID REFRESH MODEL ALSO SUGGESTS PRECIPITATION WITH
THIS NEXT WAVE SHOULD LIFT UP TOWARD THE REGION TOWARD 12Z
FRIDAY...AND LIKELY MISS MOST OF THE FAR EASTERN ZONES WITH ANY
ADDITIONAL PRECIPITATION.
WHILE SKIES PARTIALLY CLEAR AND WINDS RELAX WITHIN/NEAR THE
SLOWING SURFACE TROF...WENT AHEAD AND TOSSED IN SOME AREAS OF FOG
MENTION TO COVER ANY SURFACE MOISTURE LEFT OVER FROM THE PERIODS
OF LIGHT RAIN EARLIER IN THE DAY.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
COLD FRONT IS SLOWLY WORKING ITS WAY EAST ACROSS WESTERN SD AND IS
APPROACHING THE WESTERN FRINGE OF THE CWA. AHEAD OF THE
FRONT...STRONG SOUTHEAST WINDS CONTINUE...WELL INTO ADVISORY
LEVELS FOR MANY LOCATIONS. ALTHOUGH...AS PRESSURE GRADIENT RELAXES
A BIT WITH THE APPROACH OF THE SFC TROUGH...WE ARE SEEING A SUBTLE
AND SLOW DROP OFF IN SPEEDS OUT OF CRITERIA LEVELS FROM WEST TO
EAST. WILL LET THE JAMES VALLEY PORTION OF THE WIND ADVISORY
EXPIRE AT 21Z WITH THE REMAINING EASTERN AREA GOING UNTIL 00Z.
ASIDE FROM THE WIND...ALSO DEALING WITH SCT SHOWERS AHEAD OF THE
FRONT. AS WAS SUGGESTED BY THE HRRR AND OTHER HI RES MODELS...WE
ARE SEEING A BIT OF REDEVELOPMENT ALONG AND EAST OF THE MISSOURI
RIVER. SO...EXPECTING DECENT CHANCES FOR PRECIP YET THIS AFTERNOON
AND INTO THE EVENING HOURS BEFORE COLD FRONT SCOURS OUT MOST OF
THE AVAILABLE MOISTURE.
NEXT AREA OF CONCERN IS THE CRITICAL FIRE DANGER ON THURSDAY.
BEHIND THE COLD FRONT...DRY AIR MOVES BACK INTO THE REGION ALONG
WITH BREEZY NORTHWEST WINDS GUSTING OVER 30 MPH. MIN RH VALUES ARE
EXPECTED TO FALL CLOSE TO 20 PERCENT IN THE JAMES VALLEY WITH
VALUES LIKELY GOING BELOW 20 PERCENT ACROSS CENTRAL/SOUTH CENTRAL
SD. HAVE THEREFORE UPGRADED THE FIRE WEATHER WATCH TO A RED FLAG
WARNING EFFECTIVE FROM 18Z TO 00Z TOMORROW.
TEMPS STAY MILD THROUGH THE SHORT TERM...AND THERE HAS BEEN AN
UPWARD TREND IN TEMPS ON FRIDAY. GFS IS STILL STUBBORN IN BRINGING
COOLER TEMPS AT 850 MB INTO THE NORTHERN/EASTERN CWA DURING THE
DAY FRIDAY...SHOWING A BIT MORE INFLUENCE OF THE COOLER HIGH TO THE
NORTH. THIS REALLY IS NOT SUPPORTED BY OTHER MODELS THOUGH SO HAVE
GONE WITH THE WARMER SOLUTIONS SEEN IN THE EC AND GEM.
.LONG TERM...SATURDAY THROUGH WEDNESDAY
THE MODELS SHOW GOOD AGREEMENT IN THE LONG TERM WITH A MAINLY WET
AND COOL PATTERN FROM SATURDAY THROUGH MONDAY NIGHT. THE MODELS
SHOW A SURFACE LOW PRESSURE AREA INTENSIFYING IN EASTERN COLORADO
THROUGH SATURDAY AFTERNOON. THIS SURFACE LOW PRESSURE AREA THEN
WOBBLES AND MOVES SLOWLY EAST AND SOUTHEAST ACROSS THE CENTRAL
PLAINS THROUGH MONDAY NIGHT. DEEP AND MOIST EAST TO SOUTHEAST FLOW
NORTH OF THE LOW PRESSURE AREA WILL BRING MAINLY RAIN TO MUCH OF
OUR CWA STARTING SATURDAY AFTERNOON. THE CHANCES OF RAIN CONTINUE
TO BE GOOD THROUGH MONDAY NIGHT. IT LOOKS LIKE MUCH OF THE CWA
WILL GET SOME DECENT RAINFALL ACCUMULATIONS WITH THIS SYSTEM.
OTHERWISE...THE SYSTEM WILL SLOWLY PUSH OUT FOR TUESDAY AND
WEDNESDAY WITH COOL CANADIAN SURFACE HIGH PRESSURE BUILDING IN.
WITH THE RAIN...CLOUDS AND CANADIAN AIR TEMPERATURES WILL BE MUCH
BELOW NORMAL THROUGH THE ENTIRE LONG TERM. HIGHS WILL BE MOSTLY
IN THE 40S AND 50S THROUGH THE PERIOD.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
PRECIPITATION CHANCES ARE BASICALLY DONE AT KPIR/KMBG AND KABR.
HOWEVER...LATER TONIGHT INTO EARLY THURSDAY MORNING...ANOTHER
PIECE OF LOW PRESSURE ENERGY COULD POTENTIALLY GENERATE SOME LIGHT
PRECIPITATION AT THE KATY TERMINAL.
MEANWHILE...WEST OF THE COLD FRONT /KPIR AND KMBG/ THAT IS SLOWING
DOWN RIGHT NOW...VFR CONDITIONS SHOULD PREVAIL OVER THE NEXT 24
HOURS. EAST OF THE COLD FRONT KABR AND KATY...BUT ESPECIALLY
KATY...COULD SEE VFR CONDITIONS DETERIORATE INTO MVFR AND POSSIBLY
IFR STRATUS AND FOG MAINLY BETWEEN 09Z AND 15Z THURSDAY.
EVENTUALLY...THE COLD FRONT WILL PUSH EAST OF KABR AND KATY DRYING
THINGS OUT AS BREEZY WEST-NORTHWEST WINDS DEVELOP.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ THIS AFTERNOON TO 7 PM
CDT /6 PM MDT/ THIS EVENING FOR LOWER BAD RIVER-MISSOURI
COTEAU-UPPER CHEYENNE-UPPER JAMES RIVER-UPPER MISSOURI
COTEAU.
MN...NONE.
&&
$$
UPDATE...DORN
SHORT TERM...TMT
LONG TERM...MOHR
AVIATION...TDK
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1028 PM CDT FRI APR 25 2014
.UPDATE...
QUICK UPDATE TO THE FORECAST TO ADD A LITTLE MORE CLOUD COVER
EARLY SATURDAY MORNING...MAINLY TO THE SOUTHERN HALF OF THE CWA AS
STRONG MOISTURE RETURN CONTINUES. A LOOK AT THE LATEST NAM
GUIDANCE CONTINUES TO SHOW SEVERE CONVECTIVE POTENTIAL TOMORROW
AFTERNOON/EVENING ACROSS WEST CENTRAL TEXAS. NO CHANGES MADE TO
THE CURRENT CONVECTIVE FORECAST FOR TOMORROW INTO TOMORROW NIGHT.
THE RAP DOES SHOW SOME WEAKENING OF THE CAP EARLIER IN THE
AFTERNOON OUT WEST WHICH COULD LEAD TO A SLIGHTLY EARLIER
INITIATION TIME BUT OTHERWISE THE GENERAL THINKING IS UNCHANGED.
FOR SUNDAY...MODEL GUIDANCE IS IN GOOD AGREEMENT WITH MOVING THE
DRYLINE/FRONT EAST INTO SUNDAY MORNING...ACTUALLY BEHAVING MORE
LIKE A FRONT WITH COOLING TEMPERATURES BEHIND IT AT 850MB. IT IS
APPEARING MORE LIKELY THAT THIS FEATURE WILL BE ALONG OR EAST OF
I-35 BEFORE SURFACE BASED CONVECTION CAN DEVELOP ON SUNDAY. THE
HIGHEST THREAT FOR SEVERE WEATHER ON SUNDAY WILL BE ACROSS THE
EASTERN COUNTIES INTO THE ARKLATEX. SOME ELEVATED CONVECTION IS
EXPECTED TO BE ONGOING EARLY SUNDAY MORNING AND THIS COULD QUICKLY
BECOME SURFACE BASED BY EARLY AFTERNOON GENERALLY EAST OF I-35.
CURRENT FORECAST HANDLES THIS WELL AND NO CHANGES ARE NEEDED AT
THIS TIME.
DUNN
&&
.AVIATION...
MAIN CONCERN IN TAFS IS THE POTENTIAL FOR LOW CLOUDS TONIGHT AS
MOISTURE RETURNS TO THE REGION. SHARP MOISTURE GRADIENT EXPECTED
TO ARRIVE AFTER 8Z...WITH SURFACE DEWPOINTS SURGING INTO THE LOW
60S. SURFACE TEMPS SHOULD BE WARM ENOUGH TO LIMIT ANY ADVECTION
FOG...BUT LOW STRATUS APPEARS LIKELY FOR KACT AFTER 10Z...AND
PERHAPS EVENTUALLY AS FAR AS NORTH AS THE METROPLEX BY 12Z.
STRATUS SHOULD LIFT/SCATTER FAIRLY QUICKLY WITH SOME SUNSHINE AND
MIXING BY 15Z FOR THE METROPLEX TAFS AND BY 17Z FOR WACO. JUST
SOME FAIR WEATHER CUMULUS EXPECTED SATURDAY AFTERNOON WITH SOUTH
WINDS INCREASING TO NEAR 20KT AND GUSTY.
ANY THREAT OF CONVECTION WILL BE BEYOND TAF PERIOD...WITH BEST
WINDOW FOR METROPLEX SITES SHAPING UP AROUND DAYBREAK SUNDAY.
TR.92
&&
.SHORT TERM/THOUGH MONDAY/...
A STRONG UPPER LOW CONTINUES MOVING INLAND OVER THE WESTERN STATES
WITH A SHORTWAVE RIDGE ACROSS NORTH AND CENTRAL TEXAS LINGERING
THROUGH TONIGHT. THIS SYSTEM IS A WAYS OFF WITH A SUBSTANTIAL CAP
THAT SHOULD KEEP THE WEATHER DRY TONIGHT AND THROUGH THE DAY
SATURDAY. BREEZY SOUTH WINDS AND RAPIDLY INCREASING DEW POINTS
FROM THE TEXAS COASTAL AREAS ARE EXPECTED TO HOLD LOWS TONIGHT
BETWEEN 55 AND 66 DEGREES WITH HIGHS WARMING WELL INTO THE 80S
SATURDAY AND EVEN THE LOWER 90S ACROSS THE WEST. IF YOU WANT TO
ENJOY PART OF THE WEEKEND AND BE OUTDOORS...SATURDAY IS YOUR BEST
BET.
SATURDAY NIGHT THROUGH SUNDAY EVENING IS EXPECTED TO BE AN ACTIVE
PERIOD WEATHER-WISE...AS LEAD SHORTWAVE ENERGY BEGINS NEGATIVELY
ROTATING THROUGH THE FOUR CORNERS AND OVER THE WESTERN HIGH
PLAINS BY SUNRISE SUNDAY. RAPID HEIGHT FALLS MOVING OUT OF THE
ROCKIES WILL HELP DEEPEN A SURFACE DRYLINE ACROSS THE SOUTH PLAINS
AND TEXAS PANHANDLE THROUGH SATURDAY EVENING. IT WILL LIKELY TAKE
UNTIL LATE AFTERNOON OR NEAR 00Z BEFORE A FEW DISCRETE STORMS
INITIATE FROM NORTHWEST OF ABILENE AND UP THROUGH CHILDRESS AND
SOUTHWEST OKLAHOMA...VERY FAST SSW FLOW STEERING THE MAJORITY OF
ACTIVITY TO THE NORTHEAST. THE DRYLINE SHOULD BEGIN TRANSVERSING
EAST THROUGH THE EVENING HOURS WITH ISOLATED TO SCATTERED STORMS
POSSIBLY ENTERING OUR FAR W/NW COUNTIES BEFORE MIDNIGHT. IN
ADDITION...SURFACE-BASED STORMS WILL REMAIN POSSIBLE MOST OF THE
EVENING WITH ALL MODES OF SEVERE WEATHER POSSIBLE WITH ANY
SUPERCELLS BEFORE AN INCREASING LLJ OVERNIGHT AND WAA HELP RE-
INTENSIFY THE CAPPING INVERSION WITH CONVECTION EXPECTED TO BE
ELEVATED OVERNIGHT AND THROUGH THE SUNRISE HOURS SUNDAY. STORM
CHANCES SHOULD BE HIGHEST ACROSS THE NORTHERN COUNTIES WHERE BULK OF
FORCING FROM ENHANCED ELEVATED WAA AND FASTER EASTWARD PROGRESSION
OF THE SURFACE DRYLINE WILL OCCUR. DESPITE THE ELEVATED NATURE OF
STORMS...VERY STEEP LAPSE RATES BETWEEN 850-650MB WILL ALLOW FOR
PLENTY OF MUCAPE IN THE HAIL GROWTH ZONE. HAVE LEFT SEVERE MENTION
IN FOR THE OVERNIGHT PERIOD FOR THE POTENTIAL OF SOME LARGER HAIL.
THE CHALLENGES CONTINUE AS WE MOVE THROUGH THE DAY SUNDAY AS THE
STRONG SHORTWAVE TROUGH CONTINUES TO NEGATIVELY TILT OVER CENTRAL
HIGH PLAINS. THE STRONG WEST- SOUTHWEST COMPONENT ATOP THE APPROACHING
SURFACE DRYLINE WILL HELP MOVE IT EAST FASTER ACROSS NORTH TEXAS
VERSUS FURTHER SOUTH OVER OUR CENTRAL TEXAS COUNTIES THROUGH EARLY
AFTERNOON. MODELS STILL SHOW A VARIANCE OF THE DRYLINE POSITION
SUNDAY AFTERNOON WITH AS FAR WEST AS I-35/35E...TO AS FAR EAST AS
I-45 UP THROUGH I-30. WITH THIS IN MIND...HAVE ORIENTED POPS NE-SW
ALONG THE DRYLINE WITH HIGHEST CHANCES FOR SEVERE SUPERCELL STORMS
OCCURRING MAINLY EAST OF A BONHAM-TERRELL-HEARNE LINE. THE VERY
WARM TEMPERATURES AND HIGH DEW PTS PRODUCING SBCAPE VALUES OF
2500-3500 J/KG EAST OF THE DRYLINE AND WESTERLY EFFECTIVE SHEAR
VALUES 30-35 KTS WITH SOUTHERLY 0-1KM SHEAR 20 KTS+...SURFACE-
BASED STORMS SHOULD ALLOW FOR ALL POSSIBLE MODES OF SEVERE WEATHER
INCLUDING A FEW TORNADOES. THE WINDOW FOR SEVERE WEATHER LOOKS TO
BE EARLY AFTERNOON THROUGH EARLY EVENING...WHEN BETTER FORCING
BOTH SURFACE AND ALOFT SHOULD SHIFT EAST OUT OF THE AREA TOWARD
THE MODERATE RISK AREA ACROSS THE ARKLATEX.
WINDY AND WARM CONDITIONS WILL LIKELY RAMP UP THE FIRE DANGER ACROSS
THE WESTERN TWO THIRDS OF THE AREA WITH MINIMUM HUMIDITY VALUES
FALLING BELOW 20 PERCENT. GREEN UP OF GRASSES AND LIGHTER WINDS ON
SUNDAY SHOULD KEEP THE FIRE DANGER ONLY AT ELEVATED LEVELS. WE
MAY HAVE TO WATCH FOR HIGH TO CRITICAL FIRE WEATHER CONDITIONS FOR
MONDAY AFTERNOON WITH MORE GUSTIER WEST WINDS.
&&
.LONG TERM/MON NIGHT AND BEYOND/...
THE FIRST OF A COUPLE OF LATE SEASON COLD FRONTS ARRIVES MONDAY
NIGHT WITH SLIGHTLY COOLER TEMPERATURES ON TUESDAY. IT APPEARS IT
WILL BE A RELATIVELY BENIGN WEEK FOR THE SOUTHERN PLAINS WITH THE
UPPER LOW OVER THE PLAINS BEING HELD UP BY SEMI OMEGA BLOCKING
UPPER HIGH OVER EASTERN CANADA. THE UPPER LOW WILL ONLY MIGRATE
SLOWLY NORTHEAST TOWARD THE GREAT LAKES THROUGH THE END OF THE
WEEK. THIS SHOULD ALLOW FOR PERIODIC FRONTAL PASSAGES AND KEEP A
NORTH COMPONENT TO THE WIND AND A DRY AIRMASS IN PLACE THROUGH
MUCH OF THE WEEK AND KEEP TEMPERATURES 5-10 DEGREES BELOW NORMALS.
IT APPEARS MOISTURE WILL BE TOO SHALLOW AND SCANT WITH A STRONG
SHORTWAVE ROTATING ACROSS TEXAS THURSDAY INTO FRIDAY AND HAVE LEFT
A DRY FORECAST FOR NOW ALL THE WAY INTO NEXT WEEKEND.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 61 86 69 90 61 / 0 5 40 40 5
WACO, TX 62 85 68 90 55 / 0 5 20 30 5
PARIS, TX 54 85 67 80 56 / 0 5 40 70 30
DENTON, TX 60 85 68 87 55 / 5 5 60 40 5
MCKINNEY, TX 58 85 68 87 56 / 0 5 50 50 10
DALLAS, TX 61 87 69 90 62 / 0 5 40 50 5
TERRELL, TX 58 85 68 84 54 / 0 5 30 50 10
CORSICANA, TX 60 84 68 85 57 / 0 5 20 50 10
TEMPLE, TX 63 86 69 89 57 / 0 10 20 30 5
MINERAL WELLS, TX 61 88 69 88 55 / 5 10 50 20 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
730 PM CDT FRI APR 25 2014
.DISCUSSION...THE PAST SEVERAL RUNS OF THE HRRR HAVE CONTINUED TO
INDICATE THAT SOME OF THE ONGOING SIERRA MADRE CONVECTION MAY
AFFECT WESTERN PORTIONS OF WEBB COUNTY LATER THIS EVENING BEFORE
EVENTUALLY DISSIPATING IN AN INCREASINGLY CAPPED ENVIRONMENT.
CURRENT RADAR TRENDS LEAD CREDENCE TO THE HRRR. WL THUS INTRODUCE
SLIGHT CHC POPS FOR WESTERN WEBB COUNTY FOR THIS EVENING.
OTHERWISE...MOSTLY MINOR CHANGES WERE MADE FOR THIS EVENING
PACKAGE BASED UPON CURRENT AND EXPECTED TRENDS. MORE WIND TNT WL
KEEP FOG FROM GETTING TOO WIDESPREAD AND TOO LOW VSBY-WISE.
&&
.MARINE...THE OVERALL GRADIENT HAS INCREASED FROM 24 HOURS AGO BUT
IS STILL EXPECTED TO REMAIN BELOW SCA THRESHOLDS FOR TNT. DID
LOWER THE WAVEHEIGHTS BY AROUND 1 FOOT FROM THE PREVIOUS PACKAGE
FOR TONIGHT AND SATURDAY. AN INCREASING GRADIENT/LLJ IN RESPONSE
TO AN APPROACHING STRONG S/WV CURRENTLY MOVING THROUGH CALIFORNIA
WL PRODUCE SCA CONDITIONS FOR THE SRN BAYS SATURDAY AFTN AND MOST
AREAS SAT NIGHT INTO SUNDAY.
&&
.PREV DISCUSSION... /ISSUED 632 PM CDT FRI APR 25 2014/
DISCUSSION...SEE AVIATION SECTION FOR 00Z TAFS.
AVIATION...OTHER THAN SOME SPOTTY MVFR CEILINGS NEAR THE COAST...VFR
CONDITIONS WILL CONTINUE OVER THE REGION DURING THE EARLY EVENING HOURS.
EXPECT STRATUS/MVFR CEILINGS AROUND 1500 FEET TO DEVELOP OVER THE COASTAL
PLAINS 03-04Z. CEILINGS ARE EXPECTED TO LOWER TO IFR FROM 06-07Z WITH
MVFR VSBYS WITH FOG OVER COASTAL SITES. OCCASIONAL IFR VSBYS WILL BE
POSSIBLE OVER THE VICTORIA CROSSROADS BEFORE SUNRISE. MVFR CIGS WILL
SPREAD WEST INTO LAREDO AREA BY 08Z AND PERSIST UNTIL 16Z SATURDAY.
WILL CONTINUE TO MONITOR ISOLATED CONVECTION THAT DEVELOPED OVER THE
HIGHER TERRAIN IN NORTHEAST MEXICO AHEAD OF A WEAK UPPER LEVEL
DISTURBANCE. ADVECTION OF DRIER AIR IN THE LOWER LEVELS SHOULD INHIBIT
ACTIVITY FROM REACHING THE RIO GRANDE LATER THIS EVENING. MVFR CIGS
WILL PERSIST THROUGH THE MORNING WITH CLOUDS SCATTERING OUT FOR MOST
OF THE REGION EXCEPT FOR THE COASTAL BEND WHERE MVFR CIGS MAY PERSIST
THROUGH THE AFTERNOON.
PREV DISCUSSION... /ISSUED 323 PM CDT FRI APR 25 2014/
SHORT TERM...25 TO 30 KT LLJ EXPECTED TO DEVELOP TONIGHT IN RESPONSE
TO A DEEPENING LOW PRESSURE SYSTEM OVER THE HIGH PLAINS. THIS...IN
COMBINATION WITH AMPLE MOISTURE TO AID IN NOCTURNAL STRATUS
DEVELOPMENT...SHOULD PREVENT MUCH IN THE WAY OF FOG DEVELOPMENT
TONIGHT...THOUGH WIDESPREAD LOW STRATUS IS LIKELY. AFTER THE CLOUD
DECK BURNS OFF...TOMORROW WILL SEE TEMPS ABOVE AVERAGE...BECOMING
DOWNRIGHT TOASTY OVER THE WESTERN BRUSH COUNTRY AS A DRYLINE
CROSSES THE RIO GRANDE IN THE AFTERNOON WITH NEAR TRIPLE DIGIT
HIGHS. BY LATE AFTERNOON...UPPER LEVEL DIFLUENCE FROM THE PHASING
OF THE POLAR AND SUBTROPICAL JETS WILL BEGIN TO AFFECT THE REGION.
30-40 KT 0-6 KM BULK SHEAR...2000-3000 J/KG OF MLCAPE...AND
MODERATE HELICITY VALUES MAY ALLOW FOR SOME STRONG THUNDERSTORMS
TO DEVELOP...PARTICULARLY DEVELOPING OFF OF THE SIERRA MADRE AND
CROSSING THE RIO GRANDE. THE STORM ENVIRONMENT LOOKS TO BE
SLIGHTLY LESS FAVORABLE NEAR THE COAST...BUT HAVE STILL INCLUDED
MUCH OF THE AREA WITH 20 POPS. THE ENVIRONMENT WILL REMAIN
FAVORABLE OVERNIGHT.
LONG TERM (SUNDAY THROUGH FRIDAY)...PERIOD COULD BEGIN ACTIVE WITH
THUNDERSTORMS /POSSIBLY MCS/ MOVING EASTWARD THROUGH THE CWA AS
THETA E RIDGE PROGRESSES EASTWARD. MOST OF THE AREA SHOULD BE CAPPED
WITH 850 TEMPS 20 DEGREES OR HIGHER...BUT IF CONVECTION DEVELOPS IT
MAY SUSTAIN ITSELF INTO NORTHEASTERN PARTS OF CWA.
DRYLINE MOVES THROUGH MUCH OF THE AREA ON SUNDAY WITH TEMPERATURES
VERY WARM...INTO THE 90S FOR MOST OF THE AREA...WITH ABOVE 100
DEGREES POSSIBLE ALONG THE RIO GRANDE. THIS IS DEPENDENT THOUGH ON
ANY LINGERING MID/HIGH CLOUD THAT COULD BE LEFTOVER FROM POTENTIAL
MCS SATURDAY NIGHT/SUNDAY. MONDAY HAS SIMILAR SETUP...BUT WITHOUT
THE CAVEAT OF MID/HIGH CLOUDS. SHOULD SEE HOT TEMPERATURES BEHIND
DRYLINE THAT WILL MOVE THROUGH MOST OF THE AREA.
TRICKY TEMPERATURES FOR TUESDAY WITH COLD FRONT TIMING AROUND NOON.
WILL SEE SOME /THOUGH NOT SIGNIFICANT/ COLD ADVECTION BEHIND THE
FRONT...SO THINK TEMPS SHOULD BE SEVERAL DEGREES COOLER THAN
MONDAY...THOUGH STILL IN THE 90S UNLESS TIMING SPEEDS UP. MOISTURE
POOLING ALONG AND OFF THE COAST WILL PRODUCE A SLIGHT CHANCE FOR
SHOWERS AND THUNDERSTORMS MAINLY IN OFFSHORE AREAS TUESDAY WITH THE
FRONT.
COLD FRONT SHOULD KNOCK TEMPERATURES BACK INTO THE 80S FOR THE
FOLLOWING FEW DAYS WITH MUCH DRIER CONDITIONS AS DPTS DROP TO MUCH
MORE PLEASANT LEVELS /40S AND 50S/. ONSHORE FLOW REDEVELOPS LATE
THURSDAY AND WILL BRING A GRADUAL INCREASE IN MOISTURE FOR FRIDAY.
MODELS NOT IN GOOD AGREEMENT FOR FRIDAY...BUT MODELS HINTING AT
ANOTHER UPPER TROUGH FOR FRIDAY INTO THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 71 88 73 94 71 / 10 10 20 20 10
VICTORIA 69 87 71 88 69 / 10 10 20 30 10
LAREDO 73 99 73 101 71 / 10 20 30 10 10
ALICE 71 93 73 97 70 / 10 10 30 20 10
ROCKPORT 71 81 71 82 72 / 10 10 20 30 10
COTULLA 69 95 71 98 68 / 10 20 30 10 10
KINGSVILLE 72 91 73 96 71 / 10 10 20 20 10
NAVY CORPUS 72 83 73 83 72 / 10 10 20 20 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
MB/80...SHORT TERM
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1156 PM CDT WED APR 23 2014
.DISCUSSION...
SEE THE 06Z AVIATION DISCUSSION BELOW.
40
&&
.AVIATION...
MOISTURE ADVECTION WILL CONTINUE OVERNIGHT TONIGHT AND THURSDAY
MORNING. MODEL SOUNDINGS FORECAST AN IFR DECK FORMING BY AROUND
09Z AND LIFTING AROUND OR SHORTLY AFTER 15Z...ALTHOUGH THE
CEILINGS MAY BE SLOWER TO LIFT AND SCATTER OUT LATER IN THE
MORNING. BEST CHANCES FOR ISOLATED THUNDERSTORMS STILL LOOK TO BE
AT KCLL AND KUTS BETWEEN 21Z AND 03Z. THE MODELS ARE SHOWING A
WIND SHIFT MOVING INTO SE TX THURSDAY EVENING. MVFR FOG CONDITIONS
ARE POSSIBLE AHEAD OF THE WIND SHIFT BY LATE THURSDAY EVENING.
40
&&
.PREV DISCUSSION... /ISSUED 909 PM CDT WED APR 23 2014/
UPDATE...
SEE EVENING UPDATE.
DISCUSSION...
NOT MANY CHANGES PLANNED FOR THE EVENING UPDATE. AT 01Z...A DEEP
SURFACE LOW PRESSURE SYSTEM WAS LOCATED OVER WESTERN KANSAS WITH A
WEAK TROUGH AXIS EXTENDING S-SW. THE PRESSURE GRADIENT IS FAIRLY
TIGHT SO NOT EXPECTING WINDS TO DECOUPLE OVERNIGHT. WINDS JUST OFF
THE SURFACE ARE ALSO ROBUST SO FEEL FOG THREAT IS LESS THAN LAST
NIGHT. STORMS ARE FIRING ALONG THE SFC TROUGH AND THESE STORMS
WILL STAY WEST OF THE REGION BUT THEY WILL SEND A THICK CIRRUS
SHIELD THIS WAY. LOW CLOUDS WILL ALSO BE ON THE INCREASE OVERNIGHT
SO BETWEEN THE TWO CLOUD DECKS...FEEL THERMAL INSULATION WILL
KEEP MIN TEMPS A LITTLE WARMER THAN LAST COUPLE OF NIGHTS. TWEAKED
MIN TEMP GRIDS A BIT.
ON THURSDAY...A WEAK S/WV WILL MOVE EAST ACROSS NORTH TEXAS. FCST
SOUNDINGS SUGGEST A STRONG CAPPING INVERSION WILL REMAIN IN PLACE.
THE TEXAS TECH 3 KM WRF AND THE RAP DEVELOP SOME CONVECTION OVER
CENTRAL TEXAS AND MOVE THIS AREA ACROSS SE TX AROUND 18Z. THE
ECMWF IS QUITE BULLISH WITH POPS OVER THE NE PART OF THE AREA
DURING THE AFTN. THE ECMWF HAS THE BEST JET DYNAMICS AS WELL WITH
A SPLITTING JET AND A RRQ. 00Z NAM12 STILL KEEPING THE AREA CAPPED
ON THURSDAY. THINK THE CURRENT FCST WITH 20 POPS OVER THE NORTH
IS STILL VALID. NEW ZONES OUT BY 915 PM. 43
PREV DISCUSSION... /ISSUED 626 PM CDT WED APR 23 2014/
DISCUSSION...
GOOD MOISTURE ADVECTION COUPLED WITH A TIGHT PRESSURE GRADIENT AND
A LOW-LEVEL INVERSION WILL LEAD TO THE WINDS STAYING UP AND AN IFR
LAYER FORMING TONIGHT. THE TIME PERIOD FORECASTED BY THE MODELS
FOR IFR WAS BETWEEN 09Z AND 14Z...ALTHOUGH THE MOISTURE LAYER WILL
BE FAIRLY SHALLOW. THE INVERSION SHOULD BREAK AND ALLOW FOR MIXING
TO SCATTER OUT THE CLOUD DECK MID MORNING THURSDAY. LIKED THE GFS
IN BRINGING IN CHANCES FOR ISOLATED THUNDERSTORMS TO KCXO...
KCLL...AND KUTS THURSDAY AFTERNOON. FOR NOW WENT WITH A VCTS
MENTION AT ALL THREE SITES.
40
PREV DISCUSSION... /ISSUED 349 PM CDT WED APR 23 2014/
DISCUSSION...
WARM AFTERNOON ACROSS THE REGION TODAY (83-88 INLAND) WITH MOIST
S-SE FLOW IN PLACE. UPPER RIDGING OVER THE AREA THIS MORNING WILL
CONTINUE TO SLIDE EAST TONIGHT WITH A LARGE UPPER TROUGH OVER THE
WESTERN HALF OF THE COUNTRY. THIS UPPER TROUGH WILL LIFT NORTHEAST
INTO THE PLAINS AND S/W ENERGY ROTATES UP OVER THE RED RIVER WHICH
WILL PROBABLY BE TOO FAR NORTH FOR SETX TO MUCH IN THE WAY OF
RAINFALL EXCEPT PERHAPS THE FAR NORTH THURSDAY. THE ASSOCIATED
MILD PACIFIC COLD FRONT SWINGS INTO THE NORTHERN CWA LATE THURSDAY
AND STALLS WITH A GOOD CAP IN PLACE. WHICH SHOULD BRING SOME DRIER
AIR ALBEIT BRIEFLY BEFORE SE TO SOUTH FLOW INCREASES.
THIS MOIST FLOW WILL LIKELY LEAD TO A ROUND OF WIDESPREAD STRATUS
AND POSSIBLY SOME PATCHY FOG TONIGHT AND AGAIN FRIDAY WITH FOG
THREAT A LITTLE GREATER FRIDAY WITH DRIER AIR IN THE NORTH AND
NOTICEABLE DEWPOINT GRADIENT ACROSS THE AREA WITH GREATER
RADIATIONAL COOLING POTENTIAL.
SATURDAY WARM AND MOIST AND AS NEXT TROUGH MOVES INTO NM SUNDAY
MORNING RAIN CHANCES INCREASE WITH LLJ OVERHEAD AND NEARLY
SPLITTING UPPER JET BUT MAY BE TOO CAPPED. BY MONDAY MORNING THE
PACIFIC FRONT IS PUSHING EAST INTO THE REGION AND INCREASING PVA
AND SLIGHTLY MORE FAVORABLE UPPER JET MAY GIVE THE AREA THE BEST
CHANCE OF RAIN BUT FOR NOW WILL KEEP IT AT 30 NORTH EARLY THEN
TAPERING DOWN TO 20S BY AFTERNOON. STILL PLENTY OF TIME FOR MODELS
TO FLIP FLOP ON TIMING AND TRACK OF THE UPPER LOW (WHICH MAY BE
FURTHER NORTH). DRY AIR WRAPS AROUND AS FRONT PUSHES THROUGH
TUESDAY AND SLIGHTLY COOLER WEATHER (AROUND NORMAL TO JUST
SLIGHTLY BELOW NORMAL) SHOULD PREVAIL WED/THU/FRI.
45
MARINE...
LIGHT TO MODERATE ONSHORE FLOW WILL CONTINUE THROUGH THE END OF
THE WEEK. WINDS AND SEAS WILL BEGIN TO BUILD THIS WEEKEND AS THE
PRESSURE GRADIENT TIGHTENS ACROSS THE STATE. CAUTION FLAGS ARE
POSSIBLE AS EARLY AS SATURDAY AFTERNOON WITH ADVISORY CONDITIONS
LIKELY BY SUNDAY. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 66 85 65 85 66 / 20 20 10 10 10
HOUSTON (IAH) 65 84 66 84 67 / 10 10 10 10 10
GALVESTON (GLS) 69 76 68 78 69 / 10 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
802 PM EDT FRI APR 25 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE EAST ACROSS THE REGION THIS EVENING
BRINGING AN END TO THE ONGOING SHOWERS AND STORMS. HIGH PRESSURE
WILL MOVE ACROSS THE MID ATLANTIC AND SOUTHEAST STATES THIS
WEEKEND INTO EARLY NEXT WEEK. A SLOW MOVING COMPLEX STORM SYSTEM
WILL AFFECT THE REGION BY THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 405 PM EDT FRIDAY...
WATER VAPOR LOOP SHOWED COMPACT UPPER LOW OVER NORTHERN WEST
VIRGINIA...MOVING EAST-NORTHEAST. THE ASSOCIATED SURFACE LOW WAS
OVER LAKE ERIE AT 3PM...WITH A FRONT EXTENDING INTO WESTERN NORTH
CAROLINA THEN INTO LOUISIANA. THIS FRONT WILL CONTINUE TO MOVE
EAST THIS EVENING...LOCAL WRF AND LATEST HRRR GUIDANCE HAS FRONT
AND THE BANDS OF SHOWERS AND THUNDERSTORMS AHEAD OF THE BOUNDARY
EAST OF THE FORECAST AREA BY 02Z/10PM.
THE MOST UNSTABLE AIR AND THE REGION WITH THE HIGHEST STORM
RELATIVE HELICITY IS EAST OF LYNCHBURG AND DANVILLE. THE THREAT OF
SEVERE WEATHER IS TRANSITIONING FROM DISCRETE ROTATING STORMS MORE
TO LINES AND BOWING SEGMENTS AS THE COLD FRONT ENCOUNTERS THE
FAVORABLE ENVIRONMENT.
BEHIND THE COLD FRONT MODEL WERE SHOWING 40 TO 50 KNOT 850 MB
WINDS AND SOME DECENT PRESSURE RISES THROUGH EARLY SATURDAY
MORNING. A FEW SPOTS AT THE HIGHEST ELEVATIONS MAY GET CLOSE TO
ADVISORY CRITERIA BUT DO NOT EXPECT IT TO BE WIDESPREAD ENOUGH FOR
A HEADLINE.
THE AIR MASS COMING IN BEHIND IS NOT MUCH COOLER...BUT SURFACE DEW
POINTS WILL DROP BACK INTO THE 30S AND 40S. EXPECT CLOUD COVER TO
CLEAR OUT SHORTLY AFTER THE FRONT GOES THROUGH IN ALL BUT THE FAR
NORTHWEST COUNTIES OF THE FORECAST AREA.
A SECONDARY FRONT DROPS DOWN INTO THE FORECAST AREA TOMORROW.
DEEPEST MOISTURE AND THREAT OF SHOWERS AND REMAIN IN THE FAR
NORTHERN COUNTY WARNING AREA.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM EDT FRIDAY...
WEAK HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE NORTH SAT
NIGHT AS A RESIDUAL WEAK BOUNDARY WASHES OUT AND SHORTWAVE
RIDGING STARTS TO TAKE CONTROL. MAY SEE A RENEGADE -SHRA ACROSS
THE EXTREME NW SAT EVENING OTRW MAINLY CLEAR OVERNIGHT. OMEGA
BLOCK ALOFT GAINS AMPLITUDE THE REST OF THE WEEKEND INTO EARLY
NEXT WEEK WITH A COMPLICATED SCENARIO GIVEN A WARM FRONT TO THE
SOUTH...HIGH PRESSURE WEDGING DOWN THE MOUNTAINS...AND MOISTURE
INCREASING UNDER THE SHARP RIDGING ALOFT. THIS LOOKS TO MAINLY
PLAY OUT SUNDAY NIGHT INTO MONDAY WITH DRY AIR HOLDING THE LOW
LEVELS DRY UNTIL LATER SUNDAY NIGHT AND ESPCLY MONDAY WHEN
GUIDANCE BRINGS A FAINT MID LEVEL WAVE UP UNDER THE RIDGE ALOFT.
THIS SHOULD ALLOW FOR A GRADUAL INCREASE IN CLOUDS SUNDAY...THEN
BECOMING MOSTLY CLOUDY SUNDAY NIGHT WITH SLOWLY INCREASING ISENT
LIFT AS THE LOW LEVEL FLOW BECOMES MORE EAST/SE. RAIN CHANCES PICK
UP ON MONDAY AS A LOBE OF DEEPER MOISTURE ARRIVES INTO THE
DEVELOPING WEDGE ALTHOUGH COVERAGE LOOKS DISORGANIZED FOR THE MOST
PART. WILL RUN WITH MOSTLY CHANCE POPS ON MONDAY GIVEN ENOUGH
MOISTURE AND VEERING ALOFT FOR SOME LIGHT PRECIP.
TEMPS TO REMAIN MILD INTO SUNDAY NIGHT WITH HIGHS MOSTLY IN THE
70S SUNDAY PROVIDED ENOUGH INSOLATION...THEN COOLER PER ONLY 60S
WITHIN THE WEDGE AREA IN THE CENTRAL/EASTERN SECTIONS AND 70-75
PERIMETER SOUTH AND SW ZONES.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 1230 PM EDT FRIDAY...
ACTIVE WEATHER PERIOD IN STORE AS STRONG UPPER LEVEL LOW PRESSURE
DEVELOPS OVER THE CENTRAL STATES AND THEN SPIRALS VERY SLOWLY NE
REACHING THE WESTERN GREAT LAKES BY THE END OF THE WEEK. THIS WILL
KEEP AN INCREASING FLUX OF DEEP MOISTURE INTO THE AREA THROUGH AT
LEAST MID WEEK BEFORE THE TRAILING COLD FRONT FINALLY MOVES OVER AND
TO THE EAST THURSDAY INTO FRIDAY. DEVELOPING WEDGE ACROSS THE REGION
EARLY ON WILL GET DEEPLY ENTRENCHED MONDAY NIGHT AND ESPCLY TUESDAY
AS THE INITIAL SURGE OF LIGHT RAIN CROSSES AND FORMS A WEAK WAVE
ALONG THE COASTAL WARM FRONT. THIS COOL POOL SHOULD KEEP THE
BOUNDARY TO THE SOUTH AND EVENTUALLY ALONG THE APPALACHIANS BEFORE
PERHAPS WARM ADVECTION PUNCHES IT OUT LATER WEDNESDAY AHEAD OF A
FRONT ALOFT PRESSING IN FROM THE WEST. OVERRUNNING IN ADVANCE OF
THIS BOUNDARY LIKELY TO KEEP PERIODS OF RAIN GOING TUE INTO TUE
NIGHT THEN POSSIBLY A MORE ENHANCED BAND OF HEAVIER SHOWERS/STORMS
WED WEST AS THIS FEATURE PUSHES EAST PER GFS/EC BLEND. PENDING
LATER RUNS...THIS COULD BRING SOME WATER ISSUES TO SPOTS DESPITE
CURRENT DRYNESS PER LATEST ENSEMBLE OUTPUT. ALSO BOUNDARY LIFTING
NORTH COULD POSE SOME SEVERE THREAT AS WELL PENDING HOW FAST THE
WEDGE LIFTS OUT BY WED EVENING. OTRW BUMPING POPS FROM CHANCE
MONDAY NIGHT TO LIKELYS TUE AND CATEGORICAL INTO WED AFTERNOON.
ACTUAL SURFACE FRONT LOOKS TO FINALLY CROSS THE MOUNTAINS THU BUT
LACKING MOISTURE BY THEN SO KEEPING SOME CHANCE POPS. SHOULD DRY OUT
FURTHER IN THE WAKE OF THE FRONT ON FRIDAY WITH ANY ISOLATED SHRA
CONFINED MOSTLY TO THE UPSLOPE AREAS OF THE FAR NW AT BEST.
TEMPS WILL BE TRICKY UNDER THE WEDGE WITH POTENTIAL FOR A VERY COOL
DAY ON TUE AND MUCH OF WED BEFORE SEEING READINGS SURGE FROM SOUTH
TO NORTH LATE WED AFTERNOON. THUS PLAN TO STAY WELL BELOW MOS/HPC
ESPCLY ON TUE AND ACROSS THE NORTH WED. SHOULD RETURN TO NORMAL OR
ABOVE HIGHS THU THEN COOLER POST FRONTAL FRI WITH MOST IN THE 60S
TO LOW 70S PIEDMONT.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 750 PM EDT FRIDAY...
MAIN UPPER TROUGH AXIS AND FRONT AS WELL AS ASSOCIATED TSRA HAVE
MOVED EAST OF THE CWA WITH NO ADDITIONAL IMPACT ON THE TAF SITES.
HOWEVER...COLD POCKET ASSOCIATED WITH UPPER TROUGH TRAILING BEHIND
ACROSS THE REGION WITH STILL SOME SCT -SHRA NOTED...MAINLY ACROSS
WV/SW VA. WILL KEEP THESE GOING BCB/BLF/LWB FOR A FEW MORE
HOURS...BUT THIS ACTIVITY WILL DISSIPATE FAIRLY QUICKLY WITH THE
LOSS OF DIURNAL HEATING AS WELL AS WITH THE UPPER TROUGH SHIFTING
FURTHER EAST FAIRLY RAPIDLY. UPSLOPE CLOUDS WILL LINGER EASTERN
WV...AFFECTING BLF-LWB FOR A FEW MORE HOURS...BUT COMPARED TO
TYPICAL SUCH SYNOPTIC PATTERNS...WOULD EXPECT THIS TO BE SOMEWHAT
MORE LIMITED THAN USUAL. EAST OF THE ALLEGHANY FRONT...EXPECT
MAINLY VFR CIGS...BUT LOW END VFR CIGS MAY LINGER TOWARD ROA FOR A
COUPLE MORE HOURS. ALL SITES WILL SEE VFR CIGS AFT 12Z SAT. A WEAK
POLAR FRONT WILL SINK SOUTHWARD TOWARD THE REGION LATE SAT. MID-
LEVEL CLOUDS WILL BE ON THE INCREASE WITH THIS SYSTEM...BUT -SHRA
AND LOWER CIGS ARE NOT EXPECTED. VSBYS...VFR THROUGH THE TAF VALID
PERIOD...WINDS...WNW BRIEFLY GUSTY 10-15KTS GUSTING 20-25KTS
TOWARD 04Z...DIMINISHING SOME...THEN BECOME WEST AGAIN 10-15KTS
GUSTING 20-25KTS AFT 15Z SAT.
MEDIUM TO HIGH CONFIDENCE IN CIGS THROUGH THE TAF VALID PERIOD.
HIGH CONFIDENCE IN VFR VSBYS THROUGH THE TAF VALID PERIOD.]
MEDIUM TO HIGH CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID
PERIOD.
EXTENDED AVIATION DISCUSSION...
VFR CONDITIONS SHOULD PREVAIL BOTH SATURDAY AND SUNDAY.
CLOUD COVER WILL STEADILY INCREASE BY MONDAY...AS A DEEP AREA OF
LOW PRESSURE ALOFT SLOWLY DRIFTS INTO THE REGION FROM THE WEST.
ONCE THIS SYSTEM ARRIVES...IT WILL LINGER ACROSS THE REGION FOR
SEVERAL DAYS. SUB VFR CONDITIONS CAN BE EXPECTED AT INCREASING
FREQUENCY AS THE WEEK PROGRESSES IN -SHRA/-TSRA AND EVENTUALLY
MORE -RA/-DZ WITH A COLD AIR WEDGE DEVELOPING AND PERSISTING FROM
MID WEEK ON.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...AMS
SHORT TERM...JH
LONG TERM...JH
AVIATION...RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
637 PM EDT THU APR 24 2014
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT. MEANWHILE...A COLD
FRONT WILL HEAD EASTWARD...AND SHOULD CROSS OVER THE MID ATLANTIC
BY FRIDAY TO BRING SCATTERED SHOWERS. HIGH PRESSURE WILL RETURN TO
PROVIDE A DRY AND MILD WEEKEND...BEFORE AN UPPER LEVEL AREA OF LOW
PRESSURE PROVIDES COOLER AND WETTER CONDITIONS NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 635 PM EDT THURSDAY...
RAISED EARLY EVENING TEMPERATURES UP A FEW DEGREES WITH SOLAR
HEATING. HIGH PRESSURE WILL SLIDE EAST INTO THE ATLANTIC THIS EVENING
INTO TONIGHT. A COLD FRONT AND ITS ASSOCIATED WARM FRONT WILL
TRAVEL EAST TONIGHT INTO FRIDAY AND PUSH OFFSHORE BY FRIDAY NIGHT.
LOW TEMPERATURES OVERNIGHT WILL GENERALLY BE IN THE MID 40S TO THE
LOWER 50S WITH CLOUDS AND WEAK WARM AIR ADVECTION ALOFT. LATEST
RNK WRFARW AND HRRR SUPPORT CURRENT ARRIVAL TIME FOR CONVECTION
ALONG AND AHEAD OF COLD FRONT. NO MAJOR CHANGES IN CLOUDS...PRECIPITATION
AND POPS TONIGHT INTO FRIDAY. WILL MAKE ADDITIONAL CHANGES IN ISC
GRIDS LATER THIS EVENING.
AS OF 355 PM EDT THURSDAY...
SKIES HAVE CLEARED DURING THE PAST FEW HOURS TO ALLOW TEMPERATURES
TO REACH THE LOWER 60S TO THE LOWER 70S THIS AFTERNOON. HIGH
PRESSURE SHOULD DRIFT OFFSHORE LATER TONIGHT. MEANWHILE...A COLD
FRONT WILL CROSS OVER THE OHIO RIVER VALLEY. THE 12Z NAM/ECMWF/GFS
MODEL GUIDANCES HAVE SLOWED DOWN THE ARRIVAL OF THIS FRONT BY A
FEW HOURS...SO POPS WERE TAPERED DOWNWARD DURING THURSDAY NIGHT
FROM THE PREVIOUS FORECAST. LOW TEMPERATURES WERE HELD IN THE MID
40S TO THE LOWER 50S DUE TO CLOUD COVER AND WEAK WARM AIR
ADVECTION ALOFT.
POPS WERE INCREASED LATER ON FRIDAY MORNING HOURS DUE TO GOOD
AGREEMENT AND A LITTLE MORE OVERALL COVERAGE PORTRAYED IN THE
MODELS. SHOWERS SHOULD LINGER INTO THE AFTERNOON...BEFORE THE
FRONT HEADS TOWARD THE COAST BY SUNSET. QPF AMOUNTS WERE ALSO
INCREASED SLIGHTLY TO AROUND A QUARTER OF AN INCH. HOWEVER...WINDS
SHOULD TURN TO THE WEST AND BECOME GUSTY AFTER THE FRONTAL
PASSAGE...AND END ANY OF THE REMAINING RAINFALL. CHANCES OF
THUNDER WERE ONLY PLACED IN SOUTHSIDE VIRGINIA WERE BUFKIT MODEL
SOUNDINGS SHOW CAPE EXCEEDING 500 J/KG DURING THE AFTERNOON. SPC
KEEPS ANY SEVERE WEATHER THREAT WELL TO THE EAST OF OUR CWA. HIGHS
ON FRIDAY WERE KEPT ON THE SLIGHTLY COOLER SIDE OF GUIDANCE DUE TO
CLOUDS AND RAIN...WITH LOWER 60S TO LOWER 70S EXPECTED.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 315 PM EDT THURSDAY...
MOST PRECIP WILL HAVE EXITED THE REGION AT THE BEGINNING OF THIS
PERIOD...SAVE SOUTHSIDE VA/NC PIEDMONT AND THE GREENBRIER VALLEY.
GOOD BURST OF WIND BEHIND THIS COMPACT YET DECENT SHRTWV...WITH SOME
30 KT GUSTS FRIDAY EVENING AT THE USUAL LOCATIONS. SLIGHTLY COOLER
AIR SLIPS INTO THE GREENBRIER VALLEY AND SOUTHERN SHENANDOAH BEHIND
THIS BOUNDARY...BUT WAA RETURNS QUICKLY ACROSS THE SOUTHERN HALF OF
THE CWA. ANOTHER DISTURBANCE DROPPING THROUGH THE GREAT LAKES LATE
SATURDAY...MAY ALLOW SCATTERED SHOWERS AND A THUNDERSTORMS TO FORM
JUST AHEAD OF A COLD FRONT WHICH STALLS AROUND ELKINS WV...WITH SOME
OF THESE WEAKENING...PERHAPS AS THEY MOVE INTO THE GREENBRIER VALLEY
AND THE SOUTHERN SHENANDOAH. SOMETIMES MODELS STRUGGLE WITH THIS
REGIME...SO FOR NOW AT LEAST WENT WITH SLT CHC POPS IN THESE AREAS.
H85 TEMPS IN THE LOWER TEENS TO NEAR +15C CONTINUE FOR SUNDAY...WITH
SOME SPOTS TOUCHING 80F POSSIBLY SATURDAY AND SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 330 PM EDT THURSDAY...
THE NEXT WORKWEEK IS SHAPING UP TO BE ON THE WET SIDE AS A MASSIVE
UPPER LEVEL LOW PINWHEELS EAST FROM THE CENTRAL AND NORTHERN PLAINS.
WILL START MONDAY OUT WITH COOL HIGH PRESSURE WEDGING SOUTHWARD
AGAINST THE EASTERN FACE OF THE APPALACHIANS...MAINTAINING A COOL
EASTERLY WIND ACROSS OUR AREA. A WARM FRONT WILL NORTH ALONG THE
MISSISSIPPI RIVER VALLEY...BUT WILL GET HUNG UP AGAINST THE
APPALACHIANS. AS SUCH...EXPECT SHOWERY WEATHER MONDAY AND TUESDAY...
WITH AN OUTSIDE CHANCE FOR THUNDERSTORMS ACROSS THE MOUNTAIN EMPIRE
AND PERHAPS THE NORTH CAROLINA FOOTHILLS...WHERE THE STABILIZING
AFFECT OF THE HIGH PRESSURE WEDGE WILL BE WEAKEST. WILL SEE A BETTER
THREAT FOR THUNDERSTORMS ON WEDNESDAY AS THE LOW PRESSURE SYSTEM
NEARS THE REGION...ALLOWING THE WARM FRONT TO LIFT NORTHWARD BEFORE
THE TRAILING COLD FRONT MOVES IN.
EASTERLY FLOW AROUND THE HIGH WILL ALSO RESULT IN COOLER
TEMPERATURES...AND THEREFORE UNDERCUT MODEL GUIDANCE BY A FEW
DEGREES. HOWEVER...TEMPERATURES REMAIN LOW CONFIDENCE...AND BELIEVE
IT IS POSSIBLE THAT DID NOT GO LOW ENOUGH FOR AFTERNOON HIGHS MONDAY
AND PARTICULARLY TUESDAY.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 150 PM EDT THURSDAY...
THERE IS HIGH CONFIDENCE OF VFR CONDITIONS CONTINUING THROUGH THE
REST OF TODAY INTO EARLY TONIGHT. HIGH PRESSURE WILL DRIFT TOWARD
THE EAST COAST THIS AFTERNOON. WINDS SHOULD REMAIN LIGHT AND
GENERALLY FROM THE SOUTH...AND SOME CIRRUS WILL CONTINUE TO SPILL
OVER THE AREA FROM A COLD FRONT WELL UPSTREAM IN THE GREAT PLAINS.
AS HIGH PRESSURE HEADS OFFSHORE TONIGHT...CLOUDS SHOULD GRADUALLY
INCREASE IN COVERAGE AHEAD OF THE APPROACHING COLD FRONT. THIS
FRONT IS PROGGED TO TRACK OVER THE MID ATLANTIC BY FRIDAY.
CEILINGS SHOULD LOWER BY DAYBREAK...WITH A FAIRLY GOOD POSSIBILITY
OF MVFR AS NOTED IN THE LAMP GUIDANCE. PRECIPITATION ASSOCIATED
WITH THE FRONT SHOULD MAINLY BE SHOWERS. THERE IS A SMALL THREAT
FOR THUNDERSTORMS IN THE NORTH CAROLINA AND VIRGINIA PIEDMONT
TOWARD FRIDAY AFTERNOON...BUT THE CHANCES ARE TOO LOW TO WARRANT
MENTION IN ANY OF THE TAFS.
EXTENDED AVIATION DISCUSSION...
THE COLD FRONT SHOULD DEPART OFFSHORE BY FRIDAY NIGHT. WINDS WILL
TURN TO THE NORTHWEST AND INCREASE DURING FRIDAY NIGHT INTO
SATURDAY. VFR CONDITIONS SHOULD PREVAIL THROUGH THIS WEEKEND...AS
HIGH PRESSURE MOVES OVERHEAD. CLOUD COVER WILL STEADILY INCREASE
BY MONDAY...AS A LOW PRESSURE SYSTEM SLOWLY ARRIVES FROM THE
WEST. CONDITIONS MAY DROP BELOW VFR WHEN SCATTERED SHOWERS MOVE
OVER THE MID ATLANTIC DURING LATE MONDAY...AND CHANCES FOR MVFR
ARE EVEN BETTER ON TUESDAY DUE TO PROLONGED CLOUDS AND RAIN.
&&
.FIRE WEATHER...
AS OF 637 PM EDT THURSDAY...
LOW RH VALUES SHOULD RECOVER AFTER SUNSET THIS EVENING INTO
TONIGHT. BY FRIDAY...A COLD FRONT SHOULD PROVIDE SOME WETTING
SHOWERS FOR FRIDAY...ALTHOUGH AMOUNTS WILL BE AROUND A QUARTER OF
AN INCH.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PW
NEAR TERM...KK/PW
SHORT TERM...KM
LONG TERM...NF
AVIATION...PW
FIRE WEATHER...KK/PW
AREA FORECAST DISCUSSION
NWS MIAMI FL
420 AM EDT SAT APR 26 2014
.DISCUSSION...
WATER VAPOR AND RUC ANALYSIS THIS MORNING SHOWED A SHORTWAVE
TROUGH FROM THE GREAT LAKES SOUTHEAST TO OFF THE EAST COAST OF
NORTH CAROLINA. AN UPPER LEVEL RIDGE STRETCHED FROM THE WESTERN
GULF OF MEXICO INTO CANADA...AND ANOTHER SHORTWAVE TROUGH WAS
PUSHING INTO CENTRAL CALIFORNIA. A NEARLY ZONAL FLOW WAS NOTED
OVER SOUTH FLORIDA.
AT THE SURFACE...AN AREA OF LOW PRESSURE WAS LOCATED OVER THE
WESTERN ATLANTIC JUST SOUTH OF NEW JERSEY...AND A WEAK FRONTAL
BOUNDARY WAS DRAPED SOUTH AND WEST ALONG THE SOUTHEAST STATES
COASTS AND INTO SOUTHERN GEORGIA AND ALONG THE NORTHERN GULF
COAST. WEAK SURFACE HIGH PRESSURE REMAINED ACROSS FLORIDA AND THE
KEYS...WITH A LIGHT NORTHERLY LOW LEVEL FLOW OVER SOUTH FLORIDA.
FOR TODAY...DRIER AIR WILL MOVE IN FROM THE WEST...WITH PWATS A
LITTLE OVER AN INCH. SO DRY AND WARM CONDITIONS ARE EXPECTED.
LIGHT WINDS WILL CONTINUE THIS MORNING...WITH SEA BREEZE
BOUNDARIES PUSHING INLAND ALONG BOTH COASTS THIS AFTERNOON.
TONIGHT...THE UPPER LEVEL RIDGE OVER THE WESTERN GULF IS FORECAST
TO PUSH TOWARDS THE EASTERN GULF AS THE SHORTWAVE OVER CALIFORNIA
EJECTS EAST INTO THE INTERMOUNTAIN WEST. THE SURFACE RIDGE OF
HIGH PRESSURE OVER THE REGION WILL BEGIN TO SHIFT TO THE EAST INTO
THE WESTERN ATLANTIC...WITH EASTERLY FLOW DEVELOPING. LIGHT WINDS
ARE FORECAST ACROSS THE INTERIOR...AND PATCHY FOG MAY DEVELOP ONCE
AGAIN. AREAS OF SMOKE ARE LIKELY NEAR THE WILDFIRE ACROSS EASTERN
COLLIER COUNTY.
SUNDAY THROUGH TUESDAY...THE SURFACE RIDGE WILL CONTINUE TO PUSH
EAST...AND THE EASTERLY FLOW WILL INCREASE. SEA BREEZE BOUNDARIES
ARE FORECAST TO INTERACT ACROSS THE INTERIOR NEAR THE LAKE REGION
IN THE AFTERNOON. THIS MAY BE ENOUGH TO SPARK A FEW SHOWERS OR
STORMS IN THIS REGION ON SUNDAY. ABOVE NORMAL TEMPERATURES WILL
CONTINUE WITH HIGHS IN THE MID 80S TO LOWER 90S. AN UPPER LEVEL
LOW WILL CUTOFF ACROSS THE INTERMOUNTAIN WEST AND THE CENTRAL
PLAINS SUNDAY...AND THEN MEANDER ACROSS THE CENTRAL PLAINS THROUGH
EARLY NEXT WEEK. THE UPPER LEVEL RIDGE WILL MOVE OVER SOUTH
FLORIDA ON SUNDAY AND THEN REMAIN THROUGH THE MIDDLE OF THE WEEK.
MAINLY DRY AND VERY WARM CONDITIONS WILL CONTINUE.
A LARGE UPPER TROUGH/LOW WILL ENVELOP ABOUT THE EASTERN TWO-
THIRDS OF THE CONUS WEDNESDAY AND THURSDAY. UPPER HEIGHTS WILL
BEGIN TO LOWER...BUT SOME RIDGING WILL REMAIN OVER SOUTH FLORIDA.
A COLD FRONT IS FORECAST TO PUSH INTO NORTHERN FLORIDA BY
WEDNESDAY EVENING. HOWEVER...THE FRONT IS FORECAST TO REMAIN OVER
NORTH OR CENTRAL FLORIDA THROUGH FRIDAY. THE FLOW WILL SHIFT TO
THE SOUTHEAST. MOISTURE IS FORECAST TO SLOWLY INCREASE THROUGH
THE END OF THE WEEK...AND RAIN CHANCES ARE FORECAST TO INCREASE.
DEWPOINTS ARE FORECAST TO INCREASE BACK TO AROUND 70 BY
TUESDAY...AND REMAIN AROUND 70 THROUGH THE END OF THE PERIOD.
SOUTHEAST WINDS ARE FORECAST TO BE 10-15 KNOTS OVER THE ATLANTIC
WATERS AS WELL...AND THIS WILL KEEP LOW TEMPERATURES WELL ABOVE
NORMAL FOR THE EAST COAST. OVERNIGHT LOWS ARE FORECAST TO BE IN
THE MID/UPPER 70S FOR THE EAST COAST METRO AREAS. HIGHS ARE
FORECAST TO BE IN THE MID 80S TO LOW 90S THROUGH THE WEEK.
&&
.AVIATION...
HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER THROUGH THE TAF
PERIOD. THIS WILL KEEP VFR CONDITIONS IN PLACE. WINDS WILL PICK UP
MID DAY AS THE SEA BREEZE DEVELOPS, THEN RETURN TO LIGHT AND VARIABLE
IN THE LATE EVENING HOURS.
&&
.MARINE...
A WEAK PRESSURE GRADIENT PREVAILS ACROSS THE REGIONAL WATERS WITH
LIGHT AND SOMEWHAT VARIABLE WINDS TODAY WITH MORE EASTERLY FLOW
RETURNING ON SUNDAY INTO EARLY NEXT WEEK. IN GENERAL SEAS ARE
EXPECTED TO BE 2 FEET OR LESS THROUGH THE WEEKEND WITH JUST A
GRADUAL INCREASE IN WINDS AND SEAS EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 72 85 72 / 0 0 10 0
FORT LAUDERDALE 87 77 86 75 / 0 0 10 0
MIAMI 88 75 87 74 / 0 0 0 0
NAPLES 86 70 87 70 / 0 0 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE...84/AK
AVIATION...13/SI
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1147 PM CDT FRI APR 25 2014
.SYNOPSIS...
ISSUED AT 238 PM CDT FRI APR 25 2014
BEAUTIFUL DAY TODAY WITH PLENTIFUL SUNSHINE AND TEMPERATURES AS
OF 2 PM ALREADY IN THE UPPER 60S/LOW 70S AREA WIDE. DEWPOINTS HAVE
MANAGED TO STAY IN THE 40S THROUGH MUCH OF THE MORNING AND ARE
ONLY NOW DROPPING INTO THE 30S.
UPPER AIR ANALYSIS THIS MORNING DEPICTED CUTOFF UPPER LOW SPINNING
OVER NORTHEAST MINNESOTA AND LAKE SUPERIOR WITH BROAD RIDGING
TAKING PLACE FROM WESTERN KANSAS INTO ALBERTA CANADA. AT THE
SURFACE...WEAK RIDGING THAT WAS OVER THE CWA HAS NOW PUSHED EAST
INTO INDIANA. A WEAK COLD FRONT WAS SEEN SLOWLY PUSHING SOUTH OVER
MINNESOTA WITH MAINLY MID-HIGH LEVEL CLOUDS SEEN BEHIND THE FRONT.
LATEST WV IMAGERY SHOWS STRONG SYSTEM JUST OFF THE WEST COAST. THIS
SYSTEM WILL BRING UNSETTLED WEATHER TO THE REGION THIS WEEKEND AND
BEYOND.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 238 PM CDT FRI APR 25 2014
FORECAST FOCUS ON SMALL CHANCE OF PCPN THIS EVENING...OTHERWISE
QUIET AND DRY CONDITIONS EXPECTED.
WEAK COLD FRONT OVER MINNESOTA WILL DROP SOUTH ACROSS THE CWA
TONIGHT AND STALL AS IT REACHES THE IOWA-MISSOURI BORDER. HI-RES
MODELS AND THE LATEST RAP TRENDS ALL SHOW LOW LEVEL CONVERGENCE...
OMEGAS...AND MOISTURE IN THE 850-700MB LAYER ALONG AND BEHIND THE
FRONT INCREASING TONIGHT AND SHOULD BE SUFFICIENT ENOUGH TO
PRODUCE VERY LIGHT SHOWERS OR SPRINKLES MAINLY NORTH AND EAST OF A
LINE FROM THE QUAD CITIES TO PRINCETON ILLINOIS. HAVE MAINTAINED SLIGHT
CHANCE POPS IN THIS AREA FOR THIS POSSIBILITY. I AM CONCERNED THAT
THE SURFACE TO 850MB LAYER MAY BE TOO DRY FOR ANY PCPN TO REACH
THE GROUND AND WILL PASS THIS ON TO THE NIGHT SHIFT. WINDS TO
GRADUALLY SHIFT TO THE NORTHEAST AS FRONT TRACKS THROUGH THE CWA.
OVERNIGHT LOW TEMPERATURES WILL DEPEND ON HOW FAST THE FRONT MOVES
THROUGH AND ITS POSITION EARLY SATURDAY. LOWS SHOULD RANGE FROM
THE UPPER 30S/LOW 40S ON THE COOL SIDE OF THE BOUNDARY TO THE
LOWER 50S IN THE FAR SOUTH.
SATURDAY...ANOTHER PLEASANT DAY IN STORE AS UPPER LEVEL RIDGING
MOVES ACROSS THE AREA. A FRONTAL BOUNDARY WILL BE SITUATED ACROSS
THE SOUTHERN PORTIONS OF THE CWA WITH WINDS MAINLY FROM THE EAST
DURING THE DAY. THIS WILL RESULT IN A LARGE TEMPERATURE GRADIENT
SETTING UP ACROSS THE AREA BY THE AFTERNOON. DEEP MIXING TO 900MB
AND PARTLY SUNNY SKIES THROUGH AT LEAST THE EARLY AFTERNOON WILL
ALLOW HIGHS TO REACH THE LOWER 60S IN THE NORTHEAST TO THE UPPER
70S IN THE FAR SOUTH. AN ACTIVE PATTERN BEGINS ACROSS THE MIDWEST
STARTING SATURDAY NIGHT...SEE LONG TERM DISCUSSION FOR MORE DETAILS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 248 PM CDT FRI APR 25 2014
MODELS CONTINUE TO SHOW A HIGHLY AMPLIFIED...BLOCKED...PATTERN
EVOLVING OVER THE CONSUS DURING THE WEEKEND. THIS WILL RESULT IN A
LARGE OCCLUDED SYSTEM BECOMING NEARLY STATIONARY OVER THE UPPER
MIDWEST FOR MUCH OF THE COMING WEEK. THIS PATTERN CONTINUES TO
SUPPORT A PROLONGED RAINFALL EVENT OVER THE MID MISSISSIPPI VALLEY
WITH SIGNIFICANT RAINFALL...RESULTING IN FLOODING ON AREA
TRIBUTARIES AND THE MISSISSIPPI RIVER.
SATURDAY NIGHT SURFACE CYCLOGENESIS WILL TAKE PLACE OVER THE WESTERN
PLAINS...AHEAD OF A DEEP UPPER TROF MOVING THROUGH THE WESTERN U.S.
AS THE SURFACE LOW FORMS A WARM FRONT WILL DEVELOP FROM THE CENTRAL
PLAINS THROUGH NORTHERN MISSOURI. DEEP SOUTHERN FLOW AHEAD OF THE
WESTERN TROF WILL BRING ABUNDANT GULF MOISTURE NORTH ACROSS THE WARM
FRONT. THE LOW LEVEL JET BY LATE SATURDAY EVENING SHOULD BE POINTED
AT EASTERN NE AND WESTERN IA PROVIDING FORCING FOR MCS DEVELOPMENT.
THE MCS SHOULD TRACK EAST OVERNIGHT REACHING EASTERN IA DURING THE
EARLY MORNING HOURS. WHILE THE THREAT OF SEVERE STORMS WITH THIS
MCS WILL BE THE GREATEST OVER WESTERN IA AND EASTERN NE...SOME
ISOLATED SEVERE STORMS COULD REACH PARTS OF EASTERN IOWA AFTER
MIDNIGHT WITH HAIL BEING THE GREATEST THREAT. SUNDAY AND SUNDAY
NIGHT THE SEVERE THREAT WILL INCREASE FOR THE MID MISSISSIPPI VALLEY
AS THE WARM FRONT MOVES INTO NORTHERN MO OR SOUTHERN IA AND CENTRAL
IL AND STRONG MID LEVEL FLOW AHEAD OF THE UPPER LOW MOVES NORTH
THROUGH THE REGION. THE GREATEST THREAT OF SEVERE STORMS SHOULD BE
SUNDAY AFTERNOON AND EVENING ALONG AND SOUTH OF INTERSTATE 80. HAIL
SHOULD BE THE PRIMARY THREAT WITH MODELS SHOWING SOME MID LEVEL
DRYING. HOWEVER NEAR AND SOUTH OF THE WARM FRONT DAMAGING WINDS AND
TORNADIC STORMS CAN/T BE RULED OUT.
HEAVY RAIN POTENTIAL WILL EXIST OVER MUCH OF THE AREA FROM LATE
SATURDAY NIGHT THROUGH SUNDAY NIGHT AND POSSIBLY INTO MONDAY AS THE
SYSTEM MOVES TOWARD THE REGION. THIS MORNINGS WPC 3 DAY TOTAL QPF
ENDING MONDAY MORNING SHOWED A LARGE AREA OF 1 TO 3 INCHES OVER MUCH
OF THE FORECAST AREA...ROUGHLY CENTERED ALONG I80. THIS LOOKS
REASONABLE GIVEN PW/S OF 1 TO 1.5 INCHES OVER THE AREA MUCH OF THE
WEEKEND AND THE SLOW MOVEMENT OF THE OCCLUDED SYSTEM.
AFTER MONDAY MOST MODELS SHOW THE UPPER LOW OVER THE MISSISSIPPI
VALLEY AND MOVING SLOWLY EAST MID TO LATE WEEK. THIS SHOULD KEEP
MORE SHOWERY TYPE PRECIPITATION OVER THE AREA AT LEAST THROUGH
THURSDAY AND POSSIBLY INTO FRIDAY. ISOLATED THUNDERSTORMS WILL BE
POSSIBLE DURING THE AFTERNOON AND EVENING HOURS MONDAY AND TUESDAY
WITH SURFACE DEWPOINTS STILL IN THE 50S AND THE COLD POOL ASSOCIATED
WITH UPPER LOW STILL OVER HEAD. BY MID TO LATE WEEK DRY SURFACE AIR
MOVING IN SHOULD END THE THUNDERSTORM THREAT.
TEMPERATURES SHOULD BE NEAR NORMAL FOR THE WEEKEND THEN TREND BELOW
NORMAL...ESPECIALLY THE HIGHS...FOR MUCH OF THE UPCOMING WEEK WITH
ABUNDANT CLOUDS EXPECTED TO BE OVER THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1141 PM CDT FRI APR 25 2014
VFR CONDITIONS EXPECTED TO PERSIST THROUGH SATURDAY EVENING. WINDS
WILL BECOME EASTERLY AT OR ABOVE 10 KTS WITH OCCASIONAL GUSTS
AROUND 20 KTS POSSIBLE FROM MID AFTERNOON THROUGH EVENING. ELEVATED
WARM ADVECTION MAY RESULT IN SCATTERED SHOWERS DEVELOPING SATURDAY
EVENING...WITH INCREASING CHANCES MAINLY JUST BEYOND END OF THE TAF
CYCLE.
&&
.HYDROLOGY...
ISSUED AT 248 PM CDT FRI APR 25 2014
THREAT OF FLOODING ON AREA TRIBUTARIES AND THE MISSISSIPPI RIVER
WILL INCREASE BY EARLY NEXT WEEK AS A WIDESPREAD SIGNIFICANT
RAINFALL EVENT OCCURS OVER THE REGION. CURRENT FORECASTS SUGGEST A
WIDESPREAD AREA OF 1 TO 4 INCHES OF RAIN ARE POSSIBLE OVER MUCH OF
THE FORECAST AREA BY WEDNESDAY. LOCALLY HEAVY RAINS WILL BE POSSIBLE FROM
LATE SATURDAY NIGHT THROUGH SUNDAY NIGHT WITH SCATTERED SHOWERS
EXPECTED OVER THE AREA EARLY TO MIDWEEK. SINCE THE PRECIPITATION IS
GOING TO OCCUR OVER AN EXTENDED PERIOD OF TIME THE THREAT OF FLASH
FLOODING WILL BE LOW. HOWEVER RIVER FLOODING IS EXPECTED WITH MANY
OF THE AREA TRIBUTARIES AND THE MISSISSIPPI RIVER SEEING AT LEAST
MINOR TO MODERATE FLOODING BY THE MIDDLE OF NEXT WEEK.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...GROSS
SHORT TERM...GROSS
LONG TERM...DLF
AVIATION...05
HYDROLOGY...DLF
AREA FORECAST DISCUSSION
NWS TOPEKA KS
423 AM CDT Sat Apr 26 2014
.SHORT TERM...(Today and Tonight)
Issued at 403 AM CDT SAT APR 26 2014
The center of an intense upper level trough was located over
southern CA at 7Z. The upper level trough will lift northeast across
the desert southwest this afternoon, and then lift negative tilt
into southeast CO and across west TX by 12Z SUN.
Early this morning elevated showers were beginning to develop as
isentropic lift was developing ahead of residual 850mb moisture
return. The HRRR along with the ECMWF show the stronger
thunderstorms developing just east of the CWA after 12Z. The 00Z NAM
shows isolated elevated thunderstorms developing along and south of
the KS turnpike by 10Z, then moving east of the CWA during the mid
and late morning hours. Given MUCAPES of 400-1000 J/KG and effective
0-6KM shear of 30 KTS, some of these storms may produce small hail
and the stronger storms may even produce quarter size hail across
portions of east central KS this morning, that is if storms develop
within the CWA.
As an 80kt jet max within the base of the H5 trough lifts northeast
across eastern NM, a lee surface trough across southeast CO,
southward along the NM/TX border will deepen. This will increase the
southerly 850mb winds to 40 KTS across central KS with surface wind
increasing 20 to 30 KTS across most of KS. At this time the
strongest surface winds should remain just southwest and west of the
CWA. The southwest counties of the CWA may come close to wind
advisory criteria during the afternoon hours with sustained winds of
28 MPH and gusts to near 40 MPH.
A surface dryline will develop early this afternoon within the lee
trough axis across extreme southwest KS, then southward across the
TX PNHDL. This dryline will then move northeast into west central KS
and extend southward across extreme western OK by late this
afternoon.
At this time the deepest gulf moisture was located across southern
TX and most models show a quick transport of deep moisture northward
into south central KS by this afternoon. Deeper mixing across
central KS may keep dewpoints in the mid to upper 50s ahead of the
surface dryline.
Both the the 6Z NAM and 00Z Advanced Research WRF show a strong CAP
ahead of the dryline across central KS with no storms developing in
the late afternoon or evening hours. The 12Z ECMWF model shows the
potential for thunderstorms developing along the dryline across
south central KS and north central KS east of HLC. All the models
show temperature and dewpoint temperature depressions greater than
25 degrees along the dryline across central and north central KS.
Therefore, if storms develop they will be high based with MLLCL`s of
5,000 to 6,000 feet. The environment across central KS will have
MLCAPES of 3500 J/KG and Effective shear of 40 KTS. If storms were
able to develop the environment would be favorable for high based
supercell thunderstorms. The higher storm bases will significantly
decrease the potential for tornadoes as these isolated supercell
thunderstorms move northeast off the dryline into the western
counties of the CWA early this evening. In fact they may weaken as
the supercells leave the best area of surface convergence. However,
if any high based supercell manages to develop along the dryline
across north central and central KS, these storms will be capable of
producing large hail and damaging wind gusts.
Highs Today will range from the lower 80s across the northeast
counties to the upper 80s to near 90 across the southwest counties
of the CWA.
I think we will see a break across the CWA from any thunderstorms
from the mid evening hours until 3 or 4 AM Sunday morning, before
severe thunderstorms redevelop. Supercell thunderstorms across
western and central OK will merge into a QLCS or MCS and lift
northeast into south central KS after midnight. Once piece of the
upper level trough will pivot northward across western and central
OK, then into eastern KS through the early morning hours of Sunday.
This will probably maintain any QLCS or MCS cluster of severe
thunderstorms that develop across northern OK and southern KS, as
these storms move northeast ahead of the first H5 trough across the
eastern half of the CWA. The primary hazard with the cluster of
severe thunderstorms will be large hail along with the threat for
damaging winds. I cannot rule out a few supercell thunderstorms on
the southern edge of the severe cluster of thunderstorms. Any
supercells or meso vortices within a QLCS may bring a low chance for
an isolated tornado through early morning hours of Sunday across
portions of east central KS. The MCS/cluster of severe thunderstorms
may also bring heavy rainfall. It will be more of a mesoscale
forecast but areas along and south of the KS turnpike may see the
heaviest rainfall near 12Z SUN.
Overnight lows will only drop into the lower to mid 60s Saturday
night.
.LONG TERM...(Sunday through Friday)
Issued at 403 AM CDT SAT APR 26 2014
The most concentrated and potentially strongest convection still
appears to be on Sunday over the eastern 2/3 of the cwa in the
morning and the eastern 1/3 in the afternoon as the main shortwave
lobe over southwest KS at 12z Sunday lifts northeastward across KS
through the day. Strong to severe convection appears will be
ongoing to start the day Sunday across much of the cwa...gradually
shifting eastward ahead of dry slot in central KS...although
models such as the EC hinting that the cwa could be on the
northern fringe of a substantial MCS just to the south. Models
keep MUCAPE values in the 1500-2000 J/kg range ahead of the
dryline...however 0-6km Bulk Shear values steadily increase into
the 50-60kt range through 18z over the eastern half of the cwa or
near and just ahead of dryline. Although large hail...wind is
possible with the morning convection...any additional development
by midday/afternoon in any increasingly sheared environment would
become more supportive of supercells with all modes of severe
weather possible including a tornado threat. This will be highly
dependent on the speed/timing of the dryline and its proximity to
afternoon heating just of the mid level drying. Although will
leave a slight chance for some lingering convection early evening
in the far eastern counties...it still appears the threat for
severe weather will shift east of the cwa by 00Z as drier air
continues to push eastward across the area as the upper low slows
and occludes over western Nebraska.
Cannot totally rule out a few showers developing over the cwa on
Monday as the upper low wobbles eastward and moisture wraps around
the circulation center and back into the cwa...but will word as
showers for now as instability looks weak. Rain chances will then
linger through Wednesday...then again on Thursday as another
shortwave trough rotates southeast around the upper trough. Rainfall
amounts across the area through mid week should remain light. High
temperatures still expected to cool from the 70s on Sunday to the
60s/near 70 Monday...then the 50s and 60s through the remainder of
the week. Lows will commonly be in the 40s Tuesday through Friday.
&&
.AVIATION...(For the 06Z TAFs through 06Z Saturday Night)
Issued at 1147 PM CDT FRI APR 25 2014
Low level wind shear will be a concern through the 12Z-14Z time
period with surface winds around 10 mph from the south to
southeast and winds around 1500 ft from the southwest near 45 kts.
Still a signal for convection to be in the vicinity of TOP and FOE
from 12Z to 16Z. South winds will increase by 16Z from the south
around 18-20 kts with gusts to 28 kts. The winds will continue to
stay gusty through the end of the period. TSRA may affect MHK
after 02Z but confidence is not high enough to mention.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...63
AVIATION...53
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1135 PM CDT FRI APR 25 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 344 PM CDT FRI APR 25 2014
THE ONGOING DROUGHT WILL CONTINUE THE FOCUS FOR CRITICAL FIRE
CONDITIONS SATURDAY AS WARM FRONT LIFTS NORTH AND EAST. DEEP
MOISTURE WILL BE LACKING WHERE STORMS THAT DO FORM WILL CREATE A
BETTER CHANCE FOR HIGH BASED THUNDERSTORMS AND A LIGHTNING DANGER
FOR FIRE IGNITION. SEE FIRE WEATHER DISCUSSION BELOW FOR MORE
DETAILS.
FORECAST TONIGHT INTO SATURDAY TRENDED TOWARD THE HIRES ECMWF. THE
MODELS ARE CREATING MORE OF A SPREAD AS THE UPPER FLOW PATTERN
SLOWS. THE 250 MB JETSTREAM WILL CONTINUE TO CARVE OUT THE LONGWAVE
TROUGH MOVING INLAND ACROSS THE WEST COAST THIS EVENING. THE MODELS
MAY STILL BE TOO FAST MOVING THE SURFACE LOW PRESSURE SYSTEM OUT ON
THE PLAINS SATURDAY EVENING. FOR THE LOCAL AREA TONIGHT QUIET WITH
SOME HIGH CLOUDS WHILE TEMPERATURES DROP INTO THE 40S.
SATURDAY THE SURFACE SYSTEM WILL ORGANIZE WITH THE DRYLINE EXTENDING
SOUTH FROM NEAR IMPERIAL SOUTH ACROSS WESTERN KANSAS. A WARM FRONT
WILL LIFT NORTH AND EAST WITH TEMPERATURES CLIMBING INTO THE MID 80S
SOUTHWEST TO MID 70S NORTH CENTRAL. THE PREVAILING SOUTHWEST FLOW
WILL DO LITTLE TO IMPROVE DEEP MOISTURE THROUGH 21Z WITH A NARROW
OPPORTUNITY FOR STORM DEVELOPMENT UNTIL EVENING. ISOLATED
THUNDERSTORMS THAT FORM SHOULD BE HIGH BASED WITH BETTER FOCUS
TOWARD THE SOUTH CENTRAL BY EVENING AS LOW LEVEL JET STRENGTHENS TO
INCREASE THE MOISTURE PROFILE FOR BETTER STORM POTENTIAL IN THE
SATURDAY NIGHT PERIOD...WITH STORM MOTION TO FOCUS OVER THE NORTH
CENTRAL WHERE A SLIGHT RISK FOR SEVERE STORMS CURRENTLY EXISTS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 344 PM CDT FRI APR 25 2014
HIGHLIGHTS OF THE LONG TERM PORTION OF THE FORECAST BEGIN WITH
SEVERE THUNDERSTORM CHANCES SATURDAY NIGHT AND SUNDAY...THEN TURN TO
POTENTIAL FOR SNOW AND COLD AND WINDY CONDITIONS AS A LARGE STORM
SYSTEM SLOWLY MAKES ITS WAY ACROSS THE CENTRAL PART OF THE COUNTRY.
THE UPPER LEVEL TROUGH CURRENTLY OFF THE WEST COAST WILL MAKE ITS
WAY ACROSS THE GREAT BASIN THROUGH THE DAY SATURDAY THEN WILL LIFT
INTO THE CENTRAL PLAINS SATURDAY NIGHT AND SUNDAY.
AS A SURFACE LOW DEVELOPS AHEAD OF THE UPPER LEVEL SYSTEM...THE
WARM FRONT WILL LIFT NORTH ACROSS NEBRASKA SATURDAY EVENING AND
BY 06Z SHOULD BE ROUGHLY FROM EXTREME NORTHEAST COLORADO INTO
NORTHEAST NEBRASKA WITH THE SURFACE LOW SITUATED OVER THE
SOUTHEAST NEBRASKA PANHANDLE. THE MODELS HAVE BEEN CONSISTENT WITH
A DRYLINE EXTENDING SLIGHTLY EAST OF THE LOW TO NEAR HIGHWAY 83 BY
KLBF AND THEN GOING SOUTH THROUGH WESTERN KANSAS. THIS IS A FAIRLY
TIGHT DRYLINE WITH DEWPOINTS VARYING FROM THE LOW 20S TO THE MID
50S IN A SHORT AREA. THERE WILL BE A STRONG LOW LEVEL JET SATURDAY
EVENING...HOWEVER SOUNDINGS ARE SHOWING AREAS IN THE WARM SECTOR
STAYING CAPPED. THERE IS DECENT SHEAR...SO IF ENOUGH MOISTURE IS
BROUGHT NORTH TO GET STORMS TO DEVELOP ALONG THE WARM FRONT THEY
COULD BECOME ORGANIZED. SO THERE IS POTENTIAL FOR STORMS...YET
HIGHER CHANCES WILL LIE INTO EASTERN NEBRASKA WHERE MORE MOISTURE
WILL BE IN PLACE. WITH THE CAP IN PLACE AND LACK OF MOISTURE IN
THE LOWER LEVELS...BETTER CHANCES MAY BE FOR ELEVATED CONVECTION
SO THREATS FROM STORMS WOULD BE MAINLY LARGE HAIL AND STRONG
WINDS. THAT BEING SAID...THE TRACK OF THE UPPER LEVEL SYSTEM WOULD
SUGGEST MUCH OF NEBRASKA MAY GET DRY SLOTTED SATURDAY NIGHT INTO
SUNDAY. THE TREND IN THE MOST RECENT MODEL RUNS HAS BEEN IN THIS
DIRECTION SO PRECIPITATION CHANCES HAVE BEEN REDUCED ACCORDINGLY.
BY SUNDAY MORNING AT 12Z...THE UPPER LOW IS CENTERED OVER EASTERN
COLORADO AND BEYOND THAT POINT DIFFERENCES IN THE NORTH TO SOUTH
ASPECT OF THE SYSTEM START TO DIVERGE. BY 28.00Z THE DIFFERENCE IN
THE 500MB LOW RANGES FROM ROUGHLY OVER SHERIDAN AND CHERRY
COUNTIES INTO SOUTH DAKOTA IN THE GFS TO THE WESTERN NEBRASKA
SANDHILLS IN THE ECMWF AND GEM...TO THE COLBY/HILL CITY AREAS IN
KANSAS IN THE NAM. THE DIFFERENCE IN THESE SOLUTIONS BRINGS A
CONSIDERABLE LACK IN CONFIDENCE ON WHAT THE OUTCOME WILL BE FOR
SENSIBLE WEATHER SUNDAY AND BEYOND. THIS FORECAST PACKAGE TRENDED
BETWEEN THE MORE SOUTHERN SOLUTIONS WITH IT COMING FROM BLENDS OF
THESE MODELS.
WITH THE GFS NOT BEING CONSIDERED...DRY AIR DOES CONTINUE TO MOVE
INTO THE REGION AS THE UPPER LOW MOVES ACROSS THE CENTRAL PLAINS.
HOWEVER THE ECMWF/GEM RUNS WOULD KEEP A LOT OF THE AREA DRY ALL DAY
WHILE PRECIPITATION WOULD BE EXPECTED OVER MUCH OF NORTHERN
NEBRASKA. WHEREVER THE SURFACE LOW TRACKS...THERE WILL BE A TIGHT
DRYLINE ORIENTED EAST OF THE LOW...THEN SOUTHWARD THROUGH EASTERN
KANSAS. THE MODELS DO SHOW MOISTURE BING TRANSPORTED BACK INTO
NORTH CENTRAL NEBRASKA AHEAD OF THE DRYLINE AND SOUNDINGS SHOW THE
CAP ERODING BY MID AFTERNOON SO CONVECTION IS POSSIBLE. THE HIGHER
CHANCES CURRENTLY ARE OVER NORTH CENTRAL NEBRASKA...AND WHILE THE
DEEP LAYER BULK SHEAR ISN/T GREAT...THERE IS ABOUT 30KTS IN THESE
AREAS SO WHILE WIDESPREAD SEVERE STORMS MAY NOT OCCUR...ITS NOT
OUT OF THE QUESTION TO MAYBE GET A FEW STRONG TO SEVERE STORMS.
ANOTHER CONCERN FOR SUNDAY IS IF THE NAM IS ON THE RIGHT
TRACK...THERE COULD BE A VERY NARROW BAND OF WEAK CAPE THAT IS
PULLED AROUND THE LOW LEVEL CIRCULATION. THIS WOULD BE CO-LOCATED
WITH STEEP LOW LEVEL LAPSE RATES /AS COLD AIR WITH THE UPPER LEVEL
LOW MOVES INTO THE AREA/...AS WELL AS A SURFACE INVERTED TROUGH FROM
SOUTHWEST INTO NORTH CENTRAL NEBRASKA. IF THIS SITUATION WOULD PAN
OUT...ANY CONVECTION ALONG THIS SURFACE BOUNDARY COULD HAVE THE
POTENTIAL TO PRODUCE NON- SUPERCELL TORNADOS.
SUNDAY NIGHT...COLD AIR WILL ADVECT INTO THE FORECAST AREA ON THE
BACKSIDE OF THE SYSTEM. HOW COLD THE AIR WILL BE IS STILL IN
QUESTION DEPENDENT ON THE TRACK OF THE UPPER LOW. THE ECMWF/GEM/NAM
WOULD BRING ENOUGH COLD AIR INTO THE PANHANDLE AND WESTERN
SANDHILLS TO SUGGEST PRECIPITATION WILL CHANGE OVER TO SNOW
OVERNIGHT. AS THE NORTHERN SOLUTION HAS BEEN DISCOUNTED AT THIS
TIME...DID INSERT A RAIN/SNOW MIX INTO THE FORECAST FOR SUNDAY
NIGHT INTO MONDAY MORNING. AT THIS TIME AM NOT GOING TO INTRODUCE
ANY AMOUNTS DUE TO HIGH UNCERTAINTY IN ACCUMULATION...BUT WOULD
NOT BE SURPRISED TO SEE A FEW FLAKES AT LEAST. THAT BEING SAID...IF THE
NAM WOULD BE ON THE RIGHT TRACK...THERE WOULD BE POTENTIAL FOR
ACCUMULATING SNOW...ESPECIALLY FROM OGALLALA TO THEDFORD TO
AINSWORTH AND AREAS TO THE WEST.
MOVING THROUGH THE WEEK...A SHORT LIVED REX BLOCKING PATTERN SETS
UP WITH AN UPPER HIGH OVER HUDSON BAY AND CENTRAL CANADA WITH THE
WEEKEND SYSTEM STAYING CENTERED OVER THE CENTRAL PLAINS. THE UPPER
LEVEL SYSTEM IS LIKELY TO SIT AND SPIN OVER THE REGION THROUGH
MUCH OF THE NEXT WEEK. WHILE THIS IS ONGOING...TEMPERATURES WILL
BE COOL /HIGHS IN THE 40S AND 50S...LOWS IN THE 30S./ WITH CHANCES FOR
LIGHT PRECIPITATION DAILY. IT ALSO DOES LOOK COLD ENOUGH MONDAY
AND TUESDAY NIGHTS FOR ANOTHER SHOT OF SNOW FOR PORTIONS OF THE
AREA. AGAIN...CONFIDENCE ON ACCUMULATING SNOW IS LOW SO AT THIS
TIME JUST HAVE A CHANCE FOR RAIN/SNOW IN THIS TIME PERIOD. THE
MODELS ARE STARTING TO AT LEAST SLOWLY MOVE THE SYSTEM EAST BY THE
END OF THE WORK WEEK. THIS WILL ALLOW A VERY GRADUAL WARM UP INTO
NEXT WEEKEND WITH CHANCES FOR PRECIPITATION WANING.
THE LAST CONCERN IS WINDS. AS THE SYSTEM MOVES ACROSS THE
PLAINS...THERE WILL BE POTENTIAL FOR STRONG WINDS DAILY...SUNDAY
NIGHT THROUGH THURSDAY. WITH THE SLOW MOVEMENT...AREAS ESPECIALLY
WEST OF HIGHWAY 83 WILL BE ON THE BACK SIDE OF THE SYSTEM WHICH
WILL LEAD TO A TIGHT PRESSURE GRADIENT...COLD AIR
ADVECTION...SUBSIDENCE AT TIMES...AND WITH STRONG WINDS
ALOFT...ANY MIXING COULD BRING VERY STRONG WINDS TO THE AREA. WILL
NEED TO WATCH THE NEED FOR HEADLINES FOR WINDS THROUGH MUCH OF THE
WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 1135 PM CDT FRI APR 25 2014
VFR IS EXPECTED ALL AREAS TONIGHT THROUGH 21Z SATURDAY.
THEREAFTER...ISOLATED STRONG THUNDERSTORMS MAY
DEVELOP...GENERALLY ALONG AND NORTH OF NEBRASKA HIGHWAY 2. STORM
MOTION WILL BE NORTHEAST AT AROUND 25 MPH. STORM DEVELOPMENT IS
EXPECTED TO BECOME SCATTERED ACROSS NORTHWEST NEB SATURDAY EVENING
WHILE REMAINING ISOLATED ELSEWHERE.
VFR CIGS PREVAIL THROUGH AT LEAST 03Z SATURDAY EVENING. THERE IS A
CHANCE FOR MVFR CIGS IN THE NORTHEAST AS MOISTURE POOLS ALONG A
STATIONARY FRONT. THIS WOULD BECOME MORE LIKELY FROM 06Z SATURDAY
NIGHT ONWARD.
&&
.FIRE WEATHER...
ISSUED AT 1135 PM CDT FRI APR 25 2014
THE RAP AND NAM MODELS ARE GIVING A GOOD SIGNAL FOR RED FLAG
CONDITIONS ACROSS THE FRENCHMAN BASIN SATURDAY. A SURGE OF DRY AIR
WILL BE MOVING NORTH THRU KS DURING THE AFTN. A RED FLAG WARNING
IS IN PLACE FOR FRENCHMAN BASIN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 1 PM TO 10 PM CDT SATURDAY FOR NEZ210.
&&
$$
SHORT TERM...KECK
LONG TERM...BROOKS
AVIATION...CDC
FIRE WEATHER...CDC
AREA FORECAST DISCUSSION
NWS ELKO NV
111 AM PDT SAT APR 26 2014
.SYNOPSIS...A STRONG LATE WINTER STORM WILL BRING WIDESPREAD RAIN
AND SNOW TO NEVADA THROUGH SATURDAY MORNING. DRY WEATHER RETURNS
BRIEFLY SATURDAY NIGHT...FOLLOWED BY MORE SNOW SHOWERS ACROSS
NORTHERN NEVADA ON SUNDAY. DRIER AND WARMER WEATHER IS EXPECTED TO
RETURN NEXT WEEK.
&&
.SHORT TERM...TODAY THROUGH MONDAY.
STRONG BUT PROGRESSIVE LATE WINTER/SPRING STORM SHAPING UP PRETTY
MUCH AS PLANNED THIS MORNING. NAM/GFS/HRRR GUIDANCE IN EXCELLENT
AGREEMENT THAT THE PEAK OF THIS WINTER WEATHER EVENT WILL OCCUR
EARLY THIS MORNING, A FEW HOURS EITHER SIDE OF SUNRISE, ALONG A
TONOPAH-EUREKA-NW WHITE PINE COUNTY-SE ELKO COUNTY LINE. HEAVY WET
SNOW WILL FALL IN THIS CORRIDOR FOR SEVERAL HOURS FROM NOW THROUGH
EARLY SATURDAY MORNING, WITH SEVERAL INCHES EXPECTED ESPECIALLY ON
ELEVATED/VEGETATED SURFACES. IMPACTS WILL BE VERY ELEVATION
DEPENDENT, TYPICAL OF LATE APRIL SNOWSTORMS, BUT PASSES AND
SUMMITS ABOVE 5500 FEET WILL BE SLUSH/SNOW COVERED AND TREACHEROUS
THIS MORNING. WILL ALLOW WINTER STORM WARNINGS TO CONTINUE AS
PLANNED. A WILDCARD IN REGARD TO SNOWFALL AMOUNTS IS CONVECTION.
LIGHTNING DETECTION AND IR SATELLITE CONTINUES TO INDICATE
THUNDERSTORMS ROTATING NORTHWARD INTO WHITE PINE COUNTY. SNOWFALL
RATES WILL BE ERRATIC AND BRIEFLY INTENSE IN THE WINTER STORM
WARNING AREA THIS MORNING. SINCE THE SNOW IS OCCURRING ON A
SATURDAY MORNING WITH NO SCHOOL AND LIMITED COMMUTING, IMPACTS
WILL BE LIMITED, BUT NONETHELESS THESE INTENSE SNOWFALL RATES WILL
LIKELY OVERCOME ANY WARM ROADWAYS AND MAKE TRAVEL DANGEROUS AT
TIMES UNTIL THE MID-MORNING HOURS.
REGARDING ELKO COUNTY...00Z NAM AND HRRR BOTH DEPICT A VERY TIGHT
PRECIPITATION GRADIENT, WITH NW ELKO COUNTY GETTING LITTLE TO NO
SNOW, AND HEAVY SNOW FALLING ON THE RUBY MOUNTAINS AND SE ELKO
COUNTY. SNOWFALL FROM 00Z NAM SHOWS THIS TIGHT GRADIENT AND
APPEARS VERY REASONABLE ON THE NW EDGE OF THE DEFORMATION BAND.
EXPECTING ABOUT 1/2 INCH AT ELKO PROPER, 2-4 INCHES IN SPRING
CREEK, AND NEAR 6 INCHES ADJACENT TO THE RUBY MOUNTAINS, SUCH AS
JIGGS, LEE, AND LAMOILLE. WILL ALSO KEEP THE WINTER WEATHER
ADVISORY GOING FOR ELEVATIONS ABOVE 5500 FEET FOR ELKO COUNTY
THROUGH 11 AM.
PRIMARY SURFACE LOW SW OF ELY EARLY THIS MORNING WILL RAPIDLY PULL
EASTWARD THROUGH UTAH THIS MORNING, AND BE IN WYOMING BY MIDDAY.
IN OTHER WORDS, SYSTEM IS QUITE PROGRESSIVE AND SNOW SHOWERS WILL
TAPER OFF QUICKLY AFTER NOON. ALSO, IMPACTS TO ROADWAYS WILL END
RAPIDLY AFTER 11 AM WITH THE LATE APRIL SUNSHINE, SO ALL WINTER
HEADLINES WILL EXPIRE AT THAT TIME. NW FLOW AND COLD AIR ALOFT IS
QUITE AGITATED THIS AFTERNOON, SO KEPT PLENTY OF SNOW/SNOW PELLET
SHOWERS MENTIONED THIS AFTERNOON, BUT AMOUNTS WILL BE LIGHT.
NW WINDS WILL BE STRONG AND GUSTY TODAY AS THE STORM SYSTEM
DEPARTS. NW WINDS WILL AVERAGE 20-30 MPH WITH HIGHER GUSTS.
BELIEVE WINDS WILL REMAIN BELOW ADVISORY CRITERIA, WITH THE
EXCEPTION OF NW NYE COUNTY/TONOPAH. WIND GUSTS OF 50-55 MPH APPEAR
LIKELY HERE TODAY, AND ISSUED A WIND ADVISORY FOR NW NYE COUNTY
FROM 5 AM THROUGH 5 PM.
A BRIEF BREAK OF DRY WEATHER TONIGHT, WITH LOWS NEAR FREEZING.
SUNDAY...FINAL SHORTWAVE SKIRTS THROUGH NORTHERN NEVADA IN THE
CHILLY NW FLOW. THIS SHOULD BE A PROLIFIC SNOW AND GRAUPEL SHOWER
PRODUCER SUNDAY AFTERNOON MAINLY ACROSS ELKO COUNTY. INCREASED
SHOWER COVERAGE IN THE GRIDS, BUT APPEARS TO BE A HIGH POP/LOW QPF
SITUATION IN WHICH AMOUNTS WILL BE INSIGNIFICANT. STILL,
VISIBILITY WILL BE SHARPLY REDUCED BY THESE PASSING CONVECTIVE
SNOW SHOWERS. 00Z GFS DEPICTS LIFTED INDEX LESS THAN ZERO ACROSS
ELKO COUNTY SUNDAY AFTERNOON, SO MENTIONED ISOLATED THUNDER AS WELL.
SUNDAY WILL BE A DECIDEDLY UNPLEASANT "SPRING" DAY IN NEVADA WITH
TEMPERATURES STUCK IN THE 40S MOST OF THE DAY, AND STRONG GUSTY
WEST WINDS OF 20-30 MPH MAKING IT FEEL EVEN COLDER THAN THAT.
SOME DECREASE IN CLOUDS SUNDAY NIGHT, ALLOWING FOR COLDER LOWS
MONDAY MORNING IN THE MID TO UPPER 20S.
MONDAY...DRY WEATHER RETURNS UNDER DRY NW FLOW. STILL QUITE
CHILLY, WITH TEMPERATURES RUNNING ABOUT 10 DEGREES BELOW LATE
APRIL NORMALS.
TURNER
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY. THE PERIOD BEGINS WITH
STRONG UPPER RIDGE BUILDING INTO THE REGION FOR DRY AND WARMER WEATHER.
THE RIDGE WILL REACH ITS PEAK STRENGTH WEDNESDAY AND THURSDAY THEN
BEGIN TO FLATTEN ON FRIDAY. TEMPS WILL BEGIN THE PERIOD SLIGHTLY
BELOW NORMAL WITH HIGHS IN THE MID 50S TO THE MID 60S BUT WILL END
THE PERIOD MUCH ABOVE NORMAL WITH HIGHS GENERALLY IN THE UPPER 60S
TO THE MID 70S.
&&
.AVIATION...STORM SYSTEM WILL BRING WIDESPREAD SHOWERS THROUGH
SATURDAY MORNING WITH AREAS OF MVFR CONDITIONS. RAIN IS EXPECTED TO
TURN OVER TO SNOW AT KTPH AROUND 04Z, AT KELY AROUND 10Z, AND KEKO
AROUND 12Z BRINGING IFR CONDITIONS.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 11 AM PDT THIS MORNING FOR RUBY
MOUNTAINS/EAST HUMBOLDT RANGE...SOUTHERN LANDER COUNTY AND
SOUTHERN EUREKA COUNTY...WHITE PINE COUNTY.
WINTER WEATHER ADVISORY UNTIL 11 AM PDT THIS MORNING FOR SOUTH
CENTRAL ELKO COUNTY.
WINTER WEATHER ADVISORY UNTIL 11 AM PDT THIS MORNING ABOVE 5500
FEET FOR SOUTHWESTERN ELKO COUNTY.
WIND ADVISORY FROM 5 AM EARLY THIS MORNING TO 5 PM PDT THIS
AFTERNOON FOR NORTHWESTERN NYE COUNTY.
&&
$$
99/92/92
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
324 AM EDT SAT APR 26 2014
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL TRACK EAST ACROSS THE AREA TONIGHT
BRINGING SOME SHOWERS. A FEW SHOWERS WILL LINGER SATURDAY AND
SATURDAY NIGHT AS UPPER LEVEL LOW PRESSURE MOVES ACROSS THE AREA.
HIGH PRESSURE OVER EASTERN CANADA WILL BRING A RETURN TO MAINLY
DRY WEATHER SUNDAY AND MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
810 PM UPDATE...
NUMEROUS LOPRES CNTRS ON SFC ANALYSIS THIS EVNG, ONE OVR UP OF
MICHIGAN, ANOTHER OVR WRN NY AND YET ANOTHER DOWN OVR THE PIEDMONT
OF NC. TWO AREAS OF SHOWERS AFFECTING CWA AT THIS TIME, WITH FIRST
BATCH HVG MVD UP FM PA IN AREA OF ISENTROPIC LIFT. AREA OF SHOWERS
MVG IN FM WRN NY ASSOC WITH FRONTAL BNDRY PUSHING EWRD. BACK EDGE
OF RAIN SHIELD IS HANDLED BEAUTIFULLY BY LATEST HRRR AND EXPECT
THIS TO BE ALONG THE I-81 CORRIDOR BY 07Z. CURRENT GRIDS REFLECT
THIS WELL AND THE ONLY CHG NEEDED WAS TO RMV THUNDER MENTION THRU
THE OVRNGT. NEAREST IN-CLOUD LIGHTNING STRIKES ARE DOWN ACRS THE
VA CAPES WITH LATEST GUIDANCE KEEPING SHOWALTERS WELL ABV ZERO
TONIGHT.
EXPECT LO CLDS TO LINGER THRU THE MRNG HRS WITH A BRIEF POTENTIAL
FOR PCLDY SKIES DRG THE MRNG HRS UNTIL PARENT H5 LOW DROPS ACRS NY
STATE DRG THE DAY. WITH LOW-LVL MOISTURE RMNG, ESPECIALLY IN CNTR
NY, SKIES WL CLD BACK UP BY NOON WITH POSSIBLE SHOWERS DVLPNG DRG
THE DAY.
PREV DISCUSSION BLO...
MID TO HI CLOUDS ARE RAPIDLY INCREASING OVER CENTRAL NY AND
NORTHEAST PA AS PER VISIBLE SATELLITE IMAGERY AS MOISTURE
STREAMS EASTWARD ALOFT AHEAD OF NEXT UPPER LEVEL WAVE AND
ASSOCIATED SURFACE SYSTEM. THIS UPPER LEVEL WAVE WAS SEEN WELL ON
THE WATER VAPOR IMAGERY OVER OHIO AND WAS MOVG EAST/NORTHEAST.
THERE WAS SIGNIFICANT MID TO HIGH LEVEL ISENTROPIC LIFT OR
ALTERNATELY WARM AIR ADVECTION FOR THOSE WHO LIKE PRESSURE
COORDINATES! WITH THIS, WAS ALSO SIGNIFICANT MOISTURE ADVECTION.
THE END RESULT WAS INCREASING MID TO HI CLDS THAT WILL CONTINUE
FOR THE REST OF THE AFTERNOON INTO THE EARLY EVENING HOURS. BY
00Z, THE POTENTIAL VORTICITY MAXIMUM WITH THE UPPER LEVEL WAVE
WILL REACH WRN PA TO WRN NY AND PROVIDE SIGNIFICANT MID LEVEL
LIFTG OF AIR THAT IS ALREADY RISING UP THE MOIST AND SATURATED
ADIABATS. THIS WILL USHER IN A STEADY RAIN FROM SW TO NE ACRS C
NY/NE PA BTWN ABT 22Z FROM SW STEUBEN CO TO WILKES BARRE TO 02Z IN
THE RME AREA. THIS UPPER LEVEL POTENTIAL VORTICITY MAX WILL BECOME
MORE STRETCHED AND ELONGATED IN TIME AS IT PASSES BY C NY/NE PA
BY 6Z-10Z TONIGHT. THE RAIN WILL TAPER OFF AT THIS TIME. MODELS
INDICATE SOME ELEVATED INSTABILITY LATER THIS EVENING WITH
SHOWALTER INDICES DROPPING TO NEAR OR BELOW 0C. SO I HAVE ADDED A
SLGHT CHC TO CHC OF THUNDER IN NE PA AND SC NY LATER IN THE
EVENING. PRECIP WINDS DOWN LATE TONIGHT.
FOR SATURDAY AM, THERE WILL BE PLENTY OF LOW CLOUDS AROUND AS WE
ARE IN BETWEEN THE FIRST UPPER WAVE HEADING TO OUR NORTHEAST AND
THE NEXT SIGNIFICANT UPPER LEVEL WAVE AND SIGNIFICANT SHOT OF COLD
AIR ADVECTION COMING FROM THE GREAT LAKES REGION. HENCE I SEE LOTS
OF LEFT OVER CLOUDS AROUND SAT AM. SHRA WILL DEVELOP BY SAT
PM, AS BNDRY LAYER HEATING COMBINES WITH COOLING ALOFT ARRIVING
WITH THIS NEXT SHOT OF COLD AIR ADVECTION AND LIFTG. HENCE I SEE
PLENTY OF SHRA DEVELOP BY AFTERNOON. SAT WILL BE COOL AND BREEZY
AS WELL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
OPERATIONAL MODELS ARE IN GOOD AGREEMENT WITH THE FORECAST
SCENARIO THROUGH THIS PERIOD. UPPER LEVEL LOW PRESSURE WILL DIG
SOUTHEAST FROM THE NORTHERN GREAT LAKES TO SOUTHERN NEW ENGLAND
SATURDAY NIGHT ACCOMPANIED BY SCATTERED SHOWERS ESPECIALLY NORTH
OF THE NY/PA BORDER. A FEW SNOW FLAKES COULD MIX WITH THE RAIN
LATER SATURDAY NIGHT ESPECIALLY OVER HIGHER ELEVATIONS AS
TEMPERATURES WILL BECOME MARGINAL FOR SOME MIXED PRECIPITATION...
BUT NO ACCUMULATIONS ARE EXPECTED. PRECIPITATION AMOUNTS SATURDAY
NIGHT WILL BE LIGHT. LOW TEMPERATURES WILL BE IN THE 30S.
SCATTERED SHOWERS... SPRINKLES OF MORNING FLURRIES MAY LINGER FOR
AWHILE ON SUNDAY IN MOIST NNW FLOW PATTERN... ESPECIALLY OVER NY
STATE. 850 MB TEMPERATURES DOWN AROUND -4 C WILL NOT BE COLD
ENOUGH FOR ANY REAL LAKE ENHANCEMENT WITH LAKE ONTARIO TEMP STILL
AROUND +2... SO MAIN CONCENTRATION OF SHOWERS MAY BE INLAND FROM
THE FINGER LAKES TO THE SOUTHERN TIER OF NY... AS OPPOSED TO
FARTHER NORTH NEAR LAKE ONTARIO. DRY AIR ASSOCIATED WITH HIGH
PRESSURE OVER EASTERN CANADA WILL EVENTUALLY BREAK UP THE CLOUD
COVER ACROSS THE AREA DURING THE AFTERNOON OR EVENING HOURS.
TEMPERATURES SUNDAY WILL BE BELOW NORMAL WITH READINGS MAINLY IN
THE 50S.
AFTER A CLEAR CHILLY NIGHT SUNDAY NIGHT MONDAY WILL BE DRY WITH
NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES UNDER HIGH PRESSURE AT
THE SURFACE AND ALOFT. THE NEXT CHC OF RAIN WILL BE LATER MONDAY
NIGHT OR TUESDAY AS SURFACE THROUGH UPPER LEVEL LOW PRESSURE
APPROACHES FROM THE SOUTHWEST AND ISENTROPIC LIFT DEVELOPS WITH
INCREASING SW FLOW ALOFT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
320 AM UPDATE...MODELS CONTINUE TO BE IN EXCELLENT AGREEMENT
THROUGH THE MEDIUM RANGE AS AN UPPER LEVEL LOW AND ASSOCIATED SFC
FEATURE SLOWLY TRACK FROM THE MID WEST NORTHEAST INTO THE GREAT
LAKES REGION AND EVENTUALLY EASTERN CANADA. A PROLONGED PERIOD OF
SHOWERS AND COOL WEATHER IS EXPECTED WITH THIS PATTERN. RAISED
POPS INTO THE LIKELY CATEGORY FROM TUESDAY THROUGH WEDNESDAY NIGHT
WITH CHANCE POPS CONTINUING THROUGH FRIDAY.
PREVIOUS DISC...
A STRONG HIGH PRESSURE RIDGE DEVELOPING OVER CENTRAL CANADA WILL
FAVOR UPPER LEVEL LOW PRESSURE TO THE SOUTH-SOUTHEAST OVER THE
CENTRAL AND EASTERN U.S. THROUGH THIS PERIOD. GFS/ECMWF HAVE BEEN
ADVERTISING THIS PATTERN FOR QUITE SOME TIME NOW AND THERE IS HIGH
CONFIDENCE FOR A GENERALLY UNSETTLED PERIOD OF WEATHER DURING THE
MIDDLE AND LATE PART OF NEXT WEEK... ALTHOUGH THE DETAILS OF
COURSE REMAIN VERY UNCLEAR AT THIS TIME RANGE. CURRENT FORECAST
INDICATING AT LEAST A CHC OF SHOWERS EACH DAY FROM TUESDAY THROUGH
FRIDAY APPEARS REASONABLE. TEMPERATURES LOOK TO BE AT LEAST A
LITTLE BELOW NORMAL THROUGH THIS PERIOD... ALTHOUGH HOW FAR BELOW
NORMAL WILL DEVELOP ON EXACTLY WHERE THE UPPER LOW DEVELOPS.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
SFC COLD FRONT HAS CLEARED MOST TAF SITES AND WILL PASS THROUGH
KRME/KAVP DURING THE NEXT COUPLE OF HOURS. BEHIND BOUNDARY
WIDESPREAD IFR CIGS ARE EXPECTED UNTIL 12Z EXCEPT FOR KAVP.
BETWEEN 12Z-16Z CONDITIONS WILL GENERALLY IMPROVE TO VFR BUT A MID
LEVEL SHORT WAVE WILL PRODUCE SCATTERED SHOWERS DURING THE
AFTERNOON WITH BRIEF MVFR CONDITIONS POSSIBLE AT ALL SITES BUT
KELM/KAVP. THIS EVENING COLD NORTHWEST UPSLOPE FLOW WILL RESULT IN
WIDESPREAD MVFR CIGS EXCEPT VFR AT KELM/KAVP.
WINDS BECOMING WESTERLY EARLY THIS MORNING AT 10-12 KNOTS THEN
INCREASING BY MID MORNING TO 12-15 KNOTS WITH GUSTS 20-25 KNOTS.
WINDS DECREASING TO AROUND 10 KNOTS BY 00Z.
OUTLOOK...
SUN-MON...VFR.
TUE AND WED...RESTRICTIONS POSSIBLE IN RAIN SHOWERS.
&&
.FIRE WEATHER...
RAINFALL HAS MOVED INTO NORTHEAST PENNSYLVANIA THIS EVENING WITH
AMOUNTS RANGING FROM A FEW HUNDREDTHS OF AN INCH TO A TENTH OF AN
INCH. WITH SHOWERS EXPECTED TONIGHT AND AGAIN SATURDAY, NO THREAT
FOR FIRE WEATHER CONDITIONS EXIST THROUGH THE WEEKEND.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE/TAC
NEAR TERM...DJN/PVN
SHORT TERM...MSE
LONG TERM...MSE/RRM
AVIATION...RRM
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
158 AM EDT SAT APR 26 2014
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL TRACK EAST ACROSS THE AREA TONIGHT
BRINGING SOME SHOWERS. A FEW SHOWERS WILL LINGER SATURDAY AND
SATURDAY NIGHT AS UPPER LEVEL LOW PRESSURE MOVES ACROSS THE AREA.
HIGH PRESSURE OVER EASTERN CANADA WILL BRING A RETURN TO MAINLY
DRY WEATHER SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TODAY/...
810 PM UPDATE...
NUMEROUS LOPRES CNTRS ON SFC ANALYSIS THIS EVNG, ONE OVR UP OF
MICHIGAN, ANOTHER OVR WRN NY AND YET ANOTHER DOWN OVR THE PIEDMONT
OF NC. TWO AREAS OF SHOWERS AFFECTING CWA AT THIS TIME, WITH FIRST
BATCH HVG MVD UP FM PA IN AREA OF ISENTROPIC LIFT. AREA OF SHOWERS
MVG IN FM WRN NY ASSOC WITH FRONTAL BNDRY PUSHING EWRD. BACK EDGE
OF RAIN SHIELD IS HANDLED BEAUTIFULLY BY LATEST HRRR AND EXPECT
THIS TO BE ALONG THE I-81 CORRIDOR BY 07Z. CURRENT GRIDS REFLECT
THIS WELL AND THE ONLY CHG NEEDED WAS TO RMV THUNDER MENTION THRU
THE OVRNGT. NEAREST IN-CLOUD LIGHTNING STRIKES ARE DOWN ACRS THE
VA CAPES WITH LATEST GUIDANCE KEEPING SHOWALTERS WELL ABV ZERO
TONIGHT.
EXPECT LO CLDS TO LINGER THRU THE MRNG HRS WITH A BRIEF POTENTIAL
FOR PCLDY SKIES DRG THE MRNG HRS UNTIL PARENT H5 LOW DROPS ACRS NY
STATE DRG THE DAY. WITH LOW-LVL MOISTURE RMNG, ESPECIALLY IN CNTR
NY, SKIES WL CLD BACK UP BY NOON WITH POSSIBLE SHOWERS DVLPNG DRG
THE DAY.
PREV DISCUSSION BLO...
MID TO HI CLOUDS ARE RAPIDLY INCREASING OVER CENTRAL NY AND
NORTHEAST PA AS PER VISIBLE SATELLITE IMAGERY AS MOISTURE
STREAMS EASTWARD ALOFT AHEAD OF NEXT UPPER LEVEL WAVE AND
ASSOCIATED SURFACE SYSTEM. THIS UPPER LEVEL WAVE WAS SEEN WELL ON
THE WATER VAPOR IMAGERY OVER OHIO AND WAS MOVG EAST/NORTHEAST.
THERE WAS SIGNIFICANT MID TO HIGH LEVEL ISENTROPIC LIFT OR
ALTERNATELY WARM AIR ADVECTION FOR THOSE WHO LIKE PRESSURE
COORDINATES! WITH THIS, WAS ALSO SIGNIFICANT MOISTURE ADVECTION.
THE END RESULT WAS INCREASING MID TO HI CLDS THAT WILL CONTINUE
FOR THE REST OF THE AFTERNOON INTO THE EARLY EVENING HOURS. BY
00Z, THE POTENTIAL VORTICITY MAXIMUM WITH THE UPPER LEVEL WAVE
WILL REACH WRN PA TO WRN NY AND PROVIDE SIGNIFICANT MID LEVEL
LIFTG OF AIR THAT IS ALREADY RISING UP THE MOIST AND SATURATED
ADIABATS. THIS WILL USHER IN A STEADY RAIN FROM SW TO NE ACRS C
NY/NE PA BTWN ABT 22Z FROM SW STEUBEN CO TO WILKES BARRE TO 02Z IN
THE RME AREA. THIS UPPER LEVEL POTENTIAL VORTICITY MAX WILL BECOME
MORE STRETCHED AND ELONGATED IN TIME AS IT PASSES BY C NY/NE PA
BY 6Z-10Z TONIGHT. THE RAIN WILL TAPER OFF AT THIS TIME. MODELS
INDICATE SOME ELEVATED INSTABILITY LATER THIS EVENING WITH
SHOWALTER INDICES DROPPING TO NEAR OR BELOW 0C. SO I HAVE ADDED A
SLGHT CHC TO CHC OF THUNDER IN NE PA AND SC NY LATER IN THE
EVENING. PRECIP WINDS DOWN LATE TONIGHT.
FOR SATURDAY AM, THERE WILL BE PLENTY OF LOW CLOUDS AROUND AS WE
ARE IN BETWEEN THE FIRST UPPER WAVE HEADING TO OUR NORTHEAST AND
THE NEXT SIGNIFICANT UPPER LEVEL WAVE AND SIGNIFICANT SHOT OF COLD
AIR ADVECTION COMING FROM THE GREAT LAKES REGION. HENCE I SEE LOTS
OF LEFT OVER CLOUDS AROUND SAT AM. SHRA WILL DEVELOP BY SAT
PM, AS BNDRY LAYER HEATING COMBINES WITH COOLING ALOFT ARRIVING
WITH THIS NEXT SHOT OF COLD AIR ADVECTION AND LIFTG. HENCE I SEE
PLENTY OF SHRA DEVELOP BY AFTERNOON. SAT WILL BE COOL AND BREEZY
AS WELL.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
OPERATIONAL MODELS ARE IN GOOD AGREEMENT WITH THE FORECAST
SCENARIO THROUGH THIS PERIOD. UPPER LEVEL LOW PRESSURE WILL DIG
SOUTHEAST FROM THE NORTHERN GREAT LAKES TO SOUTHERN NEW ENGLAND
SATURDAY NIGHT ACCOMPANIED BY SCATTERED SHOWERS ESPECIALLY NORTH
OF THE NY/PA BORDER. A FEW SNOW FLAKES COULD MIX WITH THE RAIN
LATER SATURDAY NIGHT ESPECIALLY OVER HIGHER ELEVATIONS AS
TEMPERATURES WILL BECOME MARGINAL FOR SOME MIXED PRECIPITATION...
BUT NO ACCUMULATIONS ARE EXPECTED. PRECIPITATION AMOUNTS SATURDAY
NIGHT WILL BE LIGHT. LOW TEMPERATURES WILL BE IN THE 30S.
SCATTERED SHOWERS... SPRINKLES OF MORNING FLURRIES MAY LINGER FOR
AWHILE ON SUNDAY IN MOIST NNW FLOW PATTERN... ESPECIALLY OVER NY
STATE. 850 MB TEMPERATURES DOWN AROUND -4 C WILL NOT BE COLD
ENOUGH FOR ANY REAL LAKE ENHANCEMENT WITH LAKE ONTARIO TEMP STILL
AROUND +2... SO MAIN CONCENTRATION OF SHOWERS MAY BE INLAND FROM
THE FINGER LAKES TO THE SOUTHERN TIER OF NY... AS OPPOSED TO
FARTHER NORTH NEAR LAKE ONTARIO. DRY AIR ASSOCIATED WITH HIGH
PRESSURE OVER EASTERN CANADA WILL EVENTUALLY BREAK UP THE CLOUD
COVER ACROSS THE AREA DURING THE AFTERNOON OR EVENING HOURS.
TEMPERATURES SUNDAY WILL BE BELOW NORMAL WITH READINGS MAINLY IN
THE 50S.
AFTER A CLEAR CHILLY NIGHT SUNDAY NIGHT MONDAY WILL BE DRY WITH
NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES UNDER HIGH PRESSURE AT
THE SURFACE AND ALOFT. THE NEXT CHC OF RAIN WILL BE LATER MONDAY
NIGHT OR TUESDAY AS SURFACE THROUGH UPPER LEVEL LOW PRESSURE
APPROACHES FROM THE SOUTHWEST AND ISENTROPIC LIFT DEVELOPS WITH
INCREASING SW FLOW ALOFT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
A STRONG HIGH PRESSURE RIDGE DEVELOPING OVER CENTRAL CANADA WILL
FAVOR UPPER LEVEL LOW PRESSURE TO THE SOUTH-SOUTHEAST OVER THE
CENTRAL AND EASTERN U.S. THROUGH THIS PERIOD. GFS/ECMWF HAVE BEEN
ADVERTISING THIS PATTERN FOR QUITE SOME TIME NOW AND THERE IS HIGH
CONFIDENCE FOR A GENERALLY UNSETTLED PERIOD OF WEATHER DURING THE
MIDDLE AND LATE PART OF NEXT WEEK... ALTHOUGH THE DETAILS OF
COURSE REMAIN VERY UNCLEAR AT THIS TIME RANGE. CURRENT FORECAST
INDICATING AT LEAST A CHC OF SHOWERS EACH DAY FROM TUESDAY THROUGH
FRIDAY APPEARS REASONABLE. TEMPERATURES LOOK TO BE AT LEAST A
LITTLE BELOW NORMAL THROUGH THIS PERIOD... ALTHOUGH HOW FAR BELOW
NORMAL WILL DEVELOP ON EXACTLY WHERE THE UPPER LOW DEVELOPS.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
SFC COLD FRONT HAS CLEARED MOST TAF SITES AND WILL PASS THROUGH
KRME/KAVP DURING THE NEXT COUPLE OF HOURS. BEHIND BOUNDARY
WIDESPREAD IFR CIGS ARE EXPECTED UNTIL 12Z EXCEPT FOR KAVP.
BETWEEN 12Z-16Z CONDITIONS WILL GENERALLY IMPROVE TO VFR BUT A MID
LEVEL SHORT WAVE WILL PRODUCE SCATTERED SHOWERS DURING THE
AFTERNOON WITH BRIEF MVFR CONDITIONS POSSIBLE AT ALL SITES BUT
KELM/KAVP. THIS EVENING COLD NORTHWEST UPSLOPE FLOW WILL RESULT IN
WIDESPREAD MVFR CIGS EXCEPT VFR AT KELM/KAVP.
WINDS BECOMING WESTERLY EARLY THIS MORNING AT 10-12 KNOTS THEN
INCREASING BY MID MORNING TO 12-15 KNOTS WITH GUSTS 20-25 KNOTS.
WINDS DECREASING TO AROUND 10 KNOTS BY 00Z.
OUTLOOK...
SUN-MON...VFR.
TUE AND WED...RESTRICTIONS POSSIBLE IN RAIN SHOWERS.
&&
.FIRE WEATHER...
RAINFALL HAS MOVED INTO NORTHEAST PENNSYLVANIA THIS EVENING WITH
AMOUNTS RANGING FROM A FEW HUNDREDTHS OF AN INCH TO A TENTH OF AN
INCH. WITH SHOWERS EXPECTED TONIGHT AND AGAIN SATURDAY, NO THREAT
FOR FIRE WEATHER CONDITIONS EXIST THROUGH THE WEEKEND.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE/TAC
NEAR TERM...DJN/PVN
SHORT TERM...MSE
LONG TERM...MSE
AVIATION...RRM
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS BISMARCK ND
356 AM CDT SAT APR 26 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CDT SAT APR 26 2014
THE HIGHLIGHT OF THE SHORT TERM IS PRECIPITATION POTENTIAL.
FOR TODAY...THE HRRR HAS HAD A GOOD HANDLE ON THE NARROW BAND OF
RAIN SHOWERS MOVING INTO SOUTHWEST NORTH DAKOTA AS OF 0830 UTC
WITH THE LEADING SHORTWAVE. THUS...WILL FOLLOW THE 07 UTC HRRR AND
ITS PARENT RAP FOR POPS THIS MORNING AND INTO THE AFTERNOON. THESE
SOLUTIONS ARE IN AGREEMENT WITH THE 00 UTC 4 KM WRF AND LARGER
SCALE DETERMINISTIC GUIDANCE WHICH QUICKLY MOVE THE RAIN SHOWERS
TO THE INTERNATIONAL BORDER BY EARLY AFTERNOON. THUS...AFTER THE
NARROW BAND OF SHOWERS PASS...THE DAY SHOULD BE PRECIPITATION FREE
FOR NEARLY ALL OF THE CWA. IN REGARDS TO WINDS FOR
TODAY...EXPECT WIDESPREAD EAST-SOUTHEAST GUSTS OF 30-35 KTS FOR
MOST AREAS. HOWEVER...A LOW LEVEL INVERSION IN WARM AIR ADVECTION
WILL LIMIT THE TRANSFER OF HIGHER MOMENTUM AND FORGO THE NEED FOR
A WIND ADVISORY.
FOR TONIGHT...SURFACE LOW PRESSURE CONTINUES TO DEEPEN ACROSS
WESTERN NEBRASKA...AS THE OVERALL SYSTEM BECOMES NEARLY VERTICALLY
STACKED LATE TONIGHT AS THE POTENT UPPER LEVEL WAVE PROPAGATES
ONTO THE PLAINS. RESULTING MOISTURE TRANSPORT INCREASES ACROSS THE
NORTHERN PLAINS...WITH RAIN SHOWER COVERAGE INCREASING AFTER 06
UTC ACROSS WESTERN NORTH DAKOTA IN THE VICINITY OF THE INVERTED
TROUGH EXTENDING INTO EASTERN MONTANA...AND ACROSS SOUTHERN NORTH
DAKOTA IN LOW LEVEL WARM AIR ADVECTION. THE BULK OF ELEVATED
INSTABILITY TONIGHT REMAINS IN SOUTH DAKOTA...HOWEVER AN EMBEDDED
THUNDERSTORM IS POSSIBLE ACROSS FAR SOUTH CENTRAL NORTH DAKOTA .
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 329 AM CDT SAT APR 26 2014
THE MAIN FORECAST PROBLEM IN THE EXTENDED PERIOD WILL BE THE STRONG
SPRING STORM SYSTEM AFFECTING ALL OF WESTERN AND CENTRAL NORTH
DAKOTA. MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH THE TRACK OF
THE SURFACE AND UPPER LEVEL FEATURES THROUGH TUESDAY...WITH
DIFFERENCES INCREASING THEREAFTER. STILL SOME DIFFERENCES IN QPF
PATTERN THROUGH THE EVOLUTION OF THE SYSTEM WITH THE GFS BEING THE
DRIEST ACROSS PORTIONS OF CENTRAL AND EASTERN NORTH DAKOTA. ALL
MODELS HOWEVER ARE PINPOINTING THE FAR SOUTHWEST WITH SOME OF THE
HIGHEST RAINFALL AMOUNTS.
STRONG SHORTWAVE JUST MOVING ONTO THE SOUTHERN CALIFORNIA COAST WITH
AN UPPER LEVEL LOW CLOSING OFF JUST TO ITS NORTH. BROAD FETCH OF
MOISTURE IN SOUTHWEST UPPER FLOW INTO THE NORTHERN PLAINS...SETTING
THE STAGE FOR AN EXTENDED PERIOD OF RAINY WEATHER.
BY SUNDAY MORNING THE UPPER LOW IS PROGGED TO BE OVER EASTERN
COLORADO WITH A RAPIDLY DEEPENING SURFACE SYSTEM OVER THE CENTRAL
PLAINS. THE INITIAL SURGE OF ENERGY MOVES INTO THE AREA LATE TONIGHT
INTO SUNDAY MORNING. ALTHOUGH BEST ELEVATED INSTABILITY REMAINS JUST
TO OUR SOUTH...SYSTEM IS STRONG ENOUGH THAT A MENTION OF THUNDER
SEEMED WARRANTED SUNDAY MORNING. BEST PRECIPITATION CHANCES DURING
THE DAY WILL BE OVER THE SOUTHWEST HALF OF THE CWA...AND THERE MAY
BE PERIODS OF NO RAIN AS WELL AS DRIER AIR WRAPS AROUND THE STACKED
SYSTEM.
ANOTHER STRONG IMPULSE LIFTS THROUGH THE AREA SUNDAY NIGHT
AS THE UPPER LOW REACHES ITS FARTHEST POINT NORTH BEFORE WOBBLING
BACK SOUTH ON MONDAY. BY THIS TIME CHANCES OF CONVECTION WILL BE
MINIMAL AS COOLER AIR GETS PULLED INTO THE SYSTEM. THE FAR NORTH AND
HIGHER ELEVATIONS IN THE FAR WEST COULD SEE PERIODS OF SNOW LATE
SUNDAY NIGHT INTO EARLY MONDAY MORNING. LATEST MODEL RUNS ARE A
LITTLE COOLER IN THE WEST SO WILL NEED TO MONITOR FOR SOME LIGHT
ACCUMULATING SNOWS IN THE FAR WEST...BUT AT THIS TIME ITS TOO EARLY
FOR ANY MENTION OF ACCUMULATIONS.
PRECIPITATION BEGINS TO WANE ON MONDAY AS THE LOW DROPS SOUTH.
ALTHOUGH LOW LEVEL FORCING WILL BE ON THE DECREASE...SYNOPTIC SCALE
FORCING WILL REMAIN THROUGH TUESDAY AS WE REMAIN UNDER THE CYCLONIC
FLOW OF THE UPPER LEVEL LOW. THUS LIKELY POPS REMAIN MONDAY INTO
MONDAY NIGHT...WITH HIGH CHANCE POPS TUESDAY. AGAIN WE WILL SEE THE
POSSIBILITY OF SNOW MONDAY NIGHT INTO TUESDAY MORNING...AND LIGHT
ACCUMULATIONS ARE CERTAINLY NOT OUT OF THE QUESTION.
THE UPPER LOW LIFTS BACK NORTHWARD TUESDAY NIGHT INTO WEDNESDAY WITH
ANOTHER WAVE OF MOISTURE SWINGING EAST TO WEST ACROSS THE AREA ON
WEDNESDAY BRINGING A CHANCE OF RAIN OR SNOW SHOWERS. THE SYSTEM
FINALLY EXITS THE ARE LATE IN THE WORK WEEK...WITH ANOTHER IMPULSE
IN A NORTHWEST FLOW PATTERN POSSIBLE BY NEXT WEEKEND.
ALL IN ALL A WET AND COOL PERIOD IS IN STORE THROUGH MOST OF THE
EXTENDED PERIOD. WILL ISSUE A HYDROLOGIC STATEMENT MENTIONING THE
POSSIBILITY OF FLOODING DUE TO AN EXTENDED PERIOD OF RAIN. WPC
DEPICTS PORTIONS OF THE SOUTHWEST WITH A SLIGHT CHANCE OF EXCESSIVE
RAINFALL 12Z SUNDAY THROUGH 12Z MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 353 AM CDT SAT APR 26 2014
LIGHT RAIN SHOWERS HAVE MOVED INTO SOUTHWEST NORTH DAKOTA AS OF
830 UTC...AND WILL CONTINUE TO MOVE NORTH-NORTHEAST THROUGH
SATURDAY MORNING. RAIN SHOWER ACTIVITY IN THE AFTERNOON IS
EXPECTED TO LARGELY REMAIN NORTH OF KISN AND KMOT. STRONG EAST-
SOUTHEAST WINDS WITH GUSTS OF 30-35 KTS ARE EXPECTED FOR MUCH OF
THE AREA TODAY. A LARGE STORM SYSTEM WILL BEGIN TO IMPACT WESTERN
AND CENTRAL NORTH DAKOTA SATURDAY NIGHT...WITH CONDITIONS TRENDING
TOWARDS MVFR/IFR IN STRATUS AND RAIN.
&&
.HYDROLOGY...
ISSUED AT 353 AM CDT SAT APR 26 2014
ISSUED A HYDROLOGIC OUTLOOK...ESF...FOR WESTERN NORTH DAKOTA
REGARDING THE UPCOMING HEAVY RAIN EVENT AND POTENTIAL IMPACTS. AS
OF NOW...THE 00 UTC DETERMINISTIC SUITE REMAINS IN SOME
DISAGREEMENT ON THE PLACEMENT OF THE HEAVIEST QPF AXIS. THIS HAS
SIGNIFICANT IMPACTS IN BASIN HYDROLOGIC RESPONSE. FURTHERMORE...THE
REMOVAL OF FROST FROM THE GROUND AND RECENT DRY WEATHER PLACES
ADDITIONAL UNCERTAINTY IN HOW MUCH WATER THE SOILS WILL BE ABLE TO
HOLD. THAT SAID...RIVER AND STREAM RISES...POTENTIALLY ABOVE
FLOOD STAGE...ARE POSSIBLE. HOWEVER...WHICH SPECIFIC WATERWAYS
RESPOND THE MOST IS HIGHLY DEPENDENT ON QPF PLACEMENT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...AYD
LONG TERM...TWH
AVIATION...AYD
HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
108 AM CDT SAT APR 26 2014
.UPDATE...
ISSUED AT 107 AM CDT SAT APR 26 2014
FOLLOWED THE TREND OF THE 02 THROUGH 04 UTC HRRR RUNS FOR POPS THE
REMAINDER OF THE NIGHT...WHICH IS TO SCALE BACK THE OVERALL
COVERAGE AND INTENSITY OF RAIN. THIS IS ALSO IN LINE WITH THE
LARGER SCALE 00 UTC DETERMINISTIC MODELS.
UPDATE ISSUED AT 920 PM CDT FRI APR 25 2014
LATE EVENING UPDATE FOR MINOR CHANGES TO POPS FOR THE OVERNIGHT
HOURS. A SHORTWAVE TROUGH WILL LIFT NORTHEAST THROUGH THE REGION
OVERNIGHT INTO SATURDAY MORNING...SUPPORTING AN AREA OF SHOWERS.
MUCH OF THE RAIN SHOULD OCCUR PRIOR TO MIDDAY...WITH ONLY ISOLATED
SHOWERS DURING THE AFTERNOON. WINDS MAY APPROACH ADVISORY CRITERIA
SATURDAY...ESPECIALLY ACROSS THE SOUTHWEST.
UPDATE ISSUED AT 623 PM CDT FRI APR 25 2014
NO SIGNIFICANT CHANGES FOR EARLY EVENING UPDATE. A BAND OF SHOWERS
IS EXPECTED TO LIFT INTO SOUTHERN NORTH DAKOTA DURING THE EARLY
MORNING HOURS...AND CONTINUE TO LIFT NORTH ACROSS THE REST OF THE
FORECAST AREA SATURDAY MORNING. SHOWERS WILL DIMINISH ACROSS THE
NORTH SATURDAY AFTERNOON...FOLLOWED BY MORE SUBSTANTIAL RAINFALL
LATE SATURDAY NIGHT AND SUNDAY.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 235 PM CDT FRI APR 25 2014
FRIDAY AFTERNOON...A FRONTAL BOUNDARY EXTENDED FROM NORTHEAST
MONTANA ACROSS WEST CENTRAL NORTH DAKOTA INTO THE SOUTHEAST. NORTH
OF THIS FRONT COOL AIR AND CLOUDS COVERED THE NORTH CENTRAL KEEPING
THIS REGION QUITE COOL FRIDAY. TONIGHT...THE LOCATION OF THIS FRONT
WILL PLAY AN IMPORTANT ROLE IN THE LOCATION OF THE SHOWERS AND
THUNDERSTORMS. FOR THE REST OF THIS AFTERNOON...WIND CONVERGENCE
WAS RESPONSIBLE FOR INCREASING CUMULUS CLOUDS ACROSS THE FRONTAL
ZONE IN NORTHWEST NORTH DAKOTA. SEEING SOME SCATTERED SHOWERS IN
NORTHEAST MONTANA AND WILL ADD A LATE AFTERNOON/EVENING PERIOD FOR
SHOWERS NORTHWEST.
TONIGHT...THE ONSET OF SHOWERS ACROSS THE SOUTHWEST SHOULD BEGIN MID
EVENING AS THE EVENING SHOWERS ACROSS THE NORTHWEST FADE AWAY
AFTER PEAK HEATING. PLACED THE BOUNDARY FOR THUNDERSTORMS ACROSS
THE FAR SOUTHWEST TONIGHT AND THE SOUTH CENTRAL SATURDAY FOLLOWING
THE 1KM MIXED LAYER CAPE. SEE LITTLE IN THE WAY OF INSTABILITY TO
SUPPORT THUNDERSTORMS NORTH IF INTERSTATE 94 ON SATURDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 235 PM CDT FRI APR 25 2014
LATEST WATER VAPOR IMAGERY SHOWS A NICE DARKENING
SIGNATURE/SUBSIDENCE JUST BEHIND A SHORTWAVE SEEN CIRCULATING NEAR
38N/128W. WITH A JET STREAK STILL UPSTREAM OF THIS SHORTWAVE
TROUGH...EXPECT A CONTINUE DIGGING AND DEEPENING OF THE SYSTEM AS IT
SLIDES INTO THE SOUTHWEST SATURDAY...THEN CLOSES OFF AS IT EJECTS
INTO THE CENTRAL PLAINS/UPPER MIDWEST SUNDAY THROUGH WEDNESDAY. THE
OVERALL TREND CONTINUES TO SHOW A WIDESPREAD RAIN EVENT SUNDAY INTO
TUESDAY. TOTAL RAINFALL AMOUNTS THROUGH TUESDAY LOOK TO RANGE FROM 1
TO 1.25 INCHES FROM FROM THE TURTLE MOUNTAINS INTO THE JAMES RIVER
VALLEY...INCREASING TOWARDS THE WEST WITH 2 TO 3 INCHES OF LIQUID
FROM CROSBY TO WILLISTON AND SOUTH TO BOWMAN. THERE CONTINUES TO BE
A WEAK THREAT OF ELEVATED CONVECTION IN THE FAR SOUTHWEST AND FAR
SOUTH CENTRAL SUNDAY...BUT THIS LOOKS TOO MARGINAL FOR ANY MENTION
OF THUNDERSTORMS AT THIS TIME. THERE WILL LIKELY BE A MIX OF RAIN
AND SNOW AT NIGHT...ESPECIALLY SUNDAY NIGHT AND MONDAY NIGHT ACROSS
THE NORTHWEST AND NORTH CENTRAL. HOWEVER ANY SNOWFALL ACCUMULATIONS
WILL REMAIN NEGLIGIBLE. AS THE AFOREMENTIONED UPPER LOW AND
ASSOCIATED SURFACE LOW APPROACH LATE SATURDAY NIGHT INTO SUNDAY...A
STRONG EAST TO SOUTHEAST WIND WILL DEVELOP WITH WINDS OF 25 TO 40
MPH ACROSS CENTRAL NORTH DAKOTA. THE STRONGEST SUSTAINED WINDS ARE
FORECAST IN SOUTH CENTRAL NORTH DAKOTA AND THIS MAY NECESSITATE A
WINDY ADVISORY IN THE FUTURE.
THE UPPER LOW WILL SLOWLY MEANDER INTO THE UPPER MIDWEST TUESDAY AND
AND INTO THE GREAT LAKES WEDNESDAY/THURSDAY. HIGHS IN THE 40S WILL
DOMINATE SUNDAY THROUGH TUESDAY WITH A GRADUAL MODERATING TREND
WEDNESDAY THROUGH FRIDAY. PRECIPITATION WILL BEGIN TO WANE TUESDAY
WITH DRIER WEATHER WEDNESDAY.
BEYOND WEDNESDAY...THE UPPER AIR PATTERN IS IN QUESTION...WITH THE GFS
TRYING TO TRANSITION FROM A NORTHERLY FLOW TO A BROAD/SOMEWHAT
MOIST WESTERLY FLOW INTO THE UPCOMING WEEKEND. MEANWHILE THE ECMWF
MAINTAINS A STRONGER NORTHWEST FLOW WITH SUCCESSIVE SURGES OF COOLER
AIR AND SOME PRECIPITATION INTO NORTH DAKOTA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 107 AM CDT SAT APR 26 2014
LIGHT RAIN SHOWERS WILL MOVE INTO SOUTHWEST NORTH DAKOTA AFTER 08
UTC TONIGHT...AND MOVE NORTH-NORTHEAST THROUGH SATURDAY MORNING.
RAIN SHOWER ACTIVITY IN THE AFTERNOON IS EXPECTED TO LARGELY
REMAIN NORTH OF KISN AND KMOT. HOWEVER...A LARGE STORM SYSTEM WILL
BEGIN TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA SATURDAY
NIGHT...WITH CONDITIONS TRENDING TOWARDS MVFR/IFR IN STRATUS AND
RAIN.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...WAA
LONG TERM...KS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
100 AM CDT SAT APR 26 2014
.DISCUSSION...SEE AVIATION BELOW FOR 06Z TAF UPDATE.
&&
.AVIATION...MVFR TO IFR CEILINGS ONCE AGAIN FILLING IN ACROSS THE
REGION TONIGHT. EXPECT LOW CLOUD DECK TO REMAIN OVER THE REGION
OVERNIGHT AND INTO THE MID MORNING. LIGHT PATCHY FOG WILL ALSO
SLIGHTLY IMPACT VISIBILITIES ACROSS THE REGION...BUT WITH WINDS
OVERNIGHT REMAINING MORE ELEVATED THAN YESTERDAY...NOT EXPECTING
FOG TO BECOME DENSE. LOWEST VSBYS WILL OCCUR AOA
KVCT...TEMPORARILY DROPPING TO IFR CRITERIA IN THE EARLY MORNING THROUGH
SUNRISE. EXPECT INCREASED SOUTH TO SOUTHEAST WINDS DURING THE DAY
SATURDAY. DURING THE EARLY AFTERNOON CEILINGS WILL LIFT AND
DISSIPATE ENOUGH FOR VFR CRITERIA AT KVCT...KALI...AND KLRD.
MVFR CEILINGS WILL LINGER OVER KCRP DURING THE AFTERNOON HOWEVER.
SIMILAR CONDITIONS WILL BE LIKELY DURING THE LATE OVERNIGHT HOURS
THEN ONCE AGAIN.
&&
.PREV DISCUSSION... /ISSUED 730 PM CDT FRI APR 25 2014/
DISCUSSION...THE PAST SEVERAL RUNS OF THE HRRR HAVE CONTINUED TO
INDICATE THAT SOME OF THE ONGOING SIERRA MADRE CONVECTION MAY
AFFECT WESTERN PORTIONS OF WEBB COUNTY LATER THIS EVENING BEFORE
EVENTUALLY DISSIPATING IN AN INCREASINGLY CAPPED ENVIRONMENT.
CURRENT RADAR TRENDS LEAD CREDENCE TO THE HRRR. WL THUS INTRODUCE
SLIGHT CHC POPS FOR WESTERN WEBB COUNTY FOR THIS EVENING.
OTHERWISE...MOSTLY MINOR CHANGES WERE MADE FOR THIS EVENING
PACKAGE BASED UPON CURRENT AND EXPECTED TRENDS. MORE WIND TNT WL
KEEP FOG FROM GETTING TOO WIDESPREAD AND TOO LOW VSBY-WISE.
MARINE...THE OVERALL GRADIENT HAS INCREASED FROM 24 HOURS AGO BUT
IS STILL EXPECTED TO REMAIN BELOW SCA THRESHOLDS FOR TNT. DID
LOWER THE WAVEHEIGHTS BY AROUND 1 FOOT FROM THE PREVIOUS PACKAGE
FOR TONIGHT AND SATURDAY. AN INCREASING GRADIENT/LLJ IN RESPONSE
TO AN APPROACHING STRONG S/WV CURRENTLY MOVING THROUGH CALIFORNIA
WL PRODUCE SCA CONDITIONS FOR THE SRN BAYS SATURDAY AFTN AND MOST
AREAS SAT NIGHT INTO SUNDAY.
PREV DISCUSSION... /ISSUED 632 PM CDT FRI APR 25 2014/
DISCUSSION...SEE AVIATION SECTION FOR 00Z TAFS.
AVIATION...OTHER THAN SOME SPOTTY MVFR CEILINGS NEAR THE COAST...VFR
CONDITIONS WILL CONTINUE OVER THE REGION DURING THE EARLY EVENING HOURS.
EXPECT STRATUS/MVFR CEILINGS AROUND 1500 FEET TO DEVELOP OVER THE COASTAL
PLAINS 03-04Z. CEILINGS ARE EXPECTED TO LOWER TO IFR FROM 06-07Z WITH
MVFR VSBYS WITH FOG OVER COASTAL SITES. OCCASIONAL IFR VSBYS WILL BE
POSSIBLE OVER THE VICTORIA CROSSROADS BEFORE SUNRISE. MVFR CIGS WILL
SPREAD WEST INTO LAREDO AREA BY 08Z AND PERSIST UNTIL 16Z SATURDAY.
WILL CONTINUE TO MONITOR ISOLATED CONVECTION THAT DEVELOPED OVER THE
HIGHER TERRAIN IN NORTHEAST MEXICO AHEAD OF A WEAK UPPER LEVEL
DISTURBANCE. ADVECTION OF DRIER AIR IN THE LOWER LEVELS SHOULD INHIBIT
ACTIVITY FROM REACHING THE RIO GRANDE LATER THIS EVENING. MVFR CIGS
WILL PERSIST THROUGH THE MORNING WITH CLOUDS SCATTERING OUT FOR MOST
OF THE REGION EXCEPT FOR THE COASTAL BEND WHERE MVFR CIGS MAY PERSIST
THROUGH THE AFTERNOON.
PREV DISCUSSION... /ISSUED 323 PM CDT FRI APR 25 2014/
SHORT TERM...25 TO 30 KT LLJ EXPECTED TO DEVELOP TONIGHT IN RESPONSE
TO A DEEPENING LOW PRESSURE SYSTEM OVER THE HIGH PLAINS. THIS...IN
COMBINATION WITH AMPLE MOISTURE TO AID IN NOCTURNAL STRATUS
DEVELOPMENT...SHOULD PREVENT MUCH IN THE WAY OF FOG DEVELOPMENT
TONIGHT...THOUGH WIDESPREAD LOW STRATUS IS LIKELY. AFTER THE CLOUD
DECK BURNS OFF...TOMORROW WILL SEE TEMPS ABOVE AVERAGE...BECOMING
DOWNRIGHT TOASTY OVER THE WESTERN BRUSH COUNTRY AS A DRYLINE
CROSSES THE RIO GRANDE IN THE AFTERNOON WITH NEAR TRIPLE DIGIT
HIGHS. BY LATE AFTERNOON...UPPER LEVEL DIFLUENCE FROM THE PHASING
OF THE POLAR AND SUBTROPICAL JETS WILL BEGIN TO AFFECT THE REGION.
30-40 KT 0-6 KM BULK SHEAR...2000-3000 J/KG OF MLCAPE...AND
MODERATE HELICITY VALUES MAY ALLOW FOR SOME STRONG THUNDERSTORMS
TO DEVELOP...PARTICULARLY DEVELOPING OFF OF THE SIERRA MADRE AND
CROSSING THE RIO GRANDE. THE STORM ENVIRONMENT LOOKS TO BE
SLIGHTLY LESS FAVORABLE NEAR THE COAST...BUT HAVE STILL INCLUDED
MUCH OF THE AREA WITH 20 POPS. THE ENVIRONMENT WILL REMAIN
FAVORABLE OVERNIGHT.
LONG TERM (SUNDAY THROUGH FRIDAY)...PERIOD COULD BEGIN ACTIVE WITH
THUNDERSTORMS /POSSIBLY MCS/ MOVING EASTWARD THROUGH THE CWA AS
THETA E RIDGE PROGRESSES EASTWARD. MOST OF THE AREA SHOULD BE CAPPED
WITH 850 TEMPS 20 DEGREES OR HIGHER...BUT IF CONVECTION DEVELOPS IT
MAY SUSTAIN ITSELF INTO NORTHEASTERN PARTS OF CWA.
DRYLINE MOVES THROUGH MUCH OF THE AREA ON SUNDAY WITH TEMPERATURES
VERY WARM...INTO THE 90S FOR MOST OF THE AREA...WITH ABOVE 100
DEGREES POSSIBLE ALONG THE RIO GRANDE. THIS IS DEPENDENT THOUGH ON
ANY LINGERING MID/HIGH CLOUD THAT COULD BE LEFTOVER FROM POTENTIAL
MCS SATURDAY NIGHT/SUNDAY. MONDAY HAS SIMILAR SETUP...BUT WITHOUT
THE CAVEAT OF MID/HIGH CLOUDS. SHOULD SEE HOT TEMPERATURES BEHIND
DRYLINE THAT WILL MOVE THROUGH MOST OF THE AREA.
TRICKY TEMPERATURES FOR TUESDAY WITH COLD FRONT TIMING AROUND NOON.
WILL SEE SOME /THOUGH NOT SIGNIFICANT/ COLD ADVECTION BEHIND THE
FRONT...SO THINK TEMPS SHOULD BE SEVERAL DEGREES COOLER THAN
MONDAY...THOUGH STILL IN THE 90S UNLESS TIMING SPEEDS UP. MOISTURE
POOLING ALONG AND OFF THE COAST WILL PRODUCE A SLIGHT CHANCE FOR
SHOWERS AND THUNDERSTORMS MAINLY IN OFFSHORE AREAS TUESDAY WITH THE
FRONT.
COLD FRONT SHOULD KNOCK TEMPERATURES BACK INTO THE 80S FOR THE
FOLLOWING FEW DAYS WITH MUCH DRIER CONDITIONS AS DPTS DROP TO MUCH
MORE PLEASANT LEVELS /40S AND 50S/. ONSHORE FLOW REDEVELOPS LATE
THURSDAY AND WILL BRING A GRADUAL INCREASE IN MOISTURE FOR FRIDAY.
MODELS NOT IN GOOD AGREEMENT FOR FRIDAY...BUT MODELS HINTING AT
ANOTHER UPPER TROUGH FOR FRIDAY INTO THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 88 73 94 71 92 / 10 20 20 10 10
VICTORIA 87 71 88 69 92 / 10 20 30 10 10
LAREDO 99 73 101 71 99 / 20 30 10 10 10
ALICE 93 73 97 70 96 / 10 30 20 10 10
ROCKPORT 81 71 82 72 85 / 10 20 30 10 10
COTULLA 95 71 98 68 97 / 20 30 10 10 10
KINGSVILLE 91 73 96 71 95 / 10 20 20 10 10
NAVY CORPUS 83 73 83 72 82 / 10 20 20 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
LK/84...AVIATION
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1139 PM CDT FRI APR 25 2014
.AVIATION...
SURFACE DEWPOINTS ARE NOW IN THE LOW 60S ACROSS CENTRAL AND
SOUTHEAST TEXAS AND MOISTURE WILL CONTINUE TO SURGE NORTHWARD
THROUGH THE TAF SITES DURING THE NEXT FEW HOURS. SURFACE TEMPS
SHOULD BE WARM ENOUGH TO LIMIT ANY ADVECTION FOG...BUT LOW STRATUS
APPEARS LIKELY FOR KACT AFTER 10Z. MVFR/IFR STRATUS IS NOW
BEGINNING TO FORM ACROSS THE TEXAS COASTAL PLAINS...AND WACO MAY
CONTEND WITH MVFR OR PERHAPS BRIEF IFR STRATUS AROUND AND SHORTLY
AFTER DAYBREAK. STRATUS MAY STRUGGLE TO REACH AS FAR NORTH AS THE
METROPLEX...BUT WILL SHOW TEMPO MVFR CIGS FROM 12-14Z FOR
DFW/DAL/GKY WHERE SOME OF THE HIGH RES GUIDANCE AND THE RUC/NAM
INDICATE LOW LEVEL SATURATION OCCURRING. ANY STRATUS SHOULD
LIFT/SCATTER FAIRLY QUICKLY BY MID MORNING. ASIDE FROM MID-HIGH
CLOUDS JUST SOME FAIR WEATHER CUMULUS EXPECTED SATURDAY AFTERNOON
AND EVENING WITH SOUTH WINDS INCREASING TO NEAR 20KT AND GUSTY.
MVFR STRATUS WILL LIKELY RETURN AROUND MIDNIGHT SATURDAY NIGHT TO
THE TAF SITES. THUNDERSTORMS SHOULD REMAIN WELL WEST AND NORTHWEST
OF THE TAF SITES TOMORROW EVENING. HOWEVER...ELEVATED CONVECTION
WILL LIKELY BEGIN TO AFFECT THE TAF SITES BY 9Z AND HAVE INDICATED
A VCTS TO COVER THIS THREAT. MODELS CONTINUE TO INDICATE
DRYLINE/PACIFIC FRONT WILL MOVE EAST OF TAF SITES BY SUNDAY
AFTERNOON BEFORE NEXT ROUND OF SEVERE CONVECTION FIRES...BUT STILL
NEED TO MONITOR THIS POTENTIAL.
TR.92
&&
.UPDATE...
QUICK UPDATE TO THE FORECAST TO ADD A LITTLE MORE CLOUD COVER
EARLY SATURDAY MORNING...MAINLY TO THE SOUTHERN HALF OF THE CWA AS
STRONG MOISTURE RETURN CONTINUES. A LOOK AT THE LATEST NAM
GUIDANCE CONTINUES TO SHOW SEVERE CONVECTIVE POTENTIAL TOMORROW
AFTERNOON/EVENING ACROSS WEST CENTRAL TEXAS. NO CHANGES MADE TO
THE CURRENT CONVECTIVE FORECAST FOR TOMORROW INTO TOMORROW NIGHT.
THE RAP DOES SHOW SOME WEAKENING OF THE CAP EARLIER IN THE
AFTERNOON OUT WEST WHICH COULD LEAD TO A SLIGHTLY EARLIER
INITIATION TIME BUT OTHERWISE THE GENERAL THINKING IS UNCHANGED.
FOR SUNDAY...MODEL GUIDANCE IS IN GOOD AGREEMENT WITH MOVING THE
DRYLINE/FRONT EAST INTO SUNDAY MORNING...ACTUALLY BEHAVING MORE
LIKE A FRONT WITH COOLING TEMPERATURES BEHIND IT AT 850MB. IT IS
APPEARING MORE LIKELY THAT THIS FEATURE WILL BE ALONG OR EAST OF
I-35 BEFORE SURFACE BASED CONVECTION CAN DEVELOP ON SUNDAY. THE
HIGHEST THREAT FOR SEVERE WEATHER ON SUNDAY WILL BE ACROSS THE
EASTERN COUNTIES INTO THE ARKLATEX. SOME ELEVATED CONVECTION IS
EXPECTED TO BE ONGOING EARLY SUNDAY MORNING AND THIS COULD QUICKLY
BECOME SURFACE BASED BY EARLY AFTERNOON GENERALLY EAST OF I-35.
CURRENT FORECAST HANDLES THIS WELL AND NO CHANGES ARE NEEDED AT
THIS TIME.
DUNN
&&
.SHORT TERM/THOUGH MONDAY/...
A STRONG UPPER LOW CONTINUES MOVING INLAND OVER THE WESTERN STATES
WITH A SHORTWAVE RIDGE ACROSS NORTH AND CENTRAL TEXAS LINGERING
THROUGH TONIGHT. THIS SYSTEM IS A WAYS OFF WITH A SUBSTANTIAL CAP
THAT SHOULD KEEP THE WEATHER DRY TONIGHT AND THROUGH THE DAY
SATURDAY. BREEZY SOUTH WINDS AND RAPIDLY INCREASING DEW POINTS
FROM THE TEXAS COASTAL AREAS ARE EXPECTED TO HOLD LOWS TONIGHT
BETWEEN 55 AND 66 DEGREES WITH HIGHS WARMING WELL INTO THE 80S
SATURDAY AND EVEN THE LOWER 90S ACROSS THE WEST. IF YOU WANT TO
ENJOY PART OF THE WEEKEND AND BE OUTDOORS...SATURDAY IS YOUR BEST
BET.
SATURDAY NIGHT THROUGH SUNDAY EVENING IS EXPECTED TO BE AN ACTIVE
PERIOD WEATHER-WISE...AS LEAD SHORTWAVE ENERGY BEGINS NEGATIVELY
ROTATING THROUGH THE FOUR CORNERS AND OVER THE WESTERN HIGH
PLAINS BY SUNRISE SUNDAY. RAPID HEIGHT FALLS MOVING OUT OF THE
ROCKIES WILL HELP DEEPEN A SURFACE DRYLINE ACROSS THE SOUTH PLAINS
AND TEXAS PANHANDLE THROUGH SATURDAY EVENING. IT WILL LIKELY TAKE
UNTIL LATE AFTERNOON OR NEAR 00Z BEFORE A FEW DISCRETE STORMS
INITIATE FROM NORTHWEST OF ABILENE AND UP THROUGH CHILDRESS AND
SOUTHWEST OKLAHOMA...VERY FAST SSW FLOW STEERING THE MAJORITY OF
ACTIVITY TO THE NORTHEAST. THE DRYLINE SHOULD BEGIN TRANSVERSING
EAST THROUGH THE EVENING HOURS WITH ISOLATED TO SCATTERED STORMS
POSSIBLY ENTERING OUR FAR W/NW COUNTIES BEFORE MIDNIGHT. IN
ADDITION...SURFACE-BASED STORMS WILL REMAIN POSSIBLE MOST OF THE
EVENING WITH ALL MODES OF SEVERE WEATHER POSSIBLE WITH ANY
SUPERCELLS BEFORE AN INCREASING LLJ OVERNIGHT AND WAA HELP RE-
INTENSIFY THE CAPPING INVERSION WITH CONVECTION EXPECTED TO BE
ELEVATED OVERNIGHT AND THROUGH THE SUNRISE HOURS SUNDAY. STORM
CHANCES SHOULD BE HIGHEST ACROSS THE NORTHERN COUNTIES WHERE BULK OF
FORCING FROM ENHANCED ELEVATED WAA AND FASTER EASTWARD PROGRESSION
OF THE SURFACE DRYLINE WILL OCCUR. DESPITE THE ELEVATED NATURE OF
STORMS...VERY STEEP LAPSE RATES BETWEEN 850-650MB WILL ALLOW FOR
PLENTY OF MUCAPE IN THE HAIL GROWTH ZONE. HAVE LEFT SEVERE MENTION
IN FOR THE OVERNIGHT PERIOD FOR THE POTENTIAL OF SOME LARGER HAIL.
THE CHALLENGES CONTINUE AS WE MOVE THROUGH THE DAY SUNDAY AS THE
STRONG SHORTWAVE TROUGH CONTINUES TO NEGATIVELY TILT OVER CENTRAL
HIGH PLAINS. THE STRONG WEST- SOUTHWEST COMPONENT ATOP THE APPROACHING
SURFACE DRYLINE WILL HELP MOVE IT EAST FASTER ACROSS NORTH TEXAS
VERSUS FURTHER SOUTH OVER OUR CENTRAL TEXAS COUNTIES THROUGH EARLY
AFTERNOON. MODELS STILL SHOW A VARIANCE OF THE DRYLINE POSITION
SUNDAY AFTERNOON WITH AS FAR WEST AS I-35/35E...TO AS FAR EAST AS
I-45 UP THROUGH I-30. WITH THIS IN MIND...HAVE ORIENTED POPS NE-SW
ALONG THE DRYLINE WITH HIGHEST CHANCES FOR SEVERE SUPERCELL STORMS
OCCURRING MAINLY EAST OF A BONHAM-TERRELL-HEARNE LINE. THE VERY
WARM TEMPERATURES AND HIGH DEW PTS PRODUCING SBCAPE VALUES OF
2500-3500 J/KG EAST OF THE DRYLINE AND WESTERLY EFFECTIVE SHEAR
VALUES 30-35 KTS WITH SOUTHERLY 0-1KM SHEAR 20 KTS+...SURFACE-
BASED STORMS SHOULD ALLOW FOR ALL POSSIBLE MODES OF SEVERE WEATHER
INCLUDING A FEW TORNADOES. THE WINDOW FOR SEVERE WEATHER LOOKS TO
BE EARLY AFTERNOON THROUGH EARLY EVENING...WHEN BETTER FORCING
BOTH SURFACE AND ALOFT SHOULD SHIFT EAST OUT OF THE AREA TOWARD
THE MODERATE RISK AREA ACROSS THE ARKLATEX.
WINDY AND WARM CONDITIONS WILL LIKELY RAMP UP THE FIRE DANGER ACROSS
THE WESTERN TWO THIRDS OF THE AREA WITH MINIMUM HUMIDITY VALUES
FALLING BELOW 20 PERCENT. GREEN UP OF GRASSES AND LIGHTER WINDS ON
SUNDAY SHOULD KEEP THE FIRE DANGER ONLY AT ELEVATED LEVELS. WE
MAY HAVE TO WATCH FOR HIGH TO CRITICAL FIRE WEATHER CONDITIONS FOR
MONDAY AFTERNOON WITH MORE GUSTIER WEST WINDS.
&&
.LONG TERM/MON NIGHT AND BEYOND/...
THE FIRST OF A COUPLE OF LATE SEASON COLD FRONTS ARRIVES MONDAY
NIGHT WITH SLIGHTLY COOLER TEMPERATURES ON TUESDAY. IT APPEARS IT
WILL BE A RELATIVELY BENIGN WEEK FOR THE SOUTHERN PLAINS WITH THE
UPPER LOW OVER THE PLAINS BEING HELD UP BY SEMI OMEGA BLOCKING
UPPER HIGH OVER EASTERN CANADA. THE UPPER LOW WILL ONLY MIGRATE
SLOWLY NORTHEAST TOWARD THE GREAT LAKES THROUGH THE END OF THE
WEEK. THIS SHOULD ALLOW FOR PERIODIC FRONTAL PASSAGES AND KEEP A
NORTH COMPONENT TO THE WIND AND A DRY AIRMASS IN PLACE THROUGH
MUCH OF THE WEEK AND KEEP TEMPERATURES 5-10 DEGREES BELOW NORMALS.
IT APPEARS MOISTURE WILL BE TOO SHALLOW AND SCANT WITH A STRONG
SHORTWAVE ROTATING ACROSS TEXAS THURSDAY INTO FRIDAY AND HAVE LEFT
A DRY FORECAST FOR NOW ALL THE WAY INTO NEXT WEEKEND.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 61 86 69 90 61 / 0 5 40 40 5
WACO, TX 62 85 68 90 55 / 0 5 20 30 5
PARIS, TX 54 85 67 80 56 / 0 5 40 70 30
DENTON, TX 60 85 68 87 55 / 5 5 60 40 5
MCKINNEY, TX 58 85 68 87 56 / 0 5 50 50 10
DALLAS, TX 61 87 69 90 62 / 0 5 40 50 5
TERRELL, TX 58 85 68 84 54 / 0 5 30 50 10
CORSICANA, TX 60 84 68 85 57 / 0 5 20 50 10
TEMPLE, TX 63 86 69 89 57 / 0 10 20 30 5
MINERAL WELLS, TX 61 88 69 88 55 / 5 10 50 20 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
347 AM CDT SAT APR 26 2014
.SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
SURFACE OBS AND LOCAL RADAR SHOW COLD FRONT HAD PUSHED THROUGH ALL
BUT THE FAR SW PORTION OF CWA BY 07Z. AS VORT MAX OVER THE SOO
MOVES OFF TO THE EAST OVER LAKE HURON...A COMBINATION OF 700 MB WARM
AIR ADVECTION AND CONVERGENCE ON PERIPHERY OF MID-LEVEL CYCLONIC
FLOW IS PRODUCING ACCAS SHOWERS OVER NRN IL...WELL DEPICTED ON 00Z
GFS AND HI-RES/RAPID UPDATE MODELS. STEEP LAPSE RATES ABOVE 850 MB
AND MEAGER ELEVATED CAPE...REFLECTED ON RAP SOUNDINGS...PRODUCING
LIGHT SHOWERS WITH REPORTS OF IN-CLOUD LIGHTNING OVER NRN IL. MODELS
ALL KEEP THIS BAND OUT OF THE CWA AS IT SHIFTS TO THE EAST-SOUTHEAST
OF IL BY 12Z.
SOUTHERN PORTION OF SURFACE HIGH SETTLING OVER STATE TODAY AND 500
MB RIDGING WILL KEEP THE DAYTIME HOURS DRY...WITH A COOL NORTHEAST
TO EAST WIND PREVENTING HIGHS IN THE LAKESHORE COUNTIES FROM GETTING
OUT OF THE 40S. LOW TO MID 50S EXPECTED WEST OF THE KETTLE
MORAINE...WITH MID-UPR 50S FROM MADISON WEST...WITH A 60 OR TWO IN
THE FAR SW.
MODELS DEPICTING NICE BAND OF MAINLY ISENTROPICALLY-DRIVEN 700 MB
OMEGA AND HIGHER RH CROSSING REGION AFTER 00Z SUNDAY...AND ARE
PRODUCING SOME LIGHT QPF. BUT SIMILAR TO EARLIER THIS WEEK...CROSS
SECTIONS AND FORECAST SOUNDINGS SHOWING RELATIVELY DRY EASTERLY FLOW
PREVENTING SATURATION BELOW 7K-8K FEET THROUGH MOST OF THE
NIGHT...WITH SOME SATURATION IN THE FAR WEST AFTER 06Z. WILL KEEP
POPS NO HIGHER THAN THE CHANCE CATEGORY PRIOR TO 12Z EXCEPT FOR LOW
LIKELY POPS IN THE EXTREME WEST AFTER 09Z.
SUNDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM.
THE OCCLUDED LOW PRESSURE SYSTEM WILL STALL OVER THE CENTRAL PLAINS
UNTIL EARLY NEXT WEEK. THE 925MB WARM FRONT WILL BE STATIONED ACROSS
NORTHERN IL ON SUNDAY...THEN CREEP NORTHWARD INTO FAR SOUTHERN WI
THROUGH MONDAY NIGHT. MEANWHILE...THE 850MB WARM FRONT WILL REMAIN
STATIONARY OVER CENTRAL WI.
THE INITIAL WARM AIR ADVECTION SHOWERS ON SUNDAY WILL STRUGGLE TO
OVERCOME THE LOW LEVEL DRY AIR IN PLACE. THE DEEP MOISTURE WILL
FINALLY ARRIVE SUNDAY EVENING AS WAVES OF VORTICITY AND WARM AIR
ADVECTION LEAD TO STRONG UPWARD MOTION OVER SOUTHERN WI. STEEP MID
LEVEL LAPSE RATES AND THE STRONG OMEGA WILL ALLOW FOR EMBEDDED
THUNDERSTORMS.
MODERATE RAIN SHOWERS WITH PERIODS OF HEAVY RAIN WILL BE POSSIBLE
SUNDAY NIGHT THROUGH MONDAY NIGHT. RAINFALL TOTALS DURING THIS TIME
ARE ESTIMATED TO BE IN THE 1.3 TO 1.8 INCH RANGE WITH THE HIGHER
TOTALS IN SW WI AND THE LOWER TOTALS OVER EAST CENTRAL WI. THIS RAIN
AND THE ADDITIONAL EXPECTED NEXT WEEK WILL CAUSE MANY RIVERS TO
REACH BANKFULL STAGE AND AT LEAST A FEW REACHING MINOR FLOOD STAGE.
PLAN ON BREEZY EAST WINDS SUNDAY AND MONDAY WITH THE SURFACE LOW
PARKED OVER NEBRASKA. THIS WILL KEEP TEMPERATURES VERY COOL IN THE
UPPER 40S AND LOWER 50S.
.LONG TERM...
TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM.
THE OCCLUDED LOW WILL MEANDER NORTHEAST OVER THE UPPER GREAT LAKES
THROUGH THURSDAY. THE DRY SLOT IS EXPECTED TO ARRIVE INTO SOUTHERN
WI SOMETIME TUESDAY OR TUESDAY NIGHT WHICH WOULD CUT OFF THE DEEP
MOISTURE. CLOUDS AND SCATTERED SHOWERS WILL CONTINUE TO BE POSSIBLE
THROUGH FRIDAY DUE TO THE CYCLONIC FLOW AND LINGERING LOW LEVEL
MOISTURE. WINDS WILL GENERALLY BE OUT OF THE EAST FOR THE WEEK WHICH
MEANS COOLER NEAR THE LAKE WITH HIGHS IN THE UPPER 40S THERE AND
LOWER 50S INLAND.
MODELS ARE SHOWING ANOTHER UPPER TROUGH SWINGING DOWN THROUGH WI FOR
NEXT WEEKEND WHICH WOULD ALLOW FOR MORE CLOUDS AND SHOWERS. THERE IS
STILL UNCERTAINTY IN TIMING...SO THERE MAY BE A PERIOD OF DRY
WEATHER ON FRIDAY OR SATURDAY.
&&
.AVIATION/12Z TAFS/...
VFR CONDITIONS THROUGH THE PERIOD WITH RAIN EXPECTED TO HOLD OFF
UNTIL AROUND/SHORTLY AFTER 12Z SUNDAY...THOUGH A FEW SPRINKLES
POSSIBLER BEFORE...ESPECIALLY AT KMSN AND WEST.
NORTH WINDS THIS MORNING BEHIND COLD FRONT WILL TURN NORTHEAST AND
THEN EAST AS RIDGE OF SURFACE HIGH PRESSURE NOSES OVER STATE...THEN
INCREASE LATER TONIGHT WITH TIGHTENING GRADIENT AS RIDGE SHIFTS OVER
LOWER MICHIGAN AND DEEPENING LOW PRESSURE MOVES OUT INTO THE CENTRAL
PLAINS.
&&
.MARINE...
LOOKING AT NORTH WINDS THIS MORNING TURNING NORTHEAST AND EAST AS
RIDGE OF SURFACE HIGH PRESSURE NOSES DOWN OVER STATE AND LAKE
MICHIGAN...THEN INCREASE LATER TONIGHT WITH TIGHTENING GRADIENT AS
RIDGE SHIFTS OVER LOWER MICHIGAN AND DEEPENING LOW PRESSURE MOVES
OUT INTO THE CENTRAL PLAINS. THE SOMETIMES GUSTY ONSHORE WINDS ARE
EXPECTED TO PERSIST FROM SUNDAY INTO WEDNESDAY...AS THE LOW PRESSURE
SLOWLY APPROACHES THE AREA. THESE WIND GUSTS WILL LIKELY REACH SMALL
CRAFT CRITERIA AT TIMES....WITH WINDS JUST A FEW HUNDRED FEET OFF
THE SURFACE REACHING 40 KTS. DO NOT FEEL THESE STRONGER WINDS WILL
MIX DOWN THROUGH THE NEAR-WATER STABLE LAYER...BUT A FEW GALE GUSTS
ARE NOT OUT OF THE QUESTION...ESPECIALLY SUNDAY NIGHT INTO MONDAY
EVENING. THE ONSHORE WINDS SHOULD ALSO GENERATE WAVES IN THE 3 TO 6
FOOT RANGE. A SMALL CRAFT ADVISORY MAY BE NEEDED AT TIMES DURING
THIS PERIOD.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
SUNDAY THROUGH FRIDAY...MRC
AREA FORECAST DISCUSSION
NWS ALBANY NY
1059 AM EDT SAT APR 26 2014
.SYNOPSIS...
A COMPLEX LOW PRESSURE SYSTEM WILL IMPACT OUR REGION
THIS AFTERNOON...AS IT SLOWLY DRIFTS NORTHEAST. AN UPPER LEVEL LOW
WILL IMPACT THE REGION TONIGHT INTO TOMORROW BRINGING ANOTHER PERIOD
OF RAIN SHOWERS. DRIER WEATHER AND MILDER TEMPERATURES WILL RETURN
BY MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1058 AM EDT...THE OCCLUDED FRONT ASSOCIATED WITH THE DOUBLE
BARREL LOW PRESSURE SYSTEM HAS MOVED THROUGH THE ERN PORTION OF
THE FCST AREA LATE MORNING. A FEW LINGERING SHOWERS/DRIZZLE ARE
LINGERING OVER THE SRN GREENS AND BERKSHIRES. THE SATELLITE
PICTURE IS SHOWING SOME CLEARING OVER CNTRL AND SRN NY. THIS
SHOULD MAKE ITS WAY INTO THE SRN PORTIONS OF THE FCST AREA FOR THE
EARLY PM WITH SOME PARTIAL SUNSHINE. A BATCH OF SHOWERS AHEAD OF
THE CLOSED UPPER LEVEL LOW OVER GEORGIAN BAY/SE ONTARIO ACCORDING
TO THE RUC40/RR WILL BRING SHOWERS BACK INTO THE FCST AREA IN THE
MID TO LATE PM. THERE COULD BE A FEW RUMBLES OF THUNDER OVER THE
SE EXTREME /ULSTER...DUTCHESS...AND LITCHFIELD COUNTIES/. THE
LAPSE RATES STEEPEN...AND THERE ARE SMALL AMOUNTS OF INSTABILITY
FORECASTED /LESS 250 J/KG/. A SLIGHT CHC OF TSRAS WAS ADDED THERE.
THE LATEST HRRR 3-KM COLUMNAR REF PRODUCT INDICATES THE THREAT FOR
SHOWERS INCREASES OVER THE MAJORITY OF THE FCST AREA BTWN 20Z-23Z.
POPS WERE KEPT IN THE HIGH CHC AND LIKELY CATEGORY.
HIGHS TODAY ARE EXPECTED TO BE A TAD ON THE COOL SIDE MAINLY
RANGING FROM THE UPPER 40S OVER THE SRN DACKS TO L60S IN THE MID
HUDSON VALLEY. TEMPS WERE LOWERED INTO THE U40S TO L50S OVER
PORTIONS OF THE SRN GREENS/NRN BERKS WHERE THE CLOUDS MAY LINGER
THE LONGEST IN THE RAIN COOLED AIR.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE UPPER LEVEL LOW IS CENTERED OVER THE FA THIS EVENING WITH A
STRONG VORT LOBE PASSING ACRS THE FA AS WELL. THIS SHOULD RESULT IN
MORE SHOWERS WHICH WILL LINGER INTO SUNDAY MORNING AS THE VORT
LOBE DOES NOT DRIFT OFF THE EAST COAST UNTIL SUNDAY AFTERNOON.
THUS EXPECT THE SECOND HALF OF SUNDAY TO BE DRIER THAN THE FIRST
HALF OF THE DAY. EXPECT LOWS TONIGHT IN THE 30S WITH THE HIGHS ON
SUNDAY IN THE UPPER 40S NORTHWEST TO AROUND 60 SOUTHEAST.
HIGH PRESSURE WILL BUILD INTO THE FA FOR LATER SUNDAY NIGHT INTO
MONDAY WITH MAINLY DRY CONDITIONS. LOWS SUNDAY NIGHT WILL BE IN
THE UPPER 20S NORTHWEST TO MID 30S SOUTHEAST. HIGHS ON MONDAY ARE
EXPECTED TO BE MILDER THAN OVER THE WEEKEND WITH HIGHS RANGING
FROM THE MID 50S NORTHWEST TO MID 60S SOUTHEAST.
MONDAY NIGHT WILL FEATURE INCREASING CLOUDS AS A STORM SYSTEM
APPROACHES FROM THE GREAT LAKES REGION. EXPECT LOWS TO BE IN THE
MID 30S TO MID 40S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
UNSETTLED CONDITIONS APPEAR TO DOMINATE MUCH OF THE LONG TERM
PERIOD...ALTHOUGH THERE REMAINS SOME UNCERTAINTY AS TO HOW FAST THIS
UNSETTLED WEATHER DEVELOPS...AND HOW LONG IT WILL LINGER. MOST
00Z/26 DETERMINISTIC AND ENSEMBLE GUIDANCE INDICATE A RATHER BLOCKY
PATTERN IN PLACE AT THE START OF THE LONG TERM PERIOD...WITH A
SPRAWLING MID/UPPER LEVEL LOW ACROSS THE CENTRAL U.S...WITH ANOTHER
CLOSED MID/UPPER LEVEL LOW MOVING EAST WELL OFF THE NEW ENGLAND
COAST. IN BETWEEN THESE TWO FEATURES WILL BE A STRONG BUT SOMEWHAT
NARROW RIDGE OF HIGH PRESSURE. THIS RIDGE MAY THWART THE
EAST/NORTHEAST PROGRESS OF THE RAIN INITIALLY INTO THE
REGION...BEFORE RAIN CHANCES ARE MAXIMIZED AROUND THE LATE WED-EARLY
THU TIME PERIOD. TEMPS SHOULD REMAIN BELOW SEASONAL LEVELS GIVEN THE
PROSPECTS FOR CLOUDS...AND AT LEAST SOME RAINFALL DURING THE PERIOD.
THE STEADIEST RAINFALL MAY LIFT N AND E OF THE REGION BY LATE THU OR
FRI...TRANSITIONING TO A MORE SHOWERY REGIME AS THE LINGERING
MID/UPPER LEVEL COLD POOL MOVES CLOSER TO THE REGION.
HERE ARE SOME MORE SPECIFICS...
TUE-TUE NT...AS MENTIONED ABOVE...THERE REMAINS SOME QUESTION AS TO
HOW FAST THE MID/UPPER LEVEL RIDGE AXIS MOVES E OF THE
REGION...ALLOWING FOR INCREASING ISENTROPIC LIFT AND RAINFALL ACROSS
THE REGION. AT THIS TIME...WILL SIDE ON THE SLOWER SIDE OF
GUIDANCE...KEEPING MOST AREAS DRY TUE AM...THEN SLOWLY INCREASING
POPS INTO THE SLIGHT CHC RANGE FOR EASTERN AREAS...AND LOW CHC RANGE
FOR CENTRAL AND WESTERN AREAS BY LATE TUE. FOR TUE NT...WILL
CONTINUE TO INCREASE POPS GRADUALLY INTO THE HIGHER CHC RANGE. AS
FOR TEMPS...SIDING ON THE SLOWER SIDE OF GUIDANCE...HAVE INDICATED
SLIGHTLY WARMER MAX TEMPS FOR TUE...WITH 50S IN MOST AREAS...WITH
PERHAPS EVEN SOME LOWER 60S POSSIBLE ACROSS NORTHERN VALLEY AREAS
SHOULD THE RAIN HOLD OFF AND ANY MORNING SUNSHINE OCCUR. EXPECT
LOWER 40S IN VALLEYS...AND 35-40 ACROSS HIGHER ELEVATIONS AND
NORTHERN AREAS FOR TUE NT.
WED-THU...CHC POPS EARLY WED HAVE BEEN RAISED TO LIKELY POPS FOR
LATE WED INTO EARLY THU...WHICH APPEARS TO BE THE BEST OPPORTUNITY
FOR WIDESPREAD RAINFALL GIVEN THE GREATEST ISENTROPIC LIFT AND
MOISTURE TRANSPORT INTO AND ACROSS THE REGION. THE 00Z/26 GEFS
ACTUALLY HINT AT SOME CHC FOR HEAVY RAIN ACROSS PORTIONS OF THE MID
HUDSON VALLEY AND NW CT...WHERE THE PROB FOR ONE INCH OR GREATER
OVER A 24 HOUR PERIOD IS IN THE 40-60 PERCENT RANGE THROUGH
18Z/THU...WITH EVEN A 20-40 PERCENT CHANCE FOR 2 INCHES OR MORE OVER
A 36 HOUR PERIOD ALSO ENDING 18Z/THU. EXPECT MAX TEMPS TO MAINLY
REMAIN IN THE LOWER/MID 50S...WITH SOME UPPER 40S POSSIBLE IN HIGHER
ELEVATIONS WED. BY LATE THU...IT IS POSSIBLE THAT THE STEADIEST RAIN
BEGINS TO TAPER TO SHOWERS. HAVE INDICATED SLIGHTLY WARMER MAXES
COMPARED TO WED...WITH 50S AND LOWER 60S IN VALLEYS. WED NT/THU AM
MINS SHOULD MAINLY BE IN THE 40S...WITH SOME 30S POSSIBLE ACROSS
HIGHER ELEVATIONS.
THU NT-FRI...THE BEST FORCING APPEARS TO SHIFT MAINLY N AND E OF THE
REGION. HOWEVER...WITH THE APPROACH OF THE LINGERING MID LEVEL COLD
POOL...EXPECT AT LEAST SOME ISOLATED TO SCATTERED RAIN SHOWERS TO
OCCUR...ESP DURING FRI AFTN. MAX TEMPS SHOULD REACH THE LOWER 60S IN
VALLEYS...WITH 50S ACROSS MOST HIGHER ELEVATIONS. THU NT/FRI AM MINS
SHOULD FALL INTO THE 40S IN VALLEYS...AND MID 30S TO NEAR 40 ACROSS
NORTHERN AREAS...AND HIGHER TERRAIN.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
MVFR/IFR CONDITIONS...WITH THE IFR MAINLY FOR CIGS...WILL PERSIST
AT THE TAF SITES THROUGH AROUND 13Z-14Z...AS AN OCCLUDED FRONT
PASSES EASTWARD...AND RAIN/DRIZZLE OCCURS. IN ITS WAKE...THE RAIN
SHOULD END...AND CIGS SHOULD LIFT INTO THE MVFR...THEN VFR RANGE
BY MID MORNING. A LULL IN THE RAIN IS THEN EXPECTED THROUGH EARLY
AFTERNOON.
THEN...AS A POTENT UPPER LEVEL DISTURBANCE APPROACHES FROM THE
WEST...SHOWERS WILL DEVELOP/INCREASE IN AREAL COVERAGE ONCE
AGAIN...ESP FROM THE KALB SOUTH TO KPOU AND EAST TO KPSF DURING
THE MID TO LATE AFTERNOON HOURS. SOME LOCALLY HEAVY SHOWERS COULD
BRIEFLY OCCUR...AND CAN NOT EVEN RULE OUT AN ISOLATED
THUNDERSTORM. HOWEVER...OVERALL CONFIDENCE IN THREAT FOR THUNDER
IS VERY LOW AT THIS TIME...SO NO MENTION OF TSRA IN CURRENT TAF
ISSUANCES. ANY HEAVIER SHOWERS COULD LEAD TO BRIEF AND LOCALIZED
MVFR/IFR VSBYS.
SHOWERS SHOULD DECREASE IN AREAL COVERAGE TONIGHT. HOWEVER...SOME
MVFR CIGS MAY PERSIST AT KGFL/KPSF/KALB.
WINDS AHEAD OF THE OCCLUDED FRONT WILL BE MAINLY LIGHT AND
VARIABLE...EXCEPT FROM THE SOUTH TO SOUTHEAST AT KALB AT 5-10 KT.
WINDS WILL THEN SHIFT INTO THE WEST TO SOUTHWEST BY MID MORNING AT
5-10 KT IN THE WAKE OF THIS FRONT...WITH SOME GUSTS POSSIBLY
REACHING 20 KT AT TIMES...ESP AT KALB AND KPSF. WINDS WILL SHIFT
INTO THE NORTHWEST TO NORTH TONIGHT AT GENERALLY 5-10 KT.
OUTLOOK...
SUNDAY TO MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
TUESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
A SOAKING RAIN OCCURRED OVERNIGHT ACROSS EASTERN NEW YORK AND
ADJACENT WESTERN NEW ENGLAND ALLEVIATING ANY FIRE WEATHER CONCERNS
FOR THE TIME BEING.
RELATIVE HUMIDITY VALUES WILL ONLY DROP TO 45 TO 60 PERCENT THIS
AFTERNOON...RECOVER TO 70 TO 100 PERCENT TONIGHT AND FALL TO 35 TO
55 PERCENT ON SUNDAY.
WINDS WILL BE SOUTHEAST TO NORTHEAST AT 5 TO 10 MPH TODAY...WEST
TO NORTHWEST AT 5 TO 10 MPH TONIGHT...AND NORTHWEST AT 10 TO 15
MPH WITH GUSTS TO 25 MPH SUNDAY AFTERNOON.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDRO PROBLEMS ARE ANTICIPATED DURING THE NEXT FIVE
DAYS.
SHOWERS OVERNIGHT HAVE BROUGHT MOST AREAS A QUARTER TO HALF AN
INCH WITH MORE RAIN SHOWERS EXPECTED LATER TODAY INTO TONIGHT WITH
ANOTHER TENTH TO THIRD OF AN INCH EXPECTED. ANY PRECIPITATION WILL
END BY SUNDAY AFTERNOON FOLLOWED BY DRY WEATHER THROUGH MONDAY
NIGHT. THE NEXT CHANCE OF PCPN WILL COME DURING THE MID WEEK PERIOD.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/WASULA
NEAR TERM...KL/11/WASULA
SHORT TERM...11
LONG TERM...KL
AVIATION...KL/WASULA
FIRE WEATHER...11
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS MIAMI FL
947 AM EDT SAT APR 26 2014
.UPDATE...
THE CURRENT FORECAST IS ON TRACK. A DRY AND WARM DAY WITH PLENTY
OF SUNSHINE IS EXPECTED FOR TODAY. A LARGE AREA OF HIGH PRESSURE
IS LOCATED OVER THE GULF OF MEXICO WITH VERY DRY AIR IN PLACE
BETWEEN 700 AND 500 MB. LIGHT NORTHERLY WINDS WILL PREVAIL TODAY
AND WILL TURN EASTERLY BY SUNDAY MORNING. THIS WILL BRING A
LITTLE BIT OF MORE MOISTURE, BUT IT WILL STAY CONFINED TO THE
BOUNDARY LAYER. STRONG SUBSIDENCE BELOW 700 MB WILL DELAY ANY
SHOWERS THAT MAY FORM OVER LAND UNTIL LATE IN THE DAY. THE MID
LEVEL TEMPERATURES ARE STILL RELATIVELY COOL, AROUND -10C, WHICH
WILL ALLOW FOR THE FORMATION OF ONE OR TWO LATE AFTERNOON SHOWERS.
HOWEVER, IF ANY THING FORMS IT WILL BE VERY SPARSE IN COVERAGE, AND
IN THE AREAS WHERE THE EAST COAST AND WEST COAST SEA BREEZES
COLLIDE. OVER THE ATLANTIC WATERS WE CAN BEGIN TO OBSERVE THE SET
UP OF A CONVERGENCE LINE BETWEEN EASTERLY FLOW SOUTH OF THE PALM
BEACH WATERS AND MORE NORTHERLY FLOW TO THE NORTH. THIS COULD
TRIGGER A FEW SHOWERS OVER THE PALM BEACH WATERS. COVERAGE WILL
BE SPARSE.
&&
.PREV DISCUSSION... /ISSUED 715 AM EDT SAT APR 26 2014/
AVIATION...
DEEP LAYER HIGH PRESSURE WILL DOMINATE SOUTH FLORIDA THROUGH THE
FORECAST WITH SEA BREEZES DEVELOPING ALONG BOTH COASTS. SOME OF
THE HIGH RESOLUTION SHORT TERM MODELS ARE AGAIN SHOWING A FEW
SHOWERS ALONG THE SEA BREEZES OVER THE INTERIOR LATE IN THE
AFTERNOON. LEFT OUT OF THE FORECAST FOR NOW AS THESE WILL TOO FEW
TO CONSIDER AND MORE THAN LIKELY WELL INLAND AWAY FROM ANY
TERMINALS.
KOB
PREV DISCUSSION... /ISSUED 420 AM EDT SAT APR 26 2014/
DISCUSSION...
WATER VAPOR AND RUC ANALYSIS THIS MORNING SHOWED A SHORTWAVE
TROUGH FROM THE GREAT LAKES SOUTHEAST TO OFF THE EAST COAST OF
NORTH CAROLINA. AN UPPER LEVEL RIDGE STRETCHED FROM THE WESTERN
GULF OF MEXICO INTO CANADA...AND ANOTHER SHORTWAVE TROUGH WAS
PUSHING INTO CENTRAL CALIFORNIA. A NEARLY ZONAL FLOW WAS NOTED
OVER SOUTH FLORIDA.
AT THE SURFACE...AN AREA OF LOW PRESSURE WAS LOCATED OVER THE
WESTERN ATLANTIC JUST SOUTH OF NEW JERSEY...AND A WEAK FRONTAL
BOUNDARY WAS DRAPED SOUTH AND WEST ALONG THE SOUTHEAST STATES
COASTS AND INTO SOUTHERN GEORGIA AND ALONG THE NORTHERN GULF
COAST. WEAK SURFACE HIGH PRESSURE REMAINED ACROSS FLORIDA AND THE
KEYS...WITH A LIGHT NORTHERLY LOW LEVEL FLOW OVER SOUTH FLORIDA.
FOR TODAY...DRIER AIR WILL MOVE IN FROM THE WEST...WITH PWATS A
LITTLE OVER AN INCH. SO DRY AND WARM CONDITIONS ARE EXPECTED.
LIGHT WINDS WILL CONTINUE THIS MORNING...WITH SEA BREEZE
BOUNDARIES PUSHING INLAND ALONG BOTH COASTS THIS AFTERNOON.
TONIGHT...THE UPPER LEVEL RIDGE OVER THE WESTERN GULF IS FORECAST
TO PUSH TOWARDS THE EASTERN GULF AS THE SHORTWAVE OVER CALIFORNIA
EJECTS EAST INTO THE INTERMOUNTAIN WEST. THE SURFACE RIDGE OF
HIGH PRESSURE OVER THE REGION WILL BEGIN TO SHIFT TO THE EAST INTO
THE WESTERN ATLANTIC...WITH EASTERLY FLOW DEVELOPING. LIGHT WINDS
ARE FORECAST ACROSS THE INTERIOR...AND PATCHY FOG MAY DEVELOP ONCE
AGAIN. AREAS OF SMOKE ARE LIKELY NEAR THE WILDFIRE ACROSS EASTERN
COLLIER COUNTY.
SUNDAY THROUGH TUESDAY...THE SURFACE RIDGE WILL CONTINUE TO PUSH
EAST...AND THE EASTERLY FLOW WILL INCREASE. SEA BREEZE BOUNDARIES
ARE FORECAST TO INTERACT ACROSS THE INTERIOR NEAR THE LAKE REGION
IN THE AFTERNOON. THIS MAY BE ENOUGH TO SPARK A FEW SHOWERS OR
STORMS IN THIS REGION ON SUNDAY. ABOVE NORMAL TEMPERATURES WILL
CONTINUE WITH HIGHS IN THE MID 80S TO LOWER 90S. AN UPPER LEVEL
LOW WILL CUTOFF ACROSS THE INTERMOUNTAIN WEST AND THE CENTRAL
PLAINS SUNDAY...AND THEN MEANDER ACROSS THE CENTRAL PLAINS THROUGH
EARLY NEXT WEEK. THE UPPER LEVEL RIDGE WILL MOVE OVER SOUTH
FLORIDA ON SUNDAY AND THEN REMAIN THROUGH THE MIDDLE OF THE WEEK.
MAINLY DRY AND VERY WARM CONDITIONS WILL CONTINUE.
A LARGE UPPER TROUGH/LOW WILL ENVELOP ABOUT THE EASTERN TWO-
THIRDS OF THE CONUS WEDNESDAY AND THURSDAY. UPPER HEIGHTS WILL
BEGIN TO LOWER...BUT SOME RIDGING WILL REMAIN OVER SOUTH FLORIDA.
A COLD FRONT IS FORECAST TO PUSH INTO NORTHERN FLORIDA BY
WEDNESDAY EVENING. HOWEVER...THE FRONT IS FORECAST TO REMAIN OVER
NORTH OR CENTRAL FLORIDA THROUGH FRIDAY. THE FLOW WILL SHIFT TO
THE SOUTHEAST. MOISTURE IS FORECAST TO SLOWLY INCREASE THROUGH
THE END OF THE WEEK...AND RAIN CHANCES ARE FORECAST TO INCREASE.
DEWPOINTS ARE FORECAST TO INCREASE BACK TO AROUND 70 BY
TUESDAY...AND REMAIN AROUND 70 THROUGH THE END OF THE PERIOD.
SOUTHEAST WINDS ARE FORECAST TO BE 10-15 KNOTS OVER THE ATLANTIC
WATERS AS WELL...AND THIS WILL KEEP LOW TEMPERATURES WELL ABOVE
NORMAL FOR THE EAST COAST. OVERNIGHT LOWS ARE FORECAST TO BE IN
THE MID/UPPER 70S FOR THE EAST COAST METRO AREAS. HIGHS ARE
FORECAST TO BE IN THE MID 80S TO LOW 90S THROUGH THE WEEK.
AVIATION...
HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER THROUGH THE TAF
PERIOD. THIS WILL KEEP VFR CONDITIONS IN PLACE. WINDS WILL PICK UP
MID DAY AS THE SEA BREEZE DEVELOPS, THEN RETURN TO LIGHT AND VARIABLE
IN THE LATE EVENING HOURS.
MARINE...
A WEAK PRESSURE GRADIENT PREVAILS ACROSS THE REGIONAL WATERS WITH
LIGHT AND SOMEWHAT VARIABLE WINDS TODAY WITH MORE EASTERLY FLOW
RETURNING ON SUNDAY INTO EARLY NEXT WEEK. IN GENERAL SEAS ARE
EXPECTED TO BE 2 FEET OR LESS THROUGH THE WEEKEND WITH JUST A
GRADUAL INCREASE IN WINDS AND SEAS EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 72 85 72 / 0 0 10 0
FORT LAUDERDALE 87 77 86 75 / 0 0 10 0
MIAMI 88 75 87 74 / 0 0 0 0
NAPLES 86 70 87 70 / 0 0 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...71/JE
LONG TERM....71/JE
AREA FORECAST DISCUSSION
NWS MIAMI FL
715 AM EDT SAT APR 26 2014
.AVIATION...
DEEP LAYER HIGH PRESSURE WILL DOMINATE SOUTH FLORIDA THROUGH THE
FORECAST WITH SEA BREEZES DEVELOPING ALONG BOTH COASTS. SOME OF
THE HIGH RESOLUTION SHORT TERM MODELS ARE AGAIN SHOWING A FEW
SHOWERS ALONG THE SEA BREEZES OVER THE INTERIOR LATE IN THE
AFTERNOON. LEFT OUT OF THE FORECAST FOR NOW AS THESE WILL TOO FEW
TO CONSIDER AND MORE THAN LIKELY WELL INLAND AWAY FROM ANY
TERMINALS.
KOB
&&
.PREV DISCUSSION... /ISSUED 420 AM EDT SAT APR 26 2014/
DISCUSSION...
WATER VAPOR AND RUC ANALYSIS THIS MORNING SHOWED A SHORTWAVE
TROUGH FROM THE GREAT LAKES SOUTHEAST TO OFF THE EAST COAST OF
NORTH CAROLINA. AN UPPER LEVEL RIDGE STRETCHED FROM THE WESTERN
GULF OF MEXICO INTO CANADA...AND ANOTHER SHORTWAVE TROUGH WAS
PUSHING INTO CENTRAL CALIFORNIA. A NEARLY ZONAL FLOW WAS NOTED
OVER SOUTH FLORIDA.
AT THE SURFACE...AN AREA OF LOW PRESSURE WAS LOCATED OVER THE
WESTERN ATLANTIC JUST SOUTH OF NEW JERSEY...AND A WEAK FRONTAL
BOUNDARY WAS DRAPED SOUTH AND WEST ALONG THE SOUTHEAST STATES
COASTS AND INTO SOUTHERN GEORGIA AND ALONG THE NORTHERN GULF
COAST. WEAK SURFACE HIGH PRESSURE REMAINED ACROSS FLORIDA AND THE
KEYS...WITH A LIGHT NORTHERLY LOW LEVEL FLOW OVER SOUTH FLORIDA.
FOR TODAY...DRIER AIR WILL MOVE IN FROM THE WEST...WITH PWATS A
LITTLE OVER AN INCH. SO DRY AND WARM CONDITIONS ARE EXPECTED.
LIGHT WINDS WILL CONTINUE THIS MORNING...WITH SEA BREEZE
BOUNDARIES PUSHING INLAND ALONG BOTH COASTS THIS AFTERNOON.
TONIGHT...THE UPPER LEVEL RIDGE OVER THE WESTERN GULF IS FORECAST
TO PUSH TOWARDS THE EASTERN GULF AS THE SHORTWAVE OVER CALIFORNIA
EJECTS EAST INTO THE INTERMOUNTAIN WEST. THE SURFACE RIDGE OF
HIGH PRESSURE OVER THE REGION WILL BEGIN TO SHIFT TO THE EAST INTO
THE WESTERN ATLANTIC...WITH EASTERLY FLOW DEVELOPING. LIGHT WINDS
ARE FORECAST ACROSS THE INTERIOR...AND PATCHY FOG MAY DEVELOP ONCE
AGAIN. AREAS OF SMOKE ARE LIKELY NEAR THE WILDFIRE ACROSS EASTERN
COLLIER COUNTY.
SUNDAY THROUGH TUESDAY...THE SURFACE RIDGE WILL CONTINUE TO PUSH
EAST...AND THE EASTERLY FLOW WILL INCREASE. SEA BREEZE BOUNDARIES
ARE FORECAST TO INTERACT ACROSS THE INTERIOR NEAR THE LAKE REGION
IN THE AFTERNOON. THIS MAY BE ENOUGH TO SPARK A FEW SHOWERS OR
STORMS IN THIS REGION ON SUNDAY. ABOVE NORMAL TEMPERATURES WILL
CONTINUE WITH HIGHS IN THE MID 80S TO LOWER 90S. AN UPPER LEVEL
LOW WILL CUTOFF ACROSS THE INTERMOUNTAIN WEST AND THE CENTRAL
PLAINS SUNDAY...AND THEN MEANDER ACROSS THE CENTRAL PLAINS THROUGH
EARLY NEXT WEEK. THE UPPER LEVEL RIDGE WILL MOVE OVER SOUTH
FLORIDA ON SUNDAY AND THEN REMAIN THROUGH THE MIDDLE OF THE WEEK.
MAINLY DRY AND VERY WARM CONDITIONS WILL CONTINUE.
A LARGE UPPER TROUGH/LOW WILL ENVELOP ABOUT THE EASTERN TWO-
THIRDS OF THE CONUS WEDNESDAY AND THURSDAY. UPPER HEIGHTS WILL
BEGIN TO LOWER...BUT SOME RIDGING WILL REMAIN OVER SOUTH FLORIDA.
A COLD FRONT IS FORECAST TO PUSH INTO NORTHERN FLORIDA BY
WEDNESDAY EVENING. HOWEVER...THE FRONT IS FORECAST TO REMAIN OVER
NORTH OR CENTRAL FLORIDA THROUGH FRIDAY. THE FLOW WILL SHIFT TO
THE SOUTHEAST. MOISTURE IS FORECAST TO SLOWLY INCREASE THROUGH
THE END OF THE WEEK...AND RAIN CHANCES ARE FORECAST TO INCREASE.
DEWPOINTS ARE FORECAST TO INCREASE BACK TO AROUND 70 BY
TUESDAY...AND REMAIN AROUND 70 THROUGH THE END OF THE PERIOD.
SOUTHEAST WINDS ARE FORECAST TO BE 10-15 KNOTS OVER THE ATLANTIC
WATERS AS WELL...AND THIS WILL KEEP LOW TEMPERATURES WELL ABOVE
NORMAL FOR THE EAST COAST. OVERNIGHT LOWS ARE FORECAST TO BE IN
THE MID/UPPER 70S FOR THE EAST COAST METRO AREAS. HIGHS ARE
FORECAST TO BE IN THE MID 80S TO LOW 90S THROUGH THE WEEK.
AVIATION...
HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER THROUGH THE TAF
PERIOD. THIS WILL KEEP VFR CONDITIONS IN PLACE. WINDS WILL PICK UP
MID DAY AS THE SEA BREEZE DEVELOPS, THEN RETURN TO LIGHT AND VARIABLE
IN THE LATE EVENING HOURS.
MARINE...
A WEAK PRESSURE GRADIENT PREVAILS ACROSS THE REGIONAL WATERS WITH
LIGHT AND SOMEWHAT VARIABLE WINDS TODAY WITH MORE EASTERLY FLOW
RETURNING ON SUNDAY INTO EARLY NEXT WEEK. IN GENERAL SEAS ARE
EXPECTED TO BE 2 FEET OR LESS THROUGH THE WEEKEND WITH JUST A
GRADUAL INCREASE IN WINDS AND SEAS EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 72 85 72 / 0 0 10 0
FORT LAUDERDALE 87 77 86 75 / 0 0 10 0
MIAMI 88 75 87 74 / 0 0 0 0
NAPLES 86 70 87 70 / 0 0 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
653 AM CDT Sat Apr 26 2014
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 403 AM CDT SAT APR 26 2014
The center of an intense upper level trough was located over
southern CA at 7Z. The upper level trough will lift northeast across
the desert southwest this afternoon, and then lift negative tilt
into southeast CO and across west TX by 12Z SUN.
Early this morning elevated showers were beginning to develop as
isentropic lift was developing ahead of residual 850mb moisture
return. The HRRR along with the ECMWF show the stronger
thunderstorms developing just east of the CWA after 12Z. The 00Z NAM
shows isolated elevated thunderstorms developing along and south of
the KS turnpike by 10Z, then moving east of the CWA during the mid
and late morning hours. Given MUCAPES of 400-1000 J/KG and effective
0-6KM shear of 30 KTS, some of these storms may produce small hail
and the stronger storms may even produce quarter size hail across
portions of east central KS this morning, that is if storms develop
within the CWA.
As an 80kt jet max within the base of the H5 trough lifts northeast
across eastern NM, a lee surface trough across southeast CO,
southward along the NM/TX border will deepen. This will increase the
southerly 850mb winds to 40 KTS across central KS with surface wind
increasing 20 to 30 KTS across most of KS. At this time the
strongest surface winds should remain just southwest and west of the
CWA. The southwest counties of the CWA may come close to wind
advisory criteria during the afternoon hours with sustained winds of
28 MPH and gusts to near 40 MPH.
A surface dryline will develop early this afternoon within the lee
trough axis across extreme southwest KS, then southward across the
TX PNHDL. This dryline will then move northeast into west central KS
and extend southward across extreme western OK by late this
afternoon.
At this time the deepest gulf moisture was located across southern
TX and most models show a quick transport of deep moisture northward
into south central KS by this afternoon. Deeper mixing across
central KS may keep dewpoints in the mid to upper 50s ahead of the
surface dryline.
Both the the 6Z NAM and 00Z Advanced Research WRF show a strong CAP
ahead of the dryline across central KS with no storms developing in
the late afternoon or evening hours. The 12Z ECMWF model shows the
potential for thunderstorms developing along the dryline across
south central KS and north central KS east of HLC. All the models
show temperature and dewpoint temperature depressions greater than
25 degrees along the dryline across central and north central KS.
Therefore, if storms develop they will be high based with MLLCL`s of
5,000 to 6,000 feet. The environment across central KS will have
MLCAPES of 3500 J/KG and Effective shear of 40 KTS. If storms were
able to develop the environment would be favorable for high based
supercell thunderstorms. The higher storm bases will significantly
decrease the potential for tornadoes as these isolated supercell
thunderstorms move northeast off the dryline into the western
counties of the CWA early this evening. In fact they may weaken as
the supercells leave the best area of surface convergence. However,
if any high based supercell manages to develop along the dryline
across north central and central KS, these storms will be capable of
producing large hail and damaging wind gusts.
Highs Today will range from the lower 80s across the northeast
counties to the upper 80s to near 90 across the southwest counties
of the CWA.
I think we will see a break across the CWA from any thunderstorms
from the mid evening hours until 3 or 4 AM Sunday morning, before
severe thunderstorms redevelop. Supercell thunderstorms across
western and central OK will merge into a QLCS or MCS and lift
northeast into south central KS after midnight. Once piece of the
upper level trough will pivot northward across western and central
OK, then into eastern KS through the early morning hours of Sunday.
This will probably maintain any QLCS or MCS cluster of severe
thunderstorms that develop across northern OK and southern KS, as
these storms move northeast ahead of the first H5 trough across the
eastern half of the CWA. The primary hazard with the cluster of
severe thunderstorms will be large hail along with the threat for
damaging winds. I cannot rule out a few supercell thunderstorms on
the southern edge of the severe cluster of thunderstorms. Any
supercells or meso vortices within a QLCS may bring a low chance for
an isolated tornado through early morning hours of Sunday across
portions of east central KS. The MCS/cluster of severe thunderstorms
may also bring heavy rainfall. It will be more of a mesoscale
forecast but areas along and south of the KS turnpike may see the
heaviest rainfall near 12Z SUN.
Overnight lows will only drop into the lower to mid 60s Saturday
night.
.LONG TERM...(Sunday through Friday)
Issued at 403 AM CDT SAT APR 26 2014
The most concentrated and potentially strongest convection still
appears to be on Sunday over the eastern 2/3 of the cwa in the
morning and the eastern 1/3 in the afternoon as the main shortwave
lobe over southwest KS at 12z Sunday lifts northeastward across KS
through the day. Strong to severe convection appears will be
ongoing to start the day Sunday across much of the cwa...gradually
shifting eastward ahead of dry slot in central KS...although
models such as the EC hinting that the cwa could be on the
northern fringe of a substantial MCS just to the south. Models
keep MUCAPE values in the 1500-2000 J/kg range ahead of the
dryline...however 0-6km Bulk Shear values steadily increase into
the 50-60kt range through 18z over the eastern half of the cwa or
near and just ahead of dryline. Although large hail...wind is
possible with the morning convection...any additional development
by midday/afternoon in any increasingly sheared environment would
become more supportive of supercells with all modes of severe
weather possible including a tornado threat. This will be highly
dependent on the speed/timing of the dryline and its proximity to
afternoon heating just of the mid level drying. Although will
leave a slight chance for some lingering convection early evening
in the far eastern counties...it still appears the threat for
severe weather will shift east of the cwa by 00Z as drier air
continues to push eastward across the area as the upper low slows
and occludes over western Nebraska.
Cannot totally rule out a few showers developing over the cwa on
Monday as the upper low wobbles eastward and moisture wraps around
the circulation center and back into the cwa...but will word as
showers for now as instability looks weak. Rain chances will then
linger through Wednesday...then again on Thursday as another
shortwave trough rotates southeast around the upper trough. Rainfall
amounts across the area through mid week should remain light. High
temperatures still expected to cool from the 70s on Sunday to the
60s/near 70 Monday...then the 50s and 60s through the remainder of
the week. Lows will commonly be in the 40s Tuesday through Friday.
&&
.AVIATION...(For the 12Z TAFs through 12Z Sunday Morning)
Issued at 648 AM CDT SAT APR 26 2014
Isolated thunderstorms may develop in the vicinity of terminals
KTOP and KFOE through 14Z SAT. Expect VFR conditions through most of
the next 24 hours. Thunderstorms may move into the terminals after
8Z SUN and continue through the morning hours. Any thunderstorm
may bring Brief MVFR ceilings and visibilities through the early
morning hours of Sunday. South-Southeast winds will increase to 14 to 20
KTS with gusts of 22 to 30 KTS. Winds gust may diminish slightly
after 00Z SUN.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...63
AVIATION...Gargan
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1133 AM EDT SAT APR 26 2014
.SYNOPSIS...
SCATTERED SHOWERS ARE EXPECTED TODAY...WITH AN ISOLATED THUNDERSTORM
POSSIBLE SOUTH OF THE MASON DIXON LINE. SUNDAY SHOULD BE DRY BEFORE
AN UNSETTLED PATTERN SETS UP FOR THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
SHOWERS ASSOCIATED WITH A WEAK SHORTWAVE CONTINUE TO SLIDE ACROSS
THE REGION THIS MORNING. THE HRRR SEEMED TO HANDLE THE RESOLUTION
OF THESE SHOWERS WELL...SO POPS WERE ADJUSTED THROUGH THE AFTERNOON
TO REFLECT THIS FORECAST. EXPECT THE GREATEST COVERAGE TO REMAIN
SOUTH OF I-70 FOR THE REST OF THE DAY AS A COLD FRONT SINKS
SOUTHWARD FROM LAKE ERIE. BUFKIT SOUNDINGS SUGGEST THAT THERE COULD
BE ENOUGH INSTABILITY WITH HEATING TO SUPPORT A THUNDERSTORM OR
TWO WITH THE LIFT FROM THE COLD FRONT SO MAINTAINED THE ISOLATED
THUNDER MENTION. EXPECT GUSTY WINDS WITH THE FRONTAL PASSAGE THIS
AFTERNOON...WEAKENING AFTER SUNSET. TEMPERATURES WILL BE
SEASONABLE DURING THE DAY...BUT BELOW NORMAL TONIGHT WITH LIGHT
WINDS AND CLEARING SKIES.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY IS CURRENTLY THE ONLY DAY IN THE 7 DAY FORECAST WITHOUT A
CHANCE OF RAIN IN THE FORECAST THANKS TO HIGH PRESSURE BRIEFLY
PASSING OVER THE REGION. LOW PRESSURE WILL BEGIN TO DEVELOP IN THE
PLAINS...AND THE ASSOCIATED WARM FRONT WILL SWEEP TOWARDS THE REGION
ON MONDAY. RAIN IS EXPECTED TO WORK ITS WAY INTO EASTERN OHIO ON
MONDAY...AND ACROSS THE ENTIRE FORECAST AREA MONDAY NIGHT. DAYTIME
HIGHS WILL BE NEAR NORMAL...WITH OVERNIGHT LOWS ABOVE NORMAL AS
CLOUDS MOVE IN.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... MODELS IN
AGREEMENT ON A BROAD AREA OF LOW PRESSURE LINGERING OVER THE ERN
CONUS CENTERED IN THE GREAT LAKES THROUGH THE END OF NEXT WEEK.
THIS WILL PROVIDE DAILY CHANCES OF RAIN SHOWERS AND WORK TO
MODERATE TEMPERATURES UNDER CLOUDY SKIES. WITH A BLOCKED PATTERN
ALOFT DOUBT UPPER LEVEL SYSTEM WILL BE QUICK TO MOVE OFF FOR THE
WEEKEND...WITH COOL TEMPERATURES AND SHOWER CHANCES CONTINUED FOR
SATURDAY.
&&
.AVIATION /16Z SATURDAY THROUGH THURSDAY/...
VFR THROUGH THE TAF PERIOD AS A MOISTURE STARVED FRONT WORKS
ACROSS REGION THIS AFTERNOON. WINDS WILL BE GUSTY TO 25 KTS FROM
THE WEST TURNING NORTHWEST 18-22Z WITH MAIN FROPA. WINDS WILL
DIMINISH TOWARD SUNSET WITH VFR AND LIGHT NORTHERLY FLOW THROUGH
SUNDAY.
.OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
PERIODIC RSTRNS ARE EXPD MUCH OF NXT WK AS A SERIES OF DISTURBANCES
CROSS THE RGN.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS BALTIMORE MD/WASHINGTON DC
1008 AM EDT SAT APR 26 2014
.SYNOPSIS...
ANOTHER COLD FRONT WILL PASS THROUGH THE AREA LATER TODAY BEFORE
HIGH PRESSURE RETURNS SUNDAY. LOW PRESSURE WILL DEVELOP OVER THE
CENTRAL UNITED STATES EARLY NEXT WEEK. THIS WILL LIKELY BRING
CLOUDY...RAINY...AND COOL CONDITIONS TO THE REGION.
&&
.NEAR TERM /THROUGH SUNDAY/...
PART ONE OF THE UPPER LEVEL LOW PRES SYSTEM MOVED THROUGH
YESTERDAY...W/ A BIGGER BUILD-UP TO A LARGER SECTION OF PRECIP
ALONG W/ THE MAIN SYNOPTIC SYSTEM. PART TWO TODAY WILL BE THE
BACK-END LESSER POTENT PASSAGE OF A MINOR SHORTWAVE. THIS FEATURE
WILL ALSO DEVELOP A SFC LOW PRES SYSTEM...BUT VERY WEAK AND SMALL
IN SCALE. THE SFC LOW WILL BE SWINGING CLOSER TO THE NYC METRO
AREA...DRAGGING THE WEAK SFC COLD FRONT ACROSS OUR PORTION OF THE
MID ATLC REGION...BACK INTO THE CNTRL APLCNS. THE TAILEND OF THIS
FEATURE IS ALREADY KICKING-OFF SOME SCATTERED SHOWERS OVER
CNTRL/ERN OH AND SOME BANKING INTO THE WINDWARD SIDE OF THE
APLCNS.
PLENTY OF WIND UPSTAIRS BUT IT`S NOT BEING MIXED DOWN QUITE
YET. RELATIVELY LOW DEWPOINTS WILL ALLOW TEMPS TO QUICKLY SHOOT
BACK UP INTO THE 50S/60S THRU THE REST OF THE MRNG HRS. BY THE
MID-LATE AFTN...WE`LL SEE WIDESPREAD 70S AND A FEW U70S OVER THE
SRN TIER OF THE CWA/LOWER VA PIEDMONT. ONCE WLY WINDS START TO
PICK UP LATER THIS MRNG/EARLY AFTN...THE STRONGER WINDS WILL THE
DOWNSLOPING AND THEREFORE THE WARMING PROCESS - AND BRING TEMPS
UP A FEW MORE DEG THAN THE SYNOPTIC ALLOWANCE.
PLENTY OF DRY AIR OVERHEAD...W/ SOME OF THE BOUNDARY LAYER
EXPECTED TO CLOSE THAT GAP HEADING INTO THE AFTN HRS BUT STILL THE
ENVIRONMENT LENDS TO LOCALIZED DOWNBURSTS OF A PORTION OF THE
LL 50-70KT JET. THE AMBIENT WINDS THIS AFTN DURING THE PEAK
HEATING HRS WILL BE GUSTY...WELL INTO THE 20-30MPH RANGE W/ A FEW
GUSTS NEAR 40MPH. THE MAIN CONCERN WILL BE W/ THE FAST-MOVING
SHOWER...THAT COULD HELP PULL DOWN LOCALLY STRONGER GUSTS. THESE
SHOWERS DON`T EVEN NEED TO BE TSTMS...JUST WEAKLY CONVECTIVELY
INDUCED TO TAP INTO THE MID/BOUNDARY LAYER WINDS.
PRECIP ACTIVITY FOR THE AREA WILL BE RELATIVELY BRIEF IN TERMS OF
THE ENTIRE DAY AND ISOLATED. A COUPLE OF WAVES OF ISOLATED TO
SCATTERED SHOWERS WILL LIKELY SWING THRU THE CWA ALONG A NW-SE
TREK...SOME LOCAL MODELS LIKE THE RECENT WRF AND HRRR RUNS
BRINGING AT LEAST ONE WAVE OVER DC AND BALT REGIONS LATER THIS
AFTN.
PREV DISC...
THE WAVE WILL EXIT THE AREA THIS EVENING AND HIGH PRESSURE WILL
REBUILD SATURDAY NIGHT AND SUNDAY. A CHILLY NIGHT SATURDAY NIGHT
IN THE 40/S IS EXPECTED...AND HIGH TEMPERATURES SUNDAY WILL BE A
BIT BELOW NORMAL IN THE 60/S. SUNDAY WILL BE DRY.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
SFC RDG AXIS WL BE ATOP CWFA SUN NGT...WHILE THE UPR RDG SHUD BE
POSITIONED ACRS THE GRTLKS/OHVLY/SRN APLCNS. THEREFORE...FAIR WX
SHUD PREVAIL...BUT THERE WL STILL BE ITEMS TO ADDRESS. MOST
NOTABLY WL BE THE INCRS IN CLDS IN ASSOC W/ H8 WAA. AM KEEPING
MIN-T A BIT ABV THE MOS MEAN AS A RSLT.
THE WMFNT CROSSES CWFA MON...PROVIDING MDT-STRONG ISENT LIFT. GDNC
SUGGESTING THERE WL BE A 30-40 KT LLJ PRESENT...BUT ARE AT ODDS ON
EXACTLY WHERE TO PLACE IT. REGARDLESS...THINK THERE WL BE ENUF UVV
TO SUPPORT DVLPG RA...AND AM FEATURING AN UPTICK IN POPS NOT JUST
DURING THE DAY...BUT ALSO MON NGT. ONCE AGN...GDNC TIMING WM FROPA A
BIT DIFFERENTLY...WHICH WL AFFECT THE TIME FRAME WHEN THE MOST SGFNT
RAFL WL OCCUR. EITHER WAY...MON WL MARK THE START OF A WET PD.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
THE MIDDLE OF THE WEEK WILL BE RATHER SOGGY AND COOL. LOW PRESSURE
OVER THE GREAT PLAINS WILL APPROACH THE AREA FOR THE MIDDLE OF
NEXT WEEK. OVERCAST CONDITIONS SHOULD PERSIST THROUGHOUT THE DAY
ON TUES IN MOIST ONSHORE LOW LEVEL FLOW. WEAK COLD AIR DAMMING
COULD ALSO OCCUR...HELPING TO KEEP HIGH TEMPS IN THE MID 50S FOR
MOST OF THE AREA...ABOUT 15 DEG BELOW NORMAL FOR THIS TIME OF
YEAR. A WARM FRONT WILL CROSS THE AREA FROM SOUTH TO NORTH
BEGINNING TUESDAY AFTERNOON. THIS WARM FRONT WILL INITIALLY
OVERRUN COOLER AIR AT THE SURFACE AND SHOULD BRING SHOWERS TO THE
AREA THROUGHOUT THE DAY TUES.
SHOWERS REMAIN LIKELY THROUGH THE DAY ON WEDNESDAY AS A SERIES OF
WEAK DISTURBANCES PASS OVER THE AREA AND WARM MOIST AIR CONTINUES
TO FILL IN ON THE BACK OF SOUTHEASTERLY FLOW IN THE LOWER LEVELS.
THE LOW WILL STALL OVER THE GREAT LAKES WED NIGHT AND THURS AND THE
ASSOCIATED COLD FRONT WILL BEGIN TO APPROACH THE AREA WED EVENING.
GUIDANCE IS CURRENTLY SHOWING WEAK TO MODERATE INSTABILITY FOCUSED
OVER THE SOUTHERN PORTION OF THE CWA AHEAD OF THE FRONT WEDNESDAY
NIGHT AND TUES MORNING...THUS HAVE PUT ISOLATED THUNDERSTORMS ALONG
WITH LIKELY RAIN SHOWERS IN THE FORECAST FOR THIS TIME PERIOD
GENERALLY SOUTH OF A LINE FROM PENDLETON CO WV TO CALVERT CO MD.
HIGH PRESSURE WILL BEGIN TO FILL BACK INTO THE AREA BEHIND THE COLD
FRONT OVERNIGHT THURS AND FRI SHOULD ALLOW FOR US TO START DRYING
OUT UNDER MOSTLY SUNNY SKIES AND TEMPS NEAR 70.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS THRU THE TAF PERIOD. THE MAIN CONCERNS FROM THE
GUSTY SFC WINDS FROM LATE THIS MRNG INTO EARLY AFTN. WDLY SCT
-SHRA SPREADING FROM HGR TO IAD/DCA/BWI AFTER 18Z. TS POSSIBLE CB
TOPS FL380 SFC WIND G30KT 21Z- 00Z. VFR AFTER 00Z SUNDAY. RA
OVERSPREADING TERMINALS MON. VFR SHUD HOLD UP FOR THE MRNG
PUSH...THEN FLGT CAT DROPPING THRU MVFR. SUSPECT IFR WONT ARRIVE
TIL AFDK. IFR CONDITIONS ARE LIKELY IN LOW CEILINGS AND RAIN
SHOWERS AS A WARM FRONT SLOWLY CROSSES THE AREA TUESDAY AND INTO
WEDNESDAY.
&&
.MARINE...
STRONG MIXING WITHIN THE NEXT COUPLE HRS WILL ALLOW FOR GUSTS TO
CONTINUE INTO THE 20-25 MPH RANGE. SMALL CRAFT ADVISORIES WILL
CONTINUE INTO THE AFTERNOON. A GALE WARNING MAY BE WARRANTED IN
THE AFTERNOON AS CONVECTIVE SHOWERS MAY PRODUCE SMALL HAIL AND
STRONG WIND GUSTS. SCA HAS BEEN EXTENDED INTO SAT NGT AS HIGH PRES
BUILDS INTO THE AREA. SUN LOOKS TO HAVE LESS WIND. RDG AXIS SHUD
PROVIDE WNDS AOB 10 KT THRU MON. DIRECTION MAINLY NE VEERING SE AS
A WMFNT CROSSES THE WATERS. WNDS CUD BE CLSR TO 15 KT MON NGT MID
BAY/LWR PTMC...BUT MOMENTUM TRANSFER LOOKS QUITE POOR. A SMALL
CRAFT ADVISORY MAY BE NECESSARY FOR THE LOWER MARYLAND CHESAPEAKE
BAY IN SOUTHERLY FLOW TUESDAY NIGHT.
&&
.TIDES/COASTAL FLOODING...
ADVY FOR ANNAPOLIS EXPIRED...AND WATER BACK W/IN BANKS. LOOKS LIKE
STRONGER WINDS REACHED BALT AS XPCTD BASED ON FLATLINING OF
HYDROGRAPH. DC PEAKING JUST UNDER ADVY CRITERIA. NW FLOW SHUD
ASSIST IN RETURNING WATER LVLS TO NORMAL BY THE PM TIDE CYCLE.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR ANZ530>543.
&&
$$
UPDATE...GMS
PREV DISCUSSION...SDG/HTS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
936 AM EDT SAT APR 26 2014
.SYNOPSIS...
SCATTERED SHOWERS ARE EXPECTED TODAY...WITH AN ISOLATED THUNDERSTORM
POSSIBLE SOUTH OF THE MASON DIXON LINE. SUNDAY SHOULD BE DRY BEFORE
AN UNSETTLED PATTERN SETS UP FOR THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
SHOWERS ASSOCIATED WITH A WEAK SHORTWAVE CONTINUE TO SLIDE ACROSS
THE REGION THIS MORNING. THE HRRR SEEMED TO HANDLE THE RESOLUTION
OF THESE SHOWERS WELL...SO POPS WERE ADJUSTED THROUGH THE AFTERNOON
TO REFLECT THIS FORECAST. EXPECT THE GREATEST COVERAGE TO REMAIN
SOUTH OF I-70 FOR THE REST OF THE DAY AS A COLD FRONT SINKS
SOUTHWARD FROM LAKE ERIE. BUFKIT SOUNDINGS SUGGEST THAT THERE COULD
BE ENOUGH INSTABILITY WITH HEATING TO SUPPORT A THUNDERSTORM OR
TWO WITH THE LIFT FROM THE COLD FRONT SO MAINTAINED THE ISOLATED
THUNDER MENTION. EXPECT GUSTY WINDS WITH THE FRONTAL PASSAGE THIS
AFTERNOON...WEAKENING AFTER SUNSET. TEMPERATURES WILL BE
SEASONABLE DURING THE DAY...BUT BELOW NORMAL TONIGHT WITH LIGHT
WINDS AND CLEARING SKIES.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY IS CURRENTLY THE ONLY DAY IN THE 7 DAY FORECAST WITHOUT A
CHANCE OF RAIN IN THE FORECAST THANKS TO HIGH PRESSURE BRIEFLY
PASSING OVER THE REGION. LOW PRESSURE WILL BEGIN TO DEVELOP IN THE
PLAINS...AND THE ASSOCIATED WARM FRONT WILL SWEEP TOWARDS THE REGION
ON MONDAY. RAIN IS EXPECTED TO WORK ITS WAY INTO EASTERN OHIO ON
MONDAY...AND ACROSS THE ENTIRE FORECAST AREA MONDAY NIGHT. DAYTIME
HIGHS WILL BE NEAR NORMAL...WITH OVERNIGHT LOWS ABOVE NORMAL AS
CLOUDS MOVE IN.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
MODELS IN AGREEMENT ON A BROAD AREA OF LOW PRESSURE LINGERING OVER
THE ERN CONUS CENTERED IN THE GREAT LAKES THROUGH THE END OF NEXT WEEK.
THIS WILL PROVIDE DAILY CHANCES OF RAIN SHOWERS AND WORK TO
MODERATE TEMPERATURES UNDER CLOUDY SKIES.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
MID-LEVEL CLOUDS CONTINUE TO STREAM IN AHEAD OF ANOTHER WEAK COLD
FRONT TODAY. SPOTTY MVFR CONDITIONS FOR VISBY WILL QUICKLY GIVE
WAY TO VFR AS CLOUDS INCREASE. INCLUSION OF MARGINAL LLVL WIND SHEAR AS
20-30KT SOUTHWEST WINDS EXIST ABOUT 2KFT OFF THE DECK. THE
WEAK COLDFRONT TODAY WILL SPAWN MORE SCT SHOWERS AND MOSTLY VFR
STRATOCU ON THIS AFTERNOON WITH GUSTY WINDS.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
PERIODIC RSTRNS ARE EXPD ERLY NXT WK AS A SERIES OF DISTURBANCES
CROSS THE RGN.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1025 AM CDT SAT APR 26 2014
.UPDATE...SUNNY SKIES PREVAIL THIS MORNING ACROSS THE ARKLAMISS.
TEMPERATURES LATE THIS MORNING WERE MAINLY IN THE LOW TO MID
70S...WITH AFTERNOON HIGHS EXPECTED TO REACH THE MID 80S. AS FOR THE
CURRENT FORECAST...WENT AHEAD AND ADDED A MENTION OF THUNDER TO THE
SHOWER ACTIVITY FOR LATER THIS AFTERNOON ALONG AND SOUTH OF THE I20
CORRIDOR DUE TO SOME ELEVATED INSTABILITY. ONLY OTHER CHANGE WAS TO
MAKE SOME SLIGHT ADJUSTMENTS TO THE CLOUD COVER FOR THIS MORNING INTO
THE EARLY AFTERNOON HOURS. /27/
&&
.AVIATION...CLEAR SKIES WERE BEING OBSERVED AT 15Z. THE STALLED
BOUNDARY JUST SOUTH OF HBG WILL BEGIN LIFTING NORTH THIS AFTN. THIS
WL BRING AN INCREASE IN CLOUD COVER AND A SLIGHT CHANCE OF A SHOWER
OT TSTM...ALONG AND SOUTH OF INTERSTATE 20. OTHERWISE...VFR
CONDITIONS WL CONTINUE THROUGH THIS EVENING. WIDESPREAD IFR CATEGORY
STRATUS IS EXPECTED TO SPREAD NORTH ACROSS THE FORECAST AREA TOWARD
10Z SUNDAY. TSTM POTENTIAL WILL BE ON THE INCREASE SUNDAY INTO
SUNDAY NIGHT AS A POTENT LOW PRESSURE SYSTEM APPROACHES. THIS LOW
PRESSURE SYSTEM WL TAKE UNTIL WEDNESDAY TO SHIFT EAST OF OUR AREA
RESULTING IN A STRETCH OF ROUGH WEATHER FOR AVIATION INTERESTS SUN
THROUGH TUESDAY. /EC/22/
&&
.PREV DISCUSSION... /ISSUED 513 AM CDT SAT APR 26 2014/
..SEVERE WEATHER OUTBREAK EXPECTED FROM SUNDAY NIGHT THROUGH
TUESDAY AND SIGNIFICANT FLOOD EVENT POSSIBLE AS WELL...
DISCUSSION...
TODAY AND TONIGHT...
THERE IS A WRINKLE IN WHAT WAS SUPPOSED TO CLEARLY BE A DRY FORECAST
FOR SATURDAY. THE NCEP WRF AND HRRR GUIDANCE SUGGEST AN EAST-WEST
ORIENTED BROKEN LINE OF SHOWERS MAY DEVELOP LATER TODAY WITH DAYTIME
HEATING ALONG THE NORTHERN EDGE OF RICHER LOW LEVEL MOISTURE NEAR THE
GULF COAST. HAVE RAISED POPS TO SLIGHT CHANCE CATEGORY FOR LOCATIONS
ALONG AND SOUTH OF I-20. CONFIDENCE IS LOW IN THIS ACTIVITY
MATERIALIZING GIVEN THE DRY AIR (PRECIPITABLE WATER < .50 INCH) THAT
NEEDS TO BE OVERCOME AND GENERAL LACK OF LIFT ON ANY SCALE. EXPECT
ANY SHOWER ACTIVITY TO DIMINISH QUICKLY WITH SUNSET THIS
EVENING. OTHERWISE...EXPECT INCREASING LOW CLOUDS AS HIGHER QUALITY
BOUNDARY LAYER MOISTURE BEGINS TO SURGE INLAND.
SUNDAY THROUGH MONDAY NIGHT...
HIGH FORECAST CONFIDENCE CONTINUES REGARDING A DANGEROUS SET-UP FOR
SEVERE WEATHER AND HEAVY RAINFALL FROM LATE SUNDAY THROUGH TUESDAY
NIGHT. ALL MODES OF SEVERE WEATHER INCLUDING THE POTENTIAL FOR STRONG
TORNADOES WILL BE POSSIBLE AS A LARGE AND DEEP VORTEX LOCKS IN OVER
THE CENTRAL CONUS AND SENDS SEVERAL LOBES OF SHORTWAVE TROUGH ENERGY
ACROSS THE ARKLAMISS. GIVEN THE PERSISTENCE OF THIS PATTERN AND
AVAILABILITY OF ANOMALOUS MOISTURE...A SIGNIFICANT FLOODING EVENT IS
PROBABLE AS WELL.
THE RISK FOR SEVERE WEATHER COULD RAMP UP QUICKLY LATE SUNDAY
AFTERNOON INTO THE EVENING IN THE DELTA REGION. GUIDANCE CONTINUES
TO INDICATE THAT RAPID MOISTENING AND DESTABILIZATION ASSOCIATED
WITH INCREASINGLY CYCLONIC FLOW ALOFT WILL ALLOW FOR SHOWER/THUNDERSTORM
ACTIVITY TO BREAK OUT AS EARLY AS SUNDAY MORNING. BY SUNDAY AFTERNOON
AND EVENING A VERY UNSTABLE (ML CAPE > 2500 J/KG) AND HIGHLY SHEARED
ENVIRONMENT (0-1KM ~45 KTS) IS EXPECTED AS LAPSE RATES STEEPEN ABOVE
A STRENGTHENING LOW LEVEL JET (50-60KTS). LARGE CLOCKWISE HODOGRAPHS
WILL SUPPORT SUPERCELL THUNDERSTORMS WITH INTENSE ROTATING UPDRAFTS
AND STRONG TORNADO POTENTIAL OVER THE DELTA REGION BY SUNDAY
EVENING. CONFIDENCE IS INCREASING THAT THE GREATER RISK FOR SEVERE
WEATHER WILL REMAIN MAINLY OVER THE DELTA REGION SUNDAY NIGHT. BUT
A QUASI-LINEAR CONVECTIVE SYSTEM COULD EVENTUALLY EVOLVE...AND IF
THIS HAPPENS WE WOULD EXPECT COLD POOL GENERATION TO HELP GIVE THE
SYSTEM SOME EASTWARD ACCELERATION ALONG THE HWY 82 CORRIDOR...PERHAPS
REACHING THE NATCHEZ TRACE CORRIDOR. IT IS UNCLEAR HOW MUCH SUCH AN
MCC WILL DIMINISH DURING THE EARLY MONDAY MORNING HOURS...BUT THERE
MAY BE SOMEWHAT OF A LULL BEFORE THE NEXT ROUND OF SHORTWAVE ENERGY
APPROACHES.
AS WE GO INTO MONDAY AFTERNOON AND EVENING...EXPECT RE-NEWED SEVERE
THUNDERSTORM ACTIVITY WHEN A RIBBON OF STRONGER PACIFIC JET ENERGY
ROUNDS THE BASE OF THE DEEP CENTRAL CONUS TROUGH AND ENHANCES WIND
SHEAR/LIFT AND THE SEVERE WEATHER RISK OVER THE FORECAST AREA. MIXED
LAYER CAPE NEAR 3000 J/KG COULD HELP MAKE FOR A VOLATILE SET-UP WITH
THIS SYNOPTIC PATTERN. THE INITIAL CONVECTION SHOULD EVENTUALLY
EVOLVE INTO ANOTHER LINEAR CONVECTIVE SYSTEM...AND WITH DEEP LAYER
SHEAR VECTORS BECOMING MORE PARALLEL RESULTING IN GREATER POTENTIAL
FOR TRAINING AND BACK-BUILDING OF STORMS...THE RISK FOR HEAVY
RAINFALL AND FLOODING COULD REALLY RAMP UP MONDAY NIGHT. THE ECMWF IS
A LITTLE MORE PROGRESSIVE WITH SUCH A SYSTEM WHILE THE GFS SHOWS A
GREATER PROPENSITY FOR PARALLEL DEEP LAYER FLOW AND CORFIDI VECTOR
RIDGING SUGGESTIVE OF MCS BACK-BUILDING AND SLOW SYSTEM SPEED. WHILE
IT IS DIFFICULT TO KNOW WHERE IT WILL SET UP EXACTLY...WITH K INDICES
IN THE LOW 40S AND PRECIPITABLE WATER APPROACHING 2 INCHES...THERE
WILL LIKELY BE INTENSE RAINFALL RATES OF WHICH ANY LONG DURATION
COULD LEAD TO SERIOUS FLOODING CONCERNS.
CIPS ANALOGS ARE STILL SHOWING VERY SIGNIFICANT EVENTS FOR COMPARISON
TO THIS SET-UP ADDING MORE CONFIDENCE THAT SIGNIFICANT SEVERE WEATHER
AND FLOODING WILL BE POSSIBLE. THE LATEST ANALOG CONSENSUS HAS
SHIFTED BACK A LITTLE FARTHER NORTH WITH HIGHER SEVERE WEATHER/HEAVY
RAINFALL PROBS FROM SUNDAY NIGHT THROUGH MONDAY NIGHT...BEFORE
SHIFTING SOUTHWARD FOR THE TIME CENTERED ON THE MORE UNCERTAIN
TUESDAY EVENING PERIOD. TO MAINTAIN CONSISTENCY WILL NOT MAKE ANY
SIGNIFICANT ADJUSTMENTS AT THIS POINT TO THE RISK AREAS...BUT WILL
ADD SOME MORE DETAIL. /EC/
TUESDAY THROUGH NEXT SATURDAY...
A VOLATILE PATTERN SUPPORTIVE OF SEVERE WEATHER/TORNADOES AND
ADDITIONAL HEAVY RAIN MAY CONTINUE TUESDAY INTO TUESDAY NIGHT. THE
FORECAST FOR THIS PERIOD IS MORE UNCERTAIN HOWEVER AS IT WILL HINGE
GREATLY ON THE BEHAVIOR OF MONDAY NIGHT CONVECTIVE ACTIVITY. A
STRONG CLOSED H5 CLOSED LOW WILL EXIST OVER IOWA EARLY TUESDAY WHICH
IS CHARACTERIZED BY A 120KT CYCLONICALLY CURVED JET WITH MULTIPLE
EJECTING LOBES OVERTOP A MOIST UNSTABLE MODERATELY SHEARED
ENVIRONMENT ACROSS THE ARKLAMISS. THIS SET-UP WILL SUPPORT VIGOROUS
CONVECTIVE DEVELOPMENT AGAIN FOR TUESDAY AFTERNOON AND EVENING.
ADDITIONAL HEAVY RAIN WILL BE POSSIBLE WITH PRECIPITABLE WATER
AROUND 1.8 INCHES AND FAVORABLE WIND PROFILES FOR TRAINING OF STORMS
LEADING TO FLASH FLOODING AND SIGNIFICANT RIVER RISES. THE ASSOCIATED
COLD FRONT WILL FINALLY MOVE THROUGH THE REGION BY EARLY WEDNESDAY.
AS WE GO INTO WEDNESDAY THE LAST OF THE CONVECTION WILL EXIT THE
REGION BY WEDNESDAY AFTERNOON. A BROAD UPPER TROUGH WILL CONTINUE
OVER THE REGION FOR MOST OF THE PERIOD THROUGH FRIDAY BEFORE THE
UPPER TROUGH FINALLY LIFTS OUT OVER THE WEEKEND. THE MODEL GUIDANCE
TRIES TO BRING IN LOW POPS FOR WEDNESDAY THROUGH SATURDAY. THE EURO
TRIED TO SHOW SOME LOW QPF FROM THURSDAY THROUGH SATURDAY...BUT OPTED
TO KEEP THE REGION DRY. SOME COOL AIR WILL PUSH INTO THE REGION FOR
THURSDAY INTO FRIDAY WITH LOWS IN THE 40S AND 50S REACHING INTO THE
FIRST FEW DAYS OF MAY...WHICH WILL RUN AROUND TEN DEGREES BELOW
NORMAL. /17/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 85 66 82 69 / 18 12 30 43
MERIDIAN 85 63 83 66 / 13 9 24 30
VICKSBURG 85 68 82 71 / 18 14 41 53
HATTIESBURG 87 67 83 68 / 19 12 20 22
NATCHEZ 85 68 84 70 / 20 12 32 37
GREENVILLE 84 67 80 69 / 5 18 71 79
GREENWOOD 86 67 82 70 / 4 11 56 63
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
27/22/EC/17
AREA FORECAST DISCUSSION
NWS JACKSON MS
513 AM CDT SAT APR 26 2014
...SEVERE WEATHER OUTBREAK EXPECTED FROM SUNDAY NIGHT THROUGH
TUESDAY AND SIGNIFICANT FLOOD EVENT POSSIBLE AS WELL...
.DISCUSSION...
TODAY AND TONIGHT...
THERE IS A WRINKLE IN WHAT WAS SUPPOSED TO CLEARLY BE A DRY FORECAST
FOR SATURDAY. THE NCEP WRF AND HRRR GUIDANCE SUGGEST AN EAST-WEST
ORIENTED BROKEN LINE OF SHOWERS MAY DEVELOP LATER TODAY WITH DAYTIME
HEATING ALONG THE NORTHERN EDGE OF RICHER LOW LEVEL MOISTURE NEAR THE
GULF COAST. HAVE RAISED POPS TO SLIGHT CHANCE CATEGORY FOR LOCATIONS
ALONG AND SOUTH OF I-20. CONFIDENCE IS LOW IN THIS ACTIVITY
MATERIALIZING GIVEN THE DRY AIR (PRECIPITABLE WATER < .50 INCH) THAT
NEEDS TO BE OVERCOME AND GENERAL LACK OF LIFT ON ANY SCALE. EXPECT
ANY SHOWER ACTIVITY TO DIMINISH QUICKLY WITH SUNSET THIS
EVENING. OTHERWISE...EXPECT INCREASING LOW CLOUDS AS HIGHER QUALITY
BOUNDARY LAYER MOISTURE BEGINS TO SURGE INLAND.
SUNDAY THROUGH MONDAY NIGHT...
HIGH FORECAST CONFIDENCE CONTINUES REGARDING A DANGEROUS SET-UP FOR
SEVERE WEATHER AND HEAVY RAINFALL FROM LATE SUNDAY THROUGH TUESDAY
NIGHT. ALL MODES OF SEVERE WEATHER INCLUDING THE POTENTIAL FOR STRONG
TORNADOES WILL BE POSSIBLE AS A LARGE AND DEEP VORTEX LOCKS IN OVER
THE CENTRAL CONUS AND SENDS SEVERAL LOBES OF SHORTWAVE TROUGH ENERGY
ACROSS THE ARKLAMISS. GIVEN THE PERSISTENCE OF THIS PATTERN AND
AVAILABILITY OF ANOMALOUS MOISTURE...A SIGNIFICANT FLOODING EVENT IS
PROBABLE AS WELL.
THE RISK FOR SEVERE WEATHER COULD RAMP UP QUICKLY LATE SUNDAY
AFTERNOON INTO THE EVENING IN THE DELTA REGION. GUIDANCE CONTINUES
TO INDICATE THAT RAPID MOISTENING AND DESTABILIZATION ASSOCIATED
WITH INCREASINGLY CYCLONIC FLOW ALOFT WILL ALLOW FOR SHOWER/THUNDERSTORM
ACTIVITY TO BREAK OUT AS EARLY AS SUNDAY MORNING. BY SUNDAY AFTERNOON
AND EVENING A VERY UNSTABLE (ML CAPE > 2500 J/KG) AND HIGHLY SHEARED
ENVIRONMENT (0-1KM ~45 KTS) IS EXPECTED AS LAPSE RATES STEEPEN ABOVE
A STRENGTHENING LOW LEVEL JET (50-60KTS). LARGE CLOCKWISE HODOGRAPHS
WILL SUPPORT SUPERCELL THUNDERSTORMS WITH INTENSE ROTATING UPDRAFTS
AND STRONG TORNADO POTENTIAL OVER THE DELTA REGION BY SUNDAY
EVENING. CONFIDENCE IS INCREASING THAT THE GREATER RISK FOR SEVERE
WEATHER WILL REMAIN MAINLY OVER THE DELTA REGION SUNDAY NIGHT. BUT
A QUASI-LINEAR CONVECTIVE SYSTEM COULD EVENTUALLY EVOLVE...AND IF
THIS HAPPENS WE WOULD EXPECT COLD POOL GENERATION TO HELP GIVE THE
SYSTEM SOME EASTWARD ACCELERATION ALONG THE HWY 82 CORRIDOR...PERHAPS
REACHING THE NATCHEZ TRACE CORRIDOR. IT IS UNCLEAR HOW MUCH SUCH AN
MCC WILL DIMINISH DURING THE EARLY MONDAY MORNING HOURS...BUT THERE
MAY BE SOMEWHAT OF A LULL BEFORE THE NEXT ROUND OF SHORTWAVE ENERGY
APPROACHES.
AS WE GO INTO MONDAY AFTERNOON AND EVENING...EXPECT RE-NEWED SEVERE
THUNDERSTORM ACTIVITY WHEN A RIBBON OF STRONGER PACIFIC JET ENERGY
ROUNDS THE BASE OF THE DEEP CENTRAL CONUS TROUGH AND ENHANCES WIND
SHEAR/LIFT AND THE SEVERE WEATHER RISK OVER THE FORECAST AREA. MIXED
LAYER CAPE NEAR 3000 J/KG COULD HELP MAKE FOR A VOLATILE SET-UP WITH
THIS SYNOPTIC PATTERN. THE INITIAL CONVECTION SHOULD EVENTUALLY
EVOLVE INTO ANOTHER LINEAR CONVECTIVE SYSTEM...AND WITH DEEP LAYER
SHEAR VECTORS BECOMING MORE PARALLEL RESULTING IN GREATER POTENTIAL
FOR TRAINING AND BACK-BUILDING OF STORMS...THE RISK FOR HEAVY
RAINFALL AND FLOODING COULD REALLY RAMP UP MONDAY NIGHT. THE ECMWF IS
A LITTLE MORE PROGRESSIVE WITH SUCH A SYSTEM WHILE THE GFS SHOWS A
GREATER PROPENSITY FOR PARALLEL DEEP LAYER FLOW AND CORFIDI VECTOR
RIDGING SUGGESTIVE OF MCS BACK-BUILDING AND SLOW SYSTEM SPEED. WHILE
IT IS DIFFICULT TO KNOW WHERE IT WILL SET UP EXACTLY...WITH K INDICES
IN THE LOW 40S AND PRECIPITABLE WATER APPROACHING 2 INCHES...THERE
WILL LIKELY BE INTENSE RAINFALL RATES OF WHICH ANY LONG DURATION
COULD LEAD TO SERIOUS FLOODING CONCERNS.
CIPS ANALOGS ARE STILL SHOWING VERY SIGNIFICANT EVENTS FOR COMPARISON
TO THIS SET-UP ADDING MORE CONFIDENCE THAT SIGNIFICANT SEVERE WEATHER
AND FLOODING WILL BE POSSIBLE. THE LATEST ANALOG CONSENSUS HAS
SHIFTED BACK A LITTLE FARTHER NORTH WITH HIGHER SEVERE WEATHER/HEAVY
RAINFALL PROBS FROM SUNDAY NIGHT THROUGH MONDAY NIGHT...BEFORE
SHIFTING SOUTHWARD FOR THE TIME CENTERED ON THE MORE UNCERTAIN
TUESDAY EVENING PERIOD. TO MAINTAIN CONSISTENCY WILL NOT MAKE ANY
SIGNIFICANT ADJUSTMENTS AT THIS POINT TO THE RISK AREAS...BUT WILL
ADD SOME MORE DETAIL. /EC/
TUESDAY THROUGH NEXT SATURDAY...
A VOLATILE PATTERN SUPPORTIVE OF SEVERE WEATHER/TORNADOES AND
ADDITIONAL HEAVY RAIN MAY CONTINUE TUESDAY INTO TUESDAY NIGHT. THE
FORECAST FOR THIS PERIOD IS MORE UNCERTAIN HOWEVER AS IT WILL HINGE
GREATLY ON THE BEHAVIOR OF MONDAY NIGHT CONVECTIVE ACTIVITY. A
STRONG CLOSED H5 CLOSED LOW WILL EXIST OVER IOWA EARLY TUESDAY WHICH
IS CHARACTERIZED BY A 120KT CYCLONICALLY CURVED JET WITH MULTIPLE
EJECTING LOBES OVERTOP A MOIST UNSTABLE MODERATELY SHEARED
ENVIRONMENT ACROSS THE ARKLAMISS. THIS SET-UP WILL SUPPORT VIGOROUS
CONVECTIVE DEVELOPMENT AGAIN FOR TUESDAY AFTERNOON AND EVENING.
ADDITIONAL HEAVY RAIN WILL BE POSSIBLE WITH PRECIPITABLE WATER
AROUND 1.8 INCHES AND FAVORABLE WIND PROFILES FOR TRAINING OF STORMS
LEADING TO FLASH FLOODING AND SIGNIFICANT RIVER RISES. THE ASSOCIATED
COLD FRONT WILL FINALLY MOVE THROUGH THE REGION BY EARLY WEDNESDAY.
AS WE GO INTO WEDNESDAY THE LAST OF THE CONVECTION WILL EXIT THE
REGION BY WEDNESDAY AFTERNOON. A BROAD UPPER TROUGH WILL CONTINUE
OVER THE REGION FOR MOST OF THE PERIOD THROUGH FRIDAY BEFORE THE
UPPER TROUGH FINALLY LIFTS OUT OVER THE WEEKEND. THE MODEL GUIDANCE
TRIES TO BRING IN LOW POPS FOR WEDNESDAY THROUGH SATURDAY. THE EURO
TRIED TO SHOW SOME LOW QPF FROM THURSDAY THROUGH SATURDAY...BUT OPTED
TO KEEP THE REGION DRY. SOME COOL AIR WILL PUSH INTO THE REGION FOR
THURSDAY INTO FRIDAY WITH LOWS IN THE 40S AND 50S REACHING INTO THE
FIRST FEW DAYS OF MAY...WHICH WILL RUN AROUND TEN DEGREES BELOW
NORMAL./17/
&&
.AVIATION...VFR CONDITIONS ARE ANTICIPATED FOR THE MOST PART TODAY
THROUGH THIS EVENING. WIDESPREAD IFR CATEGORY STRATUS MAY SPREAD
NORTH ACROSS THE FORECAST AREA LATE TONIGHT. THUNDERSTORM POTENTIAL
WILL BE ON THE POTENTIAL FOR SUNDAY INTO SUNDAY NIGHT...AND EARLY
NEXT WEEK LOOKS LIKE A STRETCH OF ROUGH WEATHER FOR AVIATION
INTERESTS. /EC/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 85 66 82 69 / 18 12 30 43
MERIDIAN 85 63 83 66 / 13 9 24 30
VICKSBURG 85 68 82 71 / 18 14 41 53
HATTIESBURG 87 67 83 68 / 19 12 20 22
NATCHEZ 85 68 84 70 / 20 12 32 37
GREENVILLE 84 67 80 69 / 5 18 71 79
GREENWOOD 86 67 82 70 / 4 11 56 63
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
EC/17/
AREA FORECAST DISCUSSION
NWS ELKO NV
815 AM PDT SAT APR 26 2014
.SYNOPSIS...A STRONG LATE WINTER STORM WILL BRING WIDESPREAD RAIN
AND SNOW TO NEVADA THROUGH SATURDAY MORNING. DRY WEATHER RETURNS
BRIEFLY SATURDAY NIGHT...FOLLOWED BY MORE SNOW SHOWERS ACROSS
NORTHERN NEVADA ON SUNDAY. DRIER AND WARMER WEATHER IS EXPECTED TO
RETURN NEXT WEEK.
&&
.SHORT TERM...TODAY THROUGH MONDAY.
STRONG BUT PROGRESSIVE LATE WINTER/SPRING STORM SHAPING UP PRETTY
MUCH AS PLANNED THIS MORNING. NAM/GFS/HRRR GUIDANCE IN EXCELLENT
AGREEMENT THAT THE PEAK OF THIS WINTER WEATHER EVENT WILL OCCUR
EARLY THIS MORNING, A FEW HOURS EITHER SIDE OF SUNRISE, ALONG A
TONOPAH-EUREKA-NW WHITE PINE COUNTY-SE ELKO COUNTY LINE. HEAVY WET
SNOW WILL FALL IN THIS CORRIDOR FOR SEVERAL HOURS FROM NOW THROUGH
EARLY SATURDAY MORNING, WITH SEVERAL INCHES EXPECTED ESPECIALLY ON
ELEVATED/VEGETATED SURFACES. IMPACTS WILL BE VERY ELEVATION
DEPENDENT, TYPICAL OF LATE APRIL SNOWSTORMS, BUT PASSES AND
SUMMITS ABOVE 5500 FEET WILL BE SLUSH/SNOW COVERED AND TREACHEROUS
THIS MORNING. WILL ALLOW WINTER STORM WARNINGS TO CONTINUE AS
PLANNED. A WILDCARD IN REGARD TO SNOWFALL AMOUNTS IS CONVECTION.
LIGHTNING DETECTION AND IR SATELLITE CONTINUES TO INDICATE
THUNDERSTORMS ROTATING NORTHWARD INTO WHITE PINE COUNTY. SNOWFALL
RATES WILL BE ERRATIC AND BRIEFLY INTENSE IN THE WINTER STORM
WARNING AREA THIS MORNING. SINCE THE SNOW IS OCCURRING ON A
SATURDAY MORNING WITH NO SCHOOL AND LIMITED COMMUTING, IMPACTS
WILL BE LIMITED, BUT NONETHELESS THESE INTENSE SNOWFALL RATES WILL
LIKELY OVERCOME ANY WARM ROADWAYS AND MAKE TRAVEL DANGEROUS AT
TIMES UNTIL THE MID-MORNING HOURS.
REGARDING ELKO COUNTY...00Z NAM AND HRRR BOTH DEPICT A VERY TIGHT
PRECIPITATION GRADIENT, WITH NW ELKO COUNTY GETTING LITTLE TO NO
SNOW, AND HEAVY SNOW FALLING ON THE RUBY MOUNTAINS AND SE ELKO
COUNTY. SNOWFALL FROM 00Z NAM SHOWS THIS TIGHT GRADIENT AND
APPEARS VERY REASONABLE ON THE NW EDGE OF THE DEFORMATION BAND.
EXPECTING ABOUT 1/2 INCH AT ELKO PROPER, 2-4 INCHES IN SPRING
CREEK, AND NEAR 6 INCHES ADJACENT TO THE RUBY MOUNTAINS, SUCH AS
JIGGS, LEE, AND LAMOILLE. WILL ALSO KEEP THE WINTER WEATHER
ADVISORY GOING FOR ELEVATIONS ABOVE 5500 FEET FOR ELKO COUNTY
THROUGH 11 AM.
PRIMARY SURFACE LOW SW OF ELY EARLY THIS MORNING WILL RAPIDLY PULL
EASTWARD THROUGH UTAH THIS MORNING, AND BE IN WYOMING BY MIDDAY.
IN OTHER WORDS, SYSTEM IS QUITE PROGRESSIVE AND SNOW SHOWERS WILL
TAPER OFF QUICKLY AFTER NOON. ALSO, IMPACTS TO ROADWAYS WILL END
RAPIDLY AFTER 11 AM WITH THE LATE APRIL SUNSHINE, SO ALL WINTER
HEADLINES WILL EXPIRE AT THAT TIME. NW FLOW AND COLD AIR ALOFT IS
QUITE AGITATED THIS AFTERNOON, SO KEPT PLENTY OF SNOW/SNOW PELLET
SHOWERS MENTIONED THIS AFTERNOON, BUT AMOUNTS WILL BE LIGHT.
NW WINDS WILL BE STRONG AND GUSTY TODAY AS THE STORM SYSTEM
DEPARTS. NW WINDS WILL AVERAGE 20-30 MPH WITH HIGHER GUSTS.
BELIEVE WINDS WILL REMAIN BELOW ADVISORY CRITERIA, WITH THE
EXCEPTION OF NW NYE COUNTY/TONOPAH. WIND GUSTS OF 50-55 MPH APPEAR
LIKELY HERE TODAY, AND ISSUED A WIND ADVISORY FOR NW NYE COUNTY
FROM 5 AM THROUGH 5 PM.
A BRIEF BREAK OF DRY WEATHER TONIGHT, WITH LOWS NEAR FREEZING.
SUNDAY...FINAL SHORTWAVE SKIRTS THROUGH NORTHERN NEVADA IN THE
CHILLY NW FLOW. THIS SHOULD BE A PROLIFIC SNOW AND GRAUPEL SHOWER
PRODUCER SUNDAY AFTERNOON MAINLY ACROSS ELKO COUNTY. INCREASED
SHOWER COVERAGE IN THE GRIDS, BUT APPEARS TO BE A HIGH POP/LOW QPF
SITUATION IN WHICH AMOUNTS WILL BE INSIGNIFICANT. STILL,
VISIBILITY WILL BE SHARPLY REDUCED BY THESE PASSING CONVECTIVE
SNOW SHOWERS. 00Z GFS DEPICTS LIFTED INDEX LESS THAN ZERO ACROSS
ELKO COUNTY SUNDAY AFTERNOON, SO MENTIONED ISOLATED THUNDER AS WELL.
SUNDAY WILL BE A DECIDEDLY UNPLEASANT "SPRING" DAY IN NEVADA WITH
TEMPERATURES STUCK IN THE 40S MOST OF THE DAY, AND STRONG GUSTY
WEST WINDS OF 20-30 MPH MAKING IT FEEL EVEN COLDER THAN THAT.
SOME DECREASE IN CLOUDS SUNDAY NIGHT, ALLOWING FOR COLDER LOWS
MONDAY MORNING IN THE MID TO UPPER 20S.
MONDAY...DRY WEATHER RETURNS UNDER DRY NW FLOW. STILL QUITE
CHILLY, WITH TEMPERATURES RUNNING ABOUT 10 DEGREES BELOW LATE
APRIL NORMALS.
TURNER
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY. HIGH PRESSURE WILL BRING
DRY CONDITIONS TO THE GREAT BASIN WITH A WARMING TREND. THERE IS
GOOD MODEL AGREEMENT INDICATING THAT A PACIFIC RIDGE WILL STRONGLY
AMPLIFY NEXT WEEK AND PROGRESS EAST AT AN EXTREMELY SLOW RATE. THE
RIDGE AXIS WILL ONLY MOVE FROM OFF THE CALIFORNIA COAST MONDAY NIGHT
TO REPOSITION THROUGH NEVADA FRIDAY...AS THE DE-AMPLIFICATION
PROCESS BEGINS. LOW TEMPERATURES WILL GENERALLY FALL INTO THE 20S
MONDAY NIGHT...AND THE 30S THEREAFTER. HIGH TEMPERATURES WILL
GENERALLY BE IN THE 50S TUESDAY...RISE INTO THE 60S WEDNESDAY...THEN
INTO THE 70S IN MANY PLACES THURSDAY AND FRIDAY.
&&
.AVIATION...A MOISTURE-LADEN STORM SYSTEM WILL CONTINUE TO BRING
WIDESPREAD RAIN AND SNOW SHOWERS THROUGH SATURDAY MORNING PRODUCING
AREAS OF MVFR CONDITIONS. SHOWERS WILL TAPER OFF THIS EVENING AND
THERE MAY BE A BRIEF BREAK AFTER THIS STORM EXITS. HOWEVER ANOTHER
WAVE OF LOW PRESSURE WILL BRING MORE SHOWER ACTIVITY THROUGH SUNDAY
MORNING.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 11 AM PDT THIS MORNING FOR RUBY
MOUNTAINS/EAST HUMBOLDT RANGE...SOUTHERN LANDER COUNTY AND
SOUTHERN EUREKA COUNTY...WHITE PINE COUNTY.
WINTER WEATHER ADVISORY UNTIL 11 AM PDT THIS MORNING FOR SOUTH
CENTRAL ELKO COUNTY.
WINTER WEATHER ADVISORY UNTIL 11 AM PDT THIS MORNING ABOVE 5500
FEET FOR SOUTHWESTERN ELKO COUNTY.
WIND ADVISORY FROM 5 AM EARLY THIS MORNING TO 5 PM PDT THIS
AFTERNOON FOR NORTHWESTERN NYE COUNTY.
&&
$$
99/92/92
AREA FORECAST DISCUSSION
NWS BISMARCK ND
940 AM CDT SAT APR 26 2014
.UPDATE...
ISSUED AT 940 AM CDT SAT APR 26 2014
NARROW BAND OF SHOWERS NOW HAD ADVANCED NORTHWARD TO
WILLISTON...MCLEAN COUNTY (NORTH OF LAKE SAKAKAWEA) TO BETWEEN
BISMARCK AND JAMESTOWN. THE BISMARCK AIRPORT RECORDED 0.07 INCHES
OF RAIN AS THE PRECIP BAND WENT THROUGH. THE BAND CONTINUES
LIFTING NORTHWARD AND EXPECT A FEW HUNDREDTHS OF AN INCH TO
PERHAPS A TENTH OF AN INCH OF RAIN MOST AREAS. ADJUSTED TIMING OF
PRECIPITATION ACCORDINGLY. BY EARLY AFTERNOON THE PRECIPITATION
BAND SHOULD BE MAINLY NORTH OF THE CANADIAN BORDER...WITH THE
SOUTHEASTERN PORTION DISSIPATING. OTHERWISE FORECAST ON TRACK -
MINOR HOURLY ADJUSTMENTS FOR WIND AND TEMPERATURES.
UPDATE ISSUED AT 642 AM CDT SAT APR 26 2014
NARROW BAND OF SHOWERS FROM WEST CENTRAL INTO SOUTH CENTRAL NORTH
DAKOTA CONTINUES TO LIFT NORTH THIS MORNING. ONLY SOME SLIGHT
MODIFICATIONS TO THE CURRENT HRRR POP PLACEMENT TODAY. ALSO BUMPED
UP SKY COVER THROUGH THE MORNING SOUTHWEST BASED ON LATEST
SATELLITE IMAGERY. OTHERWISE CURRENT FORECAST LOOKS TO BE IN GOOD
SHAPE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CDT SAT APR 26 2014
THE HIGHLIGHT OF THE SHORT TERM IS PRECIPITATION POTENTIAL.
FOR TODAY...THE HRRR HAS HAD A GOOD HANDLE ON THE NARROW BAND OF
RAIN SHOWERS MOVING INTO SOUTHWEST NORTH DAKOTA AS OF 0830 UTC
WITH THE LEADING SHORTWAVE. THUS...WILL FOLLOW THE 07 UTC HRRR AND
ITS PARENT RAP FOR POPS THIS MORNING AND INTO THE AFTERNOON. THESE
SOLUTIONS ARE IN AGREEMENT WITH THE 00 UTC 4 KM WRF AND LARGER
SCALE DETERMINISTIC GUIDANCE WHICH QUICKLY MOVE THE RAIN SHOWERS
TO THE INTERNATIONAL BORDER BY EARLY AFTERNOON. THUS...AFTER THE
NARROW BAND OF SHOWERS PASS...THE DAY SHOULD BE PRECIPITATION FREE
FOR NEARLY ALL OF THE CWA. IN REGARDS TO WINDS FOR
TODAY...EXPECT WIDESPREAD EAST-SOUTHEAST GUSTS OF 30-35 KTS FOR
MOST AREAS. HOWEVER...A LOW LEVEL INVERSION IN WARM AIR ADVECTION
WILL LIMIT THE TRANSFER OF HIGHER MOMENTUM AND FORGO THE NEED FOR
A WIND ADVISORY.
FOR TONIGHT...SURFACE LOW PRESSURE CONTINUES TO DEEPEN ACROSS
WESTERN NEBRASKA...AS THE OVERALL SYSTEM BECOMES NEARLY VERTICALLY
STACKED LATE TONIGHT AS THE POTENT UPPER LEVEL WAVE PROPAGATES
ONTO THE PLAINS. RESULTING MOISTURE TRANSPORT INCREASES ACROSS THE
NORTHERN PLAINS...WITH RAIN SHOWER COVERAGE INCREASING AFTER 06
UTC ACROSS WESTERN NORTH DAKOTA IN THE VICINITY OF THE INVERTED
TROUGH EXTENDING INTO EASTERN MONTANA...AND ACROSS SOUTHERN NORTH
DAKOTA IN LOW LEVEL WARM AIR ADVECTION. THE BULK OF ELEVATED
INSTABILITY TONIGHT REMAINS IN SOUTH DAKOTA...HOWEVER AN EMBEDDED
THUNDERSTORM IS POSSIBLE ACROSS FAR SOUTH CENTRAL NORTH DAKOTA .
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 329 AM CDT SAT APR 26 2014
THE MAIN FORECAST PROBLEM IN THE EXTENDED PERIOD WILL BE THE STRONG
SPRING STORM SYSTEM AFFECTING ALL OF WESTERN AND CENTRAL NORTH
DAKOTA. MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH THE TRACK OF
THE SURFACE AND UPPER LEVEL FEATURES THROUGH TUESDAY...WITH
DIFFERENCES INCREASING THEREAFTER. STILL SOME DIFFERENCES IN QPF
PATTERN THROUGH THE EVOLUTION OF THE SYSTEM WITH THE GFS BEING THE
DRIEST ACROSS PORTIONS OF CENTRAL AND EASTERN NORTH DAKOTA. ALL
MODELS HOWEVER ARE PINPOINTING THE FAR SOUTHWEST WITH SOME OF THE
HIGHEST RAINFALL AMOUNTS.
STRONG SHORTWAVE JUST MOVING ONTO THE SOUTHERN CALIFORNIA COAST WITH
AN UPPER LEVEL LOW CLOSING OFF JUST TO ITS NORTH. BROAD FETCH OF
MOISTURE IN SOUTHWEST UPPER FLOW INTO THE NORTHERN PLAINS...SETTING
THE STAGE FOR AN EXTENDED PERIOD OF RAINY WEATHER.
BY SUNDAY MORNING THE UPPER LOW IS PROGGED TO BE OVER EASTERN
COLORADO WITH A RAPIDLY DEEPENING SURFACE SYSTEM OVER THE CENTRAL
PLAINS. THE INITIAL SURGE OF ENERGY MOVES INTO THE AREA LATE TONIGHT
INTO SUNDAY MORNING. ALTHOUGH BEST ELEVATED INSTABILITY REMAINS JUST
TO OUR SOUTH...SYSTEM IS STRONG ENOUGH THAT A MENTION OF THUNDER
SEEMED WARRANTED SUNDAY MORNING. BEST PRECIPITATION CHANCES DURING
THE DAY WILL BE OVER THE SOUTHWEST HALF OF THE CWA...AND THERE MAY
BE PERIODS OF NO RAIN AS WELL AS DRIER AIR WRAPS AROUND THE STACKED
SYSTEM.
ANOTHER STRONG IMPULSE LIFTS THROUGH THE AREA SUNDAY NIGHT
AS THE UPPER LOW REACHES ITS FARTHEST POINT NORTH BEFORE WOBBLING
BACK SOUTH ON MONDAY. BY THIS TIME CHANCES OF CONVECTION WILL BE
MINIMAL AS COOLER AIR GETS PULLED INTO THE SYSTEM. THE FAR NORTH AND
HIGHER ELEVATIONS IN THE FAR WEST COULD SEE PERIODS OF SNOW LATE
SUNDAY NIGHT INTO EARLY MONDAY MORNING. LATEST MODEL RUNS ARE A
LITTLE COOLER IN THE WEST SO WILL NEED TO MONITOR FOR SOME LIGHT
ACCUMULATING SNOWS IN THE FAR WEST...BUT AT THIS TIME ITS TOO EARLY
FOR ANY MENTION OF ACCUMULATIONS.
PRECIPITATION BEGINS TO WANE ON MONDAY AS THE LOW DROPS SOUTH.
ALTHOUGH LOW LEVEL FORCING WILL BE ON THE DECREASE...SYNOPTIC SCALE
FORCING WILL REMAIN THROUGH TUESDAY AS WE REMAIN UNDER THE CYCLONIC
FLOW OF THE UPPER LEVEL LOW. THUS LIKELY POPS REMAIN MONDAY INTO
MONDAY NIGHT...WITH HIGH CHANCE POPS TUESDAY. AGAIN WE WILL SEE THE
POSSIBILITY OF SNOW MONDAY NIGHT INTO TUESDAY MORNING...AND LIGHT
ACCUMULATIONS ARE CERTAINLY NOT OUT OF THE QUESTION.
THE UPPER LOW LIFTS BACK NORTHWARD TUESDAY NIGHT INTO WEDNESDAY WITH
ANOTHER WAVE OF MOISTURE SWINGING EAST TO WEST ACROSS THE AREA ON
WEDNESDAY BRINGING A CHANCE OF RAIN OR SNOW SHOWERS. THE SYSTEM
FINALLY EXITS THE ARE LATE IN THE WORK WEEK...WITH ANOTHER IMPULSE
IN A NORTHWEST FLOW PATTERN POSSIBLE BY NEXT WEEKEND.
ALL IN ALL A WET AND COOL PERIOD IS IN STORE THROUGH MOST OF THE
EXTENDED PERIOD. WILL ISSUE A HYDROLOGIC STATEMENT MENTIONING THE
POSSIBILITY OF FLOODING DUE TO AN EXTENDED PERIOD OF RAIN. WPC
DEPICTS PORTIONS OF THE SOUTHWEST WITH A SLIGHT CHANCE OF EXCESSIVE
RAINFALL 12Z SUNDAY THROUGH 12Z MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 642 AM CDT SAT APR 26 2014
A NARROW BAND OF LIGHT RAIN SHOWERS HAS MOVED INTO WESTERN INTO
SOUTH CENTRAL NORTH DAKOTA AS OF 1130 UTC...AND WILL CONTINUE TO
MOVE NORTH-NORTHEAST THROUGH THE MORNING. RAIN SHOWER ACTIVITY IN
THE AFTERNOON IS EXPECTED TO LARGELY REMAIN NORTH OF KISN AND
KMOT. STRONG EAST-SOUTHEAST WINDS WITH GUSTS OF 30-35 KTS ARE
EXPECTED FOR MUCH OF THE AREA TODAY. A LARGE STORM SYSTEM WILL
BEGIN TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA SATURDAY
NIGHT...WITH CONDITIONS TRENDING TOWARDS MVFR/IFR IN STRATUS AND
RAIN.
&&
.HYDROLOGY...
ISSUED AT 353 AM CDT SAT APR 26 2014
ISSUED A HYDROLOGIC OUTLOOK...ESF...FOR WESTERN NORTH DAKOTA
REGARDING THE UPCOMING HEAVY RAIN EVENT AND POTENTIAL IMPACTS. AS
OF NOW...THE 00 UTC DETERMINISTIC SUITE REMAINS IN SOME
DISAGREEMENT ON THE PLACEMENT OF THE HEAVIEST QPF AXIS. THIS HAS
SIGNIFICANT IMPACTS IN BASIN HYDROLOGIC RESPONSE. FURTHERMORE...THE
REMOVAL OF FROST FROM THE GROUND AND RECENT DRY WEATHER PLACES
ADDITIONAL UNCERTAINTY IN HOW MUCH WATER THE SOILS WILL BE ABLE TO
HOLD. THAT SAID...RIVER AND STREAM RISES...POTENTIALLY ABOVE
FLOOD STAGE...ARE POSSIBLE. HOWEVER...WHICH SPECIFIC WATERWAYS
RESPOND THE MOST IS HIGHLY DEPENDENT ON QPF PLACEMENT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...AYD
LONG TERM...TWH
AVIATION...AYD
HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
642 AM CDT SAT APR 26 2014
.UPDATE...
ISSUED AT 642 AM CDT SAT APR 26 2014
NARROW BAND OF SHOWERS FROM WEST CENTRAL INTO SOUTH CENTRAL NORTH
DAKOTA CONTINUES TO LIFT NORTH THIS MORNING. ONLY SOME SLIGHT
MODIFICATIONS TO THE CURRENT HRRR POP PLACEMENT TODAY. ALSO BUMPED
UP SKY COVER THROUGH THE MORNING SOUTHWEST BASED ON LATEST
SATELLITE IMAGERY. OTHERWISE CURRENT FORECAST LOOKS TO BE IN GOOD
SHAPE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CDT SAT APR 26 2014
THE HIGHLIGHT OF THE SHORT TERM IS PRECIPITATION POTENTIAL.
FOR TODAY...THE HRRR HAS HAD A GOOD HANDLE ON THE NARROW BAND OF
RAIN SHOWERS MOVING INTO SOUTHWEST NORTH DAKOTA AS OF 0830 UTC
WITH THE LEADING SHORTWAVE. THUS...WILL FOLLOW THE 07 UTC HRRR AND
ITS PARENT RAP FOR POPS THIS MORNING AND INTO THE AFTERNOON. THESE
SOLUTIONS ARE IN AGREEMENT WITH THE 00 UTC 4 KM WRF AND LARGER
SCALE DETERMINISTIC GUIDANCE WHICH QUICKLY MOVE THE RAIN SHOWERS
TO THE INTERNATIONAL BORDER BY EARLY AFTERNOON. THUS...AFTER THE
NARROW BAND OF SHOWERS PASS...THE DAY SHOULD BE PRECIPITATION FREE
FOR NEARLY ALL OF THE CWA. IN REGARDS TO WINDS FOR
TODAY...EXPECT WIDESPREAD EAST-SOUTHEAST GUSTS OF 30-35 KTS FOR
MOST AREAS. HOWEVER...A LOW LEVEL INVERSION IN WARM AIR ADVECTION
WILL LIMIT THE TRANSFER OF HIGHER MOMENTUM AND FORGO THE NEED FOR
A WIND ADVISORY.
FOR TONIGHT...SURFACE LOW PRESSURE CONTINUES TO DEEPEN ACROSS
WESTERN NEBRASKA...AS THE OVERALL SYSTEM BECOMES NEARLY VERTICALLY
STACKED LATE TONIGHT AS THE POTENT UPPER LEVEL WAVE PROPAGATES
ONTO THE PLAINS. RESULTING MOISTURE TRANSPORT INCREASES ACROSS THE
NORTHERN PLAINS...WITH RAIN SHOWER COVERAGE INCREASING AFTER 06
UTC ACROSS WESTERN NORTH DAKOTA IN THE VICINITY OF THE INVERTED
TROUGH EXTENDING INTO EASTERN MONTANA...AND ACROSS SOUTHERN NORTH
DAKOTA IN LOW LEVEL WARM AIR ADVECTION. THE BULK OF ELEVATED
INSTABILITY TONIGHT REMAINS IN SOUTH DAKOTA...HOWEVER AN EMBEDDED
THUNDERSTORM IS POSSIBLE ACROSS FAR SOUTH CENTRAL NORTH DAKOTA .
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 329 AM CDT SAT APR 26 2014
THE MAIN FORECAST PROBLEM IN THE EXTENDED PERIOD WILL BE THE STRONG
SPRING STORM SYSTEM AFFECTING ALL OF WESTERN AND CENTRAL NORTH
DAKOTA. MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH THE TRACK OF
THE SURFACE AND UPPER LEVEL FEATURES THROUGH TUESDAY...WITH
DIFFERENCES INCREASING THEREAFTER. STILL SOME DIFFERENCES IN QPF
PATTERN THROUGH THE EVOLUTION OF THE SYSTEM WITH THE GFS BEING THE
DRIEST ACROSS PORTIONS OF CENTRAL AND EASTERN NORTH DAKOTA. ALL
MODELS HOWEVER ARE PINPOINTING THE FAR SOUTHWEST WITH SOME OF THE
HIGHEST RAINFALL AMOUNTS.
STRONG SHORTWAVE JUST MOVING ONTO THE SOUTHERN CALIFORNIA COAST WITH
AN UPPER LEVEL LOW CLOSING OFF JUST TO ITS NORTH. BROAD FETCH OF
MOISTURE IN SOUTHWEST UPPER FLOW INTO THE NORTHERN PLAINS...SETTING
THE STAGE FOR AN EXTENDED PERIOD OF RAINY WEATHER.
BY SUNDAY MORNING THE UPPER LOW IS PROGGED TO BE OVER EASTERN
COLORADO WITH A RAPIDLY DEEPENING SURFACE SYSTEM OVER THE CENTRAL
PLAINS. THE INITIAL SURGE OF ENERGY MOVES INTO THE AREA LATE TONIGHT
INTO SUNDAY MORNING. ALTHOUGH BEST ELEVATED INSTABILITY REMAINS JUST
TO OUR SOUTH...SYSTEM IS STRONG ENOUGH THAT A MENTION OF THUNDER
SEEMED WARRANTED SUNDAY MORNING. BEST PRECIPITATION CHANCES DURING
THE DAY WILL BE OVER THE SOUTHWEST HALF OF THE CWA...AND THERE MAY
BE PERIODS OF NO RAIN AS WELL AS DRIER AIR WRAPS AROUND THE STACKED
SYSTEM.
ANOTHER STRONG IMPULSE LIFTS THROUGH THE AREA SUNDAY NIGHT
AS THE UPPER LOW REACHES ITS FARTHEST POINT NORTH BEFORE WOBBLING
BACK SOUTH ON MONDAY. BY THIS TIME CHANCES OF CONVECTION WILL BE
MINIMAL AS COOLER AIR GETS PULLED INTO THE SYSTEM. THE FAR NORTH AND
HIGHER ELEVATIONS IN THE FAR WEST COULD SEE PERIODS OF SNOW LATE
SUNDAY NIGHT INTO EARLY MONDAY MORNING. LATEST MODEL RUNS ARE A
LITTLE COOLER IN THE WEST SO WILL NEED TO MONITOR FOR SOME LIGHT
ACCUMULATING SNOWS IN THE FAR WEST...BUT AT THIS TIME ITS TOO EARLY
FOR ANY MENTION OF ACCUMULATIONS.
PRECIPITATION BEGINS TO WANE ON MONDAY AS THE LOW DROPS SOUTH.
ALTHOUGH LOW LEVEL FORCING WILL BE ON THE DECREASE...SYNOPTIC SCALE
FORCING WILL REMAIN THROUGH TUESDAY AS WE REMAIN UNDER THE CYCLONIC
FLOW OF THE UPPER LEVEL LOW. THUS LIKELY POPS REMAIN MONDAY INTO
MONDAY NIGHT...WITH HIGH CHANCE POPS TUESDAY. AGAIN WE WILL SEE THE
POSSIBILITY OF SNOW MONDAY NIGHT INTO TUESDAY MORNING...AND LIGHT
ACCUMULATIONS ARE CERTAINLY NOT OUT OF THE QUESTION.
THE UPPER LOW LIFTS BACK NORTHWARD TUESDAY NIGHT INTO WEDNESDAY WITH
ANOTHER WAVE OF MOISTURE SWINGING EAST TO WEST ACROSS THE AREA ON
WEDNESDAY BRINGING A CHANCE OF RAIN OR SNOW SHOWERS. THE SYSTEM
FINALLY EXITS THE ARE LATE IN THE WORK WEEK...WITH ANOTHER IMPULSE
IN A NORTHWEST FLOW PATTERN POSSIBLE BY NEXT WEEKEND.
ALL IN ALL A WET AND COOL PERIOD IS IN STORE THROUGH MOST OF THE
EXTENDED PERIOD. WILL ISSUE A HYDROLOGIC STATEMENT MENTIONING THE
POSSIBILITY OF FLOODING DUE TO AN EXTENDED PERIOD OF RAIN. WPC
DEPICTS PORTIONS OF THE SOUTHWEST WITH A SLIGHT CHANCE OF EXCESSIVE
RAINFALL 12Z SUNDAY THROUGH 12Z MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 642 AM CDT SAT APR 26 2014
A NARROW BAND OF LIGHT RAIN SHOWERS HAS MOVED INTO WESTERN INTO
SOUTH CENTRAL NORTH DAKOTA AS OF 1130 UTC...AND WILL CONTINUE TO
MOVE NORTH-NORTHEAST THROUGH THE MORNING. RAIN SHOWER ACTIVITY IN
THE AFTERNOON IS EXPECTED TO LARGELY REMAIN NORTH OF KISN AND
KMOT. STRONG EAST-SOUTHEAST WINDS WITH GUSTS OF 30-35 KTS ARE
EXPECTED FOR MUCH OF THE AREA TODAY. A LARGE STORM SYSTEM WILL
BEGIN TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA SATURDAY
NIGHT...WITH CONDITIONS TRENDING TOWARDS MVFR/IFR IN STRATUS AND
RAIN.
&&
.HYDROLOGY...
ISSUED AT 353 AM CDT SAT APR 26 2014
ISSUED A HYDROLOGIC OUTLOOK...ESF...FOR WESTERN NORTH DAKOTA
REGARDING THE UPCOMING HEAVY RAIN EVENT AND POTENTIAL IMPACTS. AS
OF NOW...THE 00 UTC DETERMINISTIC SUITE REMAINS IN SOME
DISAGREEMENT ON THE PLACEMENT OF THE HEAVIEST QPF AXIS. THIS HAS
SIGNIFICANT IMPACTS IN BASIN HYDROLOGIC RESPONSE. FURTHERMORE...THE
REMOVAL OF FROST FROM THE GROUND AND RECENT DRY WEATHER PLACES
ADDITIONAL UNCERTAINTY IN HOW MUCH WATER THE SOILS WILL BE ABLE TO
HOLD. THAT SAID...RIVER AND STREAM RISES...POTENTIALLY ABOVE
FLOOD STAGE...ARE POSSIBLE. HOWEVER...WHICH SPECIFIC WATERWAYS
RESPOND THE MOST IS HIGHLY DEPENDENT ON QPF PLACEMENT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...AYD
LONG TERM...TWH
AVIATION...AYD
HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS NORMAN OK
1057 AM CDT SAT APR 26 2014
.UPDATE...
AS NEW DATA CONTINUES TO FILTER IN THIS MORNING... IT APPEARS THAT
STORM CHANCES ARE LESS LIKELY TODAY AND THIS EVENING. 12Z OUN
SOUNDING SHOWS ENOUGH OF A CAPPING INVERSION TO BE AN ISSUE FOR
STORM DEVELOPMENT... ESPECIALLY WITH THE RELATIVELY LATE RETURN OF
LOW-LEVEL MOISTURE. THE HRRR AND RAP CONTINUE WITH SOME LATE
AFTERNOON DEVELOPMENT IN THE KNOX CITY-HOBART-ENID CORRIDOR LATE
THIS AFTERNOON... BUT THIS IS ALSO WITH FORECAST TEMPERATURES
CLIMBING INTO THE UPPER 90S TO TRIPLE DIGITS. IF TEMPERATURES DO
GET WARMER THAN OUR CURRENT FORECAST... THEN THERE WILL BE A
CHANCE OF ISOLATED HIGH-BASED STORMS DEVELOPING ALONG THE WESTERN
EDGE OF THE MOISTURE AXIS... BUT CURRENT THOUGHTS ARE TO LOWER
STORM CHANCES TO ISOLATED/LESS THAN 20 PERCENT FOR THIS AFTERNOON
AND LOWER POPS FOR THIS EVENING AS WELL. THE EXPECTED HIGH BASES
OF THE STORMS WILL ALSO MAKE THE SEVERE WEATHER SCENARIO /IF
STORMS FORM/ PRIMARILY A HAIL/WIND THREAT.
WILL CONTINUE TO WATCH TRENDS IN THE WEATHER THROUGH THE AFTERNOON
AND MAKE ADDITIONAL ADJUSTMENTS AS NECESSARY. .26.
&&
.PREV DISCUSSION... /ISSUED 643 AM CDT SAT APR 26 2014/
AVIATION...
26/12Z TAFS...VFR CONDITIONS EXPECTED TO PREVAIL MAJORITY OF
FORECAST PERIOD WITH DEVELOPMENT OF STRONG SOUTH-SOUTHWEST WINDS.
TSRA CHANCES WILL INCREASE TOWARD AND AFTER 00Z FROM SOUTHWEST
OKLAHOMA AND KSPS TOWARD CENTRAL OKLAHOMA TERMINALS TOWARD AND
AFTER 06Z. PRIMARILY MVFR/IFR IN TSRA WITH MVFR CIGS OUTSIDE OF
TSRA SOUTHERN OKLAHOMA LATE TONIGHT AHEAD OF DRYLINE.
PREV DISCUSSION... /ISSUED 501 AM CDT SAT APR 26 2014/
DISCUSSION...
LATEST ITERATION OF FINE-SCALE MODELS STILL POINT TO AT LEAST
ISOLATED THUNDERSTORM DEVELOPMENT ACROSS SOUTHWEST OKLAHOMA TOWARD
OR JUST AFTER 00Z. TAKING THESE INTO ACCOUNT...AND LOOKING AT 00Z
GFS/ECM AND NOW 06Z WRF... PROBABLE INITIATION AREAS AND MODE
EVOLUTION FAIRLY DIVERSE. WE DO NOT THINK THAT THE MODELS HAVE A
GOOD HANDLE ON QUALITY/DEPTH OF MOISTURE RETURN BUT ECM HAS
VERIFIED MUCH BETTER THAN THE OTHER MODELS LAST 12 TO 24
HOURS AND WILL BE FOLLOWED CLOSER FOR NOW. WITH NEW OBS-U/A THIS
MORNING HOPEFULLY THERE WILL BE BETTER CONSENSUS WITH 12Z MODELS.
WE STILL EXPECT THE GREATEST POTENTIAL FOR RELATIVELY HIGH-BASED
SUPERCELLS SW OKLAHOMA AND WRN NORTH TEXAS TOWARD AND AFTER 6 PM
WHERE COINCIDENCE OF HOTTER TEMPS AND DEEPER MOISTURE WILL
RESIDE. ADDITIONAL AND MORE WIDESPREAD DEVELOPMENT OF STORMS
POSSIBLE AHEAD OF DRYLINE/PAC-FRONT LATE EVENING AND OVERNIGHT AS
SUBSTANTIAL FORCING FINALLY APPROACHES. WITH INTENSE FORCING AND
BACKING DEEP LAYER SHEAR...WE STILL EXPECT THE EVOLUTION OF A (OR
MULTIPLE) ELEVATED CLUSTERS/BOW SEGMENTS THROUGH THE OVERNIGHT
HOURS. THERE COULD STILL BE STRONG/SEVERE STORMS EARLY SUNDAY
MORNING/DAYBREAK ACROSS CENTRAL AND EASTERN PORTIONS OF OKLAHOMA.
REDEVELOPMENT SUNDAY AFTERNOON/EVENING ARE EXPECTED TO BE
PRIMARILY EAST OF OUR CWA.
GOING TO BE WINDY TODAY...WITH CURRENT GRIDS MARGINALLY
APPROACHING WIND ADVISORY. SUNDAY WILL BE WINDIER MOST LOCATIONS
AND A WIND ADVISORY IS EXPECTED. ALSO...WE HAVE ISSUED A FIRE
WEATHER WATCH FOR MAJORITY OF WESTERN OKLAHOMA AND ADJACENT PARTS
OF NORTH TEXAS WITH DRY/WARM AND WINDY CONDITIONS BEHIND
DRYLINE/PAC-FRONT. DID NOT BRING WATCH INTO OKC METRO WITH
TRANSITION TO GREEN FUELS. WATCH WAS PRIMARILY FOCUSED ON AREAS
THAT ARE JUST ENTERING TRANSITION PHASE OF FUELS AND DROUGHT
STRICKEN LOCATIONS.
COOL WEEK WITH OCCASIONAL WINDY DAYS WITH PERSISTENT NORTHWEST
FLOW. LIGHT SHOWERS WILL BE POSSIBLE MAINLY WEST/NORTH PARTS OF
OKLAHOMA DURING THE WEEK WITH PASSAGE OF THERMAL TROUGHS THAT WILL
ROTATE AROUND LARGE U.S. UPPER CYCLONE.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 87 66 81 51 / 10 60 30 10
HOBART OK 89 60 81 50 / 20 50 10 0
WICHITA FALLS TX 88 65 84 52 / 20 60 10 0
GAGE OK 90 58 77 46 / 10 30 10 10
PONCA CITY OK 88 66 81 49 / 10 60 40 10
DURANT OK 85 67 83 56 / 10 50 60 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR OKZ004>007-009>012-014>018-021>024-033>038-044.
TX...FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR TXZ083>089.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBANY NY
157 PM EDT SAT APR 26 2014
.SYNOPSIS...
A COMPLEX LOW PRESSURE SYSTEM WILL IMPACT OUR REGION
THIS AFTERNOON...AS IT SLOWLY DRIFTS NORTHEAST. AN UPPER LEVEL LOW
WILL IMPACT THE REGION TONIGHT INTO TOMORROW BRINGING ANOTHER PERIOD
OF RAIN SHOWERS. DRIER WEATHER AND MILDER TEMPERATURES WILL RETURN
BY MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1058 AM EDT...THE OCCLUDED FRONT ASSOCIATED WITH THE DOUBLE
BARREL LOW PRESSURE SYSTEM HAS MOVED THROUGH THE ERN PORTION OF
THE FCST AREA LATE MORNING. A FEW LINGERING SHOWERS/DRIZZLE ARE
LINGERING OVER THE SRN GREENS AND BERKSHIRES. THE SATELLITE
PICTURE IS SHOWING SOME CLEARING OVER CNTRL AND SRN NY. THIS
SHOULD MAKE ITS WAY INTO THE SRN PORTIONS OF THE FCST AREA FOR THE
EARLY PM WITH SOME PARTIAL SUNSHINE. A BATCH OF SHOWERS AHEAD OF
THE CLOSED UPPER LEVEL LOW OVER GEORGIAN BAY/SE ONTARIO ACCORDING
TO THE RUC40/RR WILL BRING SHOWERS BACK INTO THE FCST AREA IN THE
MID TO LATE PM. THERE COULD BE A FEW RUMBLES OF THUNDER OVER THE
SE EXTREME /ULSTER...DUTCHESS...AND LITCHFIELD COUNTIES/. THE
LAPSE RATES STEEPEN...AND THERE ARE SMALL AMOUNTS OF INSTABILITY
FORECASTED /LESS 250 J/KG/. A SLIGHT CHC OF TSRAS WAS ADDED THERE.
THE LATEST HRRR 3-KM COLUMNAR REF PRODUCT INDICATES THE THREAT FOR
SHOWERS INCREASES OVER THE MAJORITY OF THE FCST AREA BTWN 20Z-23Z.
POPS WERE KEPT IN THE HIGH CHC AND LIKELY CATEGORY.
HIGHS TODAY ARE EXPECTED TO BE A TAD ON THE COOL SIDE MAINLY
RANGING FROM THE UPPER 40S OVER THE SRN DACKS TO L60S IN THE MID
HUDSON VALLEY. TEMPS WERE LOWERED INTO THE U40S TO L50S OVER
PORTIONS OF THE SRN GREENS/NRN BERKS WHERE THE CLOUDS MAY LINGER
THE LONGEST IN THE RAIN COOLED AIR.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE UPPER LEVEL LOW IS CENTERED OVER THE FA THIS EVENING WITH A
STRONG VORT LOBE PASSING ACRS THE FA AS WELL. THIS SHOULD RESULT IN
MORE SHOWERS WHICH WILL LINGER INTO SUNDAY MORNING AS THE VORT
LOBE DOES NOT DRIFT OFF THE EAST COAST UNTIL SUNDAY AFTERNOON.
THUS EXPECT THE SECOND HALF OF SUNDAY TO BE DRIER THAN THE FIRST
HALF OF THE DAY. EXPECT LOWS TONIGHT IN THE 30S WITH THE HIGHS ON
SUNDAY IN THE UPPER 40S NORTHWEST TO AROUND 60 SOUTHEAST.
HIGH PRESSURE WILL BUILD INTO THE FA FOR LATER SUNDAY NIGHT INTO
MONDAY WITH MAINLY DRY CONDITIONS. LOWS SUNDAY NIGHT WILL BE IN
THE UPPER 20S NORTHWEST TO MID 30S SOUTHEAST. HIGHS ON MONDAY ARE
EXPECTED TO BE MILDER THAN OVER THE WEEKEND WITH HIGHS RANGING
FROM THE MID 50S NORTHWEST TO MID 60S SOUTHEAST.
MONDAY NIGHT WILL FEATURE INCREASING CLOUDS AS A STORM SYSTEM
APPROACHES FROM THE GREAT LAKES REGION. EXPECT LOWS TO BE IN THE
MID 30S TO MID 40S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
UNSETTLED CONDITIONS APPEAR TO DOMINATE MUCH OF THE LONG TERM
PERIOD...ALTHOUGH THERE REMAINS SOME UNCERTAINTY AS TO HOW FAST THIS
UNSETTLED WEATHER DEVELOPS...AND HOW LONG IT WILL LINGER. MOST
00Z/26 DETERMINISTIC AND ENSEMBLE GUIDANCE INDICATE A RATHER BLOCKY
PATTERN IN PLACE AT THE START OF THE LONG TERM PERIOD...WITH A
SPRAWLING MID/UPPER LEVEL LOW ACROSS THE CENTRAL U.S...WITH ANOTHER
CLOSED MID/UPPER LEVEL LOW MOVING EAST WELL OFF THE NEW ENGLAND
COAST. IN BETWEEN THESE TWO FEATURES WILL BE A STRONG BUT SOMEWHAT
NARROW RIDGE OF HIGH PRESSURE. THIS RIDGE MAY THWART THE
EAST/NORTHEAST PROGRESS OF THE RAIN INITIALLY INTO THE
REGION...BEFORE RAIN CHANCES ARE MAXIMIZED AROUND THE LATE WED-EARLY
THU TIME PERIOD. TEMPS SHOULD REMAIN BELOW SEASONAL LEVELS GIVEN THE
PROSPECTS FOR CLOUDS...AND AT LEAST SOME RAINFALL DURING THE PERIOD.
THE STEADIEST RAINFALL MAY LIFT N AND E OF THE REGION BY LATE THU OR
FRI...TRANSITIONING TO A MORE SHOWERY REGIME AS THE LINGERING
MID/UPPER LEVEL COLD POOL MOVES CLOSER TO THE REGION.
HERE ARE SOME MORE SPECIFICS...
TUE-TUE NT...AS MENTIONED ABOVE...THERE REMAINS SOME QUESTION AS TO
HOW FAST THE MID/UPPER LEVEL RIDGE AXIS MOVES E OF THE
REGION...ALLOWING FOR INCREASING ISENTROPIC LIFT AND RAINFALL ACROSS
THE REGION. AT THIS TIME...WILL SIDE ON THE SLOWER SIDE OF
GUIDANCE...KEEPING MOST AREAS DRY TUE AM...THEN SLOWLY INCREASING
POPS INTO THE SLIGHT CHC RANGE FOR EASTERN AREAS...AND LOW CHC RANGE
FOR CENTRAL AND WESTERN AREAS BY LATE TUE. FOR TUE NT...WILL
CONTINUE TO INCREASE POPS GRADUALLY INTO THE HIGHER CHC RANGE. AS
FOR TEMPS...SIDING ON THE SLOWER SIDE OF GUIDANCE...HAVE INDICATED
SLIGHTLY WARMER MAX TEMPS FOR TUE...WITH 50S IN MOST AREAS...WITH
PERHAPS EVEN SOME LOWER 60S POSSIBLE ACROSS NORTHERN VALLEY AREAS
SHOULD THE RAIN HOLD OFF AND ANY MORNING SUNSHINE OCCUR. EXPECT
LOWER 40S IN VALLEYS...AND 35-40 ACROSS HIGHER ELEVATIONS AND
NORTHERN AREAS FOR TUE NT.
WED-THU...CHC POPS EARLY WED HAVE BEEN RAISED TO LIKELY POPS FOR
LATE WED INTO EARLY THU...WHICH APPEARS TO BE THE BEST OPPORTUNITY
FOR WIDESPREAD RAINFALL GIVEN THE GREATEST ISENTROPIC LIFT AND
MOISTURE TRANSPORT INTO AND ACROSS THE REGION. THE 00Z/26 GEFS
ACTUALLY HINT AT SOME CHC FOR HEAVY RAIN ACROSS PORTIONS OF THE MID
HUDSON VALLEY AND NW CT...WHERE THE PROB FOR ONE INCH OR GREATER
OVER A 24 HOUR PERIOD IS IN THE 40-60 PERCENT RANGE THROUGH
18Z/THU...WITH EVEN A 20-40 PERCENT CHANCE FOR 2 INCHES OR MORE OVER
A 36 HOUR PERIOD ALSO ENDING 18Z/THU. EXPECT MAX TEMPS TO MAINLY
REMAIN IN THE LOWER/MID 50S...WITH SOME UPPER 40S POSSIBLE IN HIGHER
ELEVATIONS WED. BY LATE THU...IT IS POSSIBLE THAT THE STEADIEST RAIN
BEGINS TO TAPER TO SHOWERS. HAVE INDICATED SLIGHTLY WARMER MAXES
COMPARED TO WED...WITH 50S AND LOWER 60S IN VALLEYS. WED NT/THU AM
MINS SHOULD MAINLY BE IN THE 40S...WITH SOME 30S POSSIBLE ACROSS
HIGHER ELEVATIONS.
THU NT-FRI...THE BEST FORCING APPEARS TO SHIFT MAINLY N AND E OF THE
REGION. HOWEVER...WITH THE APPROACH OF THE LINGERING MID LEVEL COLD
POOL...EXPECT AT LEAST SOME ISOLATED TO SCATTERED RAIN SHOWERS TO
OCCUR...ESP DURING FRI AFTN. MAX TEMPS SHOULD REACH THE LOWER 60S IN
VALLEYS...WITH 50S ACROSS MOST HIGHER ELEVATIONS. THU NT/FRI AM MINS
SHOULD FALL INTO THE 40S IN VALLEYS...AND MID 30S TO NEAR 40 ACROSS
NORTHERN AREAS...AND HIGHER TERRAIN.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
A STRONG UPPER LEVEL DISTURBANCE ASSOCIATED WITH A CLOSED
UPPER LEVEL APPROACHING FROM SE ONTARIO WILL BRING SHOWERS BACK
INTO THE ERN NY AND WRN NEW ENGLAND TERMINALS LATE THIS AFTERNOON
INTO THIS EVENING. THE UPPER LEVEL LOW WILL MOVE EAST TO SOUTHEAST
OF NEW ENGLAND ON SUNDAY WITH LINGERING CLOUDS AND ISO-SCT SHOWERS
AROUND THROUGH THE MORNING.
VFR CONDITIONS WILL BE SHORT-LIVED FOR KALB/KPOU/KGFL/KPSF IN THE
EARLY TO MID PM...BEFORE THE NEXT ROUND OF SHOWERS ARRIVES. THERE
MAY EVEN BE A RUMBLE OF THUNDER AROUND NEAR KPOU...BUT THE
PROBABILITY WAS NOT GREAT ENOUGH TO INCLUDE IN THE TERMINALS. THE
SHOWERS ARRIVE BTWN 20Z-22Z...AND LINGER UNTIL 02Z-05Z/SUN. CIGS
AND VSBYS WILL GENERALLY BE IN THE MVFR RANGE...BUT IFR CIGS/VSBYS
WERE INCLUDED AT KPSF...ESPECIALLY FOR LOW STRATUS IN THE SHOWERS
PRIOR TO MIDNIGHT. THE RESIDUAL LOW-LEVEL MOISTURE SHOULD LAST IN
THE BOUNDARY LAYER THROUGH THE OVERNIGHT PERIOD THERE...AND THE IFR
CIGS WERE KEPT IN THERE UNTIL 13Z/SUN. ELSEWHERE...MVFR CIGS IN
THE MOIST CYCLONIC FLOW WERE KEPT IN THE FCST FOR KGFL/KALB
THROUGH OVERNIGHT. KPOU SHOULD HAVE ENOUGH DRY AIR FILTERING IN
TO HAVE CIGS RISE TO THE VFR LEVELS BY 07Z/SUN. CIGS WILL GENERALLY
BE IN THE HIGH MVFR/VFR LEVELS BY 13Z-15Z/SUN AT ALL THE TERMINALS
WITH ISOLD-SCT INSTABILITY SHOWERS IN THE VICINITY.
THE WINDS WILL VARY FROM THE SW TO N AT LESS THAN 10 KTS THIS
AFTERNOON...THEN EXPECT A WIND SHIFT TO THE W TO NW AT 5-10 KTS
WITH THE UPPER LEVEL DISTURBANCE MOVING ACROSS THE REGION. N TO NW
WINDS WILL PERSIST OVERNIGHT INTO TOMORROW MORNING AT 10 KTS OR LESS.
OUTLOOK...
SUNDAY PM TO MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
TUESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WEDNESDAY-THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
A SOAKING RAIN OCCURRED OVERNIGHT ACROSS EASTERN NEW YORK AND
ADJACENT WESTERN NEW ENGLAND ALLEVIATING ANY FIRE WEATHER CONCERNS
FOR THE TIME BEING.
RELATIVE HUMIDITY VALUES WILL ONLY DROP TO 45 TO 60 PERCENT THIS
AFTERNOON...RECOVER TO 70 TO 100 PERCENT TONIGHT AND FALL TO 35 TO
55 PERCENT ON SUNDAY.
WINDS WILL BE SOUTHEAST TO NORTHEAST AT 5 TO 10 MPH TODAY...WEST
TO NORTHWEST AT 5 TO 10 MPH TONIGHT...AND NORTHWEST AT 10 TO 15
MPH WITH GUSTS TO 25 MPH SUNDAY AFTERNOON.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDRO PROBLEMS ARE ANTICIPATED DURING THE NEXT FIVE
DAYS.
SHOWERS OVERNIGHT HAVE BROUGHT MOST AREAS A QUARTER TO HALF AN
INCH WITH MORE RAIN SHOWERS EXPECTED LATER TODAY INTO TONIGHT WITH
ANOTHER TENTH TO THIRD OF AN INCH EXPECTED. ANY PRECIPITATION WILL
END BY SUNDAY AFTERNOON FOLLOWED BY DRY WEATHER THROUGH MONDAY
NIGHT. THE NEXT CHANCE OF PCPN WILL COME DURING THE MID WEEK PERIOD.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/WASULA
NEAR TERM...KL/11/WASULA
SHORT TERM...11
LONG TERM...KL
AVIATION...WASULA
FIRE WEATHER...11
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS MIAMI FL
116 PM EDT SAT APR 26 2014
.AVIATION...
VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST AS HIGH PRESSURE
REMAINS THE DOMINANT WEATHER FEATURE. SEA BREEZES WILL BE THE
DOMINANT WEATHER MAKER ALONG BOTH COASTS EACH AFTERNOON. THERE
COULD BE ONE OR TWO SHOWERS LATE THIS AFTERNOON AS THE BOUNDARIES
CONVERGE OVER THE INTERIOR BUT TOO FAR INLAND FROM THE TERMINALS
TO PLACE IN THE TAFS.
KOB
&&
.PREV DISCUSSION... /ISSUED 947 AM EDT SAT APR 26 2014/
UPDATE...
THE CURRENT FORECAST IS ON TRACK. A DRY AND WARM DAY WITH PLENTY
OF SUNSHINE IS EXPECTED FOR TODAY. A LARGE AREA OF HIGH PRESSURE
IS LOCATED OVER THE GULF OF MEXICO WITH VERY DRY AIR IN PLACE
BETWEEN 700 AND 500 MB. LIGHT NORTHERLY WINDS WILL PREVAIL TODAY
AND WILL TURN EASTERLY BY SUNDAY MORNING. THIS WILL BRING A
LITTLE BIT OF MORE MOISTURE, BUT IT WILL STAY CONFINED TO THE
BOUNDARY LAYER. STRONG SUBSIDENCE BELOW 700 MB WILL DELAY ANY
SHOWERS THAT MAY FORM OVER LAND UNTIL LATE IN THE DAY. THE MID
LEVEL TEMPERATURES ARE STILL RELATIVELY COOL, AROUND -10C, WHICH
WILL ALLOW FOR THE FORMATION OF ONE OR TWO LATE AFTERNOON SHOWERS.
HOWEVER, IF ANY THING FORMS IT WILL BE VERY SPARSE IN COVERAGE, AND
IN THE AREAS WHERE THE EAST COAST AND WEST COAST SEA BREEZES
COLLIDE. OVER THE ATLANTIC WATERS WE CAN BEGIN TO OBSERVE THE SET
UP OF A CONVERGENCE LINE BETWEEN EASTERLY FLOW SOUTH OF THE PALM
BEACH WATERS AND MORE NORTHERLY FLOW TO THE NORTH. THIS COULD
TRIGGER A FEW SHOWERS OVER THE PALM BEACH WATERS. COVERAGE WILL
BE SPARSE.
PREV DISCUSSION... /ISSUED 715 AM EDT SAT APR 26 2014/
AVIATION...
DEEP LAYER HIGH PRESSURE WILL DOMINATE SOUTH FLORIDA THROUGH THE
FORECAST WITH SEA BREEZES DEVELOPING ALONG BOTH COASTS. SOME OF
THE HIGH RESOLUTION SHORT TERM MODELS ARE AGAIN SHOWING A FEW
SHOWERS ALONG THE SEA BREEZES OVER THE INTERIOR LATE IN THE
AFTERNOON. LEFT OUT OF THE FORECAST FOR NOW AS THESE WILL TOO FEW
TO CONSIDER AND MORE THAN LIKELY WELL INLAND AWAY FROM ANY
TERMINALS.
KOB
PREV DISCUSSION... /ISSUED 420 AM EDT SAT APR 26 2014/
DISCUSSION...
WATER VAPOR AND RUC ANALYSIS THIS MORNING SHOWED A SHORTWAVE
TROUGH FROM THE GREAT LAKES SOUTHEAST TO OFF THE EAST COAST OF
NORTH CAROLINA. AN UPPER LEVEL RIDGE STRETCHED FROM THE WESTERN
GULF OF MEXICO INTO CANADA...AND ANOTHER SHORTWAVE TROUGH WAS
PUSHING INTO CENTRAL CALIFORNIA. A NEARLY ZONAL FLOW WAS NOTED
OVER SOUTH FLORIDA.
AT THE SURFACE...AN AREA OF LOW PRESSURE WAS LOCATED OVER THE
WESTERN ATLANTIC JUST SOUTH OF NEW JERSEY...AND A WEAK FRONTAL
BOUNDARY WAS DRAPED SOUTH AND WEST ALONG THE SOUTHEAST STATES
COASTS AND INTO SOUTHERN GEORGIA AND ALONG THE NORTHERN GULF
COAST. WEAK SURFACE HIGH PRESSURE REMAINED ACROSS FLORIDA AND THE
KEYS...WITH A LIGHT NORTHERLY LOW LEVEL FLOW OVER SOUTH FLORIDA.
FOR TODAY...DRIER AIR WILL MOVE IN FROM THE WEST...WITH PWATS A
LITTLE OVER AN INCH. SO DRY AND WARM CONDITIONS ARE EXPECTED.
LIGHT WINDS WILL CONTINUE THIS MORNING...WITH SEA BREEZE
BOUNDARIES PUSHING INLAND ALONG BOTH COASTS THIS AFTERNOON.
TONIGHT...THE UPPER LEVEL RIDGE OVER THE WESTERN GULF IS FORECAST
TO PUSH TOWARDS THE EASTERN GULF AS THE SHORTWAVE OVER CALIFORNIA
EJECTS EAST INTO THE INTERMOUNTAIN WEST. THE SURFACE RIDGE OF
HIGH PRESSURE OVER THE REGION WILL BEGIN TO SHIFT TO THE EAST INTO
THE WESTERN ATLANTIC...WITH EASTERLY FLOW DEVELOPING. LIGHT WINDS
ARE FORECAST ACROSS THE INTERIOR...AND PATCHY FOG MAY DEVELOP ONCE
AGAIN. AREAS OF SMOKE ARE LIKELY NEAR THE WILDFIRE ACROSS EASTERN
COLLIER COUNTY.
SUNDAY THROUGH TUESDAY...THE SURFACE RIDGE WILL CONTINUE TO PUSH
EAST...AND THE EASTERLY FLOW WILL INCREASE. SEA BREEZE BOUNDARIES
ARE FORECAST TO INTERACT ACROSS THE INTERIOR NEAR THE LAKE REGION
IN THE AFTERNOON. THIS MAY BE ENOUGH TO SPARK A FEW SHOWERS OR
STORMS IN THIS REGION ON SUNDAY. ABOVE NORMAL TEMPERATURES WILL
CONTINUE WITH HIGHS IN THE MID 80S TO LOWER 90S. AN UPPER LEVEL
LOW WILL CUTOFF ACROSS THE INTERMOUNTAIN WEST AND THE CENTRAL
PLAINS SUNDAY...AND THEN MEANDER ACROSS THE CENTRAL PLAINS THROUGH
EARLY NEXT WEEK. THE UPPER LEVEL RIDGE WILL MOVE OVER SOUTH
FLORIDA ON SUNDAY AND THEN REMAIN THROUGH THE MIDDLE OF THE WEEK.
MAINLY DRY AND VERY WARM CONDITIONS WILL CONTINUE.
A LARGE UPPER TROUGH/LOW WILL ENVELOP ABOUT THE EASTERN TWO-
THIRDS OF THE CONUS WEDNESDAY AND THURSDAY. UPPER HEIGHTS WILL
BEGIN TO LOWER...BUT SOME RIDGING WILL REMAIN OVER SOUTH FLORIDA.
A COLD FRONT IS FORECAST TO PUSH INTO NORTHERN FLORIDA BY
WEDNESDAY EVENING. HOWEVER...THE FRONT IS FORECAST TO REMAIN OVER
NORTH OR CENTRAL FLORIDA THROUGH FRIDAY. THE FLOW WILL SHIFT TO
THE SOUTHEAST. MOISTURE IS FORECAST TO SLOWLY INCREASE THROUGH
THE END OF THE WEEK...AND RAIN CHANCES ARE FORECAST TO INCREASE.
DEWPOINTS ARE FORECAST TO INCREASE BACK TO AROUND 70 BY
TUESDAY...AND REMAIN AROUND 70 THROUGH THE END OF THE PERIOD.
SOUTHEAST WINDS ARE FORECAST TO BE 10-15 KNOTS OVER THE ATLANTIC
WATERS AS WELL...AND THIS WILL KEEP LOW TEMPERATURES WELL ABOVE
NORMAL FOR THE EAST COAST. OVERNIGHT LOWS ARE FORECAST TO BE IN
THE MID/UPPER 70S FOR THE EAST COAST METRO AREAS. HIGHS ARE
FORECAST TO BE IN THE MID 80S TO LOW 90S THROUGH THE WEEK.
AVIATION...
HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER THROUGH THE TAF
PERIOD. THIS WILL KEEP VFR CONDITIONS IN PLACE. WINDS WILL PICK UP
MID DAY AS THE SEA BREEZE DEVELOPS, THEN RETURN TO LIGHT AND VARIABLE
IN THE LATE EVENING HOURS.
MARINE...
A WEAK PRESSURE GRADIENT PREVAILS ACROSS THE REGIONAL WATERS WITH
LIGHT AND SOMEWHAT VARIABLE WINDS TODAY WITH MORE EASTERLY FLOW
RETURNING ON SUNDAY INTO EARLY NEXT WEEK. IN GENERAL SEAS ARE
EXPECTED TO BE 2 FEET OR LESS THROUGH THE WEEKEND WITH JUST A
GRADUAL INCREASE IN WINDS AND SEAS EARLY NEXT WEEK.
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1229 PM CDT Sat Apr 26 2014
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 403 AM CDT SAT APR 26 2014
The center of an intense upper level trough was located over
southern CA at 7Z. The upper level trough will lift northeast across
the desert southwest this afternoon, and then lift negative tilt
into southeast CO and across west TX by 12Z SUN.
Early this morning elevated showers were beginning to develop as
isentropic lift was developing ahead of residual 850mb moisture
return. The HRRR along with the ECMWF show the stronger
thunderstorms developing just east of the CWA after 12Z. The 00Z NAM
shows isolated elevated thunderstorms developing along and south of
the KS turnpike by 10Z, then moving east of the CWA during the mid
and late morning hours. Given MUCAPES of 400-1000 J/KG and effective
0-6KM shear of 30 KTS, some of these storms may produce small hail
and the stronger storms may even produce quarter size hail across
portions of east central KS this morning, that is if storms develop
within the CWA.
As an 80kt jet max within the base of the H5 trough lifts northeast
across eastern NM, a lee surface trough across southeast CO,
southward along the NM/TX border will deepen. This will increase the
southerly 850mb winds to 40 KTS across central KS with surface wind
increasing 20 to 30 KTS across most of KS. At this time the
strongest surface winds should remain just southwest and west of the
CWA. The southwest counties of the CWA may come close to wind
advisory criteria during the afternoon hours with sustained winds of
28 MPH and gusts to near 40 MPH.
A surface dryline will develop early this afternoon within the lee
trough axis across extreme southwest KS, then southward across the
TX PNHDL. This dryline will then move northeast into west central KS
and extend southward across extreme western OK by late this
afternoon.
At this time the deepest gulf moisture was located across southern
TX and most models show a quick transport of deep moisture northward
into south central KS by this afternoon. Deeper mixing across
central KS may keep dewpoints in the mid to upper 50s ahead of the
surface dryline.
Both the the 6Z NAM and 00Z Advanced Research WRF show a strong CAP
ahead of the dryline across central KS with no storms developing in
the late afternoon or evening hours. The 12Z ECMWF model shows the
potential for thunderstorms developing along the dryline across
south central KS and north central KS east of HLC. All the models
show temperature and dewpoint temperature depressions greater than
25 degrees along the dryline across central and north central KS.
Therefore, if storms develop they will be high based with MLLCL`s of
5,000 to 6,000 feet. The environment across central KS will have
MLCAPES of 3500 J/KG and Effective shear of 40 KTS. If storms were
able to develop the environment would be favorable for high based
supercell thunderstorms. The higher storm bases will significantly
decrease the potential for tornadoes as these isolated supercell
thunderstorms move northeast off the dryline into the western
counties of the CWA early this evening. In fact they may weaken as
the supercells leave the best area of surface convergence. However,
if any high based supercell manages to develop along the dryline
across north central and central KS, these storms will be capable of
producing large hail and damaging wind gusts.
Highs Today will range from the lower 80s across the northeast
counties to the upper 80s to near 90 across the southwest counties
of the CWA.
I think we will see a break across the CWA from any thunderstorms
from the mid evening hours until 3 or 4 AM Sunday morning, before
severe thunderstorms redevelop. Supercell thunderstorms across
western and central OK will merge into a QLCS or MCS and lift
northeast into south central KS after midnight. Once piece of the
upper level trough will pivot northward across western and central
OK, then into eastern KS through the early morning hours of Sunday.
This will probably maintain any QLCS or MCS cluster of severe
thunderstorms that develop across northern OK and southern KS, as
these storms move northeast ahead of the first H5 trough across the
eastern half of the CWA. The primary hazard with the cluster of
severe thunderstorms will be large hail along with the threat for
damaging winds. I cannot rule out a few supercell thunderstorms on
the southern edge of the severe cluster of thunderstorms. Any
supercells or meso vortices within a QLCS may bring a low chance for
an isolated tornado through early morning hours of Sunday across
portions of east central KS. The MCS/cluster of severe thunderstorms
may also bring heavy rainfall. It will be more of a mesoscale
forecast but areas along and south of the KS turnpike may see the
heaviest rainfall near 12Z SUN.
Overnight lows will only drop into the lower to mid 60s Saturday
night.
.LONG TERM...(Sunday through Friday)
Issued at 403 AM CDT SAT APR 26 2014
The most concentrated and potentially strongest convection still
appears to be on Sunday over the eastern 2/3 of the cwa in the
morning and the eastern 1/3 in the afternoon as the main shortwave
lobe over southwest KS at 12z Sunday lifts northeastward across KS
through the day. Strong to severe convection appears will be
ongoing to start the day Sunday across much of the cwa...gradually
shifting eastward ahead of dry slot in central KS...although
models such as the EC hinting that the cwa could be on the
northern fringe of a substantial MCS just to the south. Models
keep MUCAPE values in the 1500-2000 J/kg range ahead of the
dryline...however 0-6km Bulk Shear values steadily increase into
the 50-60kt range through 18z over the eastern half of the cwa or
near and just ahead of dryline. Although large hail...wind is
possible with the morning convection...any additional development
by midday/afternoon in any increasingly sheared environment would
become more supportive of supercells with all modes of severe
weather possible including a tornado threat. This will be highly
dependent on the speed/timing of the dryline and its proximity to
afternoon heating just of the mid level drying. Although will
leave a slight chance for some lingering convection early evening
in the far eastern counties...it still appears the threat for
severe weather will shift east of the cwa by 00Z as drier air
continues to push eastward across the area as the upper low slows
and occludes over western Nebraska.
Cannot totally rule out a few showers developing over the cwa on
Monday as the upper low wobbles eastward and moisture wraps around
the circulation center and back into the cwa...but will word as
showers for now as instability looks weak. Rain chances will then
linger through Wednesday...then again on Thursday as another
shortwave trough rotates southeast around the upper trough. Rainfall
amounts across the area through mid week should remain light. High
temperatures still expected to cool from the 70s on Sunday to the
60s/near 70 Monday...then the 50s and 60s through the remainder of
the week. Lows will commonly be in the 40s Tuesday through Friday.
&&
.AVIATION...(For the 18Z TAFs through 18Z Sunday Afternoon)
Issued at 1223 PM CDT SAT APR 26 2014
VFR prevails as strong southerly winds gust between 30 and 35 kts
through 01Z. Speeds weaken slightly however remain strong above
15 kts sustained through end of TAF period as strong upper
disturbance approaches. Therefore LLWS should not be an issue
as long as winds stay up. Delayed onset of VCTS being in the area
until 09Z at KMHK and 10Z at KTOP/KFOE. High resolution models
develop SCT TS after midnight in southern KS, lifting north and
east towards terminals by Sunday morning. Thunderstorms are
possible through 18Z. Strong warm advection and moistening
boundary layer aft 09Z will lower ceilings to MVFR. IFR or lower
is possible if storms directly impact terminals.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...63
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1238 PM EDT SAT APR 26 2014
.SYNOPSIS...
MOISTURE STARVED COLD FRONT CROSSES TODAY...WITH AN ISOLATED
SHOWER OR THUNDERSTORM POSSIBLE SOUTH OF THE MASON DIXON LINE.
SUNDAY SHOULD BE DRY BEFORE AN UNSETTLED PATTERN SETS UP FOR THE
WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
COLD FRONT IS SLOWLY SAGGING TOWARDS THE FORECAST AREA EARLY THIS
AFTERNOON. JUST AHEAD OF IT...STRONG MIXING WITH THE TIGHTENING
PRESSURE GRADIENT HAS HAS ALLOWED FOR A SURGE IN TEMPERATURES.
HAVE UPPED HIGH TEMPERATURES FOR AREAS SOUTH OF THE FRONT THROUGH
THE AFTERNOON BUT CLOUDS MAY BE A LIMITING FACTOR FOR THE COUNTIES
SOUTH OF THE MASON-DIXON LINE. GUSTY WINDS WILL CONTINUE INTO THE
EVENING AS THE COLD FRONT CROSSES THE REGION. IN
ADDITION...ANOTHER ROUND OF SHOWERS AND AN ISOLATED THUNDERSTORM
CANNOT BE RULED OUT WHERE MOISTURE REMAINS SOUTH OF I-70. WILL
CONTINUE TO CARRY POPS THERE AS THE HRRR SUGGESTS REDEVELOPMENT
THIS AFTERNOON.
CLEARING SKIES AND LIGHT WINDS SHOULD ALLOW FOR TEMPERATURES TO
FALL BELOW SEASONAL NORMALS OVERNIGHT. SOME MID-HIGH CLOUDS MAY
LINGER OVER OUR FAR SOUTHERN ZONES WHERE THE COLD FRONT STALLS
TONIGHT...BEFORE IT LIFTS AS A WARM FRONT TOMORROW.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY IS CURRENTLY THE ONLY DAY IN THE 7 DAY FORECAST WITHOUT A
CHANCE OF RAIN IN THE FORECAST THANKS TO HIGH PRESSURE BRIEFLY
PASSING OVER THE REGION. LOW PRESSURE WILL BEGIN TO DEVELOP IN THE
PLAINS...AND THE ASSOCIATED WARM FRONT WILL SWEEP TOWARDS THE REGION
ON MONDAY. RAIN IS EXPECTED TO WORK ITS WAY INTO EASTERN OHIO ON
MONDAY...AND ACROSS THE ENTIRE FORECAST AREA MONDAY NIGHT. DAYTIME
HIGHS WILL BE NEAR NORMAL...WITH OVERNIGHT LOWS ABOVE NORMAL AS
CLOUDS MOVE IN.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
MODELS IN AGREEMENT ON A BROAD AREA OF LOW PRESSURE LINGERING OVER
THE ERN CONUS CENTERED IN THE GREAT LAKES THROUGH THE END OF NEXT
WEEK. THIS WILL PROVIDE DAILY CHANCES OF RAIN SHOWERS AND WORK TO
MODERATE TEMPERATURES UNDER CLOUDY SKIES. WITH A BLOCKED PATTERN
ALOFT DOUBT UPPER LEVEL SYSTEM WILL BE QUICK TO MOVE OFF FOR THE
WEEKEND...WITH COOL TEMPERATURES AND SHOWER CHANCES CONTINUED FOR
SATURDAY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR THROUGH THE TAF PERIOD AS A MOISTURE STARVED FRONT WORKS
ACROSS REGION THIS AFTERNOON. WINDS WILL BE GUSTY TO 25 KTS FROM
THE WEST TURNING NORTHWEST 18-22Z WITH MAIN FROPA. WINDS WILL
DIMINISH TOWARD SUNSET WITH VFR AND LIGHT NORTHERLY FLOW THROUGH
SUNDAY.
.OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
PERIODIC RSTRNS ARE EXPD MUCH OF NXT WK AS A SERIES OF DISTURBANCES
CROSS THE RGN.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
422 PM EDT SAT APR 26 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 417 PM EDT SAT APR 26 2014
WV IMAGERY AND RUC ANALYSIS INDICATED CONFLUENT MID/UPPER LEVEL FLOW
THROUGH THE NRN LAKES BETWEEN A TROUGH INTO THE NE CONUS AND A RIDGE
FROM THE MID MS VALLEY INTO THE NRN PLAINS SASK. AT THE SFC...A
RIDGE EXTENDED FROM HUDSON BAY INTO THE WRN GREAT LAKES RESULTING IN
N TO NE FLOW INTO UPPER MICHIGAN. VIS LOOP SHOWED A CLEARING TREND
WITH THE COMBINATION OF DRY ADVECTION AND DAYTIME MIXING HELPING TO
SCOUR OUT THE LOW CLOUDS. AFTERNOON TEMPS RANGED FROM THE MID 30S
NORTH...DOWNWIND OF LAKE SUPERIOR...TO THE MID 40S OVER THE SOUTH.
TONIGHT...EVEN THOUGH THERE MAY BE SOME INCREASE IN HIGH CLOUDS
OVERNIGHT AND SOME LIGHT EAST WINDS...EXPECT RADIATIONAL
COOLING CONDITIONS WILL BE FAVORABLE ENOUGH TO ALLOW TEMPS TO DROP
TOWARD THE LOWER 20S INLAND NORTH AND TO AROUND 30 NEAR THE WI
BORDER.
SUN...AS THE STRONG MID LEVEL AND SFC LOW MOVE INTO THE CNTRL PLAINS
WAA PCPN AHEAD OF THE 850 MB WARM FRONT MAY APPROACH UPPER MI AS IT
SPREADS THROUGH WI. HOWEVER...WITH PERSISTENT ERLY LOW LEVEL DRY
ADVECTION AND THE VERY DRY PROFILE BELOW 750 MB...PER FCST
SOUNDINGS...EXPECT THAT THE PCPN WILL STAY TO THE SOUTH OF THE CWA.
TEMPS WILL REMAIN BELOW NORMAL...WITH HIGHS IN THE MID 40S TO AROUND
50 OVER MUCH OF UPPER MICHIGAN. HOWEVER...OVER N CNTRL UPPER MI AND
THE KEWEENAW...THE EAST WIND OFF OF LAKE SUPERIOR WILL KEEP HIGHS
FROM AROUND 40 TO 45.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 417 PM EDT SAT APR 26 2014
UPPER LOW BEGINS THE LONG TERM PERIOD LUMBERING OUT OF THE SOUTHWEST
CONUS ACROSS THE CENTRAL PLAINS. SFC LOW NEARBY THE UPPER LOW CENTER
WHILE HIGH PRESSURE RIDGE EXTENDS SOUTHWARD FROM HUDSON BAY TO THE
GREAT LAKES. UPPER LOW AND ASSOCIATED BLOCKING ALOFT ON ITS EDGES
WILL BE MAIN WEATHER INSTIGATORS FOR THE UPCOMING WEEK. IT SEEMS TO
ALWAYS BE A STRUGGLE FOR THE MODELS WITH THIS TYPE OF SITUATION WHERE
THE UPPER LOW AND ASSOCIATED MOISTURE TRANSPORT RUN INTO THE SFC HIGH
AND DRY LOW-LEVEL AIR. MOISTURE ADVECTION ALOFT COULD ALLOW FOR A LOT
OF MID CLOUDS AND PERHAPS SOME LGT RAIN OVER THE SOUTHERN CWA MONDAY
AFTN INTO MONDAY EVENING. FARTHER NORTH...THINK LOWER SFC-H85 RH OUT
OF THE HUDSON BAY HIGH WILL LIMIT ANY PRECIP TO ISOLD SHOWERS OR
SPRINKLES. EAST-NORTHEAST WINDS WILL KEEP LK SUPERIOR AREAS IN THE
LOWER 40S ON MONDAY...BUT INLAND AREAS CLOSER TO WI BORDER AND OVER
THE EASTERN CWA MAY BE ABLE TO PUSH INTO THE 50S WITH BETTER MIXING
HEIGHTS UP TO H85. POSSIBLE THAT MID 50S COULD OCCUR OVER FAR EAST IF
CLOUDS HOLD OFF LONG ENOUGH.
ENOUGH CONFIDENCE THAT ONCE TUESDAY AND WEDNESDAY ARRIVE...UPPER LOW
WILL BE EXERTING ENOUGH OF AN INFLUENCE TO RESULT IN PRECIPITATION
ACROSS THE CWA. EAST WINDS WITH CLOUDS AND PRECIP WILL KEEP TEMPS IN
ALL AREAS WELL BLO NORMAL...WITH HIGHS THIS PERIOD UPR 30S TO LOW
40S NEAR LK SUPERIOR AND MAINLY IN THE 40S INLAND. AS IT APPEARS
NOW...AND THIS IS SUBJECT TO CHANGE...SEEMS THAT PRECIPITATION COMES
IN TWO WAVES. FIRST MAIN AREA OF PRECIPITATION SUPPORTED BY INITIAL
SHORTWAVES ROTATING AROUND THE UPR LOW AND H85-H7 MOISTURE TRANSPORT
LIFTS ACROSS THE CWA ON TUESDAY. GFS AND ECMWF SUGGESTS STEADIER
PRECIP COULD CHANGE TO MAINLY DRIZZLE TUESDAY AFTN INTO TUESDAY
EVENING. PTYPE COULD BE AN ISSUE INITIALLY AS H85 TEMPS BLO ZERO OVER
THE WESTERN CWA AND SFC TEMPS IN THE LOW-MID 30S MONDAY NIGHT INTO
TUESDAY MORNING POINT TO POSSIBLE RAIN/SNOW MIX. 1000-850MB
THICKNESSES RIGHT ON THE 1300-1305M LINE WOULD INDICATE DIFFERENCE
BTWN SEEING RAIN...SNOW...OR A MIX WILL BE DEPENDANT ON ELEVATION
HEIGHT. THERE IS NOT A LOT OF PRECIP EXPECTED MOST OF MONDAY NIGHT
FOR AREAS IN THE RAIN/SNOW ZONE...BUT PRECIP TUESDAY MORNING COULD BE
MORE IMPACTED. WOULD NOT BE SURPRISED TO SEE SLUSHY SNOW ACCUMS ON
TUESDAY MORNING OVER THE HIGHER TERRAIN OF THE NORTHWEST AND NORTH
CENTRAL CWA. ANY MIX WOULD CHANGE TO RAIN IN THE AFTN AS RELATIVELY
WARMER AIR ARRIVES FROM THE SOUTH.
KEPT RAIN CHANCES FOR TUESDAY NIGHT BUT IT COULD BE DRIZZLE AT
TIMES. BEST CHANCE OF RAIN OVER THE EASTERN CWA AHEAD OF STRONGER
SHORTWAVE LIFTING IN LATER TUESDAY NIGHT. SHORTWAVE LIFTS ACROSS
AREA ON WEDNESDAY WHICH IS ALSO WHEN MAIN SFC LOW ARRIVES OVER THE
REGION. EVEN THOUGH BETTER MOISTURE TRANSPORT IS HEADING EAST BY
THAT TIME...THERE IS HINT OF WARM AND MOIST AIR WRAPPING BACK ACROSS
UPR LAKES AS THE SFC LOW BEGINS TO OCCLUDE. KIND OF EARLY TO BE
LOOKING AT TROWAL SPECIFICS BUT THAT MAY BE WHAT MODELS ARE KEYING
ON TO BOOST QPF TOTALS ALONG TRACK OF H85 LOW TRACK. UPSLOPE NNW
FLOW MAY ALSO INCREASE TOTALS OVER WEST AND NCNTRL LATER WEDNESDAY
INTO WEDNESDAY NIGHT. STILL APPEARS THAT TOTAL PRECIP TUESDAY AND
WEDNESDAY...AT LEAST IN SOME AREAS...MAY REACH 1 TO 1.5 INCHES.
LATER WEDNESDAY NIGHT INTO THURSDAY MAY HAVE TO DEAL WITH MORE PTYPE
ISSUES AGAIN AS VERTICALLY STACKED LOW PRESSURE ALLOWS FOR GRADUALLY
COOLING TEMPERATURES JUST ABOVE SFC. H85 TEMPS DROP BACK BLO 0C SO
COULD SEE MORE RAIN AND SNOW MIX FOR THE WEST HALF OF CWA WEDNESDAY
NIGHT INTO THURSDAY MORNING. UNRAVELLING UPPER/SFC LOWS ONLY SLOWLY
MOVE OUT OF THE AREA LATE THIS WEEK. ADDITIONAL SHORTWAVES MAY BRING
MORE UNSETTLED WEATHER FRIDAY INTO SATURDAY /BOTH RAIN AND SNOW
POSSIBLE/...BUT GRADUALLY POPS WILL DROP BACK TO SLIGHT CHANCES BY
THAT TIME. CONSENSUS MAX TEMPS CONTINUING TO STAY BLO NORMAL ARE NOT
NECESSARILY DESIRED...BUT APPEAR REASONABLE TO CLOSE THE LONG TERM
PERIOD. MADE FEW CHANGES TO CONSENSUS TEMPS/POPS/WINDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 148 PM EDT SAT APR 26 2014
AS DRIER AIR MOVES IN FROM THE NORTH AND DAYTIME MIXING
CONTINUES...EXPECT MVFR CIGS TO GIVE WAY TO VFR CONDITIONS BY MID TO
LATE AFTERNOON. VFR CONDITIONS WILL THEN PREVAIL THROUGH THE REST OF
THE TAF PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 417 PM EDT SAT APR 26 2014
EAST WINDS INCREASE ON SUNDAY INTO SUNDAY NIGHT AS LOW
PRESSURE DEEPENS OVER THE PLAINS. GUSTS COULD REACH GALE FORCE TO
35KTS OVER FAR WESTERN LK SUPERIOR TOWARD DULUTH BY LATE AFTERNOON.
EAST GALES ARE THEN EXPECTED SUN NIGHT INTO MON OVER THE WEST.
WINDS WILL GRADUALLY DIMINISH MON NIGHT INTO TUE AS THE LOW PRESSURE
SYSTEM LIFTS TO THE NORTH TOWARD THE WRN GREAT LAKES AND THE PRES
GRADIENT WEAKENS. HOWEVER WINDS TO 30 KNOTS ARE STILL EXPECTED INTO
TUE. WINDS ARE EXPECTED TO DROP OFF TO 25 KNOTS OR LESS FROM WED
INTO THU AS THE LOW FILLS AND REMAINS NEAR UPPER MICHIGAN.
&&
.HYDROLOGY...
ISSUED AT 417 PM EDT SAT APR 26 2014
RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH
THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA
STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR
ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR
CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS AND THE STURGEON RIVER
NEAR NAHMA JUNCTION. WHILE THE PAINT RIVER NEAR CRYSTAL FALLS AND
THE STURGEON RIVER NEAR NAHMA JUNCTION ARE NOT EXPECTED TO REACH
FLOOD STAGE IN THE SHORT TERM...THE STURGEON RIVER NEAR CHASSELL
REMAINS NEAR FLOOD STAGE AND IS EXPECTED TO REMAIN STEADY FOR THE
REST OF THE WEEKEND.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
A LARGE LOW PRESSURE SYSTEM WILL MOVE INTO THE GREAT LAKES BY THE
MIDDLE OF NEXT WEEK. PERIODS OF RAIN ARE POSSIBLE FROM LATE MONDAY
THROUGH THURSDAY WITH THE POTENTIAL FOR TOTAL AMOUNTS OF AN INCH TO
AN INCH AND A HALF. THIS WOULD ADD TO THE FLOOD RISK...ESPECIALLY
OVER THE NORTHWEST HALF OF UPPER MICHIGAN WHERE SNOWMELT WILL ALSO
ADD TO THE RUNOFF.
WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. HOWEVER...THOSE
LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER
LEVELS OVER THE NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY EVENING FOR
LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...JLB
MARINE...JLB
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS BILLINGS MT
328 PM MDT SAT APR 26 2014
.SHORT TERM...VALID FOR SUN AND MON...
SCATTERED SHOWERS AND THUNDERSTORMS WERE MOVING N TOWARD THE
FORECAST AREA FROM WY THIS AFTERNOON PER RADAR IMAGERY AND
LIGHTNING DATA. CAPES HAVE BEEN INCREASING OVER THE AREA SO HAVE
INCREASED THE CHANCE OF THUNDER FOR THIS EVENING. THE CAPES WERE
FORECAST TO DIMINISH BY THE RAP AFTER 03Z...SO WILL ONLY HAVE A
SLIGHT CHANCE OF THUNDER FOR THE LATE EVENING. BULK SHEAR WAS ALSO
FAVORABLE ACROSS THE REGION IN SUPPORT OF THUNDERSTORMS.
COMPACT UPPER LOW WAS SEEN ON WATER VAPOR IMAGERY MOVING THROUGH
AZ THIS AFTERNOON. PLENTY OF MOISTURE WAS SPREADING N OUT FROM THE
LOW IN SW FLOW ALOFT. MODELS AGREED THAT THE UPPER LOW WILL REACH
SE CO BY 12Z SUN...ALLOWING THE TROUGH TO GO NEGATIVE TILT AND TAP
GULF OF MEXICO MOISTURE. THE LOW WILL MERGE WITH THE NORTHERN
BRANCH OF THE TROUGH AS IT MOVES NE THROUGH MON INTO THE CENTRAL
PLAINS. THE LARGER CUTOFF WILL THEN MEANDER E MON NIGHT.
AT THE SURFACE...AMORPHOUS LOW CENTERS WERE ALONG THE SOUTHERN
EDGE OF THE FORECAST AREA THIS AFTERNOON. THESE LOWS WERE FORECAST
TO MERGE OVER NE OR E CO BY 12Z SUN WITH AN INVERTED TROUGH
EXTENDING FROM THE MERGED LOW INTO THE EASTERN FORECAST AREA. A
HALF INCH TO AN INCH OF QPF WILL FALL OVER THE WESTERN ZONES
TONIGHT BEFORE THE PRECIPITATION FOCUS SHIFTS TO SE MT...E OF
KBIL...DURING SUN MORNING DUE TO THE INVERTED TROUGH. THE INVERTED
TROUGH WILL SHIFT SLOWLY E DURING SUN AND A HALF INCH TO AN INCH
OF PRECIPITATION IS EXPECTED TO FALL OVER SE MT. THE BEST CHANCES
FOR SNOW WILL BE THIS EVENING OVER THE BEARTOOTHS AND ABSAROKAS
DUE TO A COMBINATION OF LIFT AND INSTABILITY...BUT DENDRITIC
GROWTH WILL BE HIGHER IN THE ATMOSPHERE LIMITING THE GREATER
ACCUMULATIONS TO THE HIGHEST ELEVATIONS. THE MAJORITY OF THE
MODELS KEPT THE INVERTED TROUGH AND ASSOCIATED PRECIPITATION GOING
OVER THE SE THROUGH MON WITH THE ECMWF BEING FURTHEST E OVER THE
DAKOTAS. ANOTHER THREE-QUARTERS OF AN INCH OF PRECIPITATION WILL
BE POSSIBLE SUN NIGHT...WITH MUCH LESSER AMOUNTS EXPECTED MON.
SOME LINGERING PRECIPITATION IS EXPECTED OVER THE SE MON NIGHT.
CONTINUED THE FORECAST OF RAIN MIXING WITH THE SNOW LATE SUN NIGHT
AND MON NIGHT. A COUPLE INCHES OF SNOW WILL BE POSSIBLE OVER THE
SE SUN NIGHT. ONLY MADE SLIGHT POP AND TEMPERATURE ADJUSTMENTS
THROUGH THE PERIOD. HIGHS WILL BE IN THE 40S AND 50S SUN AND MON.
STILL EXPECTING GUSTY NW WINDS BEHIND THE SURFACE LOW BEGINNING
TONIGHT. WILL CONTINUE THE ESF FOR RISING RIVERS AND STREAMS. ARTHUR
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
THE LARGE SCALE SYNOPTIC PATTERN ACROSS THE CONUS WILL EVOLVE
SLOWLY THROUGH MIDDLE TO LATE NEXT WEEK AS A BLOCKING PATTERN
CONTINUES. TUESDAY THROUGH THURSDAY THE LARGE UPPER-LEVEL LOW
WILL DRIFT FROM THE CENTRAL PLAINS TO THE GREAT LAKES AREA...
WHICH WILL RESULT IN A CONTINUED WET AND COOL PATTERN FOR THE
EASTERN PORTIONS OF THE FORECAST AREA. THE MOISTURE TRANSPORT
WILL SLOWLY DIMINISH EACH DAY... AND WILL ALLOW PRECIPITATION
TO SLOWLY TAPER OFF. WHILE MODELS HAVE CONTINUED TO SHOW SLOW
BREAKDOWN OF THE BLOCKING PATTERN... THURSDAY WILL FINALLY BE
WARMER AND DRIER AS ANTICYCLONIC FLOW FINALLY BUILDS IN ALOFT
ALONG WITH WARMER 850 MB TEMPERATURES.
THE MODEL TREND HAS BEEN TOWARD A SLIGHTLY SLOWER PROGRESSION
OF THE MEAN UPPER-LEVEL LOW ON TUESDAY AND WEDNESDAY... WHICH
WILL COMBINE WITH SOME ADDITIONAL VORTICITY BEING ADVECTED IN
TO THE FORECAST AREA FROM THE EAST ON TUESDAY. THIS WILL MAKE
FOR A WETTER TUESDAY ACROSS EASTERN MONTANA THAN WE INITIALLY
THOUGHT. THUS...HAVE DECIDED TO INCREASE POPS TO LIKELIES FOR
AREAS EAST OF FORSYTH ON TUESDAY AFTERNOON. TEMPERATURES WILL
ALSO BE FAIRLY COOL ACROSS THE EAST ... WITH THERMAL PROFILES
SHOWING THE POTENTIAL FOR SNOW TO MIX WITH RAIN EARLY TUESDAY
MORNING AND THEN AGAIN EARLY WEDNESDAY MORNING. FARTHER WEST
THE TEMPERATURES WILL SLOWLY START TO MODERATE INTO WEDNESDAY
AS THE NORTH-SOUTH ORIENTED JET STREAM SLOWLY PUSHES EASTWARD
AND ALLOWS FOR +10C 850 MB TEMPERATURES TO MOVE INTO THE WEST
HALF OF THE FORECAST AREA. SHOWERS ARE STILL POSSIBLE ACROSS
SOUTH CENTRAL MONTANA ON TUESDAY AND WEDNESDAY ... GIVEN SOME
ADDITIONAL FORCING WRAPPING BACK AROUND THE LOW...HOWEVER THE
MAIN DETERRENT TO REALIZING THIS POTENTIAL REMAINS THE STRONG
NORTHWESTERLY DOWNSLOPE WINDS.
ANOMALOUSLY STRONG NORTHWESTERLY WINDS WILL CONTINUE FOR MUCH
OF THE FORECAST AREA ON TUESDAY..WITH THE WINDS SLOWLY TAPER-
ING OFF WEDNESDAY INTO THURSDAY. THE PATTERN FAVORS STRONGEST
WINDS ACROSS SOUTHEAST MONTANA AND INTO SHERIDAN WY GIVEN THE
SURFACE LOW ACROSS THE CENTRAL CONUS SUPPORTING A TIGHT PRES-
SURE GRADIENT ACROSS THE CENTRAL AND EASTERN CWA. CIPS ANALOG
GUIDANCE SHOWS 50 TO 70 PCT CHANCE OF WIND GUSTS GREATER THAN
30 KTS FROM BILLINGS TO SHERIDAN AND ACROSS SE MT ON TUESDAY.
AFTER THE WARMING AND DRYING TREND ON THURSDAY... MODEL SOLU-
TIONS DIVERGE READILY. HOWEVER ... THE OVERALL TREND SEEMS TO
BE TOWARD NORTHWESTERLY FLOW... WHICH KEEP US FROM WARMING UP
SIGNIFICANTLY AND WILL KEEP A SLGT CHANCE OF PRECIPITATION IN
THE FORECAST TO END THE WEEK.
CHURCH
&&
.AVIATION...
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP AND SPREAD INTO
THE FORECAST AREA THIS EVENING. ACCOMPANYING THESE SHOWERS WILL BE
MOUNTAIN OBSCURATIONS AS WELL AS LOCALIZED MVFR CONDITIONS. EXPECT
TO SEE THUNDER ACTIVITY DECREASE THIS EVENING AS INSTABILITY LESS-
ENS AFTER SUNSET. SHOWERS WILL BECOME MORE WIDESPREAD FOR THE AREA
TONIGHT AND COULD EVEN BECOME HEAVY AT TIMES.
CHURCH
&&
.PRELIMINARY POINT TEMP/POPS...
SUN MON TUE WED THU FRI SAT
-----------------------------------------------------------
BIL 042/056 036/051 035/053 036/057 037/062 039/065 041/058
97/W 32/W 23/W 21/N 11/B 12/W 22/W
LVM 035/057 033/047 032/051 033/057 035/060 035/062 037/061
+5/W 33/W 23/W 11/B 11/U 12/W 22/W
HDN 041/056 033/051 035/052 033/058 032/061 035/066 038/059
89/W 65/W 34/W 42/W 11/B 12/W 22/W
MLS 043/047 034/047 035/048 032/051 033/058 037/063 039/058
9+/R 97/O 56/R 53/W 11/B 12/W 22/W
4BQ 042/048 033/046 035/046 032/050 031/057 034/062 037/058
9+/R 97/O 56/R 53/W 11/B 12/W 22/W
BHK 042/045 033/044 034/042 031/049 031/054 034/058 036/057
7+/R +8/O 66/R 43/W 12/W 12/W 22/W
SHR 039/053 031/046 033/048 033/050 032/056 033/060 036/060
88/W 55/W 24/W 42/W 11/B 12/W 22/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS GLASGOW MT
241 PM MDT SAT APR 26 2014
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH MONDAY...
NOT TOO MANY CHANGES IN REGARD TO CHANCES OF PRECIPITATION...BUT
MODELS DID BACK OFF ON SNOW CHANCES/AMOUNTS.
UPPER TROUGH THE MAIN WEATHER MAKER FOR THE AREA THROUGH THE PERIOD.
PRECIPITATION WILL BE MAINLY CONVECTIVE INTO THIS EVENING THEN
TRANSITION TO STRATIFORM BY SUNDAY. THEREFORE AMOUNTS TONIGHT WILL
BE LOWER CONFIDENCE THAN SUNDAY.
SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP THIS LATE THIS
AFTERNOON AND MOVE NORTH. HRRR HAS THIS AREA INITIATING NEAR A
BOUNDARY NEAR MILES CITY LATE THIS AFTERNOON AT ABOUT 4 PM. AREA
GRADUALLY FILLS IN OVERNIGHT AND SUNDAY AS ISENTROPIC FLOW DEVELOPS.
SUNDAY NIGHT AND MONDAY...ISENTROPIC FLOW CONTINUES AS THE UPPER LOW
TROUGH CUTS OFF NEAR SD/NE. PERIOD OF RAIN LOOKS TO MOVE NW BACK
INTO THE AREA MONDAY MORNING. THE EC KEEPS IT AWAY FROM THE WESTERN
ZONES...SO LOWERED QPFS/POPS THERE. TEMPERATURES LOOK COLDER NOW OVER
THE NE ZONES RATHER THAN OPHEIM AREA FOR SNOW OR A SNOW/RAIN MIX
MAINLY MONDAY MORNING. CONFIDENCE IS STILL LOW BUT AN INCH STILL
LOOKS POSSIBLE. TFJ
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
BY MONDAY NIGHT THE LINGERING OUTER BANDS OF PRECIPITATION FROM
THE CURRENT STORM SYSTEM WILL STILL BE AFFECTING NORTHEAST
MONTANA...EVEN WITH THE CENTER OF THE 500-MB LOW BEING OVER KANSAS
CITY. THIS WILL LIKELY MATERIALIZE FOR OUR CWA IN THE FORM OF
SCATTERED BANDS OF RAIN SHOWERS...OCCASIONALLY MIXED WITH SNOW
DURING THE NIGHTTIME AND OVER THE HIGHER ELEVATIONS. MONDAY NIGHT
THROUGH TUESDAY...THE UPPER-LEVEL FLOW OVER NORTHEAST MONTANA WILL
BE RATHER BENIGN.
BY LATE THURSDAY NIGHT...A STRONG RIDGE OF HIGH PRESSURE WITH ITS
AXIS DOWN THE SPINE OF THE CASCADE RANGE...WILL START TO PUSH INTO
NORTHEAST MONTANA FROM THE WEST...WITH STRONGER FLOW ALOFT FROM
THE NORTH. THIS WILL CLEAR OUT ANY REMAINING RAIN SHOWERS...CLEAR
OUT THE SKIES...AND ALLOW TEMPERATURES TO WARM BACK UP TO MORE
NORMAL LEVELS FOR THIS TIME OF YEAR. BMICKELSON
PREVIOUS LONG TERM DISCUSSION...THE EXTENDED PERIOD BEGINS MONDAY
EVENING WITH A LONG-WAVE STACKED UP LOW CENTERED OVER THE CENTRAL
PLAINS. NORTHEAST MONTANA WILL STILL BE UNDER A WEAKENING INVERTED
SURFACE TROUGH WITH WRAP- AROUND LIGHT PRECIPITATION INTO MID-
WEEK.
MONDAY NIGHT THE SURFACE LOW WILL BE SOMEWHERE OVER SOUTH DAKOTA.
THIS WILL PULL COLDER AIR FROM CANADA SOUTH OVER NEMONT. THERE
WILL BE SOME 850MB TEMPERATURES BELOW 0C. THIS CAA COULD RESULT IN
SOME SNOW MIXING IN WITH THE RAIN. BUT QPF BY THEN WILL BE
LIMITED...SO NOT EXPECTING MUCH IN THE WAY OF ACCUMULATION.
A BLOCKING PATTERN FARTHER EAST WILL PREVENT THE LARGE TROUGH
FROM MOVING EAST TOO QUICKLY. AN AMPLIFIED RIDGE BUILDS UP WEST OF
THE ROCKY MOUNTAINS BUT DOES NOT ADVANCE MUCH...KEEPING NORTHEAST
MONTANA UNDER THE INFLUENCE OF THE TROUGH AND KEEPING TEMPERATURE
SEASONAL OR ON THE COOL SIDE AT LEAST THROUGH MID-WEEK. THE
TRANSITION FROM THE INFLUENCE OF THE COOLER LOW AND THE WARMER
RIDGE IS HARD TO DETERMINE. EXACTLY WHEN THE STATIONARY BOUNDARY
BETWEEN THE COMPETING AIR MASSES WILL SHIFT EAST OF NORTHEAST
MONTANA IS NOT CERTAIN WITHIN A COUPLE OF PERIODS. BUT AFTER MID-
WEEK THE BOUNDARY COULD BE FAR ENOUGH EAST FOR TEMPERATURES TO
ONCE AGAIN RISE ABOVE NORMAL. THE HIGH PRESSURE CONDITIONS WILL
ALSO DRY THINGS OUT.
TOWARDS THE END OF THE EXTENDED PERIOD THE GFS AND EC HAVE
DIFFERENT IDEAS AS TO HOW THE PATTERN WILL PLAY OUT. BUT BOTH
MODELS HINT AS COOLER AND WETTER CONDITIONS MOVING IN BY THE
WEEKEND. SCT
&&
.AVIATION...
SYNOPSIS: THE LARGE AND POWERFUL SPRING STORM SYSTEM...SPREADING
MULTIPLE PERIODS OF SHOWERS AND DRY SLOTS ACROSS MOST OF THE
INTER-MOUNTAIN WEST AND ADJACENT HIGH PLAINS REGIONS WILL
CONTINUE TO DO SO WELL THROUGH THE END OF THIS TAF CYCLE.
FLIGHT CATEGORY: VFR TODAY THROUGH EARLY THIS AFTERNOON. ISOLATED
MVFR WILL BE POSSIBLE WITH SOME VICINITY THUNDERSTORMS LATER THIS
AFTERNOON INTO EARLY THIS EVENING. EXPECT WIDESPREAD IFR TO
BORDERLINE LIFR TO LOCK INTO ALL TAF SITES AFTER MIDNIGHT TONIGHT.
SKY/WEATHER: WITH SKIES CLEARING IN PART TODAY TO ALLOW SOME
HEATING OF THE MOIST SURFACE LAYER...A FEW VICINITY THUNDERSTORMS
WILL BE POSSIBLE DURING THE LATE AFTERNOON AND EVENING
HOURS...ESPECIALLY FROM KGDV TOWARD KOLF. AFTER
MIDNIGHT...CEILINGS WILL LOWER DRASTICALLY AND WIDESPREAD MODERATE
TO HEAVY RAIN WILL SETTLE IN FOR ALL TAF SITES TOWARD THE END OF AND
WELL BEYOND THIS TAF PERIOD.
WIND: GENERALLY FROM THE EAST 20-30 MPH MID DAY...INCREASING 30-40
MPH THIS AFTERNOON...THEN DIMINISHING BACK TO 15-25 WITH THE
ONSET OF HEAVY RAIN LATE TONIGHT. EXPECT CROSSWIND HAZARDS FOR
NORTH-TO-SOUTH ORIENTED RUNWAYS.
BMICKELSON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 6 AM MDT SUNDAY FOR FORT PECK LAKE FOR
CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY...
GARFIELD...MCCONE...PETROLEUM.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
400 PM CDT SAT APR 26 2014
.SYNOPSIS...
ISSUED AT 358 PM CDT SAT APR 26 2014
AT 19Z...WATER VAPOR IMAGERY SHOWED A DEEP UPPER LEVEL TROUGH
ACROSS THE WESTERN CONUS...WITH A STRONG PV ANOMALY AT THE BASE OF
THE TROUGH OVER WESTERN ARIZONA. UPPER LEVEL ANALYSIS FROM 12Z
SHOWED 100+KT JET ROUNDING THE BASE OF THE TROUGH. DOWNSTREAM OF
THE TROUGH...THE RIDGE AXIS WAS FROM THE LOWER MISSISSIPPI RIVER
VALLEY...INTO THE NORTHERN PLAINS AND UP INTO THE WESTERN
NORTHWEST TERRITORIES IN CANADA. AT THE SURFACE...LOW PRESSURE WAS
OVER NORTHERN COLORADO WITH A WARM FRONT EXTENDING ACROSS NORTHERN
KANSAS. SOUTH OF THE WARM FRONT TEMPERATURES HAD WARMED INTO THE
UPPER 80S AND LOW 90S ALONG WITH BREEZY SOUTHERLY WINDS AND A GOOD
DRYLINE FROM EAST OF KHLC INTO THE OKLAHOMA PANHANDLE. TO THE
NORTH OF THE FRONT 70S AND LOW 80S WERE OBSERVED WITH SOUTHEAST
WINDS. FURTHER NORTH...A STATIONARY FRONT WAS LOCATED FROM WESTERN
SOUTH DAKOTA INTO EAST CENTRAL NEBRASKA WITH A SLIGHT WIND SHIFT
BEING DEFINED IN THE SURFACE FIELD. WINDS NORTH OF THE FRONT WERE
QUITE STRONG...WITH GUSTS OF 35KTS TO 50KTS ACROSS SOUTH DAKOTA.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 358 PM CDT SAT APR 26 2014
THE UPPER LEVEL TROUGH WILL LIFT INTO SOUTHEAST COLORADO BY 12Z
SUNDAY. MEANWHILE...THE WARM FRONT WILL LIFT NORTH THIS EVENING AS
THE SURFACE LOW SLOWLY MIGRATES EAST INTO SOUTHWEST NEBRASKA.
CURRENTLY...THE AREA IS IN THE DRY SLOT OF THE MID LEVEL FLOW AS CAN
BE SEEN FROM WATER VAPOR AS THE FETCH OF DRY AIR COMES ALL THE WAY
INTO NEBRASKA FROM THE BASE OF THE TROUGH. THE MAIN AREA OF MOISTURE
IS BEING PUSHED INTO KANSAS AND EASTERN NEBRASKA AS CAN BE SEEN BY
MID LEVEL CLOUD COVER. THIS DRY AIR WILL KEEP ANY SHOWERS/STORMS
FROM DEVELOPING NORTH OF THE WARM FRONT YET THIS AFTERNOON. AS THE
FRONT MOVES NORTH THE AREA THIS EVENING...MODELS SHOW THE WARM
SECTOR STAYING CAPPED AT LEAST UNTIL 00Z AND MUCH OF THE LOCAL AREA
STAYING CAPPED UNTIL AFTER 06Z. THE LATEST HRRR FROM 26.18Z DOES
SHOW A FEW STORMS DEVELOPING OVER EASTERN NEBRASKA AROUND 00Z. BUT
WITH THE MID LEVEL FLOW...ANYTHING THAT DEVELOPS WILL MOVE QUICKLY
NORTHEAST. IF THE FORECAST AREA WILL SEE ANY STORMS TONIGHT...WILL
NEED STORMS TO DEVELOP LOCALLY. DIDN/T REMOVE CHANCES COMPLETELY
OVERNIGHT...BUT CONFIDENCE IS NOT HIGH ON STORM DEVELOPMENT. IF
STORMS WOULD DEVELOP THIS EVENING ALONG THE WARM FRONT...SEVERE
PARAMETERS DO INDICATE THERE WOULD BE POTENTIAL FOR A FEW ORGANIZED
SUPERCELLS. AND WITH GOOD LOW LEVEL HELICITY...CAN/T COMPLETELY RULE
OUT A BRIEF ISOLATED TORNADO. HOWEVER...EVEN THOUGH SOUTHEAST AND
EASTERLY WINDS ALONG THE WARM FRONT WILL CONTINUE TO PULL MOISTURE
INTO NORTH CENTRAL NEBRASKA THIS EVENING AND OVERNIGHT.
HOWEVER...THINK SOME OF THE MODELS MAY BE A BIT ROBUST GETTING MID
TO UPPER 50 DEWPOINTS IN THESE AREAS. THE LACK OF LOW LEVEL MOISTURE
WOULD VERY LIKELY PROHIBIT ANY STORMS PRODUCING TORNADOS.
FOR SUNDAY...THE MODELS ARE FINALLY COMING INTO AGREEMENT ON THE
TRACK OF THE SYSTEM AS THEY BRING THE 500MB LOW INTO WESTERN
NEBRASKA. THERE DOES REMAIN SOME DIFFERENCES THOUGH IN THE WEST TO
EAST EXTENT AND ALTHOUGH IT IS NOT MUCH IT HAS A HIGH IMPACT ON THE
WEATHER FOR SUNDAY AND SUNDAY NIGHT. FORECAST CONFIDENCE HAS
IMPROVED...YET THERE ARE STILL CONSIDERABLE QUESTIONS. WITH THE
SURFACE LOW NOW LOOKING MORE LIKELY TO TRACK JUST NORTH OF THE
NEBRASKA-KANSAS BORDER SUNDAY AND CENTERED IN THE KLBF/KMCK AREA AT
00Z PRECIPITATION CHANCES WILL INCREASE THROUGH THE DAY...MAINLY ON
THE NORTHERN AND WESTERN PERIPHERIES OF THE LOW. SO DID INCREASE
CHANCES ACROSS NORTHERN NEBRASKA AND THE PANHANDLE. ON THE BACK SIDE
OF THE LOW...WINDS WILL STRENGTHEN CONSIDERABLY BY LATE AFTERNOON.
CURRENT FORECAST FOLLOWS A SLOWER EASTERLY PROGRESSION OF THE
SURFACE LOW WHICH KEEPS THE WINDS FROM INCREASING UNTIL AFTER 00Z.
HOWEVER QUICKER MOVEMENT COULD MEAN STRONG WINDS OF 30KTS SUSTAINED
EARLIER. WILL LET ONE MORE FORECAST CYCLE GO TO ALLOW MODELS TO COME
INTO BETTER AGREEMENT BEFORE DECIDING ON ANY HEADLINES FOR WINDS DUE
TO SOME UNCERTAINTY.
IN TERMS OF THUNDERSTORMS FOR SUNDAY...INSTABILITY ISN/T TERRIBLY
HIGH...WITH MUCAPE VALUES OF 100J/KG TO 1500 J/KG...BUT WITH STEEP
LOW LEVEL LAPSE RATES AND SUFFICIENT SHEAR CAN/T DISCOUNT ANY STORMS
AS WELL AS ANY STORMS BECOMING SEVERE. THE PRIMARY AREAS OF CONCERN
WILL BE OVER NORTH CENTRAL NEBRASKA /EAST OF HIGHWAY 183/ WHERE
THERE WILL BE MORE MOISTURE. SOMETHING TO CONSIDER WATCHING THROUGH
THE DAY WILL BE IF ANY CONVECTION GOES UP ON THE WESTERN EDGE OF THE
SURFACE LOW AND THE INVERTED TROUGH ACROSS THE WESTERN SANDHILLS.
THERE IS ONLY LOW INSTABILITY BUT WITH LOW LEVEL TURNING IN THE
VICINITY OF THE BOUNDARY...COULD CAUSE ANY CONVECTION TO SPIN.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 358 PM CDT SAT APR 26 2014
MID RANGE...SUNDAY NIGHT THROUGH TUESDAY...A PERSISTENT...SLOW
MOVING UPPER LEVEL LOW...WILL MEANDER FROM SOUTHWESTERN TO
NORTHEASTERN NEBRASKA DURING THE PERIOD...EVENTUALLY MOVING EAST OF
THE STATE TUESDAY NIGHT. A PLETHORA OF WEATHER WILL OCCUR ON THE
BACK SIDE OF THIS FEATURE AS IT MIGRATES ACROSS WESTERN AND NORTH
CENTRAL NEBRASKA SUNDAY NIGHT INTO TUESDAY AND THIS WILL BE THE
MAIN FORECASTING CHALLENGE FOR THE BEGINNING OF THE
WEEK.
SUNDAY NIGHT INTO MONDAY...FOR THESE PERIODS...THE THREAT FOR WINTRY
WEATHER IN THE NORTHWEST SUNDAY NIGHT THEN WIND POTENTIAL SUNDAY
NIGHT INTO MONDAY ARE THE MAIN FORECAST CONCERNS. SUNDAY NIGHT INTO
MONDAY...AN INTENSE UPPER LEVEL LOW AND STRONG SURFACE LOW...WILL
MEANDER SLOWLY ACROSS NEBRASKA. ON THE BACK SIDE OF THIS FEATURE
SUNDAY NIGHT INTO MONDAY...A NICE DEFORMATION BAND OF PCPN IS
EXPECTED TO DEVELOP ALONG WITH STRONG WINDS WHICH WILL TRANSITION
FROM WEST TO EAST SUNDAY NIGHT INTO MONDAY. HOW FAR EAST THE STRONG
WINDS DEVELOP SUNDAY NIGHT INTO MONDAY IS STILL UP IN THE AIR SOME.
MORE ON THAT TWO PARAGRAPHS BELOW.
EVEN AT ONLY 36 TO 48 HOURS OUT...THE LATEST NAM...GFS
AND ECMWF SOLNS ARE STILL HAVING ISSUES WITH THE TRACK OF THE H5 LOW
AND TRACK OF THE SURFACE LOW. THE NAM LIFTS THE H5 LOW FROM AROUND
ARNOLD NEBRASKA TO NORTH OF ONEILL NEBRASKA FROM 00Z TO 12Z MONDAY.
THE GFS LIFTS THE LOW FROM FAR EASTERN FRONTIER COUNTY TO NEAR
SPRINGVIEW NEBRASKA DURING THE SAME PERIOD...WHILE THE ECMWF LIFTS
THE LOW FROM WESTERN LINCOLN COUNTY TO NEAR VALENTINE. NO
SURPRISE...THE NAM IS COLDEST AT H85 WITH SUB FREEZING TEMPS IN THE
NORTHWESTERN FORECAST AREA OVERNIGHT SUNDAY NIGHT...WHICH WOULD
FAVOR SNOW FOR PRECIPITATION TYPE. THE GFS AND ECMWF ARE
CONSIDERABLY WARMER WITH H85 TEMPS OF 2 TO 3 C AT 12Z MONDAY
MORNING...FAVORING ALL RAIN OR POSSIBLE RAIN SNOW MIX. ATTM...WILL
GO WITH A RAIN/SNOW MIX FOR PTYPE OVERNIGHT SUNDAY NIGHT IN THE FAR
NORTHWEST GIVEN THE TRACK DIFFERENCES IN THE UPPER LEVEL SYSTEM.
ATTM...WITH TEMPERATURES HOVERING IN THE MIDDLE 30S SUNDAY NIGHT IN
THE FAR NORTHWEST...NOT EXPECTING ANY ACCUMS ATTM.
THEN THERE IS THE WIND THREAT ON THE BACK SIDE OF THE EXITING
SYSTEM. FOR SUNDAY NIGHT...THE ECMWF AND GFS SOLNS ARE IN GENERAL
AGREEMENT WITH LOCATION OF THE SURFACE LOW AT 12Z MONDAY...IE OVER
THE FAR NERN CWA...WHILE THE NAM12 HAS THE LOW NEAR SIOUX CITY IOWA.
NO SURPRISE...THERE ARE SIGNIFICANT DIFFERENCES IN WIND SPEEDS
BETWEEN THE MET AND MAV GUIDANCE FOR SUNDAY NIGHT. IF THE MET
VERIFIES...WE WOULD PROBABLY NEED SOME SORT OF WIND HEADLINE FOR AT
LEAST THE WESTERN HALF OF THE FORECAST AREA SUNDAY NIGHT. WITH THE
GFS SOLN...ANY WIND ADVISORY IF NEEDED WOULD BE CONFINED TO THE FAR
SOUTHWESTERN AND EASTERN PANHANDLE COUNTIES. THIS LEADS TO THE
HEADLINE DILEMMA FOR SUNDAY NIGHT...WINTER HEADLINES IN THE NERN
PANHANDLE OR WIND HEADLINES. GIVEN THE DISCREPANCIES IN THE LOCATION
OF THE SURFACE LOW AND UPPER LEVEL LOW...WILL HOLD OFF ON HEADLINES
FOR SUNDAY NIGHT AND WAIT FOR ANOTHER MODEL RUN TO COME IN.
ON MONDAY...THE SURFACE LOW WILL MIGRATE EAST OF THE UPPER LEVEL LOW
INTO EASTERN NEBRASKA. AT THE SAME TIME...A DOWNSTREAM BLOCKING
RIDGE WILL LIMIT ANY EWD MOVEMENT OF THE H5 LOW...WHICH WILL REMAIN
IN PLACE ACROSS CENTRAL NEBRASKA. WRAP AROUND PCPN WILL CONTINUE
PARTICULARLY OVER NORTH CENTRAL AND NORTHWESTERN NEBRASKA AS
FAVORABLE ISENTROPIC LIFT CONTINUES. IN ADDITION TO COLD RAIN...VERY
WINDY CONDITIONS WILL DEVELOP ESPECIALLY ACROSS THE WESTERN 2/3RDS
OF THE FORECAST AREA. AGAIN...LIKE SUNDAY NIGHT...WIND SPEEDS WILL
BE HIGHLY DEPENDENT ON WHERE THE SURFACE LOW SETS UP ON MONDAY
AFTERNOON. BETTER CONFIDENCE EXISTS IN THE WIND FORECAST FOR MONDAY
AS THE MODELS HAVE THE SURFACE LOW OVER NERN NEBRASKA BY 00Z
TUESDAY.
MONDAY NIGHT AND TUESDAY...FROM MONDAY NIGHT INTO TUESDAY
AFTERNOON...THE UPPER LEVEL LOW WILL CRAWL SLOWLY EAST INTO THE MID
MISSISSIPPI VALLEY. ON MONDAY NIGHT...A STRONG SHORTWAVE WILL ROTATE
AROUND THE WESTERN PERIPHERY OF THE CLOSED LOW BRINGING ANOTHER SHOT
OF RAIN AND OR SNOW SHOWERS TO THE FORECAST AREA. THE LATEST ECMWF
AND GFS SOLNS ARE INDICATING ENOUGH COLD AIR FOR AT LEAST A RAIN
SNOW MIX OVERNIGHT MONDAY NIGHT INTO TUESDAY MORNING ACROSS PORTIONS
OF NORTH CENTRAL NEBRASKA AND WILL INSERT THIS IN THE UPDATED
FORECAST. WINDS WILL BE AN ISSUE ONCE AGAIN ON TUESDAY 40+ KT H85
WINDS WILL BE PRESENT ACROSS WESTERN AND NORTH CENTRAL NEBRASKA.
TEMPERATURES TUESDAY WILL BE COOLER AS WELL AND IS SHAPING UP TO BE
THE COOLEST DAY OF THE PERIOD ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA AS H85 TEMPS DROP DOWN TO -2C TO 5C. ACROSS NORTH CENTRAL
NEBRASKA...TEMPERATURES WILL BE COOL ENOUGH TO FACILITATE AT LEAST A
RAIN SNOW MIX TROUGH THE MORNING HOURS AND WILL INCLUDE THIS MENTION
IN THE FORECAST.
TUESDAY NIGHT AND BEYOND...UPPER LOW PRESSURE WILL MEANDER OVER
EASTERN IOWA BEFORE LIFTING INTO THE WESTERN GREAT LAKES ON THURSDAY
INTO THURSDAY NIGHT. THE THREAT FOR LIGHT PRECIPITATION WILL
CONTINUE THROUGH THURSDAY WITH A LIMITED CHANCE FOR RAIN OR SNOW
OVER NORTHERN NEBRASKA DURING THE OVERNIGHT AND EARLY MORNING HOURS.
WILL KEEP POPS SLIGHT AS MOISTURE WILL BE FAIRLY LIMITED AS WE HEAD
INTO THE MIDDLE AND END OF THE WEEK. TEMPERATURES WILL SLOWLY
MODERATE INTO THE 50S FOR WEDNESDAY AND THURSDAY...APPROACHING THE
LOWER 60S FOR FRIDAY AND SATURDAY AS THE UPPER LEVEL LOW IS ABSORBED
BY THE NRN STREAM AND LIFTED INTO EASTERN CANADA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 127 PM CDT SAT APR 26 2014
A SURFACE LOW OVER NORTHEAST COLORADO WILL SLOWLY MOVE EASTWARD
THROUGH SUNDAY AFTERNOON. AS THIS OCCURS...BREEZY SOUTHEAST TO
EASTERLY WINDS WILL OCCUR FOR MUCH OF THE NIGHT HOURS FOR PORTIONS
OF CENTRAL INTO NORTH CENTRAL NEBRASKA. TO THE WEST...LIGHTER
WINDS WILL BE OBSERVED IN THE REGION OF THE LOW...AND UP THROUGH
THE PANHANDLE. WINDS WILL INCREASE IN THE WESTERN AREAS SUNDAY
AFTERNOON AS THE LOW DRIFTS EAST. THERE WILL BE CHANCES FOR
THUNDERSTORMS LATER THIS EVENING AND OVERNIGHT...MAINLY ACROSS THE
PANHANDLE AND NORTH CENTRAL NEBRASKA.
&&
.FIRE WEATHER...
ISSUED AT 358 PM CDT SAT APR 26 2014
FIRE WEATHER CONCERNS WILL REMAIN HIGH THIS EVENING AS THE WARM
FRONT LIFTS NORTH TO KEEP DRY AND BREEZY CONDITIONS ACROSS FIRE ZONE
210. CONDITIONS WILL IMPROVE AROUND MID EVENING AS TEMPERATURES FALL
AND HUMIDITY STARTS TO RECOVER. TEMPERATURES WILL BE ON THE
DOWNSLIDE FOR THE NEXT WEEK AS A LARGE STORM SYSTEM SITS OVER THE
REGION. MUCH OF THE WEEK WILL SEE HIGHS IN THE 40S AND 50S...WITH
PERIODIC CHANCES FOR RAIN...AND EVEN A CHANCE FOR SNOW IN SOME
AREAS. HOWEVER...THIS SYSTEM WILL ALSO BRING AN EXTENDED PERIOD OF
STRONG WINDS. IT LOOKS LIKELY FOR STRONG WINDS OF 30 TO 40 MPH TO BE
POSSIBLE ALMOST DAILY IN PARTS OF THE AREA THROUGH THURSDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 10 PM CDT THIS EVENING FOR NEZ210.
&&
$$
SYNOPSIS...BROOKS
SHORT TERM...BROOKS
LONG TERM...CLB
AVIATION...BROOKS
FIRE WEATHER...BROOKS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
323 PM CDT SAT APR 26 2014
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 322 PM CDT SAT APR 26 2014
STORM SYSTEM IS DEEPENING AND BEGINNING TO AFFECT THE PLAINS.
SUBJECTIVE 12Z UPPER AIR ANALYSIS INDICATES DEEPENING 500MB TROUGH
IN THE WESTERN US...WITH 500MB HEIGHT FALLS UP TO 170M CENTERED IN
THE CA/NV/AZ BORDER REGION...AND WITH SOUTHWESTERLY UPPER-LEVEL FLOW
ACROSS THE CENTRAL US. 300MB JET UP TO 130KT WAS STILL ON THE WEST
SIDE OF THE TROUGH...WITH 105-115KT AROUND THE BASE AND TOWARD THE
EAST OF THE TROUGH AXIS. 850MB MOISTURE AT 12Z WAS FOCUSED IN TWO
SEPARATE AREAS...ONE RIGHT ALONG THE GULF COAST...AND FROM WEST TX
THROUGH OK INTO SOUTHWEST MO...WITH 850MB WINDS UP TO AROUND 50KT
TRANSPORTING MOISTURE NORTHWARD INTO THE CENTRAL PLAINS. WEAK 850MB
FRONT WAS NOTED FROM LOW IN NORTHERN WY/SOUTHERN MT THROUGH NEB INTO
NORTHERN MO. 700-500MB DELTA-T OF 20-24C WAS NOTED ACROSS THE
PLAINS...WITH THE HIGHEST VALUES ALONG THE HIGH PLAINS TOWARD
OK/WEST TX. SURFACE LOW AT 19Z WAS CENTERED IN NORTHEAST CO...WITH
WIND SHIFT WARM FRONT EXTENDING ACROSS NEB NEAR THE PLATTE RIVER
TOWARD WEST CENTRAL TO SOUTHEAST IA...AND WITH MOISTURE GRADIENT
NEAR THE KS/NE BORDER AS UPPER 50S DEWPOINTS HAD ADVANCED INTO
NORTHEAST TO CENTRAL KS.
MAIN FORECAST CONCERN IS VERY CONDITIONAL CONVECTIVE POTENTIAL THIS
EVENING...CONVECTION ON CWA MARGINS TONIGHT...AND MORE WIDESPREAD
CONVECTIVE POTENTIAL TOMORROW. RAP CONTINUES TO MIX OUT PROFILE
DEEPLY BY 23-00Z AND DEVELOP VERY HIGH-BASED CONVECTION...WHILE HRRR
HAS TRENDED FROM PRODUCING A CELL OR TWO THIS EVENING TO NEARLY
DRY...AND 12Z 4KM WRF KEPT THE AREA MAINLY DRY THROUGH TONIGHT.
MODELS THAT DO PRODUCE SOME CONVECTION LATER TONIGHT ARE DOING SO
JUST IN OUR NORTHEASTERNMOST CWA. HAVE KEPT A VERY LOW-CONFIDENCE
SMALL AREA OF POPS ADVANCING FROM SOUTHEAST NEB TO NEAR THE I-80
CORRIDOR IN THE EARLY EVENING...THEN SLIGHT CHANCES IN THE NORTHERN
CWA THE REST OF THE EVENING BEFORE FOCUSING ON THE NORTHEASTERNMOST
FRINGE FOR TONIGHT.
AS UPPER LOW EJECTS ACROSS THE ROCKIES TOWARD KS/NEB ON
SUNDAY...WITH INCREASING MOISTURE TRANSPORT INTO THE CENTRAL
PLAINS...SHOULD SEE CONVECTION DEVELOP BY MIDDAY IN EASTERN
NEB...SPREADING INTO WESTERN IA QUICKLY. WITH ABUNDANT SHEAR ACROSS
THE AREA...POTENTIAL FOR SEVERE WEATHER DOES EXIST FOR ANY
CONVECTION AS IT GETS GOING ACROSS THE AREA FROM MIDDAY THROUGH THE
AFTERNOON. ALSO...AM THINKING THAT THERE WILL BE ENOUGH OF A BREAK
IN CONVECTION TONIGHT THROUGH MUCH OF THE MORNING THAT AIRMASS WILL
HAVE TIME TO SUFFICIENTLY DESTABILIZE AT LEAST IN THE SOUTHERN HALF
OF THE CWA IF NOT ACROSS THE ENTIRE CWA. WITH SUCH STRONG UPPER-
LEVEL SUPPORT THOUGH...CONVECTION WILL BE QUITE WIDESPREAD...AND
THUS CONVECTIVE MODE/THREATS WILL BE MESSY AND COMPLICATED. WITH
VERY STRONG DEEP-LAYER SHEAR...ROTATING LARGE HAIL WILL BE A
THREAT...AS WELL AS POTENTIAL FOR DAMAGING WIND GUSTS. ENOUGH 0-1KM
SHEAR EXISTS FOR A TORNADO THREAT FOR STORMS IF THEY CAN STAND
ALONE...THOUGH WORTH NOTING THAT HODOGRAPHS ARE MORE STRAIGHT THAN
CURVED IN MOST MODEL SOLUTIONS. STORMS WILL MOVE FAIRLY RAPIDLY
TOWARD THE NORTH-NORTHEAST...AND AS THE SURFACE LOW PUSHES
EASTWARD...SHOULD EXIT THE CWA THROUGH THE LATE AFTERNOON TO EARLY
EVENING HOURS...LEAVING CWA IN DRY SLOT FOR THE REST OF THE NIGHT
AND THROUGH MUCH OF MONDAY.
ONCE UPPER LOW ADVANCES INTO NEB...IT IS PROGGED TO STALL THROUGH
MONDAY...THEN FILL AND DRIFT EASTWARD INTO IOWA ON TUESDAY.
PRECIPITATION WILL RETURN TO THE CWA IN THE WRAPAROUND AREA
BEGINNING LATE MONDAY...EXPANDING ACROSS THE CWA THROUGH MONDAY
NIGHT AND TUESDAY...WITH AT LEAST OCCASIONAL LIGHT PRECIPITATION
CONTINUING THROUGH THURSDAY AS CWA REMAINS IN COOL CYCLONIC FLOW
BEHIND THE UPPER LOW. REMOVED THUNDER MENTION FROM ANY
PRECIPITATION FROM MONDAY EVENING ONWARD...AS AIRMASS REALLY
STABILIZES ON THE COLD SIDE OF THE LOW. TEMPERATURES WILL BE MUCH
COOLER BEHIND THE LOW...WITH TEMPERATURES ON MONDAY DOWN INTO THE
50S AND LIKELY STRUGGLING TO EVEN REACH 50 ON TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 322 PM CDT SAT APR 26 2014
GENERALLY COOLER AND UNSETTLED WEATHER PATTERN WILL CONTINUE THROUGH
NEXT WEEKEND. HAVE KEPT SPECIFIC POP MENTIONS OUT OF MOST PERIODS
FOR NOW...BUT THINK THERE IS A DECENT CHANCE TO GET AT LEAST LIGHT
PRECIPITATION IN AT LEAST SOME PART OF THE CWA ON SOME PERIOD. FOR
NOW...HAVE INCREASED CLOUDS A BIT. ALSO KEPT TEMPERATURES ON THE
COOL SIDE...WITH TEMPERATURES CONTINUING IN THE 50S THROUGH THURSDAY
BEFORE POSSIBLY REBOUNDING INTO THE 60S IN AT LEAST PART OF THE AREA
BY FRIDAY OR SATURDAY.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1221 PM CDT SAT APR 26 2014
WILL LEAVE KOMA/KLNK TAF SITES DRY THROUGH THE PERIOD. ANY
TSRA DEVELOPMENT THIS AFTN/EVNG WOULD BE TO ISOLATED TO INCLUDE
AND AFTER THIS TIME THE ACTIVITY WILL LIKELY BE NORTH OF THE TAF
SITES. THERE IS AN INCREASE THREAT OF SHRA/TSRA SUN MORNING AT
THESE TAF SITES BUT TIMING AND COVERAGE CONCERNS PRECLUDE ANY
MENTION AT THIS TIME. FOR KOFK WE WILL INCLUDE SOME SHOWERS SUN
MORNING. OTHERWISE WE WILL SEEM MVFR CIGS MOVE INTO ALL TAFS AFTER
06Z TONIGHT AND MAY LOWER TO IFR AT KOFK BY SUN MORNING. WE WILL
ALSO LIKELY SEE SOME MVFR VISBY AS WELL WITH INCREASING MOISTURE.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MAYES
LONG TERM...MAYES
AVIATION...BOUSTEAD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1225 PM CDT SAT APR 26 2014
.UPDATE...
ISSUED AT 1102 AM CDT SAT APR 26 2014
THE 12Z UPPER AIR ANALYSIS AND MODELS DID LITTLE IN PROVIDING A
DECISIVE ANSWER AS TO THE THREAT OF SURFACED-BASED CONVECTIVE
INITIATION LATER THIS AFTERNOON. THE UPPER AIR ANALYSIS INDICATED
A WELL DEFINED EML EXTNG ACROSS THE PLAINS FROM THE DAKOTAS TO TX
WITH 700 TO 500 MB DELTA-T VALUES >20 C WITH KOMA/KTOP ON THE ERN
EDGE OF THIS CAPPING INVERSION AT 12Z. AT 500 MB THE MAIN STORM
SYSTEM WAS STILL IN SRN NV/CA ASSOCIATED WITH A 170 M HEIGHT FALL
AT LAS VEGAS. DOWNSTREAM HEIGHT FALLS WERE NOTED ACROSS THE HIGH
PLAINS FROM KRAP TO KDDC TO KAMA OF 10 TO 30 M. THE LOW-LEVEL
MOISTURE PROFILE AT 850 MB WAS STILL RATHER NARROW BUT DID SHOW AN
AXIS OF >+10 C FROM WRN OK INTO SW TX.
MODELS ARE INSISTENT THAT A STRONG AIRMASS ADJUSTMENT WILL TAKE
PLACE TODAY WITH THIS SRN PLAINS MOISTURE MOVING INTO SE NEB BY
LATE THIS AFTERNOON. ALTHOUGH THIS MAY BE OVERDONE TO SOME
DEGREE...COMPARISON OF THE 15Z OBS TO 3 HOUR FORECAST FROM THE NAM
INDICATES GOOD AGREEMENT. AS STRONG MIXING CONTINUES THROUGH THE
AFTERNOON WE EXPECT TO SEE A BIT MORE OF A GAP IN THE FORECAST AND
OBSERVED...BUT NEVERTHELESS LOWER TO MID 50S SHOULD MAKE IT INTO
NE KS/SE NEB BY LATE AFTERNOON. GIVEN THE SEASONABLY STEEP MID
TROPOSHERIC LAPSE RATES THIS WILL CREATE MLCAPE OF 1500-2000 J/KG
BY 00Z. MODELS...ESPECIALLY THE GFS...ADVERTISE THE 10-20 M HEIGHT
FALLS OVER-SPREADING ERN NEB THIS AFTERNOON. THIS...ALONG WITH THE
CWA RESIDING IN THE LEFT EXIT REGION OF THE 65 KT H3 JET SAMPLED
BY THE 12Z UPPER AIR ANALYSIS OVER WRN NEB/CO WILL AT LEAST CREATE
A LARGE-SCALE ENVIRONMENT ISN`T OVERALY DETRIMENTAL TO CONVECTION
INITIATION. POINT FORECAST SOUNDINGS FROM THE NAM CONT TO INSIST
THAT THE EML WILL HOLD AND NO SURFACE-BASED CONVECTION WILL OCCUR.
GIVEN THE MARGINAL MOISTURE AND LACK OF LARGE-SCALE ASCENT THIS
ISN`T OUT OF THE QUESTION. SOME OF THE HIGH-RES MODELS /I.E. HRRR-
RAP/ AS WELL AS THE OPERATIONAL GFS INDICATE THAT CI WILL OCCUR.
THE POINT FORECAST SOUNDINGS FROM THE RAP APPEAR TO OVER MIX THE
BOUNDARY LAYER LEADING TO A REDUCTION IN THE CAP THOUGH. HAVING
SAID ALL THIS WE WILL MAINTAIN SOME SCHC FOR SOME STORMS THIS
EVENING IN THE SOUTH...OTHERWISE IT STILL APPEARS THAT THE LOW-
LEVEL JET WILL INCREASE ACTIVITY IN THE NORTH LATE THIS EVENING.
IF STORMS DO DEVELOP 23-01Z IN THE SW ALL MODES OF SEVERE WEATHER
STILL APPEAR POSSIBLE OTHERWISE THE STORMS IN THE NORTH SHOULD
HAVE A MARGINAL HAIL THREAT.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 334 AM CDT SAT APR 26 2014
POTENTIAL FOR SEVERE THUNDERSTORMS THROUGH SUNDAY NIGHT REMAINS THE
PRIMARY FORECAST CHALLENGE.
SEVERAL BOUTS OF SEVERE STORMS ARE POSSIBLE TODAY AND SUNDAY IN
PARTS OF EASTERN NEBRASKA AND SOUTHWEST IOWA...BUT THERE IS STILL
WIDE VARIATION IN POSSIBLE SCENARIOS IN TIMING/LOCATION OF HIGHEST
PROBABILITIES. UPPER TROUGH MOVING THROUGH CENTRAL CALIFORNIA THIS
MORNING WILL MOVE THROUGH THE ROCKIES LATER TONIGHT AND EMERGE IN
THE HIGH PLAINS SUNDAY AS A CLOSED LOW...WITH SURFACE LOW POSITION
SETTING UP IN NORTHEAST QUADRANT OF UPPER LOW. NAM AND GFS ARE A
COUPLE HUNDRED MILES APART IN SURFACE LOW POSITION AT 18Z
SUNDAY...WITH ECMWF MORE IN LINE WITH NAM. HAVE FOLLOWED ECMWF MORE
CLOSELY THAN OTHER MODELS IN THIS REGARD.
SURFACE DEW POINTS ARE EXPECTED TO INCREASE INTO THE 50S LATER TODAY
AS PRESSURES FALL IN THE HIGH PLAINS UNDER INCREASING DIFFLUENT FLOW
ALOFT AHEAD OF UPPER WAVE. 50S DEW POINTS WERE SHOWING UP IN THE
TEXAS PANHANDLE THIS MORNING...IN LINE WITH 6-HOUR FORECASTS OF 00Z
MODELS...AND WILL ADVECT THROUGH KANSAS INTO SOUTHEAST NEBRASKA THIS
AFTERNOON. MEANWHILE SURFACE TEMPERATURES WILL CLIMB INTO THE LOWER
80S...YIELDING SURFACE-BASED CAPE VALUES CLOSE TO 1200 J/KG BY 00Z
IN SOUTHEAST NEBRASKA. HOWEVER FORECAST SOUNDINGS AND EXTRAPOLATION
OF WARM MID LEVEL AIR CURRENTLY IN WEST TEXAS AND NEW MEXICO SUGGEST
CAPPING WILL BE STRONG THROUGH THE AFTERNOON ACROSS ALL OF OUR AREA.
WHILE SOME MODEL SOLUTIONS POP A FEW SHOWERS/STORMS BY LATE
AFTERNOON...FEEL CAPPING WILL HOLD UNTIL LATER IN THE EVENING WHEN
LOW LEVEL JET KICKS IN. BROAD AREA OF MOST-UNSTABLE CAPE NEAR 2000
J/KG AS PER ECMWF WILL ADVECT NORTH FROM CENTRAL KANSAS INTO EASTERN
NEBRASKA BY 06Z. BULK SHEAR CLOSE TO 40KT WILL ALSO DEVELOP AS
STRONGER FLOW AND COOLER TEMPERATURES AT MID LEVELS SPREAD INTO THE
PLAINS. EXPECT CONVECTIVE INITIATION TO OCCUR IN SOUTH CENTRAL
NEBRASKA DURING THE EVENING AND SPREAD/DEVELOP EAST/NORTHEAST INTO
OUR AREA BY LATE EVENING. IF STORMS DO FIRE HERE...SURFACE WARM
FRONT WILL COME INTO PLAY...ENHANCING LOW LEVEL SHEAR/HELICITY FOR
AN ENHANCED RISK OF POTENTIAL TORNADIC STORMS...GENERALLY IN AREAS
FROM ALBION TO COLUMBUS TO LINCOLN AND SOUTHWEST.
A SECOND AREA OF INITIATION AROUND OR AFTER MIDNIGHT APPEARS LIKELY
ON NOSE OF LOW LEVEL JET RIDING UP AND OVER SURFACE FRONT...FOCUSING
ON AREAS FROM NORTHEAST NEBRASKA INTO WEST CENTRAL IOWA. THESE
STORMS WILL BE ELEVATED WITH CAPE NEAR 1500 J/KG AND SHEAR OF 40KT
TO WORK WITH...THUS LARGE HAIL WILL BE POSSIBLE.
BY SUNDAY MORNING...A MID LEVEL WAVE ROTATING NORTHEAST AROUND UPPER
LOW SPARKING CONVECTION IN KANSAS OVERNIGHT WILL SWING INTO EASTERN
NEBRASKA. EXPECT MORE STORMS TO INVADE SOUTHEAST NEBRASKA EARLY IN
THE DAY AND SPREAD NORTH THROUGH THE MORNING. INSTABILITY SHOULD BE
WANING DURING THE MORNING...BUT SHEAR INCREASING. SO DESPITE A
NORMAL LULL IN POTENTIAL SEVERE DURING THE MORNING
HOURS...COMBINATION OF SHEAR/INSTABILITY WILL STILL SUPPORT AT LEAST
SEVERE HAIL POTENTIAL IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA.
BY EARLY SUNDAY AFTERNOON...SURFACE DRYLINE IS FORECAST TO BE
APPROACHING OUR SOUTHWEST CWA AND ROTATING EAST/NORTHEAST TOWARD THE
MISSOURI RIVER BY LATE IN THE AFTERNOON OR EARLY EVENING. MORNING
CONVECTION WILL PLAY A ROLE IN RECOVERY OF ATMOSPHERE AHEAD OF THE
DRYLINE...WITH ECMWF SHOWING MOST-UNSTABLE CAPES DROPPING TO BELOW
1000 J/KG. BUT BULK SHEAR VALUES WILL STILL BE HIGH...AND ENHANCED
LOW LEVEL SHEAR NEAR WARM FRONT/DRYLINE TRIPLE POINT LOOKS TO SET UP
NEAR OR NORTH OF THE OMAHA METRO AREA BY 00Z. SO EXPECT EITHER A
STRENGTHENING OF ONGOING CONVECTION OR NEW CONVECTION SUNDAY
AFTERNOON IN AN ARC FROM NORTHEAST NEBRASKA INTO EAST CENTRAL
NEBRASKA AND SOUTHWEST IOWA...WITH WIND/HAIL PRIMARY SEVERE
POTENTIAL...AND A TORNADO POSSIBILITY NEAR WARM FRONT/DRYLINE
INTERSECTION NEAR/NORTH OF OMAHA AND SOUTHEAST THROUGH SOUTHWEST
IOWA.
THIS CONVECTION IS EXPECTED TO ROTATE NORTHEAST SUNDAY EVENING AND
SHOULD BE OUT OF OUR AREA SHORTLY AFTER MIDNIGHT. MEANWHILE UPPER
LOW WILL BE DRIFTING EAST SUNDAY NIGHT INTO MONDAY...BUT SHOULD
REMAIN WEST OF THE CWA. ECMWF KEEPS MOST OF OUR CWA DRY MONDAY...BUT
COLD POOL ALOFT WILL ENHANCE LAPSE RATES...SO WILL LIKELY SEE
SCATTERED SHOWERS/STORMS POPPING MONDAY AFTERNOON. SEVERE THREAT
THEN SHOULD BE MINIMAL.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 334 AM CDT SAT APR 26 2014
SPEED OF UPPER LOW DRIFTING THROUGH THE PLAINS WILL BE THE PRIMARY
CHALLENGE FOR NEXT WEEK...AND WILL BRING COOLER TEMPERATURES AND OFF-
AND-ON SHOWER CHANCES AT LEAST THROUGH THURSDAY. TUESDAY APPEARS TO
BE THE MOST LIKELY TIME OF WIDESPREAD SHOWERS AS UPPER LOW MOVES
INTO IOWA/MISSOURI AND SIGNIFICANT WAVE ROTATES AROUND THE LOW.
OTHERWISE WILL HAVE AT LEAST SMALL POPS EACH DAY/NIGHT THROUGH
THURSDAY. HIGH TEMPERATURES THROUGH THE WEEK WILL AVERAGE IN THE 50S
WITH A LITTLE WARMER WEATHER RETURNING FRIDAY AS UPPER LOW EXITS
EAST.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1221 PM CDT SAT APR 26 2014
WILL LEAVE KOMA/KLNK TAF SITES DRY THROUGH THE PERIOD. ANY
TSRA DEVELOPMENT THIS AFTN/EVNG WOULD BE TO ISOLATED TO INCLUDE
AND AFTER THIS TIME THE ACTIVITY WILL LIKELY BE NORTH OF THE TAF
SITES. THERE IS AN INCREASE THREAT OF SHRA/TSRA SUN MORNING AT
THESE TAF SITES BY TIMING AND COVERAGE CONCERNS PRECLUDE ANY
MENTION AT THIS TIME. FOR KOFK WE WILL INCLUDE SOME SHOWERS SUN
MORNING. OTHERWISE WE WILL SEEM MVFR CIGS MOVE INTO ALL TAFS AFTER
06Z TONIGHT AND MAY LOWER TO IFR AT KOFK BY SUN MORNING. WE WILL
ALSO LIKELY SEE SOME MVFR VISBY AS WELL WITH INCREASING MOISTURE.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...BOUSTEAD
SHORT TERM...DERGAN
LONG TERM...DERGAN
AVIATION...BOUSTEAD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1125 AM CDT SAT APR 26 2014
.UPDATE...
ISSUED AT 1102 AM CDT SAT APR 26 2014
THE 12Z UPPER AIR ANALYSIS AND MODELS DID LITTLE IN PROVIDING A
DECISIVE ANSWER AS TO THE THREAT OF SURFACED-BASED CONVECTIVE
INITIATION LATER THIS AFTERNOON. THE UPPER AIR ANALYSIS INDICATED
A WELL DEFINED EML EXTNG ACROSS THE PLAINS FROM THE DAKOTAS TO TX
WITH 700 TO 500 MB DELTA-T VALUES >20 C WITH KOMA/KTOP ON THE ERN
EDGE OF THIS CAPPING INVERSION AT 12Z. AT 500 MB THE MAIN STORM
SYSTEM WAS STILL IN SRN NV/CA ASSOCIATED WITH A 170 M HEIGHT FALL
AT LAS VEGAS. DOWNSTREAM HEIGHT FALLS WERE NOTED ACROSS THE HIGH
PLAINS FROM KRAP TO KDDC TO KAMA OF 10 TO 30 M. THE LOW-LEVEL
MOISTURE PROFILE AT 850 MB WAS STILL RATHER NARROW BUT DID SHOW AN
AXIS OF >+10 C FROM WRN OK INTO SW TX.
MODELS ARE INSISTENT THAT A STRONG AIRMASS ADJUSTMENT WILL TAKE
PLACE TODAY WITH THIS SRN PLAINS MOISTURE MOVING INTO SE NEB BY
LATE THIS AFTERNOON. ALTHOUGH THIS MAY BE OVERDONE TO SOME
DEGREE...COMPARISON OF THE 15Z OBS TO 3 HOUR FORECAST FROM THE NAM
INDICATES GOOD AGREEMENT. AS STRONG MIXING CONTINUES THROUGH THE
AFTERNOON WE EXPECT TO SEE A BIT MORE OF A GAP IN THE FORECAST AND
OBSERVED...BUT NEVERTHELESS LOWER TO MID 50S SHOULD MAKE IT INTO
NE KS/SE NEB BY LATE AFTERNOON. GIVEN THE SEASONABLY STEEP MID
TROPOSHERIC LAPSE RATES THIS WILL CREATE MLCAPE OF 1500-2000 J/KG
BY 00Z. MODELS...ESPECIALLY THE GFS...ADVERTISE THE 10-20 M HEIGHT
FALLS OVER-SPREADING ERN NEB THIS AFTERNOON. THIS...ALONG WITH THE
CWA RESIDING IN THE LEFT EXIT REGION OF THE 65 KT H3 JET SAMPLED
BY THE 12Z UPPER AIR ANALYSIS OVER WRN NEB/CO WILL AT LEAST CREATE
A LARGE-SCALE ENVIRONMENT ISN`T OVERALY DETRIMENTAL TO CONVECTION
INITIATION. POINT FORECAST SOUNDINGS FROM THE NAM CONT TO INSIST
THAT THE EML WILL HOLD AND NO SURFACE-BASED CONVECTION WILL OCCUR.
GIVEN THE MARGINAL MOISTURE AND LACK OF LARGE-SCALE ASCENT THIS
ISN`T OUT OF THE QUESTION. SOME OF THE HIGH-RES MODELS /I.E. HRRR-
RAP/ AS WELL AS THE OPERATIONAL GFS INDICATE THAT CI WILL OCCUR.
THE POINT FORECAST SOUNDINGS FROM THE RAP APPEAR TO OVER MIX THE
BOUNDARY LAYER LEADING TO A REDUCTION IN THE CAP THOUGH. HAVING
SAID ALL THIS WE WILL MAINTAIN SOME SCHC FOR SOME STORMS THIS
EVENING IN THE SOUTH...OTHERWISE IT STILL APPEARS THAT THE LOW-
LEVEL JET WILL INCREASE ACTIVITY IN THE NORTH LATE THIS EVENING.
IF STORMS DO DEVELOP 23-01Z IN THE SW ALL MODES OF SEVERE WEATHER
STILL APPEAR POSSIBLE OTHERWISE THE STORMS IN THE NORTH SHOULD
HAVE A MARGINAL HAIL THREAT.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 334 AM CDT SAT APR 26 2014
POTENTIAL FOR SEVERE THUNDERSTORMS THROUGH SUNDAY NIGHT REMAINS THE
PRIMARY FORECAST CHALLENGE.
SEVERAL BOUTS OF SEVERE STORMS ARE POSSIBLE TODAY AND SUNDAY IN
PARTS OF EASTERN NEBRASKA AND SOUTHWEST IOWA...BUT THERE IS STILL
WIDE VARIATION IN POSSIBLE SCENARIOS IN TIMING/LOCATION OF HIGHEST
PROBABILITIES. UPPER TROUGH MOVING THROUGH CENTRAL CALIFORNIA THIS
MORNING WILL MOVE THROUGH THE ROCKIES LATER TONIGHT AND EMERGE IN
THE HIGH PLAINS SUNDAY AS A CLOSED LOW...WITH SURFACE LOW POSITION
SETTING UP IN NORTHEAST QUADRANT OF UPPER LOW. NAM AND GFS ARE A
COUPLE HUNDRED MILES APART IN SURFACE LOW POSITION AT 18Z
SUNDAY...WITH ECMWF MORE IN LINE WITH NAM. HAVE FOLLOWED ECMWF MORE
CLOSELY THAN OTHER MODELS IN THIS REGARD.
SURFACE DEW POINTS ARE EXPECTED TO INCREASE INTO THE 50S LATER TODAY
AS PRESSURES FALL IN THE HIGH PLAINS UNDER INCREASING DIFFLUENT FLOW
ALOFT AHEAD OF UPPER WAVE. 50S DEW POINTS WERE SHOWING UP IN THE
TEXAS PANHANDLE THIS MORNING...IN LINE WITH 6-HOUR FORECASTS OF 00Z
MODELS...AND WILL ADVECT THROUGH KANSAS INTO SOUTHEAST NEBRASKA THIS
AFTERNOON. MEANWHILE SURFACE TEMPERATURES WILL CLIMB INTO THE LOWER
80S...YIELDING SURFACE-BASED CAPE VALUES CLOSE TO 1200 J/KG BY 00Z
IN SOUTHEAST NEBRASKA. HOWEVER FORECAST SOUNDINGS AND EXTRAPOLATION
OF WARM MID LEVEL AIR CURRENTLY IN WEST TEXAS AND NEW MEXICO SUGGEST
CAPPING WILL BE STRONG THROUGH THE AFTERNOON ACROSS ALL OF OUR AREA.
WHILE SOME MODEL SOLUTIONS POP A FEW SHOWERS/STORMS BY LATE
AFTERNOON...FEEL CAPPING WILL HOLD UNTIL LATER IN THE EVENING WHEN
LOW LEVEL JET KICKS IN. BROAD AREA OF MOST-UNSTABLE CAPE NEAR 2000
J/KG AS PER ECMWF WILL ADVECT NORTH FROM CENTRAL KANSAS INTO EASTERN
NEBRASKA BY 06Z. BULK SHEAR CLOSE TO 40KT WILL ALSO DEVELOP AS
STRONGER FLOW AND COOLER TEMPERATURES AT MID LEVELS SPREAD INTO THE
PLAINS. EXPECT CONVECTIVE INITIATION TO OCCUR IN SOUTH CENTRAL
NEBRASKA DURING THE EVENING AND SPREAD/DEVELOP EAST/NORTHEAST INTO
OUR AREA BY LATE EVENING. IF STORMS DO FIRE HERE...SURFACE WARM
FRONT WILL COME INTO PLAY...ENHANCING LOW LEVEL SHEAR/HELICITY FOR
AN ENHANCED RISK OF POTENTIAL TORNADIC STORMS...GENERALLY IN AREAS
FROM ALBION TO COLUMBUS TO LINCOLN AND SOUTHWEST.
A SECOND AREA OF INITIATION AROUND OR AFTER MIDNIGHT APPEARS LIKELY
ON NOSE OF LOW LEVEL JET RIDING UP AND OVER SURFACE FRONT...FOCUSING
ON AREAS FROM NORTHEAST NEBRASKA INTO WEST CENTRAL IOWA. THESE
STORMS WILL BE ELEVATED WITH CAPE NEAR 1500 J/KG AND SHEAR OF 40KT
TO WORK WITH...THUS LARGE HAIL WILL BE POSSIBLE.
BY SUNDAY MORNING...A MID LEVEL WAVE ROTATING NORTHEAST AROUND UPPER
LOW SPARKING CONVECTION IN KANSAS OVERNIGHT WILL SWING INTO EASTERN
NEBRASKA. EXPECT MORE STORMS TO INVADE SOUTHEAST NEBRASKA EARLY IN
THE DAY AND SPREAD NORTH THROUGH THE MORNING. INSTABILITY SHOULD BE
WANING DURING THE MORNING...BUT SHEAR INCREASING. SO DESPITE A
NORMAL LULL IN POTENTIAL SEVERE DURING THE MORNING
HOURS...COMBINATION OF SHEAR/INSTABILITY WILL STILL SUPPORT AT LEAST
SEVERE HAIL POTENTIAL IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA.
BY EARLY SUNDAY AFTERNOON...SURFACE DRYLINE IS FORECAST TO BE
APPROACHING OUR SOUTHWEST CWA AND ROTATING EAST/NORTHEAST TOWARD THE
MISSOURI RIVER BY LATE IN THE AFTERNOON OR EARLY EVENING. MORNING
CONVECTION WILL PLAY A ROLE IN RECOVERY OF ATMOSPHERE AHEAD OF THE
DRYLINE...WITH ECMWF SHOWING MOST-UNSTABLE CAPES DROPPING TO BELOW
1000 J/KG. BUT BULK SHEAR VALUES WILL STILL BE HIGH...AND ENHANCED
LOW LEVEL SHEAR NEAR WARM FRONT/DRYLINE TRIPLE POINT LOOKS TO SET UP
NEAR OR NORTH OF THE OMAHA METRO AREA BY 00Z. SO EXPECT EITHER A
STRENGTHENING OF ONGOING CONVECTION OR NEW CONVECTION SUNDAY
AFTERNOON IN AN ARC FROM NORTHEAST NEBRASKA INTO EAST CENTRAL
NEBRASKA AND SOUTHWEST IOWA...WITH WIND/HAIL PRIMARY SEVERE
POTENTIAL...AND A TORNADO POSSIBILITY NEAR WARM FRONT/DRYLINE
INTERSECTION NEAR/NORTH OF OMAHA AND SOUTHEAST THROUGH SOUTHWEST
IOWA.
THIS CONVECTION IS EXPECTED TO ROTATE NORTHEAST SUNDAY EVENING AND
SHOULD BE OUT OF OUR AREA SHORTLY AFTER MIDNIGHT. MEANWHILE UPPER
LOW WILL BE DRIFTING EAST SUNDAY NIGHT INTO MONDAY...BUT SHOULD
REMAIN WEST OF THE CWA. ECMWF KEEPS MOST OF OUR CWA DRY MONDAY...BUT
COLD POOL ALOFT WILL ENHANCE LAPSE RATES...SO WILL LIKELY SEE
SCATTERED SHOWERS/STORMS POPPING MONDAY AFTERNOON. SEVERE THREAT
THEN SHOULD BE MINIMAL.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 334 AM CDT SAT APR 26 2014
SPEED OF UPPER LOW DRIFTING THROUGH THE PLAINS WILL BE THE PRIMARY
CHALLENGE FOR NEXT WEEK...AND WILL BRING COOLER TEMPERATURES AND OFF-
AND-ON SHOWER CHANCES AT LEAST THROUGH THURSDAY. TUESDAY APPEARS TO
BE THE MOST LIKELY TIME OF WIDESPREAD SHOWERS AS UPPER LOW MOVES
INTO IOWA/MISSOURI AND SIGNIFICANT WAVE ROTATES AROUND THE LOW.
OTHERWISE WILL HAVE AT LEAST SMALL POPS EACH DAY/NIGHT THROUGH
THURSDAY. HIGH TEMPERATURES THROUGH THE WEEK WILL AVERAGE IN THE 50S
WITH A LITTLE WARMER WEATHER RETURNING FRIDAY AS UPPER LOW EXITS
EAST.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 608 AM CDT SAT APR 26 2014
VFR CONDITIONS ARE EXPECTED THROUGHOUT MUCH OF THE TAF CYCLE. THE
EXCEPTION WILL BE IN ANY TSTMS THAT DEVELOP. HAVE CONTINUED PROB30
GROUPS FOR ALL 3 SITES FROM THIS EVENING AND INTO EARLY SUNDAY
MORNING WHEN SCATTERED CONVECTION IS POSSIBLE. SOME SEVERE STORMS
ARE POSSIBLE. GUSTY SOUTHEAST WINDS OF 15 TO 20KTS WITH GUSTS TO
30KTS ARE LIKELY LATER THIS MORNING AND AFTERNOON.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...BOUSTEAD
SHORT TERM...DERGAN
LONG TERM...DERGAN
AVIATION...KERN
AREA FORECAST DISCUSSION
NWS ELKO NV
1124 AM PDT SAT APR 26 2014
.SYNOPSIS...LINGERING SHOWERS WILL CONTINUE ACROSS EASTERN NEVADA
TODAY BEHIND A STRONG LATE WINTER STORM. DRY WEATHER RETURNS
BRIEFLY SATURDAY NIGHT...FOLLOWED BY MORE SNOW SHOWERS ACROSS
NORTHERN NEVADA ON SUNDAY. DRIER AND WARMER WEATHER IS EXPECTED TO
RETURN NEXT WEEK.
&&
.UPDATE...LET WINTER WEATHER PRODUCTS EXPIRE AT 11 AM AS STORM
SYSTEM EXITING THE AREA WITH ONLY ISOLATED TO SCATTERED SNOW
SHOWERS OCCURRING AT THIS TIME ACROSS ERN NV WITH LITTLE OR NO
ADDITIONAL ACCUMULATION EXPECTED. ALSO REDUCED SHOWER COVERAGE
INTO THE ISOLATED TO SCATTERED CATEGORY.
&&
.PREV DISCUSSION... /ISSUED AT 815 AM /
SYNOPSIS...A STRONG LATE WINTER STORM WILL BRING WIDESPREAD RAIN
AND SNOW TO NEVADA THROUGH SATURDAY MORNING. DRY WEATHER RETURNS
BRIEFLY SATURDAY NIGHT...FOLLOWED BY MORE SNOW SHOWERS ACROSS
NORTHERN NEVADA ON SUNDAY. DRIER AND WARMER WEATHER IS EXPECTED TO
RETURN NEXT WEEK.
SHORT TERM...TODAY THROUGH MONDAY.
STRONG BUT PROGRESSIVE LATE WINTER/SPRING STORM SHAPING UP PRETTY
MUCH AS PLANNED THIS MORNING. NAM/GFS/HRRR GUIDANCE IN EXCELLENT
AGREEMENT THAT THE PEAK OF THIS WINTER WEATHER EVENT WILL OCCUR
EARLY THIS MORNING, A FEW HOURS EITHER SIDE OF SUNRISE, ALONG A
TONOPAH-EUREKA-NW WHITE PINE COUNTY-SE ELKO COUNTY LINE. HEAVY WET
SNOW WILL FALL IN THIS CORRIDOR FOR SEVERAL HOURS FROM NOW THROUGH
EARLY SATURDAY MORNING, WITH SEVERAL INCHES EXPECTED ESPECIALLY ON
ELEVATED/VEGETATED SURFACES. IMPACTS WILL BE VERY ELEVATION
DEPENDENT, TYPICAL OF LATE APRIL SNOWSTORMS, BUT PASSES AND
SUMMITS ABOVE 5500 FEET WILL BE SLUSH/SNOW COVERED AND TREACHEROUS
THIS MORNING. WILL ALLOW WINTER STORM WARNINGS TO CONTINUE AS
PLANNED. A WILDCARD IN REGARD TO SNOWFALL AMOUNTS IS CONVECTION.
LIGHTNING DETECTION AND IR SATELLITE CONTINUES TO INDICATE
THUNDERSTORMS ROTATING NORTHWARD INTO WHITE PINE COUNTY. SNOWFALL
RATES WILL BE ERRATIC AND BRIEFLY INTENSE IN THE WINTER STORM
WARNING AREA THIS MORNING. SINCE THE SNOW IS OCCURRING ON A
SATURDAY MORNING WITH NO SCHOOL AND LIMITED COMMUTING, IMPACTS
WILL BE LIMITED, BUT NONETHELESS THESE INTENSE SNOWFALL RATES WILL
LIKELY OVERCOME ANY WARM ROADWAYS AND MAKE TRAVEL DANGEROUS AT
TIMES UNTIL THE MID-MORNING HOURS.
REGARDING ELKO COUNTY...00Z NAM AND HRRR BOTH DEPICT A VERY TIGHT
PRECIPITATION GRADIENT, WITH NW ELKO COUNTY GETTING LITTLE TO NO
SNOW, AND HEAVY SNOW FALLING ON THE RUBY MOUNTAINS AND SE ELKO
COUNTY. SNOWFALL FROM 00Z NAM SHOWS THIS TIGHT GRADIENT AND
APPEARS VERY REASONABLE ON THE NW EDGE OF THE DEFORMATION BAND.
EXPECTING ABOUT 1/2 INCH AT ELKO PROPER, 2-4 INCHES IN SPRING
CREEK, AND NEAR 6 INCHES ADJACENT TO THE RUBY MOUNTAINS, SUCH AS
JIGGS, LEE, AND LAMOILLE. WILL ALSO KEEP THE WINTER WEATHER
ADVISORY GOING FOR ELEVATIONS ABOVE 5500 FEET FOR ELKO COUNTY
THROUGH 11 AM.
PRIMARY SURFACE LOW SW OF ELY EARLY THIS MORNING WILL RAPIDLY PULL
EASTWARD THROUGH UTAH THIS MORNING, AND BE IN WYOMING BY MIDDAY.
IN OTHER WORDS, SYSTEM IS QUITE PROGRESSIVE AND SNOW SHOWERS WILL
TAPER OFF QUICKLY AFTER NOON. ALSO, IMPACTS TO ROADWAYS WILL END
RAPIDLY AFTER 11 AM WITH THE LATE APRIL SUNSHINE, SO ALL WINTER
HEADLINES WILL EXPIRE AT THAT TIME. NW FLOW AND COLD AIR ALOFT IS
QUITE AGITATED THIS AFTERNOON, SO KEPT PLENTY OF SNOW/SNOW PELLET
SHOWERS MENTIONED THIS AFTERNOON, BUT AMOUNTS WILL BE LIGHT.
NW WINDS WILL BE STRONG AND GUSTY TODAY AS THE STORM SYSTEM
DEPARTS. NW WINDS WILL AVERAGE 20-30 MPH WITH HIGHER GUSTS.
BELIEVE WINDS WILL REMAIN BELOW ADVISORY CRITERIA, WITH THE
EXCEPTION OF NW NYE COUNTY/TONOPAH. WIND GUSTS OF 50-55 MPH APPEAR
LIKELY HERE TODAY, AND ISSUED A WIND ADVISORY FOR NW NYE COUNTY
FROM 5 AM THROUGH 5 PM.
A BRIEF BREAK OF DRY WEATHER TONIGHT, WITH LOWS NEAR FREEZING.
SUNDAY...FINAL SHORTWAVE SKIRTS THROUGH NORTHERN NEVADA IN THE
CHILLY NW FLOW. THIS SHOULD BE A PROLIFIC SNOW AND GRAUPEL SHOWER
PRODUCER SUNDAY AFTERNOON MAINLY ACROSS ELKO COUNTY. INCREASED
SHOWER COVERAGE IN THE GRIDS, BUT APPEARS TO BE A HIGH POP/LOW QPF
SITUATION IN WHICH AMOUNTS WILL BE INSIGNIFICANT. STILL,
VISIBILITY WILL BE SHARPLY REDUCED BY THESE PASSING CONVECTIVE
SNOW SHOWERS. 00Z GFS DEPICTS LIFTED INDEX LESS THAN ZERO ACROSS
ELKO COUNTY SUNDAY AFTERNOON, SO MENTIONED ISOLATED THUNDER AS WELL.
SUNDAY WILL BE A DECIDEDLY UNPLEASANT "SPRING" DAY IN NEVADA WITH
TEMPERATURES STUCK IN THE 40S MOST OF THE DAY, AND STRONG GUSTY
WEST WINDS OF 20-30 MPH MAKING IT FEEL EVEN COLDER THAN THAT.
SOME DECREASE IN CLOUDS SUNDAY NIGHT, ALLOWING FOR COLDER LOWS
MONDAY MORNING IN THE MID TO UPPER 20S.
MONDAY...DRY WEATHER RETURNS UNDER DRY NW FLOW. STILL QUITE
CHILLY, WITH TEMPERATURES RUNNING ABOUT 10 DEGREES BELOW LATE
APRIL NORMALS.
TURNER
LONG TERM...MONDAY NIGHT THROUGH FRIDAY. HIGH PRESSURE WILL BRING
DRY CONDITIONS TO THE GREAT BASIN WITH A WARMING TREND. THERE IS
GOOD MODEL AGREEMENT INDICATING THAT A PACIFIC RIDGE WILL STRONGLY
AMPLIFY NEXT WEEK AND PROGRESS EAST AT AN EXTREMELY SLOW RATE. THE
RIDGE AXIS WILL ONLY MOVE FROM OFF THE CALIFORNIA COAST MONDAY NIGHT
TO REPOSITION THROUGH NEVADA FRIDAY...AS THE DE-AMPLIFICATION
PROCESS BEGINS. LOW TEMPERATURES WILL GENERALLY FALL INTO THE 20S
MONDAY NIGHT...AND THE 30S THEREAFTER. HIGH TEMPERATURES WILL
GENERALLY BE IN THE 50S TUESDAY...RISE INTO THE 60S WEDNESDAY...THEN
INTO THE 70S IN MANY PLACES THURSDAY AND FRIDAY.
AVIATION...A MOISTURE-LADEN STORM SYSTEM WILL CONTINUE TO BRING
WIDESPREAD RAIN AND SNOW SHOWERS THROUGH SATURDAY MORNING PRODUCING
AREAS OF MVFR CONDITIONS. SHOWERS WILL TAPER OFF THIS EVENING AND
THERE MAY BE A BRIEF BREAK AFTER THIS STORM EXITS. HOWEVER ANOTHER
WAVE OF LOW PRESSURE WILL BRING MORE SHOWER ACTIVITY THROUGH SUNDAY
MORNING.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 5 PM PDT THIS AFTERNOON FOR NORTHWESTERN NYE
COUNTY.
&&
$$
91/99/92
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1131 AM CDT SAT APR 26 2014
.UPDATE...
ISSUED AT 1131 AM CDT SAT APR 26 2014
QUICK UPDATE TO ISSUE A WIND ADVISORY FOR THE SOUTHWEST AND PARTS
OF SOUTH CENTRAL THROUGH MUCH OF THIS EVENING. WINDS HAVE
INCREASED IN THE SOUTHWEST...AND WERE HIGHER THAN PREVIOUSLY
FORECAST. ALSO...LATEST GUIDANCE INDICATES STRONGER WINDS AND
PERSISTING INTO THE EVENING.
UPDATE ISSUED AT 940 AM CDT SAT APR 26 2014
NARROW BAND OF SHOWERS NOW HAD ADVANCED NORTHWARD TO
WILLISTON...MCLEAN COUNTY (NORTH OF LAKE SAKAKAWEA) TO BETWEEN
BISMARCK AND JAMESTOWN. THE BISMARCK AIRPORT RECORDED 0.07 INCHES
OF RAIN AS THE PRECIP BAND WENT THROUGH. THE BAND CONTINUES
LIFTING NORTHWARD AND EXPECT A FEW HUNDREDTHS OF AN INCH TO
PERHAPS A TENTH OF AN INCH OF RAIN MOST AREAS. ADJUSTED TIMING OF
PRECIPITATION ACCORDINGLY. BY EARLY AFTERNOON THE PRECIPITATION
BAND SHOULD BE MAINLY NORTH OF THE CANADIAN BORDER...WITH THE
SOUTHEASTERN PORTION DISSIPATING. OTHERWISE FORECAST ON TRACK -
MINOR HOURLY ADJUSTMENTS FOR WIND AND TEMPERATURES.
UPDATE ISSUED AT 642 AM CDT SAT APR 26 2014
NARROW BAND OF SHOWERS FROM WEST CENTRAL INTO SOUTH CENTRAL NORTH
DAKOTA CONTINUES TO LIFT NORTH THIS MORNING. ONLY SOME SLIGHT
MODIFICATIONS TO THE CURRENT HRRR POP PLACEMENT TODAY. ALSO BUMPED
UP SKY COVER THROUGH THE MORNING SOUTHWEST BASED ON LATEST
SATELLITE IMAGERY. OTHERWISE CURRENT FORECAST LOOKS TO BE IN GOOD
SHAPE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CDT SAT APR 26 2014
THE HIGHLIGHT OF THE SHORT TERM IS PRECIPITATION POTENTIAL.
FOR TODAY...THE HRRR HAS HAD A GOOD HANDLE ON THE NARROW BAND OF
RAIN SHOWERS MOVING INTO SOUTHWEST NORTH DAKOTA AS OF 0830 UTC
WITH THE LEADING SHORTWAVE. THUS...WILL FOLLOW THE 07 UTC HRRR AND
ITS PARENT RAP FOR POPS THIS MORNING AND INTO THE AFTERNOON. THESE
SOLUTIONS ARE IN AGREEMENT WITH THE 00 UTC 4 KM WRF AND LARGER
SCALE DETERMINISTIC GUIDANCE WHICH QUICKLY MOVE THE RAIN SHOWERS
TO THE INTERNATIONAL BORDER BY EARLY AFTERNOON. THUS...AFTER THE
NARROW BAND OF SHOWERS PASS...THE DAY SHOULD BE PRECIPITATION FREE
FOR NEARLY ALL OF THE CWA. IN REGARDS TO WINDS FOR
TODAY...EXPECT WIDESPREAD EAST-SOUTHEAST GUSTS OF 30-35 KTS FOR
MOST AREAS. HOWEVER...A LOW LEVEL INVERSION IN WARM AIR ADVECTION
WILL LIMIT THE TRANSFER OF HIGHER MOMENTUM AND FORGO THE NEED FOR
A WIND ADVISORY.
FOR TONIGHT...SURFACE LOW PRESSURE CONTINUES TO DEEPEN ACROSS
WESTERN NEBRASKA...AS THE OVERALL SYSTEM BECOMES NEARLY VERTICALLY
STACKED LATE TONIGHT AS THE POTENT UPPER LEVEL WAVE PROPAGATES
ONTO THE PLAINS. RESULTING MOISTURE TRANSPORT INCREASES ACROSS THE
NORTHERN PLAINS...WITH RAIN SHOWER COVERAGE INCREASING AFTER 06
UTC ACROSS WESTERN NORTH DAKOTA IN THE VICINITY OF THE INVERTED
TROUGH EXTENDING INTO EASTERN MONTANA...AND ACROSS SOUTHERN NORTH
DAKOTA IN LOW LEVEL WARM AIR ADVECTION. THE BULK OF ELEVATED
INSTABILITY TONIGHT REMAINS IN SOUTH DAKOTA...HOWEVER AN EMBEDDED
THUNDERSTORM IS POSSIBLE ACROSS FAR SOUTH CENTRAL NORTH DAKOTA .
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 329 AM CDT SAT APR 26 2014
THE MAIN FORECAST PROBLEM IN THE EXTENDED PERIOD WILL BE THE STRONG
SPRING STORM SYSTEM AFFECTING ALL OF WESTERN AND CENTRAL NORTH
DAKOTA. MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH THE TRACK OF
THE SURFACE AND UPPER LEVEL FEATURES THROUGH TUESDAY...WITH
DIFFERENCES INCREASING THEREAFTER. STILL SOME DIFFERENCES IN QPF
PATTERN THROUGH THE EVOLUTION OF THE SYSTEM WITH THE GFS BEING THE
DRIEST ACROSS PORTIONS OF CENTRAL AND EASTERN NORTH DAKOTA. ALL
MODELS HOWEVER ARE PINPOINTING THE FAR SOUTHWEST WITH SOME OF THE
HIGHEST RAINFALL AMOUNTS.
STRONG SHORTWAVE JUST MOVING ONTO THE SOUTHERN CALIFORNIA COAST WITH
AN UPPER LEVEL LOW CLOSING OFF JUST TO ITS NORTH. BROAD FETCH OF
MOISTURE IN SOUTHWEST UPPER FLOW INTO THE NORTHERN PLAINS...SETTING
THE STAGE FOR AN EXTENDED PERIOD OF RAINY WEATHER.
BY SUNDAY MORNING THE UPPER LOW IS PROGGED TO BE OVER EASTERN
COLORADO WITH A RAPIDLY DEEPENING SURFACE SYSTEM OVER THE CENTRAL
PLAINS. THE INITIAL SURGE OF ENERGY MOVES INTO THE AREA LATE TONIGHT
INTO SUNDAY MORNING. ALTHOUGH BEST ELEVATED INSTABILITY REMAINS JUST
TO OUR SOUTH...SYSTEM IS STRONG ENOUGH THAT A MENTION OF THUNDER
SEEMED WARRANTED SUNDAY MORNING. BEST PRECIPITATION CHANCES DURING
THE DAY WILL BE OVER THE SOUTHWEST HALF OF THE CWA...AND THERE MAY
BE PERIODS OF NO RAIN AS WELL AS DRIER AIR WRAPS AROUND THE STACKED
SYSTEM.
ANOTHER STRONG IMPULSE LIFTS THROUGH THE AREA SUNDAY NIGHT
AS THE UPPER LOW REACHES ITS FARTHEST POINT NORTH BEFORE WOBBLING
BACK SOUTH ON MONDAY. BY THIS TIME CHANCES OF CONVECTION WILL BE
MINIMAL AS COOLER AIR GETS PULLED INTO THE SYSTEM. THE FAR NORTH AND
HIGHER ELEVATIONS IN THE FAR WEST COULD SEE PERIODS OF SNOW LATE
SUNDAY NIGHT INTO EARLY MONDAY MORNING. LATEST MODEL RUNS ARE A
LITTLE COOLER IN THE WEST SO WILL NEED TO MONITOR FOR SOME LIGHT
ACCUMULATING SNOWS IN THE FAR WEST...BUT AT THIS TIME ITS TOO EARLY
FOR ANY MENTION OF ACCUMULATIONS.
PRECIPITATION BEGINS TO WANE ON MONDAY AS THE LOW DROPS SOUTH.
ALTHOUGH LOW LEVEL FORCING WILL BE ON THE DECREASE...SYNOPTIC SCALE
FORCING WILL REMAIN THROUGH TUESDAY AS WE REMAIN UNDER THE CYCLONIC
FLOW OF THE UPPER LEVEL LOW. THUS LIKELY POPS REMAIN MONDAY INTO
MONDAY NIGHT...WITH HIGH CHANCE POPS TUESDAY. AGAIN WE WILL SEE THE
POSSIBILITY OF SNOW MONDAY NIGHT INTO TUESDAY MORNING...AND LIGHT
ACCUMULATIONS ARE CERTAINLY NOT OUT OF THE QUESTION.
THE UPPER LOW LIFTS BACK NORTHWARD TUESDAY NIGHT INTO WEDNESDAY WITH
ANOTHER WAVE OF MOISTURE SWINGING EAST TO WEST ACROSS THE AREA ON
WEDNESDAY BRINGING A CHANCE OF RAIN OR SNOW SHOWERS. THE SYSTEM
FINALLY EXITS THE ARE LATE IN THE WORK WEEK...WITH ANOTHER IMPULSE
IN A NORTHWEST FLOW PATTERN POSSIBLE BY NEXT WEEKEND.
ALL IN ALL A WET AND COOL PERIOD IS IN STORE THROUGH MOST OF THE
EXTENDED PERIOD. WILL ISSUE A HYDROLOGIC STATEMENT MENTIONING THE
POSSIBILITY OF FLOODING DUE TO AN EXTENDED PERIOD OF RAIN. WPC
DEPICTS PORTIONS OF THE SOUTHWEST WITH A SLIGHT CHANCE OF EXCESSIVE
RAINFALL 12Z SUNDAY THROUGH 12Z MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 642 AM CDT SAT APR 26 2014
A NARROW BAND OF LIGHT RAIN SHOWERS HAS MOVED INTO WESTERN INTO
SOUTH CENTRAL NORTH DAKOTA AS OF 1130 UTC...AND WILL CONTINUE TO
MOVE NORTH-NORTHEAST THROUGH THE MORNING. RAIN SHOWER ACTIVITY IN
THE AFTERNOON IS EXPECTED TO LARGELY REMAIN NORTH OF KISN AND
KMOT. STRONG EAST-SOUTHEAST WINDS WITH GUSTS OF 30-35 KTS ARE
EXPECTED FOR MUCH OF THE AREA TODAY. A LARGE STORM SYSTEM WILL
BEGIN TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA SATURDAY
NIGHT...WITH CONDITIONS TRENDING TOWARDS MVFR/IFR IN STRATUS AND
RAIN.
&&
.HYDROLOGY...
ISSUED AT 353 AM CDT SAT APR 26 2014
ISSUED A HYDROLOGIC OUTLOOK...ESF...FOR WESTERN NORTH DAKOTA
REGARDING THE UPCOMING HEAVY RAIN EVENT AND POTENTIAL IMPACTS. AS
OF NOW...THE 00 UTC DETERMINISTIC SUITE REMAINS IN SOME
DISAGREEMENT ON THE PLACEMENT OF THE HEAVIEST QPF AXIS. THIS HAS
SIGNIFICANT IMPACTS IN BASIN HYDROLOGIC RESPONSE. FURTHERMORE...THE
REMOVAL OF FROST FROM THE GROUND AND RECENT DRY WEATHER PLACES
ADDITIONAL UNCERTAINTY IN HOW MUCH WATER THE SOILS WILL BE ABLE TO
HOLD. THAT SAID...RIVER AND STREAM RISES...POTENTIALLY ABOVE
FLOOD STAGE...ARE POSSIBLE. HOWEVER...WHICH SPECIFIC WATERWAYS
RESPOND THE MOST IS HIGHLY DEPENDENT ON QPF PLACEMENT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 10 PM CDT /9 PM MDT/ THIS EVENING FOR
NDZ017>020-031>035-040>047-050.
&&
$$
UPDATE...JV
SHORT TERM...AYD
LONG TERM...TWH
AVIATION...AYD
HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
413 PM EDT SAT APR 26 2014
.SYNOPSIS...
A WEAK COLD FRONT HAS SAGGED INTO CENTRAL OHIO AND INDIANA AS A
WEATHER SYSTEM SHIFTS THROUGH THE GREAT LAKES. THE FRONT WILL
STALL NEAR THE OHIO RIVER TONIGHT AS AN UPPER LEVEL RIDGE OF HIGH
PRESSURE BUILDS OVER THE FRONT AND BRINGS CONTINUED QUIET WEATHER
THROUGH SUNDAY. A LARGE...POTENT LOW PRESSURE SYSTEM WILL MOVE
SLOWLY OUT OF THE ROCKIES INTO THE HIGH PLAINS ON SUNDAY NIGHT AND
MONDAY ALLOWING THE STALLED BOUNDARY ALONG THE OHIO RIVER TO
RETURN NORTHWARD AS A WARM FRONT. WITH THIS PUSH OF SOUTHERLY
AIR...WARMTH AND MOISTURE AND WILL SPREAD NORTHWARD AND BRING
UNSETTLED WEATHER THROUGH THE FIRST HALF OF THE WORK WEEK...WITH
EPISODES OF SHOWERS AND THUNDERSTORMS ON TAP FROM LATE SUNDAY
NIGHT ALL THE WAY THROUGH WEDNESDAY. A COOLER AND STILL UNSETTLED
PATTERN WILL TAKE HOLD FOR THE END OF THE WORK WEEK AND INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AT 18Z...SURFACE ANALYSIS PLACES A RATHER WELL-DEFINED COLD FRONT
FROM NEAR PITTSBURGH TO COLUMBUS TO INDIANAPOLIS. A WARM AND
DEEPLY MIXED BOUNDARY LAYER EXISTS SOUTH OF THE FRONT ACROSS THE
LOCAL AREA WITH SCT CUMULUS BASED AROUND 7KFT AND TEMPS THAT HAVE
WARMED WELL INTO THE 70S...AND A DEWPOINT DROP INTO THE 40S. THE
FRONT IS ONLY WEAKLY CONVERGENT...AND MOST NWP SOLUTIONS ARE IN
GROSS ERROR WITH THE AMOUNT OF MOISTURE IN THE BOUNDARY LAYER.
HRRR HAS CAUGHT ONTO THIS WITH TIME - AND HAS SLOWLY DROPPED THE
COVERAGE OF ANY POTENTIAL SHOWERS DEVELOPING FROM THE HIGH-BASED
CUMULUS ALONG THE FRONT. GIVEN VERY DRY SUB-CLOUD LAYERS...AND A
REDUCTION IN INSTBY VIA THE MIXED BOUNDARY LAYER...WILL LIKELY NOT
MENTION ANY SHRA THROUGH THE NEXT 3-4 HOURS AND HOLD WITH SPRINKLE
MENTIONS IN THE SCIOTO VALLEY THROUGH SUNSET FROM SOME OF THE
DEEPER CUMULUS. AS THE BOUNDARY LAYER DECOUPLES TONIGHT...TEMPS
SHOULD DROP OFF GIVEN THE DRY BOUNDARY LAYER. MID LEVEL WARM
ADVECTION COUPLED WITH A VERY WEAK WAVE CRESTING THE BUILDING MID
LEVEL RIDGE WILL LIKELY CONTINUE TO ALLOW MID-CLOUD TO DEVELOP
ACROSS THE AREA OVERNIGHT. THIS...COUPLED WITH SOME INCREASING
CIRRUS...SHOULD ALLOW FOR PARTLY CLOUDY SKIES AND TEMPS IN THE
UPPER 30S TO LOWER 50S FROM NORTH TO SOUTH,
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
CURRENT GOES WATER VAPOR LOOPS AND 26.18Z RAP ANALYSIS CLEARLY
SHOW POTENT UPPER LOW DIGGING/TURNING EAST NOW THROUGH AZ. THIS
HAS INDUCED STRONG DOWNSTREAM RIDGING FROM THE LOWER MS VALLEY
NORTHWARD INTO THE DAKOTAS WHILE GREAT LAKES SYSTEM DRIVING THE
COLD FRONT MENTIONED ABOVE SLIDES INTO NEW ENGLAND. THE
PROGRESSION OF THE LATTER SYSTEM INTO NEW ENGLAND AND THE FORMER
SYSTEM OUT INTO COLORADO WILL ALLOW LARGE SCALE/AMPLIFIED RIDGING
INTO AND ACROSS THE OHIO VALLEY ON SUNDAY. THESE RISING HEIGHTS
WILL ACT TO STALL THE COLD FRONT CURRENTLY SAGGING THROUGH
OHIO...WITH THE FRONT SETTING UP SOMEWHERE NEAR/ALONG THE OHIO
RIVER. THERE IS A WEALTH OF MID/UPPER LEVEL MOISTURE STREAMING
NORTHEASTWARD THROUGH THE NATIONS MIDSECTION IN THE STRONGER SWLY
FLOW ON THE WEST SIDE OF THE RIDGE...SO FEEL TOMORROW WILL HAVE
MORE CLOUDS THAN TODAY...LIKELY SOME MID LEVEL AC AND CIRRUS AS
WARM/MOIST ADVECTION BEGINS FIRST AT THOSE LEVELS THE RIDGE
CROSSES THE AREA. UNDERNEATH...WEAK HIGH PRESSURE WILL BE NOSING
SOUTHWARD INTO EASTERN OHIO ON SUNDAY PROVIDING A DRY/EASTERLY
BREEZE WHICH WILL KEEP TEMPERATURES A LITTLE COOLER THAN SATURDAY
ESP NORTH OF THE OHIO RIVER. THERE WILL STILL BE QUITE A TEMP
GRADIENT FROM NRN KY /SOUTH OF THE FRONT/ WHERE TEMPS NEAR 80 WILL
BE POSSIBLE AGAIN...AND NORTH OF THE FRONT THE FACTOR OF EAST
WINDS...MORE CLOUDS...WILL KEEP TEMPS IN THE 60S. COULD BE A
SNEAKY BUST DAY IN TERMS OF TEMPS NOT WARMING AS MUCH AS EXPECTED
WITH THE EASTERLY FLOW QUITE STRONG THE FURTHER NORTH OF THE OHIO
RIVER ONE GOES.
FIRST WAVES OF STRONGER THETA-E ADVECTION ARRIVE /850-700MB/
SUNDAY NIGHT AND PRIMARILY IN LATTER HALF OF THIS PERIOD...AS
INITIAL PUSH OF MOISTURE TRANSPORT OCCURS AS SURFACE LOW SWINGS
OUT INTO NEBRASKA AND DEEPENS AS THE UPPER LOW REACHES MATURITY
AND BECOMES CUT OFF. DESPITE MID/UPPER LEVEL RIDGING STILL LARGELY
BEING INTACT OVER THE OHIO VALLEY...THERE IS ENOUGH THERMODYNAMIC
FORCING WITH THE WARM/MOIST ADVECTION THAT EXPECT A SCT-BKN WAVE
OF SHOWERS AND ISOLD STORMS TO EVOLVE LATER SUNDAY EVENING TO OUR
WEST AND CROSS THE AREA LATE SUNDAY NIGHT INTO MONDAY MORNING.
DON/T SEE MUCH SEVERE THREAT WITH THIS AT ALL...PER 26.12Z GFS/NAM
BUFR SOUNDINGS...INSTBY IS MARGINAL /LESS THAN 1000 J/KG/ AND
EFFECTIVE SHEAR FOR THE PARCELS ABOVE THE BOUNDARY LAYER IS RATHER
WEAK. THESE SHOULD BE ELEVATED STORMS AND MAIN IMPACTS/THREATS
WILL BE SMALL HAIL AND/OR LOCALLY HEAVY DOWNPOURS. HAVE CONTINUED
THE MENTION OF 60-75% RAIN CHANCES FOR THIS ACTIVITY...AS THERE
REMAINS SOME UNCERTAINTY AT LEAST WITH HOW STRONG THE PUSH OF
DEEPER MOISTURE IS AND THE REMAINING ANTECEDENT DRY AIRMASS OVER
THE FORECAST AREA.
ON MONDAY...THIS INITIAL WAVE OF ADVECTION-INDUCED SHOWERS/STORMS
SHOULD PUSH NORTHEAST QUICKLY THROUGH THE MORNING AND MAY VERY
WELL HAVE A LULL WITH BREAKS OF SUN IN THE AFTERNOON. HARD TO TELL
FOR CERTAIN...WITH LARGE UPPER SYSTEM WELL TO THE WEST...THE
ABSENCE OF SYNOPTIC FORCING IS RATHER EASY TO SEE. BUT MOIST FLOW
AND CONTINUED WARMING OF THE LOWER TROP SHOULD ALLOW INSTABILITY
TO BUILD AND THIS DEVELOPING WARM SECTOR MAY VERY WELL BE FILLED
WITH A NUMBER OF CLUSTERS OF SHOWERS AND ISOLATED STORMS. SO THE
AFTERNOON HOURS ON MONDAY REMAIN UP FOR GRABS...THERE MAY BE LESS
RAIN COVERAGE IN THIS TIME PERIOD THAN CURRENT FORECAST DEPICTS.
FEELING MORE CONFIDENT THAT CONFLUENT LOW LEVEL FLOW ALONG/EAST OF
MS RIVER INTO THE MID OHIO VALLEY WILL IGNITE WITH SHOWERS/STORMS
ON MONDAY EVENING AND NIGHT WHICH SHOULD INVOLVE THE LOCAL AREA AS
THE NEXT SHORTWAVE SWINGS THROUGH AND EJECTS NORTHEAST OUT OF THE
BASE OF THE LARGE CNTL CONUS TROUGH. GIVEN THE DEEP MSLP WAY TO
THE WEST...LOW LEVEL WIND FLOWS WILL HAVE SOME COMPONENT OF
SOUTHEAST OR EAST-SOUTHEAST TRAJECTORY ON MONDAY AFTN/EVE...AND
GIVEN FAST/SWLY MID/UPPER LEVEL FLOW...PRESENTS AN OPPORTUNITY FOR
ORGANIZED SEVERE STORMS ESP IN THE SOUTH WHERE BOUNDARY LAYER
INSTBY WILL HAVE THE MOST TIME TO BUILD IN WAKE OF MONDAY MORNING
ACTIVITY. HOWEVER...POINT FCST BUFR SOUNDINGS SHOW LACK OF DECENT
EML TO STEEPEN TROPOSPHERIC LAPSE RATES...AND CAPE IS THUS
TALL/SKINNY AND OVERALL INSTBY STILL LOOKING MARGINAL. BUT SHEAR
WILL BE GOOD ESP WITH ANY EASTERLY COMPONENT TO THE LOW LEVEL WIND
FIELD...SO IF ANY PROLONGED PERIOD OF HEATING DEVELOPS MONDAY
AFTERNOON THE SUBSEQUENT THREATS FOR SEVERE GO UP LATE MON
AFTN/NIGHT. RIGHT NOW THERE IS ENOUGH UNCERTAINTY NOT TO GET
CARRIED AWAY...AND ACTUALLY GIVEN THE THERMODYNAMICS/PWAT
ANOMALIES THERE IS JUST AS MUCH CONCERN FOR A BAND OF
HEAVY/EXCESSIVE RAINFALL DEPENDING ON WHERE THE CONFLUENCE SETS
UP. SO WATCHING THIS PERIOD CLOSELY. DECIDED NOT TO GET CUTE IN
THE FORECAST...AND JUST RUNNING A HIGHER CHANCE FOR SHOWERS/STORMS
FROM MONDAY THROUGH MONDAY NIGHT GIVEN OVERALL ENSEMBLE
PROBS...DEEP MOISTURE...AND ARRIVAL OF TWO WAVES OF FORCING
MENTIONED ABOVE.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
LARGE SLOW MOVING UPPER LEVEL LOW OVER THE NATIONS MID SECTION TO
PROGRESS INTO THE GREAT LAKES BY THE END OF THE WEEK. WITH THE UPPER
LOW POSITIONED TO OUR WEST...SFC FRONT LOOKS TO PUSH THROUGH ON
TUESDAY. SOME MODEL SOLN DIFFERENCES EXIST REGARDING TIMING...SO
UNCERTAINTY EXISTS REGARDING INSTABILITY AND POTENTIAL FOR SEVERE
WEATHER.
AS THE LOW APPROACHES... WIND FIELDS INCREASE WITH MARGINAL INSTBY
INDICATED ON LATEST RUNS. WILL BECOME MORE FAVORABLE FOR HEAVY
RAIN...ESPECIALLY ACROSS THE SE IN THE MORNING. SEVERE WEATHER
IS A POSSIBILITY WITH THE BEST THREAT ACROSS THE SOUTH BUT THE
DEGREE OF THREAT WILL DEPEND ON THE TRACK AND TIMING OF THE
APPROACHING LOW/SFC FRONTAL PASSAGE. WILL CONTINUE LKLY POPS DURG
TUESDAY IN THE EAST EARLY AND THEN ENTERING THE WEST LATE.
MODEL SOLNS WORKING SOME DRIER AIR INTO ILN/S FA WEDNESDAY AS THE
UPPER LOW PIVOTS INTO THE GREAT LAKES. WILL LIMIT POPS TO CHANCE
CATEGORY.
A DECREASING CHANCE FOR SHOWERS WILL CONTINUE THURSDAY INTO FRIDAY
WITH THE UPPER LOW POSITIONED TO OUR NORTH. EXPECT SHOWER ACTIVITY
TO BECOME MORE DIURNALLY DRIVEN WITH THE BEST CHANCE ACROSS THE
NORTH.
MODEL DIFFERENCES INCREASE ON HOW FAST THE UPPER LOW OPENS UP NEXT
WEEKEND. WILL CONTINUE LOW POP CHANCE FOR A SHOWER WITH THE BEST
THREAT ACRS THE NORTH.
TEMP WISE...READINGS TO START OUT A LTL ABOVE NORMAL ON THE WARM
SIDE OF THE SYSTEM TUESDAY AND THEN COOL DOWN TO CLOSE TO 10 DEGREES
BELOW NORMAL THURSDAY/FRIDAY AS A COOLER AIRMASS MOVES INTO THE
REGION.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
A WEAK FRONT IS MOVING SOUTH THROUGH THE TAF SITES THIS
AFTERNOON...WITH WINDS SHIFTING GENTLY TODAY FROM THE WSW TO THE
WNW. TONIGHT...THESE WINDS WILL SHIFT MORE APPRECIABLY IN
DIRECTION...TURNING COUNTERCLOCKWISE TO NORTH AND THEN ENE BY
MORNING. WIND GUSTS THIS AFTERNOON WILL PEAK OUT IN THE 20-25 KNOT
RANGE...BUT CONDITIONS OVERNIGHT (THOUGH NOT CALM) WILL BE A
LITTLE LIGHTER.`
CHANCES OF PRECIPITATION ARE VERY LOW TODAY...THOUGH A FEW PATCHES
OF CLOUDS (HIGH-BASED CUMULUS OR MID CLOUDS) WILL STILL DRIFT
THROUGH THE AREA. CLOUDS WILL THICKEN AND LOWER SOMEWHAT DURING
THE NEXT 24 HOURS...BUT STILL REMAINING EASILY IN THE VFR RANGE.
THERE WILL BE A VERY SMALL CHANCE OF LIGHT RAIN EARLY ON SUNDAY
MORNING...PERHAPS A LITTLE MORE LIKELY FOR DAYTON OR AREAS
NORTHWEST OF THERE...BUT THIS SET OF TAFS WILL ONLY INDICATE SOME
ADDITIONAL LOWERING OF THE CLOUD DECK FROM 08Z-12Z.
OUTLOOK...MVFR TO IFR CONDITIONS WILL BE POSSIBLE AT TIMES IN RAIN
AND THUNDERSTORMS FROM SUNDAY NIGHT THROUGH TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...BINAU
NEAR TERM...BINAU
SHORT TERM...BINAU
LONG TERM...AR
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS NORMAN OK
1235 PM CDT SAT APR 26 2014
.DISCUSSION...
AVIATION DISCUSSION FOR THE 18Z TAFS IS BELOW.
&&
.AVIATION...
MAINLY VFR CONDITIONS ARE EXPECTED.
TSRA COVERAGE...INTENSITY...LOCATIONS...AND TIMING REMAIN
VERY UNCERTAIN. THUS...REMOVED TEMPO/PREVAILING MENTION OF
THEM. WILL AMEND IF CONFIDENCE OF TSRA AFFECTING ANY GIVEN
SITE INCREASES.
MVFR CONDITIONS WILL DEVELOP EAST OF KEND-KLAW-KSPS 06-12Z.
BRIEF IFR CONDITIONS MAY OCCUR AS WELL...BUT WERE NOT
MENTIONED DUE TO LOW CONFIDENCE OF OCCURRENCE.
NON CONVECTIVE LOW LEVEL WIND SHEAR IS POSSIBLE 01-14Z...BUT
DID NOT MENTION DUE TO LOW CONFIDENCE.
STRONG SOUTHWEST WINDS WILL DEVELOP 14-16Z. GUSTS OVER 35 KT AND
MVFR RESTRICTIONS IN BLDU ARE POSSIBLE. DID NOT MENTION BLDU DUE
TO LOW CONFIDENCE.
MBS
&&
.PREV DISCUSSION... /ISSUED 1057 AM CDT SAT APR 26 2014/
UPDATE...
AS NEW DATA CONTINUES TO FILTER IN THIS MORNING... IT APPEARS THAT
STORM CHANCES ARE LESS LIKELY TODAY AND THIS EVENING. 12Z OUN
SOUNDING SHOWS ENOUGH OF A CAPPING INVERSION TO BE AN ISSUE FOR
STORM DEVELOPMENT... ESPECIALLY WITH THE RELATIVELY LATE RETURN OF
LOW-LEVEL MOISTURE. THE HRRR AND RAP CONTINUE WITH SOME LATE
AFTERNOON DEVELOPMENT IN THE KNOX CITY-HOBART-ENID CORRIDOR LATE
THIS AFTERNOON... BUT THIS IS ALSO WITH FORECAST TEMPERATURES
CLIMBING INTO THE UPPER 90S TO TRIPLE DIGITS. IF TEMPERATURES DO
GET WARMER THAN OUR CURRENT FORECAST... THEN THERE WILL BE A
CHANCE OF ISOLATED HIGH-BASED STORMS DEVELOPING ALONG THE WESTERN
EDGE OF THE MOISTURE AXIS... BUT CURRENT THOUGHTS ARE TO LOWER
STORM CHANCES TO ISOLATED/LESS THAN 20 PERCENT FOR THIS AFTERNOON
AND LOWER POPS FOR THIS EVENING AS WELL. THE EXPECTED HIGH BASES
OF THE STORMS WILL ALSO MAKE THE SEVERE WEATHER SCENARIO /IF
STORMS FORM/ PRIMARILY A HAIL/WIND THREAT.
WILL CONTINUE TO WATCH TRENDS IN THE WEATHER THROUGH THE AFTERNOON
AND MAKE ADDITIONAL ADJUSTMENTS AS NECESSARY. .26.
PREV DISCUSSION... /ISSUED 643 AM CDT SAT APR 26 2014/
AVIATION...
26/12Z TAFS...VFR CONDITIONS EXPECTED TO PREVAIL MAJORITY OF
FORECAST PERIOD WITH DEVELOPMENT OF STRONG SOUTH-SOUTHWEST WINDS.
TSRA CHANCES WILL INCREASE TOWARD AND AFTER 00Z FROM SOUTHWEST
OKLAHOMA AND KSPS TOWARD CENTRAL OKLAHOMA TERMINALS TOWARD AND
AFTER 06Z. PRIMARILY MVFR/IFR IN TSRA WITH MVFR CIGS OUTSIDE OF
TSRA SOUTHERN OKLAHOMA LATE TONIGHT AHEAD OF DRYLINE.
PREV DISCUSSION... /ISSUED 501 AM CDT SAT APR 26 2014/
DISCUSSION...
LATEST ITERATION OF FINE-SCALE MODELS STILL POINT TO AT LEAST
ISOLATED THUNDERSTORM DEVELOPMENT ACROSS SOUTHWEST OKLAHOMA TOWARD
OR JUST AFTER 00Z. TAKING THESE INTO ACCOUNT...AND LOOKING AT 00Z
GFS/ECM AND NOW 06Z WRF... PROBABLE INITIATION AREAS AND MODE
EVOLUTION FAIRLY DIVERSE. WE DO NOT THINK THAT THE MODELS HAVE A
GOOD HANDLE ON QUALITY/DEPTH OF MOISTURE RETURN BUT ECM HAS
VERIFIED MUCH BETTER THAN THE OTHER MODELS LAST 12 TO 24
HOURS AND WILL BE FOLLOWED CLOSER FOR NOW. WITH NEW OBS-U/A THIS
MORNING HOPEFULLY THERE WILL BE BETTER CONSENSUS WITH 12Z MODELS.
WE STILL EXPECT THE GREATEST POTENTIAL FOR RELATIVELY HIGH-BASED
SUPERCELLS SW OKLAHOMA AND WRN NORTH TEXAS TOWARD AND AFTER 6 PM
WHERE COINCIDENCE OF HOTTER TEMPS AND DEEPER MOISTURE WILL
RESIDE. ADDITIONAL AND MORE WIDESPREAD DEVELOPMENT OF STORMS
POSSIBLE AHEAD OF DRYLINE/PAC-FRONT LATE EVENING AND OVERNIGHT AS
SUBSTANTIAL FORCING FINALLY APPROACHES. WITH INTENSE FORCING AND
BACKING DEEP LAYER SHEAR...WE STILL EXPECT THE EVOLUTION OF A (OR
MULTIPLE) ELEVATED CLUSTERS/BOW SEGMENTS THROUGH THE OVERNIGHT
HOURS. THERE COULD STILL BE STRONG/SEVERE STORMS EARLY SUNDAY
MORNING/DAYBREAK ACROSS CENTRAL AND EASTERN PORTIONS OF OKLAHOMA.
REDEVELOPMENT SUNDAY AFTERNOON/EVENING ARE EXPECTED TO BE
PRIMARILY EAST OF OUR CWA.
GOING TO BE WINDY TODAY...WITH CURRENT GRIDS MARGINALLY
APPROACHING WIND ADVISORY. SUNDAY WILL BE WINDIER MOST LOCATIONS
AND A WIND ADVISORY IS EXPECTED. ALSO...WE HAVE ISSUED A FIRE
WEATHER WATCH FOR MAJORITY OF WESTERN OKLAHOMA AND ADJACENT PARTS
OF NORTH TEXAS WITH DRY/WARM AND WINDY CONDITIONS BEHIND
DRYLINE/PAC-FRONT. DID NOT BRING WATCH INTO OKC METRO WITH
TRANSITION TO GREEN FUELS. WATCH WAS PRIMARILY FOCUSED ON AREAS
THAT ARE JUST ENTERING TRANSITION PHASE OF FUELS AND DROUGHT
STRICKEN LOCATIONS.
COOL WEEK WITH OCCASIONAL WINDY DAYS WITH PERSISTENT NORTHWEST
FLOW. LIGHT SHOWERS WILL BE POSSIBLE MAINLY WEST/NORTH PARTS OF
OKLAHOMA DURING THE WEEK WITH PASSAGE OF THERMAL TROUGHS THAT WILL
ROTATE AROUND LARGE U.S. UPPER CYCLONE.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 87 66 81 51 / 10 50 30 10
HOBART OK 89 60 81 50 / 10 40 10 0
WICHITA FALLS TX 88 65 84 52 / 10 40 10 0
GAGE OK 90 58 77 46 / 10 20 10 10
PONCA CITY OK 88 66 81 49 / 10 50 40 10
DURANT OK 85 67 83 56 / 0 30 60 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR OKZ004>007-009>012-014>018-021>024-033>038-044.
TX...FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR TXZ083>089.
&&
$$
26/17/17
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
541 PM EDT SAT APR 26 2014
.SYNOPSIS...
AN UPPER LEVEL LOW WILL DROP THROUGH NEW ENGLAND TONIGHT. MINOR
RIDGING MOVES IN FROM THE WEST...AND SHOULD MAKE FOR DRY WEATHER
SUNDAY AND MOST OF MONDAY. BUT ANOTHER UPPER LEVEL LOW WILL
DEVELOP OVER THE CENTRAL U.S. DURING THE UPCOMING WEEK. THIS
FEATURE WILL CREATE A PROLONGED PERIOD OF UNSETTLED WEATHER FOR
PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
WEAK FORCING ROLLING THRU NY STATE AND N/ERN PA WILL MAKE FOR SOME
SCT SHRA. CURRENT CROP OF SHOWERS SEEMS WIDESPREAD OVER THE NERN
THIRD OF THE AREA...BUT HARDLY ANYTHING BUT SPRINKLES ARE MAKING
IT DOWN TO THE SURFACE FROM SUCH LOFTY HEIGHTS. WINDS ARE PRETTY
STRONG AND GUSTING INTO THE M30S. BUT NOT QUITE BAD ENOUGH TO
WARRANT AN ADVY. DEWPOINTS JUST A LITTTLE HIGHER IN MD AND SOME
SFC/LLVL CONVG WILL LEAD TO COUPLE OF SHOWERS OR PERHAPS A TSRA IN
THE SE BY EVENING. BUT THE DRY AIR IS MAKING IT REALLY TOUGH.
LATEST RUC BARELY MAKES A SPRINKLE ANYWHERE IN THE CWA. WILL
THEREFORE TAKE THE POPS LOWER THAN MY EARLIER THINKING. SOME
HIGHER GUSTS OUT OF THE SHRA ARE STILL POSS. ANY SHOWERS SHOULD BE
TO THE EAST/SOUTH OF THE AREA AFTER THE TROUGH/WEAK FRONT PUSHES
OUT LATE THIS AFTN/VERY EARLY THIS EVENING.
SKIES WILL CLEAR OUT OVER MUCH OF THE AREA THIS EVENING. NERN
AREAS WILL HAVE TO DEAL WITH SOME LOW CLOUDS FOR THE FIRST HALF OF
THE NIGHT. BUT AS THE UPPER LOW MOVES A LITTLE TO THE EAST AFTER
SUNRISE...IT SHOULD GET SUNNY THERE...TOO. TEMPS WILL DIP INTO THE
M30S IN THE CENTRAL MTS TONIGHT. WINDS REMAIN UP ENOUGH -
GENERALLY ABOVE 5KTS - THAT WIDESPREAD FROST IS NOT ANTICIPATED.
WILL MENTION PATCHY FROST FOR NOW IN THE CENTRAL VALLEYS. SERN
AREAS WILL REMAIN MILDER THAN FROST ADVY WORRIES AND THE NW ISN/T
IN THE GROWING SEASON YET.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
WINDS SHOULD PICK UP A BIT FROM A MINOR LULL IN THE SUNRISE/EARLY
MORNING - MAINLY IN THE EAST CLOSER TO THE LOW PRESSURE MOVING OFF
THE COAST. OTHER THAN SOME EARLY CLOUDS IN THE NE...THE SKY
SHOULD BE MAINLY CLEAR SINCE WE ARE DOWNSTREAM OF THE RIDGE OVER
THE UPPER GREAT LAKES. TEMPS WILL RISE QUICKLY AND ATTAIN 60-65F
IN THE SRN HALF OF THE AREA AND U50S ELSEWHERE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
RIDGE OVER EASTERN U.S. WILL BRING MAINLY QUIET WEATHER SUNDAY
NIGHT INTO MONDAY. LOW LEVEL WINDS TURN SE-SW...WITH CORE OF
SOMEWHAT STRONGER FLOW FOCUSED OVER OHIO VALLEY - BEGINNING SURGE
OF INCREASINGLY MOIST AIR FURTHER NORTHWARD IN THE FORM OF A WARM
FRONT.
BROAD UPPER LOW WILL CONTINUE TO SPIN OVER UPPER MIDWEST WHILE
GRADUALLY DRIFTING EASTWARD...AS PATTERN REMAINS BLOCKED INTO
EARLY NEXT WEEK. WARM FRONT BECOMES MORE DEFINED TO OUR
SOUTH...AND WILL BECOME THE FOCUS FOR WIDESPREAD SHOWERS BY
TUE/WED/THU AS LOW CREEPS EASTWARD TO PROVIDE AREA OF SYNOPTIC
LIFT. QPF TOTALS LOOK TO BE IN THE QUARTER OF AN INCH RANGE BOTH
TUE AND WED...WITH POTENTIAL FOR HEAVIER PRECIP WED NIGHT INTO THU
AS SURFACE WAVE RIDES ALONG FRONTAL BOUNDARY. A WIDESPREAD 1-2
INCH TOTAL STILL SEEMS PLAUSIBLE OVER A 24-36HR PERIOD WED AFT
INTO THU AS PWAT VALUES PEAK /AND INSTABILITY BRINGS CHANCE FOR
TSTMS/. GIVEN THE PROJECTED SYNOPTIC PATTERN WITH CLOUDS AND SE
FLOW...EXPECT DAYTIME TEMPS TO BE COOLER THAN NORMAL WHILE
OVERNIGHT TEMPS AVG A LITTLE ABOVE LATE APRIL/EARLY MAY CLIMO.
RIDGE RE-ESTABLISHES ITSELF OVER THE WEST COAST HEADING INTO NEXT
WEEKEND...WHICH WILL KEEP BROAD TROUGH IN VICINITY AND KEEP
FEEDING COOLER AIR INTO PA LATE WEEK INTO THE WEEKEND...ALONG WITH
KEEPING A MENTION OF LIGHTER SHOWERS IN THE FORECAST /ESP IN THE
NW HALF/.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
ADJUSTED WINDS SOME.
OTHER CONCERN IS SHOWERS NEAR THE MD BORDER...GIVEN STRONG
WIND FIELDS.
EXPECT THESE TWO PROBLEMS TO EASE OFF BY SUNSET.
21Z TAFS SENT.
EARLIER DISCUSSION BELOW.
WIND STRONG AND GUSTY OUT OF THE WEST. GUSTS ARE CURRENTLY OVER
35 KTS OVER THE WRN MTS. CLOUD BASES ARE VFR BUT BKN/OVC MOST
LOCATIONS IN THE DIURNAL INSTABILITY. SOME MVFR CIGS ARE SNEAKING
TOWARD KBFD AND THE COOLING BEHIND THE WEAK FRONT/DRY LINE PASSING
THROUGH MAY HELP LOWER THE BASES/CIGS THERE TO ABOUT FL025.
SHOWERS MOVING THROUGH THE NE ARE HARDLY REACHING THE GROUND. WILL
CONTINUE TO JUST MENTION VCSH INTO THE LATE AFTN/EVEN IN THE SRN
TERMINALS. THEN CLEARING SHOULD ENSUE AT ALL BUT KBFD AND PERHAPS
KIPT. THE COLD AIR/CYCLONIC FLOW MAY KEEP A BKN CIG THERE INTO THE
NIGHT BEFORE IT BREAKS UP.
WINDS WILL DIMINISH SOMEWHAT TONIGHT. HAVE OPTED TO KEEP FOG OUT
OF THE TAFS SINCE THE AIR IS SO DRY. IF IT COULD ACTUALLY
RAIN...THAT MIGHT HAPPEN. BUT SO FAR THE FL050 PLUS BASES TO THE
CLOUDS DO NOT LEND THEMSELVES TO MOD OR HEAVY RAIN.
HIGH PRESSURE BUILDS IN SUNDAY AND MONDAY...WITH GENERALLY
UNRESTRICTED CONDITIONS.
OUTLOOK...
.SUN...VFR.
.MON...VFR.
.MON NIGHT...LOWERING CIGS AS WARM FRONT PASSES WITH MVFR/IFR AND
DEVELOPING SHRA.
.TUE-WED...MVFR/IFR WITH PERIODS OF RAIN/THUNDER.
.THUR...MAINLY VFR...SCT SHRA POSS W.
&&
.FIRE WEATHER...
ANOTHER 1 TO 2 HOURS OF STRONG WIND GUST...SOME OVER 40 MPH.
DEWPOINTS ON THE LOW SIDE.
THE COMBINATION OF WINDS AND LOW DEWPOINTS WILL CONTINUE TO DRY
THINGS OUT THROUGH SUNSET.
EARLIER DISCUSSION BELOW.
THE WINDS ARE STRONG...BUT SHOULD SLACKEN BUT NOT DROP OFF
TOTALLY TONIGHT. THE RH/S SHOULD RISE ABOVE 30PCT TONIGHT AND
BARELY TOUCH THAT NUMBER SUNDAY AFTN THANKS TO SOMEWHAT COOLER DAY
TIME TEMPS. THE WINDS WILL STAY UNDER RED FLAG CRIT FOR MOST OF
THE AREA SUNDAY...ONLY IN THE EAST WHERE PRESSURE GRADIENT IS
TIGHT ENOUGH WILL THE WINDS GUST ABOVE 15 KTS. SO...IT IS A
MARGINAL SITUATION FOR WINDS AND MIN RH/S THERE. BUT NOT CONFIDENT
ENOUGH TO POST A FIRE WX WATCH AT THIS POINT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...DANGELO/MARTIN
FIRE WEATHER...DANGELO/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
352 PM EDT SAT APR 26 2014
.SYNOPSIS...
AN UPPER LEVEL LOW WILL DROP THROUGH NEW ENGLAND TONIGHT. MINOR
RIDGING MOVES IN FROM THE WEST...AND SHOULD MAKE FOR DRY WEATHER
SUNDAY AND MOST OF MONDAY. BUT ANOTHER UPPER LEVEL LOW WILL
DEVELOP OVER THE CENTRAL U.S. DURING THE UPCOMING WEEK. THIS
FEATURE WILL CREATE A PROLONGED PERIOD OF UNSETTLED WEATHER FOR
PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
WEAK FORCING ROLLING THRU NY STATE AND N/ERN PA WILL MAKE FOR SOME
SCT SHRA. CURRENT CROP OF SHOWERS SEEMS WIDESPREAD OVER THE NERN
THIRD OF THE AREA...BUT HARDLY ANYTHING BUT SPRINKLES ARE MAKING
IT DOWN TO THE SURFACE FROM SUCH LOFTY HEIGHTS. WINDS ARE PRETTY
STRONG AND GUSTING INTO THE M30S. BUT NOT QUITE BAD ENOUGH TO
WARRANT AN ADVY. DEWPOINTS JUST A LITTTLE HIGHER IN MD AND SOME
SFC/LLVL CONVG WILL LEAD TO COUPLE OF SHOWERS OR PERHAPS A TSRA IN
THE SE BY EVENING. BUT THE DRY AIR IS MAKING IT REALLY TOUGH.
LATEST RUC BARELY MAKES A SPRINKLE ANYWHERE IN THE CWA. WILL
THEREFORE TAKE THE POPS LOWER THAN MY EARLIER THINKING. SOME
HIGHER GUSTS OUT OF THE SHRA ARE STILL POSS. ANY SHOWERS SHOULD BE
TO THE EAST/SOUTH OF THE AREA AFTER THE TROUGH/WEAK FRONT PUSHES
OUT LATE THIS AFTN/VERY EARLY THIS EVENING.
SKIES WILL CLEAR OUT OVER MUCH OF THE AREA THIS EVENING. NERN
AREAS WILL HAVE TO DEAL WITH SOME LOW CLOUDS FOR THE FIRST HALF OF
THE NIGHT. BUT AS THE UPPER LOW MOVES A LITTLE TO THE EAST AFTER
SUNRISE...IT SHOULD GET SUNNY THERE...TOO. TEMPS WILL DIP INTO THE
M30S IN THE CENTRAL MTS TONIGHT. WINDS REMAIN UP ENOUGH -
GENERALLY ABOVE 5KTS - THAT WIDESPREAD FROST IS NOT ANTICIPATED.
WILL MENTION PATCHY FROST FOR NOW IN THE CENTRAL VALLEYS. SERN
AREAS WILL REMAIN MILDER THAN FROST ADVY WORRIES AND THE NW ISN/T
IN THE GROWING SEASON YET.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
WINDS SHOULD PICK UP A BIT FROM A MINOR LULL IN THE SUNRISE/EARLY
MORNING - MAINLY IN THE EAST CLOSER TO THE LOW PRESSURE MOVING OFF
THE COAST. OTHER THAN SOME EARLY CLOUDS IN THE NE...THE SKY
SHOULD BE MAINLY CLEAR SINCE WE ARE DOWNSTREAM OF THE RIDGE OVER
THE UPPER GREAT LAKES. TEMPS WILL RISE QUICKLY AND ATTAIN 60-65F
IN THE SRN HALF OF THE AREA AND U50S ELSEWHERE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
RIDGE OVER EASTERN U.S. WILL BRING MAINLY QUIET WEATHER SUNDAY
NIGHT INTO MONDAY. LOW LEVEL WINDS TURN SE-SW...WITH CORE OF
SOMEWHAT STRONGER FLOW FOCUSED OVER OHIO VALLEY - BEGINNING SURGE
OF INCREASINGLY MOIST AIR FURTHER NORTHWARD IN THE FORM OF A WARM
FRONT.
BROAD UPPER LOW WILL CONTINUE TO SPIN OVER UPPER MIDWEST WHILE
GRADUALLY DRIFTING EASTWARD...AS PATTERN REMAINS BLOCKED INTO
EARLY NEXT WEEK. WARM FRONT BECOMES MORE DEFINED TO OUR
SOUTH...AND WILL BECOME THE FOCUS FOR WIDESPREAD SHOWERS BY
TUE/WED/THU AS LOW CREEPS EASTWARD TO PROVIDE AREA OF SYNOPTIC
LIFT. QPF TOTALS LOOK TO BE IN THE QUARTER OF AN INCH RANGE BOTH
TUE AND WED...WITH POTENTIAL FOR HEAVIER PRECIP WED NIGHT INTO THU
AS SURFACE WAVE RIDES ALONG FRONTAL BOUNDARY. A WIDESPREAD 1-2
INCH TOTAL STILL SEEMS PLAUSIBLE OVER A 24-36HR PERIOD WED AFT
INTO THU AS PWAT VALUES PEAK /AND INSTABILITY BRINGS CHANCE FOR
TSTMS/. GIVEN THE PROJECTED SYNOPTIC PATTERN WITH CLOUDS AND SE
FLOW...EXPECT DAYTIME TEMPS TO BE COOLER THAN NORMAL WHILE
OVERNIGHT TEMPS AVG A LITTLE ABOVE LATE APRIL/EARLY MAY CLIMO.
RIDGE RE-ESTABLISHES ITSELF OVER THE WEST COAST HEADING INTO NEXT
WEEKEND...WHICH WILL KEEP BROAD TROUGH IN VICINITY AND KEEP
FEEDING COOLER AIR INTO PA LATE WEEK INTO THE WEEKEND...ALONG WITH
KEEPING A MENTION OF LIGHTER SHOWERS IN THE FORECAST /ESP IN THE
NW HALF/.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
WIND STRONG AND GUSTY OUT OF THE WEST. GUSTS ARE CURRENTLY OVER
35 KTS OVER THE WRN MTS. CLOUD BASES ARE VFR BUT BKN/OVC MOST
LOCATIONS IN THE DIURNAL INSTABILITY. SOME MVFR CIGS ARE SNEAKING
TOWARD KBFD AND THE COOLING BEHIND THE WEAK FRONT/DRY LINE PASSING
THROUGH MAY HELP LOWER THE BASES/CIGS THERE TO ABOUT FL025.
SHOWERS MOVING THROUGH THE NE ARE HARDLY REACHING THE GROUND. WILL
CONTINUE TO JUST MENTION VCSH INTO THE LATE AFTN/EVEN IN THE SRN
TERMINALS. THEN CLEARING SHOULD ENSUE AT ALL BUT KBFD AND PERHAPS
KIPT. THE COLD AIR/CYCLONIC FLOW MAY KEEP A BKN CIG THERE INTO THE
NIGHT BEFORE IT BREAKS UP.
WINDS WILL DIMINISH SOMEWHAT TONIGHT. HAVE OPTED TO KEEP FOG OUT
OF THE TAFS SINCE THE AIR IS SO DRY. IF IT COULD ACTUALLY
RAIN...THAT MIGHT HAPPEN. BUT SO FAR THE FL050 PLUS BASES TO THE
CLOUDS DO NOT LEND THEMSELVES TO MOD OR HEAVY RAIN.
HIGH PRESSURE BUILDS IN SUNDAY AND MONDAY...WITH GENERALLY
UNRESTRICTED CONDITIONS.
OUTLOOK...
.SUN...VFR.
.MON...VFR.
.MON NIGHT...LOWERING CIGS AS WARM FRONT PASSES WITH MVFR/IFR AND
DEVELOPING SHRA.
.TUE-WED...MVFR/IFR WITH PERIODS OF RAIN/THUNDER.
.THUR...MAINLY VFR...SCT SHRA POSS W.
&&
.FIRE WEATHER...
SHOWERS TODAY ARE NOT HELPING RAISE ANY MOISTURE LEVELS. THE WINDS
ARE STRONG...BUT SHOULD SLACKEN BUT NOT DROP OFF TOTALLY TONIGHT.
THE RH/S SHOULD RISE ABOVE 30PCT TONIGHT AND BARELY TOUCH THAT
NUMBER SUNDAY AFTN THANKS TO SOMEWHAT COOLER DAY TIME TEMPS. THE
WINDS WILL STAY UNDER RED FLAG CRIT FOR MOST OF THE AREA
SUNDAY...ONLY IN THE EAST WHERE PRESSURE GRADIENT IS TIGHT ENOUGH
WILL THE WINDS GUST ABOVE 15 KTS. SO...IT IS A MARGINAL SITUATION
FOR WINDS AND MIN RH/S THERE. BUT NOT CONFIDENT ENOUGH TO POST A
FIRE WX WATCH AT THIS POINT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...DANGELO
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
238 PM EDT SAT APR 26 2014
.SYNOPSIS...
AN UPPER LEVEL LOW WILL DROP THROUGH NEW ENGLAND TONIGHT. MINOR
RIDGING MOVES IN FROM THE WEST...AND SHOULD MAKE FOR DRY WEATHER
SUNDAY AND MOST OF MONDAY. BUT ANOTHER UPPER LEVEL LOW WILL
DEVELOP OVER THE CENTRAL U.S. DURING THE UPCOMING WEEK. THIS
FEATURE WILL CREATE A PROLONGED PERIOD OF UNSETTLED WEATHER FOR
PENNSYLVANIA.
&&
.NEAR TERM /THROUGH TONIGHT/...
WEAK FORCING ROLLING THRU NY STATE AND N/ERN PA WILL MAKE FOR SOME
SCT SHRA. CURRENT CROP OF SHOWERS SEEMS WIDESPREAD OVER THE NERN
THIRD OF THE AREA...BUT HARDLY ANYTHING BUT SPRINKLES ARE MAKING
IT DOWN TO THE SURFACE FROM SUCH LOFTY HEIGHTS. WINDS ARE PRETTY
STRONG AND GUSTING INTO THE M30S. BUT NOT QUITE BAD ENOUGH TO
WARRANT AN ADVY. DEWPOINTS JUST A LITTTLE HIGHER IN MD AND SOME
SFC/LLVL CONVG WILL LEAD TO COUPLE OF SHOWERS OR PERHAPS A TSRA IN
THE SE BY EVENING. BUT THE DRY AIR IS MAKING IT REALLY TOUGH.
LATEST RUC BARELY MAKES A SPRINKLE ANYWHERE IN THE CWA. WILL
THEREFORE TAKE THE POPS LOWER THAN MY EARLIER THINKING. SOME
HIGHER GUSTS OUT OF THE SHRA ARE STILL POSS. ANY SHOWERS SHOULD BE
TO THE EAST/SOUTH OF THE AREA AFTER THE TROUGH/WEAK FRONT PUSHES
OUT LATE THIS AFTN/VERY EARLY THIS EVENING.
SKIES WILL CLEAR OUT OVER MUCH OF THE AREA THIS EVENING. NERN
AREAS WILL HAVE TO DEAL WITH SOME LOW CLOUDS FOR THE FIRST HALF OF
THE NIGHT. BUT AS THE UPPER LOW MOVES A LITTLE TO THE EAST AFTER
SUNRISE...IT SHOULD GET SUNNY THERE...TOO. TEMPS WILL DIP INTO THE
M30S IN THE CENTRAL MTS TONIGHT. WINDS REMAIN UP ENOUGH -
GENERALLY ABOVE 5KTS - THAT WIDESPREAD FROST IS NOT ANTICIPATED.
WILL MENTION PATCHY FROST FOR NOW IN THE CENTRAL VALLEYS. SERN
AREAS WILL REMAIN MILDER THAN FROST ADVY WORRIES AND THE NW ISN/T
IN THE GROWING SEASON YET.
&&
.SHORT TERM /SUNDAY/...
WINDS SHOULD PICK UP A BIT FROM A MINOR LULL IN THE SUNRISE/EARLY
MORNING - MAINLY IN THE EAST CLOSER TO THE LOW PRESSURE MOVING OFF
THE COAST. OTHER THAN SOME EARLY CLOUDS IN THE NE...THE SKY
SHOULD BE MAINLY CLEAR SINCE WE ARE DOWNSTREAM OF THE RIDGE OVER
THE UPPER GREAT LAKES. TEMPS WILL RISE QUICKLY AND ATTAIN 60-65F
IN THE SRN HALF OF THE AREA AND U50S ELSEWHERE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
THE 26/00Z MEDIUM RANGE MODEL AND ENSEMBLE GUIDANCE CONTINUES TO
ADVERTISE A LARGE SCALE PATTERN SHIFT TO A BLOCKING REGIME ACROSS
THE CONUS FOR DAYS 4-7/MON-FRI...WITH REX BLOCK OVER CENTRAL NOAM
AND UPPER RIDGES ALONG THE WEST/EAST COASTS. AFTER AN INITIALLY
DRY PERIOD ON SUNDAY INTO EARLY MONDAY ASSOCIATED WITH A NARROW
SFC HIGH PINCHED IN-BETWEEN SFC LOWS MIGRATING OVER THE PLAINS/NRN
ATLC...THE EVOLVING PATTERN FAVORS INCREASINGLY WET AND RELATIVELY
COOL CONDITIONS OVER CENTRAL PA. THEREFORE HAVE ADJUSTED POPS
UPWARD IN THE LONG TERM...WITH INCREASING CONFIDENCE IN
SIGNIFICANT/BENEFICIAL RAINFALL FOCUSED IN THE TUE-THR TIMEFRAME.
A WIDESPREAD 1-2 INCHES SEEMS PLAUSIBLE AT THIS TIME OVER A
48-72HR PERIOD CENTERED AROUND THE MIDDLE OF NEXT WEEK. GIVEN THE
PROJECTED SYNOPTIC PATTERN WITH CLOUDS AND SE FLOW...EXPECT
DAYTIME TEMPS TO BE COOLER THAN NORMAL WHILE OVERNIGHT TEMPS AVG A
LITTLE ABOVE LATE APRIL/EARLY MAY CLIMO.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
WIND STRONG AND GUSTY OUT OF THE WEST. GUSTS ARE CURRENTLY OVER
35 KTS OVER THE WRN MTS. CLOUD BASES ARE VFR BUT BKN/OVC MOST
LOCATIONS IN THE DIURNAL INSTABILITY. SOME MVFR CIGS ARE SNEAKING
TOWARD KBFD AND THE COOLING BEHIND THE WEAK FRONT/DRY LINE PASSING
THROUGH MAY HELP LOWER THE BASES/CIGS THERE TO ABOUT FL025.
SHOWERS MOVING THROUGH THE NE ARE HARDLY REACHING THE GROUND. WILL
CONTINUE TO JUST MENTION VCSH INTO THE LATE AFTN/EVEN IN THE SRN
TERMINALS. THEN CLEARING SHOULD ENSUE AT ALL BUT KBFD AND PERHAPS
KIPT. THE COLD AIR/CYCLONIC FLOW MAY KEEP A BKN CIG THERE INTO THE
NIGHT BEFORE IT BREAKS UP.
WINDS WILL DIMINISH SOMEWHAT TONIGHT. HAVE OPTED TO KEEP FOG OUT
OF THE TAFS SINCE THE AIR IS SO DRY. IF IT COULD ACTUALLY
RAIN...THAT MIGHT HAPPEN. BUT SO FAR THE FL050 PLUS BASES TO THE
CLOUDS DO NOT LEND THEMSELVES TO MOD OR HEAVY RAIN.
HIGH PRESSURE BUILDS IN SUNDAY AND MONDAY...WITH GENERALLY
UNRESTRICTED CONDITIONS.
OUTLOOK...
.SUN...VFR.
.MON...VFR.
.MON NIGHT...LOWERING CIGS AS WARM FRONT PASSES WITH MVFR/IFR AND
DEVELOPING SHRA.
.TUE-WED...MVFR/IFR WITH PERIODS OF RAIN/THUNDER.
.THUR...MAINLY VFR...SCT SHRA POSS W.
&&
.FIRE WEATHER...
SHOWERS TODAY ARE NOT HELPING RAISE ANY MOISTURE LEVELS. THE WINDS
ARE STRONG...BUT SHOULD SLACKEN BUT NOT DROP OFF TOTALLY TONIGHT.
THE RH/S SHOULD RISE ABOVE 30PCT TONIGHT AND BARELY TOUCH THAT
NUMBER SUNDAY AFTN THANKS TO SOMEWHAT COOLER DAY TIME TEMPS. THE
WINDS WILL STAY UNDER RED FLAG CRIT FOR MOST OF THE AREA
SUNDAY...ONLY IN THE EAST WHERE PRESSURE GRADIENT IS TIGHT ENOUGH
WILL THE WINDS GUST ABOVE 15 KTS. SO...IT IS A MARGINAL SITUATION
FOR WINDS AND MIN RH/S THERE. BUT NOT CONFIDENT ENOUGH TO POST A
FIRE WX WATCH AT THIS POINT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...DANGELO
FIRE WEATHER...DANGELO
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
415 PM CDT SAT APR 26 2014
.SHORT TERM...
(Tonight and Sunday)
Conditionally severe thunderstorm threat tonight, mainly in the Big
Country and Concho Valley. West Central Texas is certainly unstable
with RUC SB CAPES up to 3000 J/KG, but warm air aloft may prevent
storms from occurring. Surface Observations show only weak low level
convergence along the dryline. Some virga indicated in the Big
Country from Abilene to west of Wichita Falls, but the mid level
instability associated with it appears to be fairly high, above
10000 FT AGL.
Both the GFS and the HRRR models develop isolated storms in the Big
Country this evening, with the GFS the only one to develop storms
later tonight, as a Pacific front catches up with dryline towards
midnight. Region should become more unstable as cooler air aloft
moves in as an upper trough approaches. There will also be stronger
low level convergence, with west winds behind the Pacific front. But
storm development is still conditional.
Strong downslope west warming winds expected Sunday behind the
Pacific Front. Should see Wind Advisory criteria of 25 to 35 mph,
with gusts to 45 mph by midmorning. Have a Red Flag Warning for
dangerous fire conditions from 11 AM to 10 PM.
.FIRE WEATHER...
A Red Flag Warning for fire weather is in effect for West Central
Texas from 11 AM to 10 PM.
Dangerous fire weather conditions Sunday as the dryline and Pacific
front sweep through, bringing dry and windy west winds Minimum RH
values will fall near 10 percent with 20 foot west winds of 20 to 30
mph gusting to 35 mph. Added Mason and San Saba counties to the Red
Flag Warning as 20 foot winds will be close to 20 mph.
Elevated fire weather conditions are also expected Monday due to
gusty west winds and very dry conditions.
.LONG TERM...
(Sunday night through next Saturday)
Warm and dry weather will prevail on Monday, with cooler
temperatures Tuesday through next Friday.
The large closed upper low will be centered over the Central Plains
late this weekend, and will move slowly northeast to the Great Lakes
region by mid week. Associated surface low currently over eastern
Colorado this evening, will move northeast into eastern Nebraska
Sunday evening. Monday will be another warm day with gusty west
winds once again with afternoon highs in the mid and upper 80s.
A cold front will move across the area Monday night, bringing much
cooler temperatures for Tuesday, with highs mainly in the 70s.
Northwest flow aloft will prevail across the area Tuesday through
much of next week. A persistent surface ridge will remain in place
and will result in unseasonably cool temperatures for West Central
Texas through Friday. High temperatures through Friday will be
mainly in the 70s, with overnight lows in the 40s and 50s. Warmer
weather is expected next weekend with near seasonal temperatures.
No rain is forecast through the period.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 92 63 88 51 83 / 20 40 0 0 0
San Angelo 94 63 90 51 88 / 10 30 0 0 0
Junction 90 66 92 50 90 / 10 30 5 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING from 11 AM to 10 PM CDT Sunday FOR THE
FOLLOWING ZONES: Brown...Callahan...Coke...Coleman...Concho...
Crockett...Fisher...Haskell...Irion...Jones...Kimble...Mason...
McCulloch...Menard...Nolan...Runnels...San Saba...Schleicher...
Shackelford...Sterling...Sutton...Taylor...Throckmorton...Tom
Green.
WIND ADVISORY from 10 AM to 7 PM CDT Sunday FOR THE FOLLOWING
ZONES: Callahan...Coke...Coleman...Concho...Crockett...Fisher...
Haskell...Irion...Jones...Nolan...Runnels...Schleicher...
Shackelford...Sterling...Taylor...Throckmorton...Tom Green.
&&
$$
04/24
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 251 PM CDT SAT APR 26 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE RIDGE
AXIS EXTENDING SOUTHWARD FROM A HUDSON BAY HIGH AND BISECTING
WISCONSIN EARLY THIS AFTERNOON. EAST OF THIS RIDGE AXIS...NORTHEAST
WINDS HAVE BEEN ADVECTING A LOW STRATUS DECK OVER MUCH OF
NORTH-CENTRAL AND NORTHEAST WISCONSIN. TEMPS HAVE BEEN HELD BACK
DUE TO THESE CLOUDS AND RANGE THROUGH THE 40S. LOOKING OUT TO THE
WEST...MID AND HIGH CLOUDS ARE SPILLING OVER A SHARP MID-LEVEL RIDGE
AXIS OVER THE NORTHERN PLAINS. THIS IS AHEAD OF A DEEP TROUGH
MOVING ACROSS THE WESTERN CONUS. ALSO TO THE EAST OF THIS
TROUGH...A SURFACE WARM FRONT IS SHIFTING NORTHWARD OVER THE CENTRAL
PLAINS WITH RETURN FLOWING INCREASING. AS THIS WARM FRONT LIFTS
NORTH OVER THE NEXT 24 HOURS...LIGHT PRECIP CHANCES ARE THE MAIN
FORECAST CONCERN.
TONIGHT...HUDSON BAY HIGH RIDGE AXIS WILL SHIFT FROM THE CENTRAL TO
THE EASTERN GREAT LAKES WHILE LOW PRESSURE EMERGES INTO THE CENTRAL
PLAINS. AHEAD OF THE LOW...MID AND HIGH CLOUDS WILL BE PUSHING
ACROSS THE STATE THIS EVENING BUT DRY NORTHEAST TO EAST WINDS WILL
KEEP THE AREA DRY. BY LATE TONIGHT THOUGH...40-50 KTS OF FLOW WILL
RIDE OVER THE MID-LEVEL THERMAL GRADIENT OVER THE NORTHERN
MISSISSIPPI VALLEY. THIS WILL CAUSE CLOUDS TO LOWER OVER CENTRAL
AND EAST-CENTRAL WISCONSIN AND VARIOUS MODELS BRING IN LIGHT PRECIP
INTO THE AREA BY 09Z. BECAUSE OF THE DRY EAST FLOW...THINK THIS IS
TOO AGGRESSIVE AND HAVE BACKED OFF PRECIP CHANCES A LITTLE AFTER
MIDNIGHT. MAY HAVE ENOUGH SATURATION FOR LIGHT RAIN BETWEEN 09-12Z
SO HAVE KEPT POPS IN THE HIGH CHANCE RANGE BUT STILL THINK THERE IS
POTENTIAL FOR THE DRY AIR TO WIN OUT. THE EAST WINDS WILL BE BREEZY
TONIGHT...WHICH WILL MAKE IT FEEL BLUSTERY AND DAMP. LOWS RANGING
FROM THE UPPER 20S NORTH TO UPPER 30S SOUTH.
SUNDAY...THE LOW PRESSURE SYSTEM WILL MOVE VERY LITTLE EASTWARD OVER
THE CENTRAL PLAINS...BUT THE RETURN FLOW WILL PUSH NORTHEAST ACROSS
THE STATE OVER THE COURSE OF THE DAY. AS THIS OCCURS...THE DRY
AIR WILL LOSE ITS INFLUENCE GRADUALLY...AND PRECIP CHANCES WILL
INCREASE OVER CENTRAL AND EAST-CENTRAL WISCONSIN. THE RAIN SHOULD
REMAIN LIGHT...BUT INCREASING MID-LEVEL FGEN COMBINED WITH PWATS
OVER AN INCH SUPPORT LIKELY POPS OVER CENTRAL WISCONSIN AND THE
SOUTHERN FOX VALLEY DURING THE AFTERNOON. TEMPS ARE DIFFICULT
DEPENDING UPON THE COVERAGE OF RAIN OVER SOUTHERN WISCONSIN...AND
THE LACK OF LOW CLOUDS OVER NORTHEAST WISCONSIN. WILL GO WITH
FAIRLY UNIFORM TEMPS RANGING FROM THE UPPER 40S TO LOWER 50S.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
ISSUED AT 251 PM CDT SAT APR 26 2014
PCPN TRENDS THROUGHOUT THE PERIOD...AND STRONG E-NE WINDS EARLY
NEXT WEEK...ARE THE MAIN FCST CONCERNS.
AN UPPER LEVEL RIDGE WILL SHIFT NORTHEAST SUNDAY NIGHT AND
MONDAY...AS AN UPPER LEVEL LOW MOVES INTO SOUTH DAKOTA/NEBRASKA.
THIS WILL CAUSE PCPN TO SLOWLY SHIFT NE ACROSS THE FORECAST
AREA...ALTHOUGH ITS PROGRESS WILL BE SLOWED ACROSS FAR N/NE
WI...DUE TO DRY AIR FEEDING OUT OF A STRONG HUDSON BAY HIGH. HAVE
ADJUSTED POPS/QPF TO ACCOUNT FOR THE DRY AIR. FARTHER
SOUTH...ACROSS C/EC WI...QPF AMOUNTS WILL PROBABLY EXCEED AN INCH
FROM LATE SUNDAY NIGHT THROUGH MONDAY. A STRONG PRESSURE GERADIENT
WILL SET UP BETWEEN THE HUDSON BAY HIGH AND LOW PRESSURE
APPROACHING FROM THE NORTHERN PLAINS. EAST WINDS OF 15 TO 25
MPH...WITH GUSTS TO 30 TO 35 MPH...CAN BE EXPECTED ACROSS THE
REGION. STRONG NE WINDS (GUSTING TO 35 TO 40 MPH) ARE ALSO
POSSIBLE OVER THE FOX VALLEY MONDAY NIGHT INTO TUESDAY.
THE UPPER LEVEL LOW IS EXPECTED TO GRADUALLY SHIFT NE...REMAIN
OVER THE WESTERN GREAT LAKES FROM TUESDAY THROUGH THURSDAY...THEN
WEAKEN INTO AN OPEN TROF AND SHIFT NE INTO CANADA BY FRIDAY.
ALTHOUGH PCPN WILL BE IN THE FCST THROUGHOUT THE PERIOD...THE BEST
CHANCES SHOULD OCCUR AS STRONG S/W TROFS ROTATE THROUGH LATE
MONDAY NIGHT INTO TUESDAY MORNING...AND OVER NORTHERN WI LATE
TUESDAY NIGHT INTO WEDNESDAY. PCPN SHOULD BECOME MORE SCATTERED IN
NATURE DURING THE LATTER HALF OF THE WEEK.
OVERALL...MOST OF THE PCPN SHOULD FALL AS RAIN...ALTHOUGH A MIX
OF RAIN/SNOW IS POSSIBLE OVER PARTS OF NC/FAR NE WI LATE MONDAY
NIGHT AND EARLY TUESDAY...AND AT TIMES FROM WEDNESDAY NIGHT
THROUGH FRIDAY.
TEMPERATURES WILL REMAIN WELL BELOW NORMAL...WITH HIGHS IN THE
40S AND LOWER 50S...THROUGH MIOST OF THE PERIOD. SOME MODERATION
IS EXPECTED LATE IN THE WEEK AS THE UPPER LOW SHIFTS OUT OF THE
REGION.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1225 PM CDT SAT APR 26 2014
SCATTERED TO BROKEN MVFR CLOUDS ACROSS THE NORTHEAST
HALF OF WISCONSIN WILL LIFT TO MVFR BY MIDDAY...BUT WILL TAKE UNTIL
MID TO LATE AFTERNOON TO DISSIPATE. MID AND HIGH CLOUDS WILL THEN
ARRIVE LATER THIS AFTERNOON AND LOWER THROUGH THE EVENING AHEAD OF
THE NEXT STORM SYSTEM. MODELS TRY TO BRING LIGHT RAIN INTO CENTRAL
WISCONSIN AFTER MIDNIGHT TONIGHT...BUT THINKING DRY EAST FLOW WILL
DELAY THIS ARRIVAL OF PRECIP UNTIL AT LEAST SUNDAY MORNING.
UNCERTAINTY IS HIGH ENOUGH TO JUST INDICATE VCSH IN THE TAFS FOR
NOW. CEILINGS AND VISIBILITIES SHOULD REMAIN RELATIVELY HIGH EVEN
IF LIGHT RAIN DOES MOVE IN. BETTER CHANCES OF LIGHT RAIN WILL OCCUR
SUNDAY AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 251 PM CDT SAT APR 26 2014
RAINFALL TOTAL OF 1.5 TO 2.5 INCHES ARE EXPECTED ACROSS
THE SOUTHERN TWO-THIRDS OF THE FORECAST AREA FROM SUNDAY NIGHT THROUGH
WEDNESDAY. THIS COULD RESULT IN SOME MINOR RIVER FLOODING...AS SEVERAL
RIVERS STILL REMAIN ABOVE BANKFULL. PLAN TO ISSUE AN ESF AND MENTION
FLOODING CONCERNS IN THE HWO.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......MPC
HYDROLOGY......KIECKBUSCH
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1210 PM CDT SAT APR 26 2014
.UPDATE...AREA OF LOW CLOUDS HAVE MOVED SOUTHWESTWARD INTO THE
NORTHEAST COUNTIES THIS MORNING AND HAVE LINGERED. THE
SOUTHWESTWARD ADVANCE SEEMS TO HAVE STOPPED FOR THE MOMENT...AS
DAYTIME HEATING ERODES THE LEADING EDGE OF THIS CLOUD BAND.
COULD STILL SEE THIS BAND SLIDE A BIT FURTHER SOUTHWEST INTO THE
AREA INTO THE AFTERNOON HOURS. THESE CLOUDS SHOULD GRADUALLY
BECOME MORE SCATTERED TO BROKEN BY THE LATE AFTERNOON HOURS...WITH
DAYTIME HEATING. MIDDLE TO HIGH CLOUDS SHOULD MOVE EAST INTO THE
AREA THIS AFTERNOON AS WELL.
NORTHEAST WINDS WITH THE CLOUDS SHOULD KEEP HIGHS IN THE MID 40S
IN THE CLOUDY AREAS THIS AFTERNOON. MID 40S WILL ALSO BE FOUND
NEAR LAKE MICHIGAN WITH THE ONSHORE WINDS. HIGHS ELSEWHERE SHOULD
RISE INTO THE 50S...NEAR 60 IN LAFAYETTE COUNTY.
&&
.AVIATION/18Z TAFS/...AREA OF MVFR CEILINGS MAY AFFECT TAF SITES
THROUGH THE MID AFTERNOON HOURS. HOWEVER...CONFIDENCE IS LOW WITH
HOW FAR SOUTHWEST THEY WILL MOVE...SO WILL LEAVE FEW TO SCATTERED
IN TAFS FOR NOW. NORTHEAST WINDS WILL BECOME EAST THIS AFTERNOON
AT MADISON...WITH NORTHEAST WINDS AT THE EASTERN SITES. SHOULD SEE
GUSTS TO 18 KNOTS AT TIMES THIS AFTERNOON.
WINDS WILL VEER EAST TONIGHT AT THE EASTERN SITES...AND BECOME
STRONGER LATER TONIGHT INTO SUNDAY AT ALL SITES. GUSTS TO 30
KNOTS ARE EXPECTED BY LATER TONIGHT...LASTING INTO SUNDAY. SOME
35 KNOT GUSTS ARE POSSIBLE. THERE IS SOME LOW LEVEL WIND SHEAR
POTENTIAL TONIGHT INTO EARLY SUNDAY MORNING...AS 1500 FOOT WINDS
MAY REACH 45 KNOTS. HOWEVER...SURFACE WINDS AND GUSTS SHOULD BE
STRONG ENOUGH TO NEGATE MENTION FOR NOW.
VFR CEILINGS TONIGHT INTO SUNDAY WILL GRADUALLY LOWER. RAIN
SHOWERS ARE POSSIBLE MAINLY LATER TONIGHT INTO SUNDAY. FOR
NOW...WILL CONTINUE MENTION IN TAFS FOR MADISON. THE EASTERN
SITES MAY NOT SEE THE SHOWERS UNTIL SUNDAY NIGHT. MVFR CEILINGS
AND VISIBILITIES ARE POSSIBLE...BUT WILL LEAVE OUT MENTION DUE TO
LOW CONFIDENCE.
&&
.MARINE...NORTHEAST WINDS OF 15 TO 20 KNOTS ARE EXPECTED THIS
AFTERNOON...WITH WAVES OF 2 TO 4 FEET. A FEW GUSTS MAY REACH 22
KNOTS...BUT NOT FREQUENT ENOUGH TO ISSUE A SMALL CRAFT ADVISORY.
A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED FOR SUNDAY INTO AT
LEAST TUESDAY...WITH PERSISTENT AND GUSTY ONSHORE WINDS AS LOW
PRESSURE APPROACHES THE REGION. HIGH WAVES ARE LIKELY AS
WELL...BUILDING INTO THE 5 TO 10 FOOT RANGE BY SUNDAY NIGHT. DO
NOT THINK GALES WILL OCCUR SUNDAY...AS INVERSION ABOVE SURFACE
SHOULD LIMIT MIXING OF WINDS TO AROUND 30 KNOTS AT BEST.
&&
.PREV DISCUSSION... /ISSUED 347 AM CDT SAT APR 26 2014/
SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
SURFACE OBS AND LOCAL RADAR SHOW COLD FRONT HAD PUSHED THROUGH ALL
BUT THE FAR SW PORTION OF CWA BY 07Z. AS VORT MAX OVER THE SOO
MOVES OFF TO THE EAST OVER LAKE HURON...A COMBINATION OF 700 MB WARM
AIR ADVECTION AND CONVERGENCE ON PERIPHERY OF MID-LEVEL CYCLONIC
FLOW IS PRODUCING ACCAS SHOWERS OVER NRN IL...WELL DEPICTED ON 00Z
GFS AND HI-RES/RAPID UPDATE MODELS. STEEP LAPSE RATES ABOVE 850 MB
AND MEAGER ELEVATED CAPE...REFLECTED ON RAP SOUNDINGS...PRODUCING
LIGHT SHOWERS WITH REPORTS OF IN-CLOUD LIGHTNING OVER NRN IL. MODELS
ALL KEEP THIS BAND OUT OF THE CWA AS IT SHIFTS TO THE EAST-SOUTHEAST
OF IL BY 12Z.
SOUTHERN PORTION OF SURFACE HIGH SETTLING OVER STATE TODAY AND 500
MB RIDGING WILL KEEP THE DAYTIME HOURS DRY...WITH A COOL NORTHEAST
TO EAST WIND PREVENTING HIGHS IN THE LAKESHORE COUNTIES FROM GETTING
OUT OF THE 40S. LOW TO MID 50S EXPECTED WEST OF THE KETTLE
MORAINE...WITH MID-UPR 50S FROM MADISON WEST...WITH A 60 OR TWO IN
THE FAR SW.
MODELS DEPICTING NICE BAND OF MAINLY ISENTROPICALLY-DRIVEN 700 MB
OMEGA AND HIGHER RH CROSSING REGION AFTER 00Z SUNDAY...AND ARE
PRODUCING SOME LIGHT QPF. BUT SIMILAR TO EARLIER THIS WEEK...CROSS
SECTIONS AND FORECAST SOUNDINGS SHOWING RELATIVELY DRY EASTERLY FLOW
PREVENTING SATURATION BELOW 7K-8K FEET THROUGH MOST OF THE
NIGHT...WITH SOME SATURATION IN THE FAR WEST AFTER 06Z. WILL KEEP
POPS NO HIGHER THAN THE CHANCE CATEGORY PRIOR TO 12Z EXCEPT FOR LOW
LIKELY POPS IN THE EXTREME WEST AFTER 09Z.
SUNDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM.
THE OCCLUDED LOW PRESSURE SYSTEM WILL STALL OVER THE CENTRAL PLAINS
UNTIL EARLY NEXT WEEK. THE 925MB WARM FRONT WILL BE STATIONED ACROSS
NORTHERN IL ON SUNDAY...THEN CREEP NORTHWARD INTO FAR SOUTHERN WI
THROUGH MONDAY NIGHT. MEANWHILE...THE 850MB WARM FRONT WILL REMAIN
STATIONARY OVER CENTRAL WI.
THE INITIAL WARM AIR ADVECTION SHOWERS ON SUNDAY WILL STRUGGLE TO
OVERCOME THE LOW LEVEL DRY AIR IN PLACE. THE DEEP MOISTURE WILL
FINALLY ARRIVE SUNDAY EVENING AS WAVES OF VORTICITY AND WARM AIR
ADVECTION LEAD TO STRONG UPWARD MOTION OVER SOUTHERN WI. STEEP MID
LEVEL LAPSE RATES AND THE STRONG OMEGA WILL ALLOW FOR EMBEDDED
THUNDERSTORMS.
MODERATE RAIN SHOWERS WITH PERIODS OF HEAVY RAIN WILL BE POSSIBLE
SUNDAY NIGHT THROUGH MONDAY NIGHT. RAINFALL TOTALS DURING THIS TIME
ARE ESTIMATED TO BE IN THE 1.3 TO 1.8 INCH RANGE WITH THE HIGHER
TOTALS IN SW WI AND THE LOWER TOTALS OVER EAST CENTRAL WI. THIS RAIN
AND THE ADDITIONAL EXPECTED NEXT WEEK WILL CAUSE MANY RIVERS TO
REACH BANKFULL STAGE AND AT LEAST A FEW REACHING MINOR FLOOD STAGE.
PLAN ON BREEZY EAST WINDS SUNDAY AND MONDAY WITH THE SURFACE LOW
PARKED OVER NEBRASKA. THIS WILL KEEP TEMPERATURES VERY COOL IN THE
UPPER 40S AND LOWER 50S.
LONG TERM...
TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM.
THE OCCLUDED LOW WILL MEANDER NORTHEAST OVER THE UPPER GREAT LAKES
THROUGH THURSDAY. THE DRY SLOT IS EXPECTED TO ARRIVE INTO SOUTHERN
WI SOMETIME TUESDAY OR TUESDAY NIGHT WHICH WOULD CUT OFF THE DEEP
MOISTURE. CLOUDS AND SCATTERED SHOWERS WILL CONTINUE TO BE POSSIBLE
THROUGH FRIDAY DUE TO THE CYCLONIC FLOW AND LINGERING LOW LEVEL
MOISTURE. WINDS WILL GENERALLY BE OUT OF THE EAST FOR THE WEEK WHICH
MEANS COOLER NEAR THE LAKE WITH HIGHS IN THE UPPER 40S THERE AND
LOWER 50S INLAND.
MODELS ARE SHOWING ANOTHER UPPER TROUGH SWINGING DOWN THROUGH WI FOR
NEXT WEEKEND WHICH WOULD ALLOW FOR MORE CLOUDS AND SHOWERS. THERE IS
STILL UNCERTAINTY IN TIMING...SO THERE MAY BE A PERIOD OF DRY
WEATHER ON FRIDAY OR SATURDAY.
AVIATION/12Z TAFS/...
VFR CONDITIONS THROUGH THE PERIOD WITH RAIN EXPECTED TO HOLD OFF
UNTIL AROUND/SHORTLY AFTER 12Z SUNDAY...THOUGH A FEW SPRINKLES
POSSIBLER BEFORE...ESPECIALLY AT KMSN AND WEST.
NORTH WINDS THIS MORNING BEHIND COLD FRONT WILL TURN NORTHEAST AND
THEN EAST AS RIDGE OF SURFACE HIGH PRESSURE NOSES OVER STATE...THEN
INCREASE LATER TONIGHT WITH TIGHTENING GRADIENT AS RIDGE SHIFTS OVER
LOWER MICHIGAN AND DEEPENING LOW PRESSURE MOVES OUT INTO THE CENTRAL
PLAINS.
MARINE...
LOOKING AT NORTH WINDS THIS MORNING TURNING NORTHEAST AND EAST AS
RIDGE OF SURFACE HIGH PRESSURE NOSES DOWN OVER STATE AND LAKE
MICHIGAN...THEN INCREASE LATER TONIGHT WITH TIGHTENING GRADIENT AS
RIDGE SHIFTS OVER LOWER MICHIGAN AND DEEPENING LOW PRESSURE MOVES
OUT INTO THE CENTRAL PLAINS. THE SOMETIMES GUSTY ONSHORE WINDS ARE
EXPECTED TO PERSIST FROM SUNDAY INTO WEDNESDAY...AS THE LOW PRESSURE
SLOWLY APPROACHES THE AREA. THESE WIND GUSTS WILL LIKELY REACH SMALL
CRAFT CRITERIA AT TIMES....WITH WINDS JUST A FEW HUNDRED FEET OFF
THE SURFACE REACHING 40 KTS. DO NOT FEEL THESE STRONGER WINDS WILL
MIX DOWN THROUGH THE NEAR-WATER STABLE LAYER...BUT A FEW GALE GUSTS
ARE NOT OUT OF THE QUESTION...ESPECIALLY SUNDAY NIGHT INTO MONDAY
EVENING. THE ONSHORE WINDS SHOULD ALSO GENERATE WAVES IN THE 3 TO 6
FOOT RANGE. A SMALL CRAFT ADVISORY MAY BE NEEDED AT TIMES DURING
THIS PERIOD.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...WOOD
TODAY/TONIGHT AND AVIATION/MARINE...REM
SUNDAY THROUGH FRIDAY...MRC