Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 03/25/12
AREA FORECAST DISCUSSION...UPDATED
NWS PUEBLO CO
927 PM MDT SAT MAR 24 2012
.UPDATE...
UPDATED FORECAST TO PUT OUT A DENSE FOG ADVISORY FOR KIOWA
COUNTY...AND TO EXPAND AREAS OF FOG WESTWARD ACROSS CROWLEY AND
OTERO COUNTIES. LATEST SFC OBS ALREADY SHOWING DEW POINTS IN THE
UPPER 40S ADVECTING WESTWARD INTO SOUTHEAST CO. WITH FAIRLY STRONG
EAST TO SOUTHEAST WINDS...EXPECT SOME LOWER 50 DEW POINTS TO MAKE
IT INTO KIOWA AND PROWERS COUNTY TOWARDS MORNING. LATEST HRRR
LOOKS A BIT OVERLY AGGRESSIVE BRINGING LOW LEVEL MOISTURE BACK AS
FAR WESTWARD AS EL PASO AND PUEBLO COUNTIES...AND HAVE GONE WITH A
COMPROMISE BETWEEN THE HRRR AND DRIER NAM12 FOR THESE AREAS.
HOWEVER...APPEARS KIOWA COUNTY MAY HAVE THE BEST SHOT OF SEEING
SOME DENSE FOG FORMATION...THUS PER COORD WITH SURROUNDING
OFFICES...HAVE PUT OUT A DENSE FOG ADVISORY FOR THIS AREA. LATER
SHIFTS WILL NEED TO MONITOR PROWERS COUNTY AS WELL...BUT MODEL
SOUNDINGS ARE NOT AS IMPRESSIVE WITH LOW LEVEL MOISTURE ACROSS
THIS ZONE...WITH RUC13 KEEPING RICHER MOISTURE FARTHER EAST AND NORTH.
SO WILL LEAVE THIS ZONE OUT FOR NOW AND CONTINUE TO MONITOR. -KT
&&
.PREV DISCUSSION... /ISSUED 308 PM MDT SAT MAR 24 2012/
SHORT TERM...
(TONIGHT AND SUNDAY)
AN UPPER LEVEL RIDGE IS FORECAST TO SHIFT EAST INTO THE CENTRAL
PLAINS TONIGHT WITH INCREASING SOUTHWESTERLY FLOW EXPECTED ON
SUNDAY. CURRENTLY A WEAK SURFACE BOUNDARY HAS BEEN TRACKING SOUTH
ACROSS THE PLAINS. THE MAIN INFLUENCE OF THIS FRONT IS A NORTHERLY
WIND SHIFT AND A FEW BRIEF GUSTS OF WIND. TEMPERATURES HAVE
EXCEEDED OR TIED RECORDS AT COLORADO SPRINGS AND PUEBLO SO FAR THIS
AFTERNOON.
TONIGHT AND TOMORROW...GIVEN CLEAR SKIES AND DIMINISHING WINDS WILL
LEAD TO OVERNIGHT LOWS IN THE 40S ACROSS SOUTHERN COLORADO. MODELS
TRYING TO DEVELOP FOG OUT ALONG THE KANSAS BORDER WHERE WEAK
SOUTHEASTERLY UPSLOPE FLOW AND DEEPER MOISTURE RESIDE. THINK AREAS
UP THE ARKANSAS RIVER VALLEY NEAR THE KANSAS BORDER STAND THE BEST
CHANCE AT SEEING FOG FOR TONIGHT.
SOUTHWESTERLY FLOW INCREASES TOMORROW WITH THE MAIN CONCERN BEING THE
NEAR RED FLAG CONDITIONS FOR PORTIONS OF THE PLAINS. HUMIDITIES
WILL BE LOW GIVEN THE DOWNSLOPE SOUTHWESTERLIES AND DRY AIR MIXING
DOWN. WINDS LOOK MARGINAL...WITH A FEW AREAS SEEING GUSTS 20 TO 25
KTS DURING THE AFTERNOON. CAUTION IS ADVISED...ESPECIALLY SOUTH OF
HIGHWAY 50 AND ALONG THE KANSAS BORDER. OTHERWISE EXPECT WARM
TEMPERATURES WITH RECORD HIGHS ONCE AGAIN FOR SOUTHEAST COLORADO.
ALSO OF NOTE...MODELS HINTING AT AN ISOLATED THUNDERSTORM OVER THE
SOUTHERN SAN JUAN AND SANGRE DE CRISTO RANGES...BUT CURRENTLY THINK
THIS WILL ONLY AMOUNT TO CUMULUS BUILD UPS IN THE AFTERNOON GIVEN
LACK OF MOISTURE. 88
LONG TERM...
(SUNDAY THROUGH FRIDAY)
..CRITICAL FIRE WEATHER CONDITIONS EXPECTED ON MONDAY...
MAIN CONCERN THIS FCST PD IS FIRE WX CONCERNS ON MONDAY.
AS HAS BEEN FCSTD BY THE SIMULATIONS FOR DAYS...IT WILL LIKELY BE
VERY WINDY WITH LOW HUMIDITY VALUES OVER THE REGION ON MONDAY.
WIDESPREAD WINDS OF 30 TO 45 MPH WILL OCCUR BY AFTERNOON ACROSS THE
ENTIRE REGION AS A VIGOROUS SHORT WAVE MOVES TO OUR NORTH DURING
PRIME HEATING. LAPSE RATED OF 8.5 TO 9.5C/KM AND 50 KNOT 700 MB
WINDS WILL ALLOW FOR VERY GUST WINDS. WITH THE STRONG
WINDS...BLOWING DUST WILL BE AN ISSUE ONCE AGAIN DUE TO THE
SUSTAINED DROUGHT CONDITIONS. ALTHOUGH BACA COUNTY RECEIVED ALMOST AN
INCH OF RAIN THE OTHER DAY...I AM CONFIDENT THAT THIS AREA WILL DRY
OUT SIGNIFICANTLY (1 HOUR FUELS...I.E., GRASSES) BY THE TIME MONDAY
ROLLS AROUND.
THE DRYLINE WILL LIKELY MIX OUT INTO KS RELATIVELY EARLY IN THE
DAY...SO I DO NOT ANTICIPATE ANY CONVECTION ALONG THE BORDER ATTM.
IN THE MTNS...SHORT WAVE MAY BE CLOSE ENOUGH ALONG WITH STRONG LIFT
TO ALLOW FOR SOME SHOWERS ALONG THE CONTDVD...MAINLY OVER THE C
MTNS.
ONCE THIS TROUGH GOES BY...GENERAL WEAK WSW FLOW ALOFT WILL BE OVER
THE REGION THROUGH LATE WEEK. WX DURING THIS PD WILL BE SEASONAL
WITH ABOVE NORMAL TEMPS.
A WEAK TROUGH AT MID LVLS WILL MOVE ACROSS THE REGION ON FRIDAY. NO
SENSIBLE WX WILL LIKELY OCCUR WITH IT. TEMPS WILL COOL A COUPLE OF
DEGREES AS COMPARED TO THURSDAY.
WE WILL LIKELY NOT SEE ANY PRECIP AT KCOS...KPUB OR KALS THROUGH THE
END OF THE MONTH. TO DATE...AT KPUB WE HAVE RECEIVED 0.11
INCHES...OUR NORMAL IS 0.93. AT KCOS...WE HAVE RECEIVED 0.06...THE
NORMAL IS 1.00 INCHES. AT KALS WE RECEIVED 0.10...NORMAL IS 0.53.
WITHOUT SAYING...WE NEED PRECIP. /34
AVIATION...
VFR CONDITIONS AT ALL TERMINALS THROUGH THE NEXT 24 HOURS. 88
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING
FOR COZ221-222-226>237.
DENSE FOG ADVISORY FROM 2 AM TO 8 AM MDT SUNDAY FOR COZ095-096.
&&
$$
31/44
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1121 PM EDT SAT MAR 24 2012
.SYNOPSIS...
SLOW MOVING LOW PRESSURE OVER THE SOUTHERN MID ATLANTIC REGION WILL
PASS TO THE SOUTH SUNDAY NIGHT...THEN HEAD NORTHEAST OUT TO SEA AND
STRENGTHEN AFTER A COLD FRONT MOVES THROUGH MONDAY MORNING.
HIGH PRESSURE WILL THEN BUILD IN FROM THE NORTH MONDAY AFTERNOON
THROUGH TUESDAY...AND THEN SLIDE EAST TUESDAY NIGHT. LOW PRESSURE
AND AN ASSOCIATED FRONTAL SYSTEM WILL MOVE ACROSS FROM WEDNESDAY
INTO EARLY THURSDAY...FOLLOWED BY HIGH PRESSURE LATER THURSDAY INTO
FRIDAY. A WARM FRONT WILL APPROACH LATE FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
RAIN ASSOCIATED WITH THE LOW TO OUR SW IS FINALLY OVERCOMING LOW
LEVEL DRY AIR IN THE NYC METRO AREA...SO HAVE ADJUSTED OVERNIGHT
POP ACCORDINGLY...WITH ALL AREAS EVENTUALLY GETTING SOME SHOWERS
OVERNIGHT. BACK EDGE OF THESE SHOWERS MOVING SLOWLY N FROM
SOUTHERN NJ SHOULD REACH THE NYC METRO AREA IN THE PREDAWN HOURS.
THE INCOMING 00Z NAM APPEARS TO AGREE WITH THIS ENDING
TIME...THOUGH THE 00Z HRRR HINTS THAT ADDITIONAL SHOWERS COULD
FILL IN TO THE SW AND SPREAD INTO THE AREA INTO THE EARLY DAYLIGHT
HOURS.
SOME ELEVATED INSTABILITY PRESENT BUT AT LEVELS TOO LOW
TO PRODUCE THUNDER. EARLIER MAV/MET MOS BLEND LOOKED GOOD FOR
LOWS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
LOW PRESSURE CENTER EMERGES OFF THE MID ATLANTIC COAST AND CONTINUES
TO HEAD EAST DURING THE DAY ON SUNDAY. WITH THE ISENTROPIC LIFT
EXITING THE EASTERN ZONES IN THE MORNING...THE ONLY OTHER SOURCES OF
LIFT WILL BE A WEAK MID LEVEL SHORTWAVE ENTERING DURING THE
AFTERNOON HOURS...WITH PERHAPS A LITTLE BIT OF ADDITIONAL SYNOPTIC
LIFT SUPPLIED BY AN UPPER JET STREAK. POPS THEREFORE NO HIGHER THAN
THE CHANCE CATEGORY ONCE THE MAIN BATCH OF RAIN EXITS TO THE EAST IN
THE MORNING. THE AFTERNOON COULD VERY WELL END UP COMPLETELY DRY FOR
MOST SPOTS. LEANED A LITTLE MORE TOWARDS THE COOLER NAM MOS FOR
HIGHS...BUT THIS STILL YIELDS HIGHS WARMER THAN NORMAL.
THE LOW BEGINS TO HEAD NORTHEAST SUNDAY NIGHT...BUT ONLY A SLIGHT
CHANCE OF A SHOWER FOR US EARLY IN THE EVENING...ASSOCIATED WITH THE
SHORTWAVE. DRY THEN FOR THE REST OF SUNDAY NIGHT.
ON MONDAY...WITH THE STORM CENTER HEADING NE FARTHER OUT TO SEA...A
COLD FRONT DROPS DOWN FROM THE NORTH EARLY ON. WITH LIMITED MOISTURE
DURING ITS PASSAGE...WILL GO WITH A DRY FORECAST. A STRONG MID LEVEL
SHORTWAVE FOLLOWS LATE IN THE DAY INTO THE EVENING HOURS...BUT AGAIN
NO RAINFALL EXPECTED WITH IT...JUST SOME CU BUILDUP AT BEST.
THE PRESSURE GRADIENT WILL TIGHTEN THROUGH THE DAY AS HIGH PRESSURE
BUILDS IN FROM THE NORTH...THIS COMBINED WITH STRONG COLD AIR
ADVECTION WILL BRING US A BREEZY DAY WITH GUSTY WINDS.
HIGH TEMPERATURE FORECAST FOR MONDAY WILL BE A LITTLE TRICKY WITH
THE COLD AIR ADVECTION INCREASING AS THE DAY WEARS ON. BUT AT THE
SAME TIME...STRONG DOWNSLOPING COULD OFFSET THIS A LITTLE. IT MIGHT
NOT BE THE TYPICAL DIURNAL HEATING PATTERN...AND HIGHS COULD BE
ACHIEVED NEAR NOONTIME INSTEAD OF MID-LATE AFTERNOON. TOOK A BLEND
OF THE NAM/MAV MOS FOR HIGHS...WHICH ENDS UP A LITTLE ABOVE NORMAL
FOR THIS TIME OF THE YEAR.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
A DEEP UPPER TROUGH WILL MOVE TO THE EAST MON NIGHT INTO EARLY TUE
MORNING...WITH THE AREA CAUGHT BETWEEN INTENSIFYING LOW PRESSURE SE
OF NOVA SCOTIA...AND A STRONG HIGH BUILDING S FROM HUDSON BAY.
THE TIGHT PRESSURE GRADIENT BETWEEN THE TWO WILL PRODUCE COLD AND
BRISK CONDITIONS MON NIGHT INTO EARLY TUE AFTERNOON. SIDED WITH
WARMER MAV MOS GUIDANCE VS NAM FOR LOWS MON NIGHT...BUT EVEN SO MON
NIGHT WILL BE QUITE COLD...WITH LOWS ABOVE FREEZING ONLY IN
NYC...BELOW 30 OUTSIDE THE NYC METRO AREA...AND POSSIBLY CLOSING IN
ON 20 IN SOME OF THE INTERIOR VALLEYS...ESPECIALLY IF WINDS DROP OFF
VERY LATE AT NIGHT. WIND CHILLS ACROSS THE INTERIOR WILL ALSO DROP
INTO THE TEENS LATE MON NIGHT.
DESPITE THE COLD OF MON NIGHT...RISING HEIGHTS ALOFT SHOULD ACTUALLY
HELP KEEP HIGHS NEAR AVG ON TUE. FULL MIXING OF 875 MB TEMPS NEAR
-2C PLUS DOWNSLOPE FLOW WILL RESULT IN HIGHS IN THE LOWER 50S IN NYC
AND COASTAL SECTIONS...AND UPPER 40S INLAND. MORE ROBUST WAA SHOULD
TAKE PLACE TUE NIGHT-WED IN RETURN S-SW FLOW AS THE HIGH SLIDES TO
THE E-SE AND A WARM FRONT APPROACHES...WITH HIGHS REBOUNDING TO THE
UPPER 50S/LOWER 60S. EXPECT A CHANCE OF SHOWERS MAINLY WED
AFTERNOON/NIGHT AS THIS FRONT MOVES THROUGH AND A COLD FRONT
TRAILING FROM LOW PRESSURE PASSING TO THE NORTH APPROACHES...THEN
ONLY SLIGHTLY COOLER BUT STILL ABOVE AVG TEMPS ON THU/FRI AS ANOTHER
HIGH BUILDS IN...WITH 50S TO NEAR 60. AFTER THIS HIGH MOVES EAST...
ANOTHER WARM FRONT WILL APPROACH LATE FRI NIGHT INTO SAT WITH
ANOTHER CHANCE OF SHOWERS.
NOTE FOR AGRICULTURAL CONCERNS...TEMPS WILL FALL TO AT OR JUST BELOW
FREEZING JUST OUTSIDE OF NYC...AND INTO THE 20S OVER THE LOWER
HUDSON VALLEY...INTERIOR NE NJ...SOUTHERN CT...AND CENTRAL/EASTERN
LONG ISLAND. SUB-FREEZING TEMPS ARE ALSO POSSIBLE TUE NIGHT OUTSIDE
OF URBAN CENTERS IF RADIATIONAL COOLING CONDITIONS ARE RIGHT.
WINDS WILL BE LIGHT BUT SOME MID LEVEL CLOUDS PASSING THROUGH MAY
MITIGATE THIS SOMEWHAT.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
A WARM FRONT WILL REMAIN TO THE SOUTH...WHILE LOW PRESSURE MOVES
SLOWLY ACROSS THE SOUTHERN MID ATLANTIC REGION.
SPOTTY LIGHT RAIN AND MVFR CIGS ARE ABOUT TO MOVE INTO THE NYC
METRO AREA...AND SHOULD SPREAD INTO AREAS FARTHER NORTH/EAST
AFTER MIDNIGHT. EXPECT PRIMARILY MVFR CONDITIONS...BUT CANNOT
TOTALLY RULE OUT TEMPO IFR CIGS NEAR OR JUST AFTER DAYBREAK...
FROM ABOUT 09Z-13Z. WITH WEAK E-NE FLOW AND LOW MOISTURE WILL NOT
GOING ANYWHERE FAST AFTER DAYBREAK...SO MVFR CONDITIONS SHOULD
LAST INTO EARLY AFTERNOON...WITH SLOW IMPROVEMENT TO VFR BY MID TO
LATE AFTERNOON EXCEPT AT KGON.
OUTLOOK FOR 00Z MON THROUGH THU...
.SUNDAY NIGHT...LINGERING MOISTURE AND LIGHT WINDS COULD LEAD TO LOW
CLOUDS AND/OR FOG WITH SUB-VFR CONDITIONS LATE...ESPECIALLY AT
KHPN/KISP/KBDR/KGON.
.MON-TUE...VFR. COLD FROPA MON MORNING...FOLLOWED BY GUSTY NW-N
FLOW. DIMINISHING WINDS TUE AFTERNOON.
.WED...MVFR CONDITIONS ARE POSSIBLE IN THE AFTERNOON AND AT NIGHT AS
LOW PRESSURE AND A WARM FRONT APPROACH. GUSTY SW FLOW IN
THE AFTERNOON.
.THU...VFR. GUSTY NW FLOW.
&&
.MARINE...
E FLOW AROUND 15 KT WILL PERSIST TONIGHT...AND OCEAN SEAS MAY COME
VERY CLOSE TO REACHING 5 FT. ANY GUSTS TO 25 KT AT THE SAME TIME
WOULD BE OCCASIONAL. HAVE THEREFORE HELD OFF ON ISSUING SCA.
WAVEWATCH APPEARS TO BE TO HIGH GIVEN THE WIND FORECAST AND LACK OF
A SIGNIFICANT SWELL LATE TONIGHT INTO SUNDAY NIGHT...AND HAVE KEPT
SEAS BELOW 5 FT. WINDS WILL AT LEAST DIMINISH DURING SUNDAY AND
SUNDAY EVENING.
FOR MON/MON NIGHT...AT LEAST AN SCA WILL LIKELY BE NEEDED BY
AFTERNOON...AND POSSIBLY A GALE WARNING ESPECIALLY ON THE OCEAN.
WINDS WILL STRENGTHEN AFTER A COLD FRONTAL PASSAGE MON
MORNING...WITH A TIGHTENING PRESSURE GRADIENT AND STRONG COLD AIR
ADVECTION MOVING IN. WILL CONTINUE TO MENTION THE THREAT OF GALES IN
THE HWO.
CONDS SHOULD GRADUALLY FALL THROUGH SCA AND THEN BELOW ON TUE.
SCA CONDS POSSIBLE ONCE AGAIN ON THE OCEAN WATERS WED
AFTERNOON/NIGHT IN STRENGTHENING S-SW FLOW AHEAD OF A COLD FRONT...
AND AGAIN THE AFTERNOON/EVENING IN POST-FRONTAL NW FLOW.
&&
.HYDROLOGY...
RELATIVELY DRY CONDITIONS WILL CONTINUE...WITH NO SIGNIFICANT QPF OF
1/2 INCH OR MORE EXPECTED FOR THE NEXT 7 DAYS. IN FACT...THE U.S.
DROUGHT MONITOR CATEGORIZES SE CT AS BEING IN MODERATE DROUGHT...AND
THE REST OF THE REGION AS ABNORMALLY DRY.
&&
.TIDES/COASTAL FLOODING...
A PERSISTENT EAST TO NORTHEAST FLOW WILL EXIST TONIGHT INTO SUNDAY
MORNING AS MID ATLANTIC LOW PRESSURE TRACKS SOUTH AND THEN EAST
OF THE AREA. THERE IS ONLY A LOW POTENTIAL AT BEST FOR MINOR
COASTAL FLOODING...AS 1 1/2 TO 2 FT POSITIVE DEPARTURES ARE NEEDED
TO REACH THESE THRESHOLDS. BASED ON CURRENT DEPARTURES AND LATEST
MODEL GUIDANCE...FLOODING IS NOT EXPECTED TONIGHT OR SUNDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JC
NEAR TERM...JC/GOODMAN
SHORT TERM...JC
LONG TERM...GOODMAN
AVIATION...GOODMAN
MARINE...JC/GOODMAN
HYDROLOGY...JC/GOODMAN
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
936 PM EDT SAT MAR 24 2012
.SYNOPSIS...
LOW PRESSURE WILL TRACK SOUTH OF US AND MOVE OFF THE COAST SUNDAY
EVENING. A COLD FRONT WILL MOVE THROUGH THE AREA DURING THE DAY ON
MONDAY. HIGH PRESSURE WILL THEN ARRIVE FOR TUESDAY AND PERSIST
THROUGH EARLY WEDNESDAY. A WARM FRONT IS FORECAST TO LIFT
NORTHEASTWARD TOWARD THE REGION LATE ON WEDNESDAY. ANOTHER COLD
FRONT, MOVING IN FROM THE WEST, SHOULD WORK ITS WAY THROUGH THE
AREA ON WEDNESDAY NIGHT. MORE HIGH PRESSURE IS FORECAST FOR
THURSDAY, FRIDAY, AND POSSIBLY SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
THE UPPER LOW ACROSS THE OHIO VALLEY WILL MOVE EWRD TONIGHT INTO
THE CAROLINAS. A SFC LOW WILL MOVE A LITTLE AHEAD OF THE UPPER LOW
AND CAUSE A FRONTAL SYSTEM TO APPROACH THE AREA TONIGHT. THE
REGIONAL RADARS ARE SHOWING SHOWERS APPROACHING FROM THE SW ATTM.
THESE SHOWERS WILL BE ACROSS THE AREA EARLY TONIGHT ALONG WITH
AREAS OF FOG WHICH SHOULD DEVELOP TOO. THE FOG WILL PROBABLY BE
MORE ABUNDANT NEAR THE SHORE...BUT WAS INCLUDED IN ALL AREAS WITH
THIS FCST. RAINFALL TOTALS WILL BE AROUND A TENTH TO ONE QUARTER
INCH. LOW TEMPERATURES WILL RANGE FROM THE LOW OR MID 50S ACROSS
THE DELMARVA TO THE LOW/MID 40S ACROSS THE NRN AREAS. WINDS WILL
BE ERLY AT 5 TO 10 MPH. BASED ON LATEST RADAR TRENDS, HAVE LOWERED
POPS FOR NEXT FEW HOURS. HRRR DATA INDICATES AN INCREASE IN PRECIP
AGAIN AFTER 02 OR 03Z, SO DIDN`T WANT TO CHANGE TOO MUCH, BUT
LATEST RADAR DOESN`T HAVE THAT MUCH BEHIND ONES BAND OF SHOWERS IN
SRN NJ.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
SLOW IMPROVEMENT IN THE WEATHER FOR SUNDAY. THE LOW PRESSURE SYSTEM
WILL BE OFFSHORE AND MOVING TO THE NORTHEAST. IT WILL SLOWLY
STRENGTHEN AND BRING MORE OF A NERLY THEN NRLY WINDS ACROSS THE
AREA. WHILE CLOUDS ARE EXPECTED MUCH OF THE DAY...A GRADUAL
IMPROVEMENT SHOULD OCCUR LATE. A FEW LINGERING SHOWERS ARE POSSIBLE
SOUTH AND EAST MOSTLY DURING THE MORNING. HIGHS ON SUN WILL BE
SOMEWHAT DEPENDENT ON HOW MUCH SUN BREAK OUT LATE IN THE DAY...I
HAVE GONE MOSTLY MID TO UPPER 60S ATTM WITH UPPER 50S ACROSS THE SRN
POCONOS...THIS IS A FEW DEGREES LOWER THAN WHAT THE GUIDANCE TEMPS
HAVE. WINDS WILL BE MOSTLY LIGHT ON SUNDAY...MOSTLY NE OR N AT 5 TO
10 MPH.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
THE MID-LEVEL LOW AXIS IS FORECAST TO SHIFT OFF THE COAST SUNDAY
NIGHT BRINGING AN END TO THE SHOWER THREAT. WHILE A DRY COLD FRONT
ON MONDAY WON`T BRING ANY RAIN TO THE REGION, IT WILL PROVIDE A
CHANGE IN AIRMASS. WITH IT`S STRONG CAA AND GUSTY WINDS, MARCH
26TH WILL ACTUALLY FEEL LIKE MARCH 26TH, NOT APRIL OR MAY 26TH. A
SURFACE HIGH, CENTERED ACROSS ONTARIO, MONDAY NIGHT WILL BEGIN TO
SAG INTO THE REGION BRINGING WITH IT A LITTLE LESS GRADIENT. THE
HIGH WILL BE ON TOP OF US ON TUESDAY AND WILL MOVE TO THE COAST ON
TUESDAY NIGHT. LOOKS LIKE A WARM FRONT IS GOING TO APPROACH US
FROM THE SOUTH ON WEDNESDAY, BUT STRUGGLE TO MOVE THROUGH. WHAT`S
MORE CERTAIN IS THE COLD FRONT, COMING IN FROM THE WEST, THAT WILL
CROSS THE REGION ON WEDNESDAY NIGHT. HIGH PRESSURE IS FORECAST TO
BUILD IN BEHIND THIS FRONT AND PERSIST INTO FRIDAY AND MAYBE EVEN
SATURDAY.
NO HEAVY PRECIPITATION IS EXPECTED THROUGH THIS PERIOD. SHOWERS WILL
BE CARRIED SUNDAY NIGHT, AT LEAST EARLY, AND AGAIN ON WEDNESDAY
INTO THURSDAY WITH THE MIDWEEK COLD FRONT.
AS FOR TEMPERATURES, NOT MUCH CHANGE FROM YESTERDAY. WE`LL SEE MORE
CHANGEABLE CONDITIONS, SYNONYMOUS OF SPRING. MONDAY SHOULD BE ABOVE
NORMAL (ALTHOUGH THE NAM MOS SAYS OTHERWISE), TUESDAY AROUND NORMAL,
WEDNESDAY/THURSDAY ABOVE NORMAL, AND BACK TO NEAR NORMAL
FRIDAY/SATURDAY.
THE REGION WILL SEE SOME 30S NEXT WEEK IN THE MORNING. THE COLDEST
MORNING STILL LOOKS TO BE TUESDAY WHERE WE SHOULD SEE SUB-FREEZING
TEMPERATURES. NOT A GOOD THING FOR SENSITIVE VEGETATION/TREES THAT
HAVE GOTTEN OFF TO A TWO TO FOUR WEEK HEAD START THANKS TO WHAT
COULD AMOUNT TO A TOP 3 MARCH TEMP-WISE.
&&
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
CONDITIONS WERE MAINLY VFR AND MVFR ERLY THIS EVENING. LATEST
GUIDANCE CONTINUED TO INDICATE DETERIORATION WILL BEGIN LATER THIS
EVENING AS ANOTHER AREA OF SHOWERS AND DEEPER MOISTURE
ARRIVE...WITH FLYING CONDITIONS EXPECTED TO GO IFR IN MOST AREAS
AFTER MIDNIGHT. ONLY SLOW IMPROVEMENT WILL OCCUR SUNDAY
MORNING...SINCE THE SFC/UPPER LOW MOVING ACROSS THE AREA WILL NOT
BE MOVING THAT FAST. BETTER CONDITIONS WILL ARRIVE LATER
SUNDAY...ONCE THE SYSTEM MOVES AWAY AND SFC WINDS TURN MORE TOWARD
THE N OR NW.
OUTLOOK...
SUNDAY NIGHT...VFR.
MONDAY...VFR WITH A GUSTY NORTHWEST WIND.
MONDAY NIGHT THROUGH TUESDAY NIGHT...VFR.
WEDNESDAY...MAINLY VFR. BUT A CHANCE OF SHOWERS WITH THE COLD FRONT.
THURSDAY...MAINLY VFR WITH SOME REMNANT POST FRONT SHOWERS POSSIBLE.
&&
.MARINE...
EAST WINDS HAVE REMAINED AROUND 10 TO 15 KTS ON THE WATERS
TODAY...THE DEVELOPING SFC LOW TO THE SOUTH SHOULD KEEP WINDS
MOSTLY ERLY TONIGHT. A SCA FLAG WILL PROBABLY NOT BE NEEDED
TONIGHT...BUT SEAS MAY GET CLOSE TO 5 FT...WE MAY HAVE TO ISSUE
SCA IF THE SEAS GET OVER 5 FT. LOW CONFID IN THIS ATTM. WINDS WILL
SLACKEN SUN MORNING AS THE SFC PRESSURE TROUGH CROSSES THE WATERS.
WINDS WILL SLOWLY VEER NERLY THEN NRLY ON SUNDAY. AREAS OF SHOWERS
AND FOG WILL BE ON THE WATERS TONIGHT AND SUN MORNING.
OUTLOOK...
A STRONG COLD FRONT, FROM THE NORTHWEST, IS EXPECTED TO CROSS THE
COASTAL WATERS OF NEW JERSEY AND DELAWARE ON MONDAY. HIGH PRESSURE
WILL FOLLOW AND PERSIST THROUGH LATE TUESDAY. A WARM FRONT IS
ANTICIPATED TO APPROACH FROM THE SOUTHWEST ON WEDNESDAY FOLLOWED BY
A COLD FRONT ON WEDNESDAY NIGHT.
A SMALL CRAFT ADVISORY MAY BE NEEDED FROM MONDAY INTO TUESDAY
MORNING FOR THE GUSTY NORTHWEST WINDS IN THE COLD ADVECTION.
ISOLATED GALE FORCE GUSTS MAY OCCUR FROM LATE MONDAY INTO MONDAY
NIGHT.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KRUZDLO
NEAR TERM...NIERENBERG/O`HARA
SHORT TERM...O`HARA
LONG TERM...KRUZDLO
AVIATION...KRUZDLO/NIERENBERG/O`HARA
MARINE...KRUZDLO/O`HARA
AREA FORECAST DISCUSSION...UPDATED
NWS TALLAHASSEE FL
1014 PM EDT Sat Mar 24 2012
.NEAR TERM (TONIGHT)...
The severe threat discussed in the previous AFD has diminished. A
few showers are popping up behind the frontal line from central
Mitchell to the Worth-Colquitt county border and into Tift. However
these showers aren`t in a region of as much instability as the
storms near Valdosta earlier this evening. Even when they interacted
with the outflow boundary from the earlier storms, they aren`t
developing further. Modified 02Z RUC VLD soundings lifted from 76/66
have a CAPE of only about 1000 J/kg...500 J/kg less than the
smallest estimated CAPE for 01Z. Lows tonight will be in the mid 50s
for most of the forecast area, upper 50s along the coast.
&&
.MARINE (TONIGHT THROUGH THURSDAY)...
A surge of 15-kt winds along the northeastern GOMEX coast will cause
some 4 ft waves overnight. A very week pressure gradient for Monday
into Tuesday will keep winds and seas minimal. Easterly flow will
increase by mid-week as high pressure builds along the eastern
seaboard.
&&
.AVIATION (THROUGH 00Z MONDAY)...
Isolated showers will remain possible in the vicinity of residual
outflow boundaries from earlier convection. These should stay away
from the VLD and ABY terminals and dissipate by ABOUT 04Z. Winds
will shift to the northwest behind a cold front with clear skies
forecast for Sunday. Winds will occasionally gust to 20 kt after 14Z
with sustained winds running 10-13 knots.
&&
.FIRE WEATHER...Drier air will be spreading across the Tri-State
Area tonight and Sunday, on the heels of a cold front that has
pushed south and east of the area. Relative humidities are forecast
to fall to critical levels across all but the immediate coastal
areas of the eastern Florida Panhandle and Big Bend on Sunday
afternoon. In addition, dispersion indices across the Florida zones
are expected to exceed 75, and a Red Flag Warning has been issued
for all but the coastal zones. On Monday and Tuesday, relative
humidities are expected to approach or briefly drop below red flag
criteria. However...durations are not expected to be met.
&&
.PREV DISCUSSION (628 PM EDT Sat Mar 24 2012)...
SHORT TERM (Tonight through Monday night)...Cold front associated
with the deep upper low will finally exit the forecast area this
evening. Showers and thunderstorms will likely linger into the
mid-evening hours over the eastern big bend before ending by
midnight. With the latest VWP data showing winds veering
substantially at KVLD, severe threat should be rather low.
A drier airmass will arrive in the wake of the front. This will
allow overnight lows to fall back into the lower to mid 50s for
the next few nights. However, highs will continue to reach the
lower to mid 80s each afternoon. After this evening, no rain is
expected through Monday night.
LONG TERM (Tuesday through next Saturday)...There is good
consensus between the models that the long term period will remain
rather calm, with a benign weather pattern in place. The northern
stream flow will remain across the northern half of the country
through the period, with a chain of shortwaves forecast to pass
through it. Across the southern part of the country, a mix of
ridging and a zonal flow regime will dominate. As each of the
aforementioned shortwaves pass well north of the local area, they
will have little effect on the local weather, with the exception
of dampening any ridging that is occurring over the southeastern
part of the country. The result of this pattern will be dry and
warm afternoons, with mild evenings. Temperatures are forecast to
climb into the lower to middle 80s each afternoon, with low
temperatures bottoming out in the middle to upper 50s. No
mentionable rain chances exist through the period.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 54 81 52 84 53 / 10 0 0 0 0
Panama City 59 79 60 79 61 / 10 0 0 0 0
Dothan 54 80 55 84 56 / 0 0 0 0 0
Albany 53 79 53 82 55 / 10 0 0 0 0
Valdosta 54 79 53 82 54 / 20 0 0 0 0
Cross City 58 81 52 83 53 / 50 10 0 0 0
Apalachicola 59 76 57 77 60 / 10 0 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...Red Flag Warning from 2 PM EDT /1 PM CDT/ to 7 PM EDT /6 PM CDT/
Sunday for Calhoun-Central Walton-Gadsden-Holmes-Inland Bay-
Inland Dixie-Inland Franklin-Inland Gulf-Inland Jefferson-
Inland Taylor-Inland Wakulla-Inland Walton-Jackson-
Lafayette-Leon-Liberty-Madison-Washington.
GM...None.
&&
$$
Aviation...Wool
Marine...Camp
Fire Weather...Duval
Previous Discussions...Camp/Harrigan
Rest of Discussion...Moore
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
340 PM EDT Fri Mar 23 2012
.SYNOPSIS...
19Z water vapor and H4 RUC analysis shows northern stream upper
level flow arriving over the northern California/Oregon coast
before ridging well to the north over south-central Canada. Main
feature of note to the south of this flow is the large and stubborn
upper level low spinning over the middle of the country. Upper level
ridge that had been in control of our region is begin de-amplified
and pushed to the east as the previously mentioned upper low begins
to migration toward the eastern seaboard.
At the surface, forecast are resides between a large area of high
pressure off the SE coast, and a weak cold front currently extending
from the western TN valley to the north-central Gulf of Mexico. Deep
southerly flow is begin experienced between these two features into
our zones providing abundant low level moisture. WAA, a slow
increase in synoptic support, and surface focus ahead of the front
are supporting a band of showers and thunderstorms from the open
waters south of Mobile northward to the FL panhandle/eastern
AL/western GA. A few of these storms have shown a tendency to rotate
over the past few hours, and will need to monitored closely.
&&
.SHORT TERM (Tonight through Sunday Night)...
Tonight,
Upper level low will slowly drift eastward with the main cool pool
influence remaining to our north. Several guidance members show a
rapid decrease in convective coverage this evening as the band of
frontal showers/storms continues it painfully slow eastward trek.
Difficult to determine why this decrease is being advertised...and
also having a hard time believing this forecast philosophy due to
the continued deep convection and extensive area of regenerating cold
cloud tops off the MS delta late this afternoon. Would not be
surprised to some decrease in the strength of convection after the
loss of diurnal heating, but will be keeping chance PoPs for showers
and storms in the grids.
Saturday,
Late tonight as we approach dawn, the upper low begins to pivot back
Southward and we see slightly better height falls/QG forcing
overspreading the NE gulf. Global guidance and several CAM members
show a resurgence of convection beginning at this time and
continuing into Saturday morning ahead of the front. This seems
reasonable and will show likely rain chances around 60% along and
east of a line roughly from Panama City to Albany. Still expecting a
scattering of showers to the west of this line during the morning
hours, however with the passage of the surface front by early
afternoon will see drier air and falling rain chances for these
western zones.
This will be at least a marginal threat for some strong to severe
thunderstorms over mainly the eastern half of the region during the
daylight hours of Saturday. Currently the most favorable
kinematics/thermodynamics appear to align a bit to our NE tomorrow,
however with 30-40kts of deep layer shear present, the potential for
organized updraft will exist, especially if we experience enough
sunny breaks to add to the instability. Will continue to monitor
this situation, and a more detailed briefing packet on the threat is
available at
http://www.srh.noaa.gov/images/tae/briefing/EMBriefingMarch232012.pdf
.
Saturday Night,
Upper level low begins to make more progressive progress. Energy
rounding the base of the low now looks to give the final push to
accelerate the surface front south and eastward out of our region.
Therefore will see the last of the showers/storms over the SE Big
Bend zones ending during the pre-dawn hours. The arrival of a drier
airmass will allow temps to drop into the 50s by sunrise.
Sunday/Sunday Night,
A pleasant and dry day on tap for the second half of the upcoming
weekend. Deep layer NW flow will continue to supply a drier airmass
to the region with just a sct fair weather cumulus field developing
in the afternoon. Despite 850mb temps dropping to between 8-9C,
decent diurnal mixing and the stronger late March sun should still
allow our temperatures to rise to within a couple of degrees of 80.
A secondary trough or dry frontal passage will occur Sunday evening
setting up several days of dry and seasonable weather for the
beginning of next week.
&&
.LONG TERM (Monday through next Friday)...
The closed upper low and associated trough will be exiting off the
mid-Atlantic coast Sunday night. A low amplitude upper ridge will
build in from the west early next week. The ridge flattens to nearly
zonal by Thursday as a strong shortwave translates across the
northern tier states into New England. The GFS shows a shortwave
tracking across Texas Thursday lifting into the Missouri/Tennessee
Valleys with a spoke of energy extending SEWD into our region by the
end of the period.
At the surface, high pressure centered north of the Great Lakes
Monday night will drop south-southeast becoming centered east of the
Carolina`s on Wednesday. The high slides east thereafter with the
ridge axis dropping south across the Florida peninsula and allowing
a cold front to drop down from the north. This boundary may slip
into our northern zones Friday before lifting north as a warm front
late in the day in response to the next cold front advancing from
the west. Temperatures will continue above seasonal levels through
the extended period.
&&
.AVIATION...
SCT TSRA will impact area terminals through the remainder of the
afternoon and into the evening. After a break overnight, rain and
thunderstorms are expected to resume around sunrise Saturday.
Outside of the thunderstorms, expect VFR conditions through the
evening, with MVFR cigs late tonight into tomorrow morning.
&&
.MARINE...
A weak cold front will approach the forecast water tonight and cross
from west to east during the Saturday. Winds may approach cautionary
levels at times ahead of the front, but not anticipating advisory
conditions. Cold front will exits south of the area Saturday night
turning winds offshore for the second half of the weekend.
&&
.FIRE WEATHER...
It is likely that many areas will see a wetting rain ahead of an
approaching cold front between this afternoon and Saturday
afternoon. The cold front will be slow to move across the region on
Saturday. However, it does appear that it will clear our Southeast
AL and inland FL Panhandle counties (along and north of I-10) early
enough to allow afternoon relative humidity to drop below 35
percent. Forecast dispersion indices are not quite high enough to
reach red flag criteria and the new forecast ERC values that will
come in later this afternoon may drop as well. We therefore do not
plan on issuing any red flag products for Saturday at this time. The
front will clear the remainder of the forecast area Saturday night
setting up a dry and breezy day on Sunday. It will not be quite dry
enough to reach red flag criteria across our AL and GA zones.
However, the combination of low RH, high dispersion and high 20-ft
winds will likely produce red flag conditions across inland portions
of FL. Watches and/or warnings will likely be issued by later shifts
for Sunday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 62 82 54 82 50 / 50 60 30 10 0
Panama City 67 80 59 80 58 / 50 60 10 10 0
Dothan 61 83 55 81 53 / 40 40 10 10 0
Albany 61 81 54 79 52 / 50 60 20 10 0
Valdosta 62 80 55 79 53 / 50 60 40 10 0
Cross City 62 81 58 81 51 / 30 60 40 10 0
Apalachicola 67 75 59 77 54 / 50 60 30 10 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
GM...None.
&&
$$
Mroczka/Camp/Barry/Wool
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
331 PM CDT FRI MAR 23 2012
.MESOSCALE DISCUSSION...
1200 PM CDT
A SWATH OF SHOWERS FROM SOUTHEAST WISCONSIN THROUGH NORTHWEST
INDIANA CONTINUE TO MOVE NORTHEAST. BASED ON THE LATEST RUC
ANALYSIS...THE SLOW MOVING UPPER LEVEL LOW IS CURRENTLY CENTERED
OVER MISSOURI. THE CORRESPONDING SURFACE LOW IS OVER EAST CENTRAL
MISSOURI AND SLOWLY MOVING INTO SOUTHERN INDIANA. LATEST WATER
VAPOR IMAGERY SHOWS SPIRALS OF DRIER AIR CIRCLING THE UPPER LEVEL
LOW...WHICH CORRELATE TO AREAS OF CLEARING OVER NORTH CENTRAL
ILLINOIS.
UNDER THE AREAS OF CLEARING...LOW LEVEL LAPSE RATES HAVE BEEN
RAPIDLY INCREASING. THE RUC HAS A GOOD HANDLE ON MID LEVEL LAPSE
RATES...AND INDICATES STEEPER MID LEVEL LAPSE RATES WILL BE
ADVECTED FROM CENTRAL ILLINOIS THROUGH NORTHERN ILLINOIS. AN AREA
OF CONVERGENCE IS ALSO VISIBLE IN THE SURFACE WIND OBS ALONG THE
ILLINOIS INDIANA STATE LINE. THE STEEP LOW LEVEL LAPSE RATES AND
AREA OF CONVERGENCE HAVE RESULTED IN CONVECTIVE SHOWERS DEVELOPING
ACROSS THE SOUTHERN HALF OF THE CWA. A FEW LIGHTNING STRIKES HAVE
BEEN DETECTED...BUT GIVEN THE ENVIRONMENT...EXPECTING AN INCREASE
IN CONVECTION THROUGH THE AFTERNOON.
CONCERNING THE SEVERE THREAT...THERE IS ADEQUATE
MOISTURE...FORCING...AND SHEAR FOR SEVERE THUNDERSTORM
DEVELOPMENT. HOWEVER INSTABILITY APPEARS TO BE WEAK TO MODERATE AT
BEST. CURRENTLY...THERE IS NO SIGNIFICANT SURFACE BASED CAPE TO
SPEAK OF. RUC AND HRR ANALYSES INDICATE A MAX OF 1500 J/KG THIS
AFTERNOON...WHILE THE SREF HINTS AT A BRIEF MAX OF AT LEAST 500
J/KG. BOTH THE RUC AND HRR SEEM A BIT AMBITIOUS WITH CAPE VALUES
THIS AFTERNOON...THEREFORE EXPECTING ABOUT 1000 J/KG TO WORK WITH.
IF INSTABILITY INCREASES...THE LIKELIHOOD OF MORE WIDESPREAD
SEVERE WEATHER WOULD ALSO INCREASE.
THE MAIN SEVERE WEATHER THREATS ARE HAIL AND DAMAGING WINDS. NAM
MODEL SOUNDINGS ARE ON TREND WITH CURRENT CONDITIONS AND SHOW A
DECENT INVERTED V FEATURE IN DOWNSTATE ILLINOIS THIS
AFTERNOON...WHICH WOULD INDICATE A GOOD CHANCE FOR STRONG
DOWNDRAFTS AND DAMAGING WINDS. MIDLAYER SHEAR IS PLENTIFUL SINCE
WE ARE ON THE NORTHEAST SIDE OF THE UPPER LEVEL LOW. LATEST RUC
ANALYSIS SHOWS UPWARDS OF 60 KT OF 0-6KM SHEAR THROUGH NORTHEAST
ILLINOIS AND NORTHWEST INDIANA. GIVEN A STRONG ENOUGH UPDRAFT AND
STRONG SHEAR...SEVERE HAIL IS POSSIBLE. HOWEVER WITH THE DRY LOW
LEVELS AND THE 12Z ILX SOUNDING INDICATING A FREEZING LEVEL
BETWEEN 9-10 KFT...ONLY EXPECTING HAIL UP TO QUARTER SIZE AT THIS
TIME. AN AREA OF ENHANCED LOW LEVEL HELICITY IS SHIFTING
NORTHWARD AND THIS COULD LEAD TO A FEW ROTATING UPDRAFTS AND
POSSIBLY AN ISOLATED TORNADO OR TWO.
JEE
&&
.DISCUSSION...
340 AM CDT
LARGE UPPER LOW ACROSS THE CENTRAL CONUS IS TAKING ITS TIME SWEET
MOVING TO THE EAST-NORTHEAST. AS THIS FEATURE CONTINUES ITS TREK
INTO THE OHIO VALLEY THROUGH THE WEEKEND...IT WILL BRING SHOWERS
WITH SOME THUNDER TO THE AREA...AS WELL AS CONTINUE TO KEEP THE
ABOVE NORMAL TEMPERATURES THROUGH THE WEEKEND. OVERNIGHT SUNDAY
AND INTO THE START OF THE WORKWEEK WILL SEE CONDITIONS
CHANGE...WITH TEMPERATURES FALLING A LITTLE CLOSER TO NORMAL...BUT
DRY.
DRY SLOT NOTED ON WATER VAPOR IMAGERY THIS MORNING WILL CONTINUE TO
CURL NORTH ACROSS THE CWA THIS MORNING AND WILL LEAD TO SOME DRYING
COME THE MORNING HOURS...AND OVERALL SHOWERY CONDITIONS WILL BE ON
THE WANE FOR MOST. AREAS ACROSS THE WEST AND SOUTH MAY ALSO HAVE THE
BETTER CHANCES AT SEEING SOME HINTS OF SUN...BUT THAT WILL BE SHORT
LIVED AS CHANCES FOR SHOWERS AND THUNDER INCREASE INTO THE AFTERNOON.
ONE OF THE BIGGER CHANGES TO THE GOING FORECAST IS WITH RESPECT TO
THE MASSIVE AND PERSISTENT STACKED LOW THAT IS SLOWLY MOVING ACROSS
THE CENTRAL US. THE CHANGE TONIGHT IS THAT THE LOW IS NOW PROGGED TO
MOVE A LITTLE FARTHER NORTH THAN EARLIER ANTICIPATED. BY BRINGING
THE CORE A LITTLE FARTHER NORTH...WE ARE NOW GOING TO INTRODUCE A
LITTLE COOLER AIR ALOFT BY THE AFTERNOON HOURS. SURFACE DEWPOINTS IN
THE UPPER 50S TO LOWER 60S TO CONTINUE INTO THE AFTERNOON
HOURS...AND WILL HELP TO SUPPORT MEAN LAYER CAPE VALUES IN THE
800-1000 J/KG REGION. LOWER LEVEL SHEAR IS PRETTY MARGINAL...THOUGH
FORECAST SOUNDINGS DO SHOW A SIGNAL OF CURL TO THE HODOGRAPH. SPC
SREF ANALYSIS INDICATES EFFECTIVE SHEAR TO BE IN THE 30-35-40 KT
REALM FROM THE 18 TO TO 00Z HOUR FROM CMI TO IKK AND FLIRTING WITH
ORD /THOUGH REACHING 40KT MAY BE A STRETCH/...THEN IN THE 00Z TO
06Z HOURS SHIFTING EAST AND ACROSS NORTHERN INDIANA. PREVIOUS OFF
HOUR RUNS OF THE NAM AND GFS ALSO INDICATE A LITTLE SPEED MAX
RIPPLING THROUGH...WITH THE FAVORED ENTRANCE REGION MOVING
OVERHEAD INTO THE AFTERNOON HOURS. THAT HAS NOW SHIFTED A LITTLE
EAST...AND WHILE IT ISNT EXACTLY THE MOST FAVORABLE SETUP FOR
CONVECTION...CANT RULE OUT MORE THAN RAIN AND WILL ADD THE MENTION
OF THUNDER THROUGH THE AFTERNOON HOURS. THE BIGGEST THREAT WITH
THE COOLING ALOFT AND THE INCREASED LAPSE RATES WILL BE MARGINAL
HAIL...BUT CAN FORESEE SOME STORMS THAT POP THIS AFTERNOON TAKING
ON SIMILAR CHARACTERISTICS TO WHAT WAS OBSERVED IN THE LATE
EVENING ON THURSDAY...WHERE A FEW MULTICELLULAR CLUSTERS SHOW
SOME MID LEVEL ROTATION...AND THAT MAY GET CLOSE TO THE SURFACE.
BUT THE THREAT APPEARS LOW AND WILL BE MORE FOCUSED ON THE HAIL
THREAT...ESPECIALLY WITH THE LACK OF LOWER LEVEL SHEAR.
THE STREAK OF RECORD BREAKING TEMPERATURES AT ORD LOOKS TO FINALLY
BE OVER...AS THE RECORD HIGH FOR THE DATE IS 80 DEGREES. THE SURFACE
GRADIENT IS INCREDIBLY BAGGY THIS MORNING AND FLOW IS GENERALLY SSE
TO SE ACROSS THE REGION. AS THE SURFACE LOW TRACKS EAST ACROSS
SOUTHERN ILLINOIS...WINDS WILL BECOME MORE EASTERLY AND AREAS ALONG
THE LAKEFRONT WILL BE UNDER THE INFLUENCE OF THE COOLER
MARINE AIRMASS...AND THAT WILL HELP TO KEEP THE TEMPERATURES
CONSIDERABLY LOWER THAN HAS BEEN FELT THE PAST WEEK...GENERALLY
PEAKING IN THE MID/UPPER 60S. AN INTERESTING NOTE...EVEN WITH FLOW
OFF OF THE LAKE IN MID MARCH...DOWN TOWN CHICAGO WAS AT 54 DEGREES
AS OF 4AM. LAST YEAR LAKE MICHIGAN TEMPERATURES WERE 42 AT THE
SHORE...39 AT THE CRIB AND 38 AT MICHIGAN CITY INTAKE. THIS
YEAR...THEY ARE 49, 46 AND 44 RESPECTIVELY. THAT GOES TO HIGHLIGHT
HOW BIG OF A PLAYER THE LAKE CONTINUES TO PLAY IN TEMPERATURES.
WHILE IT WILL BE COOLER THAN WHAT HAS FELT LIKE THE NEW NORM...IT
WILL STILL BE ABOVE THE OFFICIAL NORMAL...WHICH IS 49 DEGREES.
GRANTED...IF AREAS WEST DO CLEAR OUT FOR LONGER THAN
ANTICIPATED...THEY WILL WARM CONSIDERABLY MORE THAN AREAS TO THE
EAST...BUT STILL NOT ANTICIPATING ANY RECORDS FOR THE DAY /AS
ROCKFORD/S RECORD FOR TODAY IS 82/. CIN BUILDS INTO THE EVENING AS
UPPER FLOW BACKS TO THE NORTHWEST AND THEN NORTH...AS THE DISH POT
LOW WOBBLES/MEANDERS EAST. CHANCE OF SHOWERS TO PERSIST THROUGH
THE DAY ON SATURDAY WITH DEEP CYCLONIC FLOW...THOUGH THE BETTERS
CHANCES WILL BE CLOSER TO THE LOW AND SOUTH ACROSS CENTRAL
ILLINOIS AND WEST CENTRAL INDIANA.
LONG TERM TRENDS STILL INDICATE BIGGER COOL DOWN SUNDAY NIGHT AND
INTO MONDAY. THE DISH POT WILL BE IN THE VICINITY OF THE LOWER
OHIO VALLEY BY THE END OF THE WEEKEND...TURNING ALL FLOW TO THE
NORTH AND NORTHWEST IN THAT TIME FRAME. THE GOOD NEWS IS THAT ANY
STRONG ADVECTION OF COLDER AIR THAT THE SYSTEM MAY HAVE HAD A WEEK
OR SO AGO WHEN IT WAS RAMPING UP...HAS BUT WASHED ITSELF OUT THIS
PAST WEEK. H8 TEMPS ARE PROGGED TO ONLY DIP INTO THE +6 TO +8
REALM WHICH MEANS THAT HIGHS ONLY EXPECTED IN THE LOWER 50S NORTH
OF I-88...TOUCHING 60 WELL SOUTH AND CLOSER TOWARDS ILX/S AREA OF
RESPONSIBILITY.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SHRA/TSRA OVER/NEAR THE TERMINALS NEXT 1-2 HRS...MORE
ISOLD/SCATTERED ACTIVITY POSSIBLE REMAINDER OF AFTERNOON/EARLY
EVENING.
* BRIEF IFR POSSIBLE WITH SHRA/TSRA THAT PASS OVERHEAD.
* PRIMARILY VFR CIGS ARRIVING WITH PATCHY MVFR REMAINING INTO
EARLY EVENING.
* MVFR VSBY MAY CONTINUE AT ORD WITH FLOW OFF LAKE MICHIGAN.
* EAST TO NORTHEAST WINDS EXPECTED TO CONTINUE THROUGH THE
AFTERNOON POTENTIALLY BECOMING EAST-SOUTHEAST YET THIS AFTERNOON
BEFORE BECOMING LIGHT AND VARIABLE. MDW SHOULD HAVE THE MOST
VARIABILITY.
* ANOTHER ROUND OF SHRA/TSRA POSSIBLE THIS EVENING BUT MAY REMAIN
JUST TO THE SOUTH.
* DECENT POTENTIAL FOR DENSE FOG DEVELOPMENT OVERNIGHT THROUGH
DAYBREAK SATURDAY.
* IFR IMPROVING TO VFR SATURDAY MORNING AND POSSIBLY VFR SATURDAY
AFTERNOON.
MDB
//DISCUSSION...UPDATED 20Z...
BULK OF THE SHRA/TSRA ACTIVITY NOW SKIRTING ORD/MDW/DPA TO THE
NORTHEAST AND SHOULD CONTINUE TO LIFT AWAY FROM THE
TERMINALS...INCLUDING GYY...OVER THE NEXT HOUR OR SO. PREVAILING
CIGS ARE QUICKLY IMPROVING TO VFR AND THIS TREND SHOULD REMAIN
INTO THE EVENING AND TAF CIGS MAY BE TOO PESSIMISTIC. CONVECTION
MOVING NORTHWARD ACROSS CENTRAL ILLINOIS WILL MAKE A RUN TOWARD
THE TERMINALS THIS EVENING BUT IT IS NOT YET CLEAR AS TO HOW
ORGANIZED OR WELL DEVELOPED THEY WILL BE AS THEY APPROACH...BUT WILL
CONTINUE TO MONITOR. TS MAY NEED TO BE ADDED FOR THE EVENING.
WINDS REMAIN VARIABLE WITH SHRA/TSRA STARTING TO IMPACT THE FLOW.
EXPECT MAINLY AN EASTERLY DIRECTION WITH FLUCTUATIONS TO NORTHEAST
AND SOUTHEAST. CONDS AT RFD HAVE BEEN MORE STEADY STATE WITH MOST
SHRA/TSRA ACTIVITY TO THE NORTH AND VFR PREVAILING...BUT WINDS
HAVE BEEN MORE VARIABLE BETWEEN SOUTH AND EAST.
FROM 18Z...
UPPER LOW CONTINUES TO SPIN OVER SOUTHERN MISSOURI RESULTING IN
LOW CIGS/VSBY AND SHRA/TSRA. CONDITIONS HIGHLY VARIABLE ACROSS THE
TERMINALS WITH THE WORST CONDITIONS ACROSS THE CHICAGO METRO AND
NORTHWEST INDIANA. A BAND OF THUNDERSTORMS HAS DEVELOPED OVER THE
LAST HOUR OR SO FROM ORD SOUTHWARD AND IS LIFTING NORTH. THE BULK
OF THIS ACTIVITY WILL LIFT TO THE NORTH OF THE CHI AREA TERMINALS
IN THE NEXT FEW HOURS WITH ADDITIONAL ACTIVITY POSSIBLE THROUGH
LATE AFTERNOON BUT APPEARING TO BE MUCH LESS ORGANIZED. IFR/MVFR
CIGS CONTINUE IN THIS SAME AREA AND IFR CIGS SHOULD IMPROVE TO LOW
END MVFR OVER THE NEXT HOUR OR SO.
MVFR CIGS WILL LIKELY PERSIST THROUGH THE AFTERNOON AT
DPA/ORD/MDW/GYY WHILE VFR CONTINUES AT RFD. THERE MAY BE SOME
IMPROVEMENT TO VFR LATE THIS AFTERNOON AND EARLY THIS EVENING BUT
THIS IS NOT YET CLEAR. VARIABLE EAST TO NORTHEAST WINDS WILL
CONTINUE AT ORD/MDW/DPA WITH GYY EXPECTED TO FLIP TO EAST OR
NORTHEAST SOMETIME LATER THIS AFTERNOON BUT SHOWER ACTIVITY MAY
KEEP THIS FROM OCCURRING.
ANOTHER ROUND OF CONVECTION SHOULD MOVE NORTHWARD ACROSS CENTRAL
ILLINOIS LATE THIS AFTERNOON. THE BIG QUESTION WILL BE HOW FAR
NORTH THIS WILL BE ABLE TO MOVE. WILL LIMIT PRECIP/TS MENTION IN
THE TAF FOR THIS EVENING BUT WILL NEED TO MONITOR CLOSELY. RIGHT
NOW BEST TIME FRAME FOR THIS WOULD BE MID OR LATE EVENING. LOW
LEVEL FLOW WILL BECOME LIGHT AND VARIABLE OVERNIGHT WHICH WILL
COMBINE WITH MOIST/SATURATED GROUND TO SUPPORT GOOD POTENTIAL FOR
FOG DEVELOPMENT. NOT CLEAR HOW LOW VSBY WILL GO BUT 1/2SM OR LESS
IS PLAUSIBLE...ESPECIALLY AT DPA/RFD. LESS CONFIDENCE IN VSBY THIS
OCCURRING AT ORD/MDW AND EVEN GYY BUT SOME FORM OF IFR VSBY
APPEARS LIKELY. NORTH-NORTHEAST FLOW WILL BE IN PLACE SATURDAY AS
THE UPPER LOW STARTS TO SHIFT EASTWARD AND IFR SHOULD IMPROVE TO
MVFR SOMETIME LATER SATURDAY MORNING...WITH VFR POSSIBLE SOMETIME
SATURDAY AFTERNOON.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN MOST WIDESPREAD SHRA/TSRA ACTIVITY LIFTING
NORTH OF THE TERMINALS NEXT HOUR OR SO. LOW-MEDIUM CONFIDENCE IN
SCATTERED/ISOLD POTENTIAL THROUGH EARLY EVENING.
* MEDIUM-HIGH CONFIDENCE IN BRIEF IFR OCCURRING WITH ANY PASSING
SHRA/TSRA.
* MEDIUM-HIGH CONFIDENCE IN PREVAILING CIGS IMPROVING TO VFR AND
CONTINUING INTO MID EVENING.
* HIGH CONFIDENCE IN GENERAL EAST TO NORTHEAST WIND DIRECTION WITH
VARIABILITY BUT MEDIUM CONFIDENCE IN TIMING OF MORE EAST-
SOUTHEAST DIRECTION THIS EVENING.
* LOW CONFIDENCE IN POTENTIAL FOR ANOTHER ROUND OF SHRA/TSRA
EARLY/MID EVENING BUT THIS MAY STAY JUST TO THE SOUTH.
* MEDIUM-HIGH CONFIDENCE IN IFR FOG DEVELOPMENT TONIGHT THROUGH
MID SATURDAY MORNING WITH LOW-MEDIUM CONFIDENCE IN HOW LOW VSBY
WILL BE.
* MEDIUM CONFIDENCE IN IFR IMPROVING TO VFR THROUGH SATURDAY BUT
LOW CONFIDENCE ON TIMING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VFR. PSBL FG DEVELOPMENT.
SUNDAY...VFR.
MONDAY...VFR.
TUESDAY...VFR. PSBL MVFR CIGS WITH CHC SHRA/ISO TS.
WEDNESDAY...MVFR EARLY TRENDING VFR. CHC RA/TS EARLY.
THURSDAY...VFR.
BEACHLER
&&
.MARINE...
321 PM CDT
WHILE THERE MAY BE SOME PATCHY DENSE FOG NEAR THE WESTERN
SHORE THROUGH TONIGHT...THE PRIMARY CONCERN IS A PERIOD OF UNSTABLE
CONDITIONS LATE SUNDAY INTO EARLY MONDAY...WHICH WILL LEAD TO
STRONGER NORTHERLY WINDS. THEN ON TUESDAY...STRONG SOUTHERLY FLOW
WILL DEVELOP...BUT THE AIR MASS IS EXPECTED TO BECOME INCREASINGLY
STABLE OVER THE LAKE.
INITIALLY...BROAD LOW PRESSURE OVER THE OHIO VALLEY WILL SHIFT
SLOWLY EAST ACROSS THE OHIO VALLEY THROUGH LATE SATURDAY...WITH
WINDS TURNING NORTHERLY BUT REMAINING FAIRLY LIGHT AS THE AIR MASS
OVER THE LAKE WILL STILL BE MILD...LEADING TO STABLE CONDITIONS.
HOWEVER...ON SUNDAY...A COLD FRONT PASSAGE WILL LEAD TO A SHOT OF
REINFORCING COLD AIR AS STRONG HIGH PRESSURE PRESSES DOWN FROM
NORTHERN ONTARIO. THIS WILL BE THE FIRST PUSH OF COLD AIR OVER THE
LAKE IN QUITE A WHILE...SO THE LAKE IS EXCEPTIONALLY MILD FOR LATE
MARCH. THUS...AIR TEMPERATURES BELOW FREEZING ALOFT MOVING OVER THE
MILD LAKE WILL ENABLE MIXING DOWN OF STRONGER WINDS AS THE STRONG
HIGH PRESSURE BUILDING IN RESULTS IN A TIGHT NORTHERLY PRESSURE
GRADIENT. THE COLD AIR WILL TAKE SOME TIME TO DEEPEN...SO THE TARGET
PERIOD FOR STRONGEST NORTHERLY WINDS IS SUNDAY NIGHT INTO EARLY
MONDAY...STARTING WITH THE NORTH HALF...THEN TRANSITIONING DOWN THE
LAKE. HAVE PEGGED THIS TIME FRAME FOR NORTH AND NORTHEAST WINDS UP
TO 30 KT...BUT CANNOT RULE OUT LOW END GALES...SO THIS PERIOD WILL
NEED TO BE MONITORED. THE STRONG NORTHERLY WINDS AND BUILDING WAVES
WILL ALSO LEAD TO A HIGH LIKELIHOOD OF CONDITIONS HAZARDOUS TO SMALL
CRAFT FOR THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE WATERS LATE
SUNDAY NIGHT OR EARLY MONDAY MORNING INTO MONDAY EVENING. WINDS WILL
BRIEFLY SUBSIDE AND TURN SOUTHEAST LATE MONDAY NIGHT AS THE HIGH
QUICKLY MOVES EAST.
STRONG LOW PRESSURE WILL APPROACH THE UPPER GREAT LAKES FROM THE
NORTHERN PLAINS ON TUESDAY...STRENGTHENING THE SOUTHERLY FLOW...BUT
AT THIS POINT...THE AIR MASS MOVING ACROSS THE LAKE WILL BE
MILD...AND GUSTS WILL BE LIMITED BY INCREASINGLY STABLE CONDITIONS.
WILL CERTAINLY NEED TO MONITOR THIS PERIOD AS WELL...AS THE WINDS
NOT FAR ABOVE THE STABLE LAYER WILL BE QUITE STRONG. COLDER...UNSTABLE
CONDITIONS AND STRONGER WESTERLY WINDS WILL RETURN ON WEDNESDAY
AFTER THE COLD FRONT TRAILING FROM THE LOW PRESSURE SWEEPS ACROSS
THE LAKE.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
306 PM CDT FRI MAR 23 2012
.MESOSCALE DISCUSSION...
1200 PM CDT
A SWATH OF SHOWERS FROM SOUTHEAST WISCONSIN THROUGH NORTHWEST
INDIANA CONTINUE TO MOVE NORTHEAST. BASED ON THE LATEST RUC
ANALYSIS...THE SLOW MOVING UPPER LEVEL LOW IS CURRENTLY CENTERED
OVER MISSOURI. THE CORRESPONDING SURFACE LOW IS OVER EAST CENTRAL
MISSOURI AND SLOWLY MOVING INTO SOUTHERN INDIANA. LATEST WATER
VAPOR IMAGERY SHOWS SPIRALS OF DRIER AIR CIRCLING THE UPPER LEVEL
LOW...WHICH CORRELATE TO AREAS OF CLEARING OVER NORTH CENTRAL
ILLINOIS.
UNDER THE AREAS OF CLEARING...LOW LEVEL LAPSE RATES HAVE BEEN
RAPIDLY INCREASING. THE RUC HAS A GOOD HANDLE ON MID LEVEL LAPSE
RATES...AND INDICATES STEEPER MID LEVEL LAPSE RATES WILL BE
ADVECTED FROM CENTRAL ILLINOIS THROUGH NORTHERN ILLINOIS. AN AREA
OF CONVERGENCE IS ALSO VISIBLE IN THE SURFACE WIND OBS ALONG THE
ILLINOIS INDIANA STATE LINE. THE STEEP LOW LEVEL LAPSE RATES AND
AREA OF CONVERGENCE HAVE RESULTED IN CONVECTIVE SHOWERS DEVELOPING
ACROSS THE SOUTHERN HALF OF THE CWA. A FEW LIGHTNING STRIKES HAVE
BEEN DETECTED...BUT GIVEN THE ENVIRONMENT...EXPECTING AN INCREASE
IN CONVECTION THROUGH THE AFTERNOON.
CONCERNING THE SEVERE THREAT...THERE IS ADEQUATE
MOISTURE...FORCING...AND SHEAR FOR SEVERE THUNDERSTORM
DEVELOPMENT. HOWEVER INSTABILITY APPEARS TO BE WEAK TO MODERATE AT
BEST. CURRENTLY...THERE IS NO SIGNIFICANT SURFACE BASED CAPE TO
SPEAK OF. RUC AND HRR ANALYSES INDICATE A MAX OF 1500 J/KG THIS
AFTERNOON...WHILE THE SREF HINTS AT A BRIEF MAX OF AT LEAST 500
J/KG. BOTH THE RUC AND HRR SEEM A BIT AMBITIOUS WITH CAPE VALUES
THIS AFTERNOON...THEREFORE EXPECTING ABOUT 1000 J/KG TO WORK WITH.
IF INSTABILITY INCREASES...THE LIKELIHOOD OF MORE WIDESPREAD
SEVERE WEATHER WOULD ALSO INCREASE.
THE MAIN SEVERE WEATHER THREATS ARE HAIL AND DAMAGING WINDS. NAM
MODEL SOUNDINGS ARE ON TREND WITH CURRENT CONDITIONS AND SHOW A
DECENT INVERTED V FEATURE IN DOWNSTATE ILLINOIS THIS
AFTERNOON...WHICH WOULD INDICATE A GOOD CHANCE FOR STRONG
DOWNDRAFTS AND DAMAGING WINDS. MIDLAYER SHEAR IS PLENTIFUL SINCE
WE ARE ON THE NORTHEAST SIDE OF THE UPPER LEVEL LOW. LATEST RUC
ANALYSIS SHOWS UPWARDS OF 60 KT OF 0-6KM SHEAR THROUGH NORTHEAST
ILLINOIS AND NORTHWEST INDIANA. GIVEN A STRONG ENOUGH UPDRAFT AND
STRONG SHEAR...SEVERE HAIL IS POSSIBLE. HOWEVER WITH THE DRY LOW
LEVELS AND THE 12Z ILX SOUNDING INDICATING A FREEZING LEVEL
BETWEEN 9-10 KFT...ONLY EXPECTING HAIL UP TO QUARTER SIZE AT THIS
TIME. AN AREA OF ENHANCED LOW LEVEL HELICITY IS SHIFTING
NORTHWARD AND THIS COULD LEAD TO A FEW ROTATING UPDRAFTS AND
POSSIBLY AN ISOLATED TORNADO OR TWO.
JEE
&&
.DISCUSSION...
340 AM CDT
LARGE UPPER LOW ACROSS THE CENTRAL CONUS IS TAKING ITS TIME SWEET
MOVING TO THE EAST-NORTHEAST. AS THIS FEATURE CONTINUES ITS TREK
INTO THE OHIO VALLEY THROUGH THE WEEKEND...IT WILL BRING SHOWERS
WITH SOME THUNDER TO THE AREA...AS WELL AS CONTINUE TO KEEP THE
ABOVE NORMAL TEMPERATURES THROUGH THE WEEKEND. OVERNIGHT SUNDAY
AND INTO THE START OF THE WORKWEEK WILL SEE CONDITIONS
CHANGE...WITH TEMPERATURES FALLING A LITTLE CLOSER TO NORMAL...BUT
DRY.
DRY SLOT NOTED ON WATER VAPOR IMAGERY THIS MORNING WILL CONTINUE TO
CURL NORTH ACROSS THE CWA THIS MORNING AND WILL LEAD TO SOME DRYING
COME THE MORNING HOURS...AND OVERALL SHOWERY CONDITIONS WILL BE ON
THE WANE FOR MOST. AREAS ACROSS THE WEST AND SOUTH MAY ALSO HAVE THE
BETTER CHANCES AT SEEING SOME HINTS OF SUN...BUT THAT WILL BE SHORT
LIVED AS CHANCES FOR SHOWERS AND THUNDER INCREASE INTO THE AFTERNOON.
ONE OF THE BIGGER CHANGES TO THE GOING FORECAST IS WITH RESPECT TO
THE MASSIVE AND PERSISTENT STACKED LOW THAT IS SLOWLY MOVING ACROSS
THE CENTRAL US. THE CHANGE TONIGHT IS THAT THE LOW IS NOW PROGGED TO
MOVE A LITTLE FARTHER NORTH THAN EARLIER ANTICIPATED. BY BRINGING
THE CORE A LITTLE FARTHER NORTH...WE ARE NOW GOING TO INTRODUCE A
LITTLE COOLER AIR ALOFT BY THE AFTERNOON HOURS. SURFACE DEWPOINTS IN
THE UPPER 50S TO LOWER 60S TO CONTINUE INTO THE AFTERNOON
HOURS...AND WILL HELP TO SUPPORT MEAN LAYER CAPE VALUES IN THE
800-1000 J/KG REGION. LOWER LEVEL SHEAR IS PRETTY MARGINAL...THOUGH
FORECAST SOUNDINGS DO SHOW A SIGNAL OF CURL TO THE HODOGRAPH. SPC
SREF ANALYSIS INDICATES EFFECTIVE SHEAR TO BE IN THE 30-35-40 KT
REALM FROM THE 18 TO TO 00Z HOUR FROM CMI TO IKK AND FLIRTING WITH
ORD /THOUGH REACHING 40KT MAY BE A STRETCH/...THEN IN THE 00Z TO
06Z HOURS SHIFTING EAST AND ACROSS NORTHERN INDIANA. PREVIOUS OFF
HOUR RUNS OF THE NAM AND GFS ALSO INDICATE A LITTLE SPEED MAX
RIPPLING THROUGH...WITH THE FAVORED ENTRANCE REGION MOVING
OVERHEAD INTO THE AFTERNOON HOURS. THAT HAS NOW SHIFTED A LITTLE
EAST...AND WHILE IT ISNT EXACTLY THE MOST FAVORABLE SETUP FOR
CONVECTION...CANT RULE OUT MORE THAN RAIN AND WILL ADD THE MENTION
OF THUNDER THROUGH THE AFTERNOON HOURS. THE BIGGEST THREAT WITH
THE COOLING ALOFT AND THE INCREASED LAPSE RATES WILL BE MARGINAL
HAIL...BUT CAN FORESEE SOME STORMS THAT POP THIS AFTERNOON TAKING
ON SIMILAR CHARACTERISTICS TO WHAT WAS OBSERVED IN THE LATE
EVENING ON THURSDAY...WHERE A FEW MULTICELLULAR CLUSTERS SHOW
SOME MID LEVEL ROTATION...AND THAT MAY GET CLOSE TO THE SURFACE.
BUT THE THREAT APPEARS LOW AND WILL BE MORE FOCUSED ON THE HAIL
THREAT...ESPECIALLY WITH THE LACK OF LOWER LEVEL SHEAR.
THE STREAK OF RECORD BREAKING TEMPERATURES AT ORD LOOKS TO FINALLY
BE OVER...AS THE RECORD HIGH FOR THE DATE IS 80 DEGREES. THE SURFACE
GRADIENT IS INCREDIBLY BAGGY THIS MORNING AND FLOW IS GENERALLY SSE
TO SE ACROSS THE REGION. AS THE SURFACE LOW TRACKS EAST ACROSS
SOUTHERN ILLINOIS...WINDS WILL BECOME MORE EASTERLY AND AREAS ALONG
THE LAKEFRONT WILL BE UNDER THE INFLUENCE OF THE COOLER
MARINE AIRMASS...AND THAT WILL HELP TO KEEP THE TEMPERATURES
CONSIDERABLY LOWER THAN HAS BEEN FELT THE PAST WEEK...GENERALLY
PEAKING IN THE MID/UPPER 60S. AN INTERESTING NOTE...EVEN WITH FLOW
OFF OF THE LAKE IN MID MARCH...DOWN TOWN CHICAGO WAS AT 54 DEGREES
AS OF 4AM. LAST YEAR LAKE MICHIGAN TEMPERATURES WERE 42 AT THE
SHORE...39 AT THE CRIB AND 38 AT MICHIGAN CITY INTAKE. THIS
YEAR...THEY ARE 49, 46 AND 44 RESPECTIVELY. THAT GOES TO HIGHLIGHT
HOW BIG OF A PLAYER THE LAKE CONTINUES TO PLAY IN TEMPERATURES.
WHILE IT WILL BE COOLER THAN WHAT HAS FELT LIKE THE NEW NORM...IT
WILL STILL BE ABOVE THE OFFICIAL NORMAL...WHICH IS 49 DEGREES.
GRANTED...IF AREAS WEST DO CLEAR OUT FOR LONGER THAN
ANTICIPATED...THEY WILL WARM CONSIDERABLY MORE THAN AREAS TO THE
EAST...BUT STILL NOT ANTICIPATING ANY RECORDS FOR THE DAY /AS
ROCKFORD/S RECORD FOR TODAY IS 82/. CIN BUILDS INTO THE EVENING AS
UPPER FLOW BACKS TO THE NORTHWEST AND THEN NORTH...AS THE DISH POT
LOW WOBBLES/MEANDERS EAST. CHANCE OF SHOWERS TO PERSIST THROUGH
THE DAY ON SATURDAY WITH DEEP CYCLONIC FLOW...THOUGH THE BETTERS
CHANCES WILL BE CLOSER TO THE LOW AND SOUTH ACROSS CENTRAL
ILLINOIS AND WEST CENTRAL INDIANA.
LONG TERM TRENDS STILL INDICATE BIGGER COOL DOWN SUNDAY NIGHT AND
INTO MONDAY. THE DISH POT WILL BE IN THE VICINITY OF THE LOWER
OHIO VALLEY BY THE END OF THE WEEKEND...TURNING ALL FLOW TO THE
NORTH AND NORTHWEST IN THAT TIME FRAME. THE GOOD NEWS IS THAT ANY
STRONG ADVECTION OF COLDER AIR THAT THE SYSTEM MAY HAVE HAD A WEEK
OR SO AGO WHEN IT WAS RAMPING UP...HAS BUT WASHED ITSELF OUT THIS
PAST WEEK. H8 TEMPS ARE PROGGED TO ONLY DIP INTO THE +6 TO +8
REALM WHICH MEANS THAT HIGHS ONLY EXPECTED IN THE LOWER 50S NORTH
OF I-88...TOUCHING 60 WELL SOUTH AND CLOSER TOWARDS ILX/S AREA OF
RESPONSIBILITY.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SHRA/TSRA OVER/NEAR THE TERMINALS NEXT 1-2 HRS...MORE
ISOLD/SCATTERED ACTIVITY POSSIBLE REMAINDER OF AFTERNOON/EARLY
EVENING.
* BRIEF IFR POSSIBLE WITH SHRA/TSRA THAT PASS OVERHEAD.
* PRIMARILY VFR CIGS ARRIVING WITH PATCHY MVFR REMAINING INTO
EARLY EVENING.
* MVFR VSBY MAY CONTINUE AT ORD WITH FLOW OFF LAKE MICHIGAN.
* EAST TO NORTHEAST WINDS EXPECTED TO CONTINUE THROUGH THE
AFTERNOON POTENTIALLY BECOMING EAST-SOUTHEAST YET THIS AFTERNOON
BEFORE BECOMING LIGHT AND VARIABLE. MDW SHOULD HAVE THE MOST
VARIABILITY.
* ANOTHER ROUND OF SHRA/TSRA POSSIBLE THIS EVENING BUT MAY REMAIN
JUST TO THE SOUTH.
* DECENT POTENTIAL FOR DENSE FOG DEVELOPMENT OVERNIGHT THROUGH
DAYBREAK SATURDAY.
* IFR IMPROVING TO VFR SATURDAY MORNING AND POSSIBLY VFR SATURDAY
AFTERNOON.
MDB
//DISCUSSION...UPDATED 20Z...
BULK OF THE SHRA/TSRA ACTIVITY NOW SKIRTING ORD/MDW/DPA TO THE
NORTHEAST AND SHOULD CONTINUE TO LIFT AWAY FROM THE
TERMINALS...INCLUDING GYY...OVER THE NEXT HOUR OR SO. PREVAILING
CIGS ARE QUICKLY IMPROVING TO VFR AND THIS TREND SHOULD REMAIN
INTO THE EVENING AND TAF CIGS MAY BE TOO PESSIMISTIC. CONVECTION
MOVING NORTHWARD ACROSS CENTRAL ILLINOIS WILL MAKE A RUN TOWARD
THE TERMINALS THIS EVENING BUT IT IS NOT YET CLEAR AS TO HOW
ORGANIZED OR WELL DEVELOPED THEY WILL BE AS THEY APPROACH...BUT WILL
CONTINUE TO MONITOR. TS MAY NEED TO BE ADDED FOR THE EVENING.
WINDS REMAIN VARIABLE WITH SHRA/TSRA STARTING TO IMPACT THE FLOW.
EXPECT MAINLY AN EASTERLY DIRECTION WITH FLUCTUATIONS TO NORTHEAST
AND SOUTHEAST. CONDS AT RFD HAVE BEEN MORE STEADY STATE WITH MOST
SHRA/TSRA ACTIVITY TO THE NORTH AND VFR PREVAILING...BUT WINDS
HAVE BEEN MORE VARIABLE BETWEEN SOUTH AND EAST.
FROM 18Z...
UPPER LOW CONTINUES TO SPIN OVER SOUTHERN MISSOURI RESULTING IN
LOW CIGS/VSBY AND SHRA/TSRA. CONDITIONS HIGHLY VARIABLE ACROSS THE
TERMINALS WITH THE WORST CONDITIONS ACROSS THE CHICAGO METRO AND
NORTHWEST INDIANA. A BAND OF THUNDERSTORMS HAS DEVELOPED OVER THE
LAST HOUR OR SO FROM ORD SOUTHWARD AND IS LIFTING NORTH. THE BULK
OF THIS ACTIVITY WILL LIFT TO THE NORTH OF THE CHI AREA TERMINALS
IN THE NEXT FEW HOURS WITH ADDITIONAL ACTIVITY POSSIBLE THROUGH
LATE AFTERNOON BUT APPEARING TO BE MUCH LESS ORGANIZED. IFR/MVFR
CIGS CONTINUE IN THIS SAME AREA AND IFR CIGS SHOULD IMPROVE TO LOW
END MVFR OVER THE NEXT HOUR OR SO.
MVFR CIGS WILL LIKELY PERSIST THROUGH THE AFTERNOON AT
DPA/ORD/MDW/GYY WHILE VFR CONTINUES AT RFD. THERE MAY BE SOME
IMPROVEMENT TO VFR LATE THIS AFTERNOON AND EARLY THIS EVENING BUT
THIS IS NOT YET CLEAR. VARIABLE EAST TO NORTHEAST WINDS WILL
CONTINUE AT ORD/MDW/DPA WITH GYY EXPECTED TO FLIP TO EAST OR
NORTHEAST SOMETIME LATER THIS AFTERNOON BUT SHOWER ACTIVITY MAY
KEEP THIS FROM OCCURRING.
ANOTHER ROUND OF CONVECTION SHOULD MOVE NORTHWARD ACROSS CENTRAL
ILLINOIS LATE THIS AFTERNOON. THE BIG QUESTION WILL BE HOW FAR
NORTH THIS WILL BE ABLE TO MOVE. WILL LIMIT PRECIP/TS MENTION IN
THE TAF FOR THIS EVENING BUT WILL NEED TO MONITOR CLOSELY. RIGHT
NOW BEST TIME FRAME FOR THIS WOULD BE MID OR LATE EVENING. LOW
LEVEL FLOW WILL BECOME LIGHT AND VARIABLE OVERNIGHT WHICH WILL
COMBINE WITH MOIST/SATURATED GROUND TO SUPPORT GOOD POTENTIAL FOR
FOG DEVELOPMENT. NOT CLEAR HOW LOW VSBY WILL GO BUT 1/2SM OR LESS
IS PLAUSIBLE...ESPECIALLY AT DPA/RFD. LESS CONFIDENCE IN VSBY THIS
OCCURRING AT ORD/MDW AND EVEN GYY BUT SOME FORM OF IFR VSBY
APPEARS LIKELY. NORTH-NORTHEAST FLOW WILL BE IN PLACE SATURDAY AS
THE UPPER LOW STARTS TO SHIFT EASTWARD AND IFR SHOULD IMPROVE TO
MVFR SOMETIME LATER SATURDAY MORNING...WITH VFR POSSIBLE SOMETIME
SATURDAY AFTERNOON.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN MOST WIDESPREAD SHRA/TSRA ACTIVITY LIFTING
NORTH OF THE TERMINALS NEXT HOUR OR SO. LOW-MEDIUM CONFIDENCE IN
SCATTERED/ISOLD POTENTIAL THROUGH EARLY EVENING.
* MEDIUM-HIGH CONFIDENCE IN BRIEF IFR OCCURRING WITH ANY PASSING
SHRA/TSRA.
* MEDIUM-HIGH CONFIDENCE IN PREVAILING CIGS IMPROVING TO VFR AND
CONTINUING INTO MID EVENING.
* HIGH CONFIDENCE IN GENERAL EAST TO NORTHEAST WIND DIRECTION WITH
VARIABILITY BUT MEDIUM CONFIDENCE IN TIMING OF MORE EAST-
SOUTHEAST DIRECTION THIS EVENING.
* LOW CONFIDENCE IN POTENTIAL FOR ANOTHER ROUND OF SHRA/TSRA
EARLY/MID EVENING BUT THIS MAY STAY JUST TO THE SOUTH.
* MEDIUM-HIGH CONFIDENCE IN IFR FOG DEVELOPMENT TONIGHT THROUGH
MID SATURDAY MORNING WITH LOW-MEDIUM CONFIDENCE IN HOW LOW VSBY
WILL BE.
* MEDIUM CONFIDENCE IN IFR IMPROVING TO VFR THROUGH SATURDAY BUT
LOW CONFIDENCE ON TIMING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VFR. PSBL FG DEVELOPMENT.
SUNDAY...VFR.
MONDAY...VFR.
TUESDAY...VFR. PSBL MVFR CIGS WITH CHC SHRA/ISO TS.
WEDNESDAY...MVFR EARLY TRENDING VFR. CHC RA/TS EARLY.
THURSDAY...VFR.
BEACHLER
&&
.MARINE...
251 AM CDT
A COUPLE WEATHER FEATURES CONTINUE TO POSE CHALLENGES TO THE
WEATHER ACROSS THE MARINE COMMUNITY...AS AN UPPER LEVEL
DISTURBANCE SLOWLY LIFTS NORTHEAST FROM THE CENTRAL PLAINS TOWARDS
THE SOUTHERN GREAT LAKES TODAY. MEANWHILE A BROAD AREA OF HIGH
PRESSURE OVER NORTHERN MANITOBA WILL DRIFT EAST AND BECOME
CENTERED OVER HUDSON BAY TONIGHT INTO SATURDAY. THIS WILL ALLOW A
GRADIENT TO STEADILY INCREASE ACROSS THE NORTHERN PORTIONS OF THE
LAKE TODAY...WITH WINDS COMING UP TO 15 TO 25 KT. A FEW GUSTS UP
TO 30 KT WILL BE POSSIBLE. ELSEWHERE WITH THE LACK OF A STRONG
GRADIENT...WINDS WILL BE MUCH LIGHTER FROM THE EAST. THIS WILL
ALLOW WAVES TO BE HIGHER ALONG THE WESTERN SIDE OF LAKE MICHIGAN.
AT THIS TIME IT DOES NOT APPEAR WAVES WILL BE LARGE ENOUGH TO
WARRANT ANY HEADLINES IN THE NEARSHORE WATERS FOR
ILLINOIS/NORTHWEST INDIANA. THEN AS THE UPPER LEVEL DISTURBANCE
DRIFTS EAST...A WEAK LOW PRESSURE SYSTEM WILL TRAVERSE LAKE
SUPERIOR. BEHIND THIS SYSTEM ON SUNDAY...A STRONG HIGH PRESSURE
WILL BUILD IN AND TIGHTEN THE GRADIENT YET AGAIN. THIS SHOULD
ALLOW WINDS TO STEADILY INCREASE.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
130 PM CDT FRI MAR 23 2012
.MESOSCALE DISCUSSION...
1200 PM CDT
A SWATH OF SHOWERS FROM SOUTHEAST WISCONSIN THROUGH NORTHWEST
INDIANA CONTINUE TO MOVE NORTHEAST. BASED ON THE LATEST RUC
ANALYSIS...THE SLOW MOVING UPPER LEVEL LOW IS CURRENTLY CENTERED
OVER MISSOURI. THE CORRESPONDING SURFACE LOW IS OVER EAST CENTRAL
MISSOURI AND SLOWLY MOVING INTO SOUTHERN INDIANA. LATEST WATER
VAPOR IMAGERY SHOWS SPIRALS OF DRIER AIR CIRCLING THE UPPER LEVEL
LOW...WHICH CORRELATE TO AREAS OF CLEARING OVER NORTH CENTRAL
ILLINOIS.
UNDER THE AREAS OF CLEARING...LOW LEVEL LAPSE RATES HAVE BEEN
RAPIDLY INCREASING. THE RUC HAS A GOOD HANDLE ON MID LEVEL LAPSE
RATES...AND INDICATES STEEPER MID LEVEL LAPSE RATES WILL BE
ADVECTED FROM CENTRAL ILLINOIS THROUGH NORTHERN ILLINOIS. AN AREA
OF CONVERGENCE IS ALSO VISIBLE IN THE SURFACE WIND OBS ALONG THE
ILLINOIS INDIANA STATE LINE. THE STEEP LOW LEVEL LAPSE RATES AND
AREA OF CONVERGENCE HAVE RESULTED IN CONVECTIVE SHOWERS DEVELOPING
ACROSS THE SOUTHERN HALF OF THE CWA. A FEW LIGHTNING STRIKES HAVE
BEEN DETECTED...BUT GIVEN THE ENVIRONMENT...EXPECTING AN INCREASE
IN CONVECTION THROUGH THE AFTERNOON.
CONCERNING THE SEVERE THREAT...THERE IS ADEQUATE
MOISTURE...FORCING...AND SHEAR FOR SEVERE THUNDERSTORM
DEVELOPMENT. HOWEVER INSTABILITY APPEARS TO BE WEAK TO MODERATE AT
BEST. CURRENTLY...THERE IS NO SIGNIFICANT SURFACE BASED CAPE TO
SPEAK OF. RUC AND HRR ANALYSES INDICATE A MAX OF 1500 J/KG THIS
AFTERNOON...WHILE THE SREF HINTS AT A BRIEF MAX OF AT LEAST 500
J/KG. BOTH THE RUC AND HRR SEEM A BIT AMBITIOUS WITH CAPE VALUES
THIS AFTERNOON...THEREFORE EXPECTING ABOUT 1000 J/KG TO WORK WITH.
IF INSTABILITY INCREASES...THE LIKELIHOOD OF MORE WIDESPREAD
SEVERE WEATHER WOULD ALSO INCREASE.
THE MAIN SEVERE WEATHER THREATS ARE HAIL AND DAMAGING WINDS. NAM
MODEL SOUNDINGS ARE ON TREND WITH CURRENT CONDITIONS AND SHOW A
DECENT INVERTED V FEATURE IN DOWNSTATE ILLINOIS THIS
AFTERNOON...WHICH WOULD INDICATE A GOOD CHANCE FOR STRONG
DOWNDRAFTS AND DAMAGING WINDS. MIDLAYER SHEAR IS PLENTIFUL SINCE
WE ARE ON THE NORTHEAST SIDE OF THE UPPER LEVEL LOW. LATEST RUC
ANALYSIS SHOWS UPWARDS OF 60 KT OF 0-6KM SHEAR THROUGH NORTHEAST
ILLINOIS AND NORTHWEST INDIANA. GIVEN A STRONG ENOUGH UPDRAFT AND
STRONG SHEAR...SEVERE HAIL IS POSSIBLE. HOWEVER WITH THE DRY LOW
LEVELS AND THE 12Z ILX SOUNDING INDICATING A FREEZING LEVEL
BETWEEN 9-10 KFT...ONLY EXPECTING HAIL UP TO QUARTER SIZE AT THIS
TIME. AN AREA OF ENHANCED LOW LEVEL HELICITY IS SHIFTING
NORTHWARD AND THIS COULD LEAD TO A FEW ROTATING UPDRAFTS AND
POSSIBLY AN ISOLATED TORNADO OR TWO.
JEE
&&
.DISCUSSION...
340 AM CDT
LARGE UPPER LOW ACROSS THE CENTRAL CONUS IS TAKING ITS TIME SWEET
MOVING TO THE EAST-NORTHEAST. AS THIS FEATURE CONTINUES ITS TREK
INTO THE OHIO VALLEY THROUGH THE WEEKEND...IT WILL BRING SHOWERS
WITH SOME THUNDER TO THE AREA...AS WELL AS CONTINUE TO KEEP THE
ABOVE NORMAL TEMPERATURES THROUGH THE WEEKEND. OVERNIGHT SUNDAY
AND INTO THE START OF THE WORKWEEK WILL SEE CONDITIONS
CHANGE...WITH TEMPERATURES FALLING A LITTLE CLOSER TO NORMAL...BUT
DRY.
DRY SLOT NOTED ON WATER VAPOR IMAGERY THIS MORNING WILL CONTINUE TO
CURL NORTH ACROSS THE CWA THIS MORNING AND WILL LEAD TO SOME DRYING
COME THE MORNING HOURS...AND OVERALL SHOWERY CONDITIONS WILL BE ON
THE WANE FOR MOST. AREAS ACROSS THE WEST AND SOUTH MAY ALSO HAVE THE
BETTER CHANCES AT SEEING SOME HINTS OF SUN...BUT THAT WILL BE SHORT
LIVED AS CHANCES FOR SHOWERS AND THUNDER INCREASE INTO THE AFTERNOON.
ONE OF THE BIGGER CHANGES TO THE GOING FORECAST IS WITH RESPECT TO
THE MASSIVE AND PERSISTENT STACKED LOW THAT IS SLOWLY MOVING ACROSS
THE CENTRAL US. THE CHANGE TONIGHT IS THAT THE LOW IS NOW PROGGED TO
MOVE A LITTLE FARTHER NORTH THAN EARLIER ANTICIPATED. BY BRINGING
THE CORE A LITTLE FARTHER NORTH...WE ARE NOW GOING TO INTRODUCE A
LITTLE COOLER AIR ALOFT BY THE AFTERNOON HOURS. SURFACE DEWPOINTS IN
THE UPPER 50S TO LOWER 60S TO CONTINUE INTO THE AFTERNOON
HOURS...AND WILL HELP TO SUPPORT MEAN LAYER CAPE VALUES IN THE
800-1000 J/KG REGION. LOWER LEVEL SHEAR IS PRETTY MARGINAL...THOUGH
FORECAST SOUNDINGS DO SHOW A SIGNAL OF CURL TO THE HODOGRAPH. SPC
SREF ANALYSIS INDICATES EFFECTIVE SHEAR TO BE IN THE 30-35-40 KT
REALM FROM THE 18 TO TO 00Z HOUR FROM CMI TO IKK AND FLIRTING WITH
ORD /THOUGH REACHING 40KT MAY BE A STRETCH/...THEN IN THE 00Z TO
06Z HOURS SHIFTING EAST AND ACROSS NORTHERN INDIANA. PREVIOUS OFF
HOUR RUNS OF THE NAM AND GFS ALSO INDICATE A LITTLE SPEED MAX
RIPPLING THROUGH...WITH THE FAVORED ENTRANCE REGION MOVING
OVERHEAD INTO THE AFTERNOON HOURS. THAT HAS NOW SHIFTED A LITTLE
EAST...AND WHILE IT ISNT EXACTLY THE MOST FAVORABLE SETUP FOR
CONVECTION...CANT RULE OUT MORE THAN RAIN AND WILL ADD THE MENTION
OF THUNDER THROUGH THE AFTERNOON HOURS. THE BIGGEST THREAT WITH
THE COOLING ALOFT AND THE INCREASED LAPSE RATES WILL BE MARGINAL
HAIL...BUT CAN FORESEE SOME STORMS THAT POP THIS AFTERNOON TAKING
ON SIMILAR CHARACTERISTICS TO WHAT WAS OBSERVED IN THE LATE
EVENING ON THURSDAY...WHERE A FEW MULTICELLULAR CLUSTERS SHOW
SOME MID LEVEL ROTATION...AND THAT MAY GET CLOSE TO THE SURFACE.
BUT THE THREAT APPEARS LOW AND WILL BE MORE FOCUSED ON THE HAIL
THREAT...ESPECIALLY WITH THE LACK OF LOWER LEVEL SHEAR.
THE STREAK OF RECORD BREAKING TEMPERATURES AT ORD LOOKS TO FINALLY
BE OVER...AS THE RECORD HIGH FOR THE DATE IS 80 DEGREES. THE SURFACE
GRADIENT IS INCREDIBLY BAGGY THIS MORNING AND FLOW IS GENERALLY SSE
TO SE ACROSS THE REGION. AS THE SURFACE LOW TRACKS EAST ACROSS
SOUTHERN ILLINOIS...WINDS WILL BECOME MORE EASTERLY AND AREAS ALONG
THE LAKEFRONT WILL BE UNDER THE INFLUENCE OF THE COOLER
MARINE AIRMASS...AND THAT WILL HELP TO KEEP THE TEMPERATURES
CONSIDERABLY LOWER THAN HAS BEEN FELT THE PAST WEEK...GENERALLY
PEAKING IN THE MID/UPPER 60S. AN INTERESTING NOTE...EVEN WITH FLOW
OFF OF THE LAKE IN MID MARCH...DOWN TOWN CHICAGO WAS AT 54 DEGREES
AS OF 4AM. LAST YEAR LAKE MICHIGAN TEMPERATURES WERE 42 AT THE
SHORE...39 AT THE CRIB AND 38 AT MICHIGAN CITY INTAKE. THIS
YEAR...THEY ARE 49, 46 AND 44 RESPECTIVELY. THAT GOES TO HIGHLIGHT
HOW BIG OF A PLAYER THE LAKE CONTINUES TO PLAY IN TEMPERATURES.
WHILE IT WILL BE COOLER THAN WHAT HAS FELT LIKE THE NEW NORM...IT
WILL STILL BE ABOVE THE OFFICIAL NORMAL...WHICH IS 49 DEGREES.
GRANTED...IF AREAS WEST DO CLEAR OUT FOR LONGER THAN
ANTICIPATED...THEY WILL WARM CONSIDERABLY MORE THAN AREAS TO THE
EAST...BUT STILL NOT ANTICIPATING ANY RECORDS FOR THE DAY /AS
ROCKFORD/S RECORD FOR TODAY IS 82/. CIN BUILDS INTO THE EVENING AS
UPPER FLOW BACKS TO THE NORTHWEST AND THEN NORTH...AS THE DISH POT
LOW WOBBLES/MEANDERS EAST. CHANCE OF SHOWERS TO PERSIST THROUGH
THE DAY ON SATURDAY WITH DEEP CYCLONIC FLOW...THOUGH THE BETTERS
CHANCES WILL BE CLOSER TO THE LOW AND SOUTH ACROSS CENTRAL
ILLINOIS AND WEST CENTRAL INDIANA.
LONG TERM TRENDS STILL INDICATE BIGGER COOL DOWN SUNDAY NIGHT AND
INTO MONDAY. THE DISH POT WILL BE IN THE VICINITY OF THE LOWER
OHIO VALLEY BY THE END OF THE WEEKEND...TURNING ALL FLOW TO THE
NORTH AND NORTHWEST IN THAT TIME FRAME. THE GOOD NEWS IS THAT ANY
STRONG ADVECTION OF COLDER AIR THAT THE SYSTEM MAY HAVE HAD A WEEK
OR SO AGO WHEN IT WAS RAMPING UP...HAS BUT WASHED ITSELF OUT THIS
PAST WEEK. H8 TEMPS ARE PROGGED TO ONLY DIP INTO THE +6 TO +8
REALM WHICH MEANS THAT HIGHS ONLY EXPECTED IN THE LOWER 50S NORTH
OF I-88...TOUCHING 60 WELL SOUTH AND CLOSER TOWARDS ILX/S AREA OF
RESPONSIBILITY.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SHRA/TSRA AFFECTING THE TERMINALS EARLY THIS AFTERNOON.
* PERIODIC IFR VSBY IN SHRA/TSRA NEXT FEW HOURS.
* IFR CIGS EXPECTED TO SCATTER NEXT FEW HOURS...WITH MVFR INTO
LATE AFTERNOON.
* EAST TO NORTHEAST WINDS EXPECTED TO CONTINUE THROUGH THE
AFTERNOON POTENTIALLY BECOMING EAST-SOUTHEAST EARLY THIS
AFTERNOON BEFORE BECOMING LIGHT AND VARIABLE.
* ANOTHER ROUND OF SHRA/TSRA POSSIBLE THIS EVENING BUT MAY REMAIN
JUST TO THE SOUTH.
* DECENT POTENTIAL FOR DENSE FOG DEVELOPMENT OVERNIGHT THROUGH
DAYBREAK SATURDAY.
* IFR IMPROVING TO VFR SATURDAY MORNING AND POSSIBLY VFR SATURDAY
AFTERNOON.
MDB
//DISCUSSION...UPDATED 18Z...
UPPER LOW CONTINUES TO SPIN OVER SOUTHERN MISSOURI RESULTING IN
LOW CIGS/VSBY AND SHRA/TSRA. CONDITIONS HIGHLY VARIABLE ACROSS THE
TERMINALS WITH THE WORST CONDITIONS ACROSS THE CHICAGO METRO AND
NORTHWEST INDIANA. A BAND OF THUNDERSTORMS HAS DEVELOPED OVER THE
LAST HOUR OR SO FROM ORD SOUTHWARD AND IS LIFTING NORTH. THE BULK
OF THIS ACTIVITY WILL LIFT TO THE NORTH OF THE CHI AREA TERMINALS
IN THE NEXT FEW HOURS WITH ADDITIONAL ACTIVITY POSSIBLE THROUGH
LATE AFTERNOON BUT APPEARING TO BE MUCH LESS ORGANIZED. IFR/MVFR
CIGS CONTINUE IN THIS SAME AREA AND IFR CIGS SHOULD IMPROVE TO LOW
END MVFR OVER THE NEXT HOUR OR SO.
MVFR CIGS WILL LIKELY PERSIST THROUGH THE AFTERNOON AT
DPA/ORD/MDW/GYY WHILE VFR CONTINUES AT RFD. THERE MAY BE SOME
IMPROVEMENT TO VFR LATE THIS AFTERNOON AND EARLY THIS EVENING BUT
THIS IS NOT YET CLEAR. VARIABLE EAST TO NORTHEAST WINDS WILL
CONTINUE AT ORD/MDW/DPA WITH GYY EXPECTED TO FLIP TO EAST OR
NORTHEAST SOMETIME LATER THIS AFTERNOON BUT SHOWER ACTIVITY MAY
KEEP THIS FROM OCCURRING.
ANOTHER ROUND OF CONVECTION SHOULD MOVE NORTHWARD ACROSS CENTRAL
ILLINOIS LATE THIS AFTERNOON. THE BIG QUESTION WILL BE HOW FAR
NORTH THIS WILL BE ABLE TO MOVE. WILL LIMIT PRECIP/TS MENTION IN
THE TAF FOR THIS EVENING BUT WILL NEED TO MONITOR CLOSELY. RIGHT
NOW BEST TIME FRAME FOR THIS WOULD BE MID OR LATE EVENING. LOW
LEVEL FLOW WILL BECOME LIGHT AND VARIABLE OVERNIGHT WHICH WILL
COMBINE WITH MOIST/SATURATED GROUND TO SUPPORT GOOD POTENTIAL FOR
FOG DEVELOPMENT. NOT CLEAR HOW LOW VSBY WILL GO BUT 1/2SM OR LESS
IS PLAUSIBLE...ESPECIALLY AT DPA/RFD. LESS CONFIDENCE IN VSBY THIS
OCCURRING AT ORD/MDW AND EVEN GYY BUT SOME FORM OF IFR VSBY
APPEARS LIKELY. NORTH-NORTHEAST FLOW WILL BE IN PLACE SATURDAY AS
THE UPPER LOW STARTS TO SHIFT EASTWARD AND IFR SHOULD IMPROVE TO
MVFR SOMETIME LATER SATURDAY MORNING...WITH VFR POSSIBLE SOMETIME
SATURDAY AFTERNOON.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN SHRA/TSRA MOVING ACROSS NEXT FEW HOURS.
* MEDIUM-HIGH CONFIDENCE IN PERIODIC IFR VSBY IN SHRA/TSRA.
* HIGH CONFIDENCE IN IFR CIGS CONTINUING NEXT HOUR OR SO BUT LOW
CONFIDENCE ON HOW LONG IT WILL TAKE TO SCATTER.
* HIGH CONFIDENCE IN GENERAL EAST TO NORTHEAST WIND DIRECTION WITH
VARIABILITY BUT MEDIUM CONFIDENCE IN TIMING OF MORE EAST-
SOUTHEAST DIRECTION.
* LOW CONFIDENCE IN POTENTIAL FOR ANOTHER ROUND OF SHRA/TSRA
EARLY/MID EVENING BUT THIS MAY STAY JUST TO THE SOUTH.
* MEDIUM-HIGH CONFIDENCE IN IFR FOG DEVELOPMENT TONIGHT THROUGH
MID SATURDAY MORNING WITH LOW-MEDIUM CONFIDENCE IN HOW LOW VSBY
WILL BE.
* MEDIUM CONFIDENCE IN IFR IMPROVING TO VFR THROUGH SATURDAY BUT
LOW CONFIDENCE ON TIMING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VFR. PSBL FG DEVELOPMENT.
SUNDAY...VFR.
MONDAY...VFR.
TUESDAY...VFR. PSBL MVFR CIGS WITH CHC SHRA/ISO TS.
WEDNESDAY...MVFR EARLY TRENDING VFR. CHC RA/TS EARLY.
THURSDAY...VFR.
BEACHLER
&&
.MARINE...
251 AM CDT
A COUPLE WEATHER FEATURES CONTINUE TO POSE CHALLENGES TO THE
WEATHER ACROSS THE MARINE COMMUNITY...AS AN UPPER LEVEL
DISTURBANCE SLOWLY LIFTS NORTHEAST FROM THE CENTRAL PLAINS TOWARDS
THE SOUTHERN GREAT LAKES TODAY. MEANWHILE A BROAD AREA OF HIGH
PRESSURE OVER NORTHERN MANITOBA WILL DRIFT EAST AND BECOME
CENTERED OVER HUDSON BAY TONIGHT INTO SATURDAY. THIS WILL ALLOW A
GRADIENT TO STEADILY INCREASE ACROSS THE NORTHERN PORTIONS OF THE
LAKE TODAY...WITH WINDS COMING UP TO 15 TO 25 KT. A FEW GUSTS UP
TO 30 KT WILL BE POSSIBLE. ELSEWHERE WITH THE LACK OF A STRONG
GRADIENT...WINDS WILL BE MUCH LIGHTER FROM THE EAST. THIS WILL
ALLOW WAVES TO BE HIGHER ALONG THE WESTERN SIDE OF LAKE MICHIGAN.
AT THIS TIME IT DOES NOT APPEAR WAVES WILL BE LARGE ENOUGH TO
WARRANT ANY HEADLINES IN THE NEARSHORE WATERS FOR
ILLINOIS/NORTHWEST INDIANA. THEN AS THE UPPER LEVEL DISTURBANCE
DRIFTS EAST...A WEAK LOW PRESSURE SYSTEM WILL TRAVERSE LAKE
SUPERIOR. BEHIND THIS SYSTEM ON SUNDAY...A STRONG HIGH PRESSURE
WILL BUILD IN AND TIGHTEN THE GRADIENT YET AGAIN. THIS SHOULD
ALLOW WINDS TO STEADILY INCREASE.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1257 PM CDT FRI MAR 23 2012
.DISCUSSION...
ISSUED 1005 AM CDT FRI MAR 23 2012
LARGE STACKED LOW SPINNING OVER THE SOUTHEAST TIP OF KANSAS PER
WATER VAPOR IMAGERY...WITH SURFACE OBS AND RADAR IMAGERY SHOWING A
SECONDARY LOW PRESSURE AREA OVER CENTRAL MISSOURI. HAD QUITE A BIT
OF FOG DEVELOP OVER THE WESTERN 2/3 OF THE CWA EARLIER...BUT
VISIBILITIES WERE RAPIDLY IMPROVING BY 9 AM AND LATEST
OBSERVATIONS SHOWING MOST SITES ABOVE 4 MILES THIS HOUR. HAVE BEEN
SEEING A RAPID INCREASE IN SHOWERS AND STORMS OVER SOUTHEAST
MISSOURI RECENTLY...WITH A FEW SHOWERS/STORMS NOW MOVING INTO FAR
SOUTHERN PARTS OF OUR CWA. 12Z SOUNDING FROM SPRINGFIELD MO SHOWED
500 MB TEMPERATURES OF -26C ASSOCIATED WITH THE UPPER LOW...WHICH
WILL TRACK EASTWARD ACROSS SOUTHERN MISSOURI THIS AFTERNOON. THIS
WILL ENHANCE MID-LEVEL LAPSE RATES...WITH LATEST RUC MODEL SHOWING
RATES OF AROUND 7.5 TO 8C/KM OVER OUR AREA BY EARLY AFTERNOON
SUPPORTING HAIL DEVELOPMENT WITH THE STRONGER STORMS. SEVERE
WEATHER POTENTIAL STILL EXISTS BECAUSE OF THIS...WITH AREAS
SOUTHEAST OF I-55 MOST AT RISK.
UPDATED GRIDS HAVE BEEN SENT...WITH UPDATED ZONES TO FOLLOW AROUND
1015 AM. MOST CHANGES WERE IN THE PRECIP/WEATHER TYPES...WITH SOME
ADJUSTMENTS TO THE HOURLY GRIDS FOR OTHER ELEMENTS.
GEELHART
&&
.AVIATION...
ISSUED 1257 PM CDT FRI MAR 23 2012...FOR THE 12Z TAFS
SHOWERS ARE BEGINNING TO RETURN TO CENTRAL IL FROM THE SOUTH AS
INSTABILITY INCREASES AHEAD OF THE LOW PRESSURE SYSTEM. THE NEXT
BAND OF STORMS MAY CONTAIN HAIL...BUT THE SEVERE THUNDERSTORM
WATCH UNTIL 7 PM DOES NOT INCLUDE ANY OF THE TERMINAL SITES. WE
INCLUDED A 3 HOUR TEMPO FOR TSRAGS AT SPI/DEC/CMI THIS AFTERNOON
TO COVER THE HIGHER THREAT AREAS FOR SMALLER HAIL THAN 1 INCH. THE
MAIN WINDOW FOR HAIL LOOKS TO BE 20Z-23Z. MVFR CONDITIONS WILL BE
LIKELY DURING STORMS...WITH IFR POSSIBLE.
THERE MAY BE A BREAK BETWEEN LINES OF STORMS AFTER THAT 23Z-
00Z...BUT THAT TREND WILL BECOME BETTER DEFINED LATER THIS
AFTERNOON. WILL NOT ADD ADDITIONAL PERIODS OF STORMS FOR TONIGHT
JUST YET.
WINDS WILL BE VARIABLE AS THE LOW APPROACHES FROM SOUTHWEST
MISSOURI. THE LOW SHOULD MOVE ACROSS SOUTH CENTRAL IL...SO THE
PREVAILING WIND DIRECTION SHOULD BE SOUTHEAST UNTIL LATER
TONIGHT...WHEN THE WINDS SHIFT AROUND TO THE WEST.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT FRI MAR 23 2012
SHORT TERM...TODAY THROUGH MONDAY NIGHT
00Z MODELS REMAIN IN FAIR AGREEMENT THROUGH THIS WEEKEND AND WILL
USE A BLEND. MET AND MAV GUIDANCE TEMPS SIMILAR THROUGH THIS
WEEKEND AND STAYED CLOSE TOO. GUIDANCE CONTINUES TO GO WARMER ON
SUNDAY AND HAS HIGHS IN THE MID 70S MOST AREAS AND TRENDED THE
FORECAST IN THAT DIRECTION.
COOLER TEMPERATURES EXPECTED LATE THIS WEEK THOUGH STILL 10-15
DEGREES ABOVE NORMAL AND SUNDAY NOW LOOKS WARMER IN THE 70S.
UNSETTLED WEATHER PATTERN EXPECTED THROUGH SAT DUE TO 551 DM 500
MB LOW OVER SOUTHEAST KS THAT SLOWLY WEAKENS IT IT MOVES INTO SE
MO BY SUNSET AND THEN INTO SOUTH CENTRAL KY/MID TN BY SUNSET SAT.
SPC HAS MUCH OF CENTRAL/SE IL INTO THE LOWER OHIO VALLEY IN A
SLIGHT RISK THIS AFTERNOON FOR MAINLY LARGE HAIL (15%) RISK WHILE
WINDS AND ISOLATED TORNADOES ARE JUST 5% RISK.
SHOWERS AND ISOLATED THUNDERSTORMS OVER INDIANA AND NE IL DRIFTING
NNW AROUND THE 551 DM 500 MB LOW OVER SE KS. A SMALL BAND OF
SHOWERS AND A FEW THUNDERSTORMS OVER CENTRAL AND SOUTH CENTRAL MO
CLOSER TO THE UPPER LEVEL LOW. DRY WEDGE IN BETWEEN OVER CENTRAL
AND SW IL AND SOME CLEARING FROM LINCOLN SW HAS ALLOWED SOME FOG
TO FORM EARLY THIS MORNING...EVEN DENSE FOG AT MACOMB...KEOKUK AND
PITTSFIELD IN WEST CENTRAL IL. VSBYS GENERALLY 3-5 MILES WEST OF
LINCOLN AND MAY NEED TO ADD FOG TO THE FORECAST FOR THESE AREAS
INTO MID MORNING AND VSBYS LIKELY DROP FURTHER.
EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP BY MIDDAY
AND BECOME MORE WIDESPREAD DURING THE AFTERNOON AS UPPER LEVEL LOW
MOVES INTO SOUTHERN MO AND AIRMASS GETS MORE UNSTABLE AND HAVE
LIKELY TO EVEN CATEGORICAL POPS THIS AFTERNOON OVER SW AREAS. PER
SPC DAY1 OUTLOOK...BAND/ARC OF THUNDERSTORMS IS EXPECTED TO
INCREASE IN COVERAGE/INTENSITY FROM MIDDAY THROUGH AT LEAST MID
AFTERNOON...IN ZONE OF CONVERGENCE LOCATED NE-E OF DEEP- LAYER
LOW. COLD CORE CONVECTIVE REGIME FCST TO SHIFT EWD/NEWD ACROSS
OUTLOOK AREA...WITH DOMINANT THREAT BEING LARGE HAIL...ISOLATED
DAMAGING GUSTS POSSIBLE. TORNADO POTENTIAL APPEARS
CONDITIONAL/MARGINAL ON OUTLOOK SCALE ATTM...BUT MAY BE LOCALLY
ENHANCED BY STORM INTERACTIONS WITH BANNERS OF BOUNDARY- LAYER
VORTICITY. ENHANCED/7.5-8.5 DEG C/KM MID LEVEL LAPSE RATES AND MID
50S TO NEAR 60 F SFC DEW POINTS WILL JUXTAPOSE WITH SURFACE
HEATING TO SUPPORT 600-1200 J/KG MLCAPE...AMIDST 30-45 KT
EFFECTIVE SHEAR MAGNITUDES. THUNDERSTORMS SHOULD DIMINISH DURING
EARLY THIS EVENING WITH LOSS OF DAYTIME HEATING.
SHOWERS TO DIMINISH OVERNIGHT AND THEN INCREASE AGAIN BY SAT
AFTERNOON WITH ISOLATED THUNDERSTORMS POSSIBLE OVER EASTERN/SE IL
SAT AFTERNOON ESPECIALLY NEAR THE WABASH RIVER WHERE SHOWERS MAY
LINGER EARLY SAT EVENING BY LAWRENCEVILLE. UPPER LEVEL LOW SLOWLY
WEAKENS AS IT DRIFTS ESE INTO EASTERN TN BY MIDNIGHT SAT NIGHT.
NICE WEATHER EXPECTED EARLY NEXT WEEK WITH UPPER LEVEL LOW
PULLING AWAY INTO THE SE STATES AND STRONG UPPER LEVEL RIDGING
OVER THE GREAT PLAINS SHIFTING EASTWARD INTO THE MS VALLEY BY MON
NIGHT AND INTO IL TUE. 850 MB TEMPS WARM UP SUNDAY TO 10C OR
WARMER SW AREAS AND GIVES HIGHS IN THE LOW TO MID 70S. BACKDOOR
COLD FRONT TO MOVE FROM THE GREAT LAKES REGION THROUGH IL EARLY
NEXT WEEK...COOLING TEMPS MONDAY ESPECIALLY NE AREAS BUT DRY
CONDITIONS EXPECTED SUNDAY THROUGH TUE.
LONG TERM...TUESDAY THROUGH FRIDAY
A PROGRESSIVE NORTHERN STREAM WEATHER SYSTEM TRACKING EAST ALONG
THE US/CANADIAN BORDER TO PUSH A COLD FRONT THROUGH IL TUE NIGHT
AND THEN STALL OUT NEAR THE OHIO RIVER WED BEFORE LIFTING BACK
NORTH LATER NEXT WEEK. THIS TO BRING CHANCES OF
SHOWERS/THUNDERSTORMS BY TUE NIGHT AND MAINLY IN SE IL WED AND
THEN HAVE SLIGHT CHANCES OF CONVECTION LATE NEXT WORK WEEK WITH
FRONT LIFTING BACK NORTH. TEMPS OVERALL TO REMAIN ABOVE NORMAL AND
NO FROST OR FREEZE EXPECTED THROUGH NEXT WEEK.
HUETTL
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1256 PM CDT FRI MAR 23 2012
.MESOSCALE DISCUSSION...
1200 PM CDT
A SWATH OF SHOWERS FROM SOUTHEAST WISCONSIN THROUGH NORTHWEST
INDIANA CONTINUE TO MOVE NORTHEAST. BASED ON THE LATEST RUC
ANALYSIS...THE SLOW MOVING UPPER LEVEL LOW IS CURRENTLY CENTERED
OVER MISSOURI. THE CORRESPONDING SURFACE LOW IS OVER EAST CENTRAL
MISSOURI AND SLOWLY MOVING INTO SOUTHERN INDIANA. LATEST WATER
VAPOR IMAGERY SHOWS SPIRALS OF DRIER AIR CIRCLING THE UPPER LEVEL
LOW...WHICH CORRELATE TO AREAS OF CLEARING OVER NORTH CENTRAL
ILLINOIS.
UNDER THE AREAS OF CLEARING...LOW LEVEL LAPSE RATES HAVE BEEN
RAPIDLY INCREASING. THE RUC HAS A GOOD HANDLE ON MID LEVEL LAPSE
RATES...AND INDICATES STEEPER MID LEVEL LAPSE RATES WILL BE
ADVECTED FROM CENTRAL ILLINOIS THROUGH NORTHERN ILLINOIS. AN AREA
OF CONVERGENCE IS ALSO VISIBLE IN THE SURFACE WIND OBS ALONG THE
ILLINOIS INDIANA STATE LINE. THE STEEP LOW LEVEL LAPSE RATES AND
AREA OF CONVERGENCE HAVE RESULTED IN CONVECTIVE SHOWERS DEVELOPING
ACROSS THE SOUTHERN HALF OF THE CWA. A FEW LIGHTNING STRIKES HAVE
BEEN DETECTED...BUT GIVEN THE ENVIRONMENT...EXPECTING AN INCREASE
IN CONVECTION THROUGH THE AFTERNOON.
CONCERNING THE SEVERE THREAT...THERE IS ADEQUATE
MOISTURE...FORCING...AND SHEAR FOR SEVERE THUNDERSTORM
DEVELOPMENT. HOWEVER INSTABILITY APPEARS TO BE WEAK TO MODERATE AT
BEST. CURRENTLY...THERE IS NO SIGNIFICANT SURFACE BASED CAPE TO
SPEAK OF. RUC AND HRR ANALYSES INDICATE A MAX OF 1500 J/KG THIS
AFTERNOON...WHILE THE SREF HINTS AT A BRIEF MAX OF AT LEAST 500
J/KG. BOTH THE RUC AND HRR SEEM A BIT AMBITIOUS WITH CAPE VALUES
THIS AFTERNOON...THEREFORE EXPECTING ABOUT 1000 J/KG TO WORK WITH.
IF INSTABILITY INCREASES...THE LIKELIHOOD OF MORE WIDESPREAD
SEVERE WEATHER WOULD ALSO INCREASE.
THE MAIN SEVERE WEATHER THREATS ARE HAIL AND DAMAGING WINDS. NAM
MODEL SOUNDINGS ARE ON TREND WITH CURRENT CONDITIONS AND SHOW A
DECENT INVERTED V FEATURE IN DOWNSTATE ILLINOIS THIS
AFTERNOON...WHICH WOULD INDICATE A GOOD CHANCE FOR STRONG
DOWNDRAFTS AND DAMAGING WINDS. MIDLAYER SHEAR IS PLENTIFUL SINCE
WE ARE ON THE NORTHEAST SIDE OF THE UPPER LEVEL LOW. LATEST RUC
ANALYSIS SHOWS UPWARDS OF 60 KT OF 0-6KM SHEAR THROUGH NORTHEAST
ILLINOIS AND NORTHWEST INDIANA. GIVEN A STRONG ENOUGH UPDRAFT AND
STRONG SHEAR...SEVERE HAIL IS POSSIBLE. HOWEVER WITH THE DRY LOW
LEVELS AND THE 12Z ILX SOUNDING INDICATING A FREEZING LEVEL
BETWEEN 9-10 KFT...ONLY EXPECTING HAIL UP TO QUARTER SIZE AT THIS
TIME. AN AREA OF ENHANCED LOW LEVEL HELICITY IS SHIFTING
NORTHWARD AND THIS COULD LEAD TO A FEW ROTATING UPDRAFTS AND
POSSIBLY AN ISOLATED TORNADO OR TWO.
JEE
&&
.DISCUSSION...
340 AM CDT
LARGE UPPER LOW ACROSS THE CENTRAL CONUS IS TAKING ITS TIME SWEET
MOVING TO THE EAST-NORTHEAST. AS THIS FEATURE CONTINUES ITS TREK
INTO THE OHIO VALLEY THROUGH THE WEEKEND...IT WILL BRING SHOWERS
WITH SOME THUNDER TO THE AREA...AS WELL AS CONTINUE TO KEEP THE
ABOVE NORMAL TEMPERATURES THROUGH THE WEEKEND. OVERNIGHT SUNDAY
AND INTO THE START OF THE WORKWEEK WILL SEE CONDITIONS
CHANGE...WITH TEMPERATURES FALLING A LITTLE CLOSER TO NORMAL...BUT
DRY.
DRY SLOT NOTED ON WATER VAPOR IMAGERY THIS MORNING WILL CONTINUE TO
CURL NORTH ACROSS THE CWA THIS MORNING AND WILL LEAD TO SOME DRYING
COME THE MORNING HOURS...AND OVERALL SHOWERY CONDITIONS WILL BE ON
THE WANE FOR MOST. AREAS ACROSS THE WEST AND SOUTH MAY ALSO HAVE THE
BETTER CHANCES AT SEEING SOME HINTS OF SUN...BUT THAT WILL BE SHORT
LIVED AS CHANCES FOR SHOWERS AND THUNDER INCREASE INTO THE AFTERNOON.
ONE OF THE BIGGER CHANGES TO THE GOING FORECAST IS WITH RESPECT TO
THE MASSIVE AND PERSISTENT STACKED LOW THAT IS SLOWLY MOVING ACROSS
THE CENTRAL US. THE CHANGE TONIGHT IS THAT THE LOW IS NOW PROGGED TO
MOVE A LITTLE FARTHER NORTH THAN EARLIER ANTICIPATED. BY BRINGING
THE CORE A LITTLE FARTHER NORTH...WE ARE NOW GOING TO INTRODUCE A
LITTLE COOLER AIR ALOFT BY THE AFTERNOON HOURS. SURFACE DEWPOINTS IN
THE UPPER 50S TO LOWER 60S TO CONTINUE INTO THE AFTERNOON
HOURS...AND WILL HELP TO SUPPORT MEAN LAYER CAPE VALUES IN THE
800-1000 J/KG REGION. LOWER LEVEL SHEAR IS PRETTY MARGINAL...THOUGH
FORECAST SOUNDINGS DO SHOW A SIGNAL OF CURL TO THE HODOGRAPH. SPC
SREF ANALYSIS INDICATES EFFECTIVE SHEAR TO BE IN THE 30-35-40 KT
REALM FROM THE 18 TO TO 00Z HOUR FROM CMI TO IKK AND FLIRTING WITH
ORD /THOUGH REACHING 40KT MAY BE A STRETCH/...THEN IN THE 00Z TO
06Z HOURS SHIFTING EAST AND ACROSS NORTHERN INDIANA. PREVIOUS OFF
HOUR RUNS OF THE NAM AND GFS ALSO INDICATE A LITTLE SPEED MAX
RIPPLING THROUGH...WITH THE FAVORED ENTRANCE REGION MOVING
OVERHEAD INTO THE AFTERNOON HOURS. THAT HAS NOW SHIFTED A LITTLE
EAST...AND WHILE IT ISNT EXACTLY THE MOST FAVORABLE SETUP FOR
CONVECTION...CANT RULE OUT MORE THAN RAIN AND WILL ADD THE MENTION
OF THUNDER THROUGH THE AFTERNOON HOURS. THE BIGGEST THREAT WITH
THE COOLING ALOFT AND THE INCREASED LAPSE RATES WILL BE MARGINAL
HAIL...BUT CAN FORESEE SOME STORMS THAT POP THIS AFTERNOON TAKING
ON SIMILAR CHARACTERISTICS TO WHAT WAS OBSERVED IN THE LATE
EVENING ON THURSDAY...WHERE A FEW MULTICELLULAR CLUSTERS SHOW
SOME MID LEVEL ROTATION...AND THAT MAY GET CLOSE TO THE SURFACE.
BUT THE THREAT APPEARS LOW AND WILL BE MORE FOCUSED ON THE HAIL
THREAT...ESPECIALLY WITH THE LACK OF LOWER LEVEL SHEAR.
THE STREAK OF RECORD BREAKING TEMPERATURES AT ORD LOOKS TO FINALLY
BE OVER...AS THE RECORD HIGH FOR THE DATE IS 80 DEGREES. THE SURFACE
GRADIENT IS INCREDIBLY BAGGY THIS MORNING AND FLOW IS GENERALLY SSE
TO SE ACROSS THE REGION. AS THE SURFACE LOW TRACKS EAST ACROSS
SOUTHERN ILLINOIS...WINDS WILL BECOME MORE EASTERLY AND AREAS ALONG
THE LAKEFRONT WILL BE UNDER THE INFLUENCE OF THE COOLER
MARINE AIRMASS...AND THAT WILL HELP TO KEEP THE TEMPERATURES
CONSIDERABLY LOWER THAN HAS BEEN FELT THE PAST WEEK...GENERALLY
PEAKING IN THE MID/UPPER 60S. AN INTERESTING NOTE...EVEN WITH FLOW
OFF OF THE LAKE IN MID MARCH...DOWN TOWN CHICAGO WAS AT 54 DEGREES
AS OF 4AM. LAST YEAR LAKE MICHIGAN TEMPERATURES WERE 42 AT THE
SHORE...39 AT THE CRIB AND 38 AT MICHIGAN CITY INTAKE. THIS
YEAR...THEY ARE 49, 46 AND 44 RESPECTIVELY. THAT GOES TO HIGHLIGHT
HOW BIG OF A PLAYER THE LAKE CONTINUES TO PLAY IN TEMPERATURES.
WHILE IT WILL BE COOLER THAN WHAT HAS FELT LIKE THE NEW NORM...IT
WILL STILL BE ABOVE THE OFFICIAL NORMAL...WHICH IS 49 DEGREES.
GRANTED...IF AREAS WEST DO CLEAR OUT FOR LONGER THAN
ANTICIPATED...THEY WILL WARM CONSIDERABLY MORE THAN AREAS TO THE
EAST...BUT STILL NOT ANTICIPATING ANY RECORDS FOR THE DAY /AS
ROCKFORD/S RECORD FOR TODAY IS 82/. CIN BUILDS INTO THE EVENING AS
UPPER FLOW BACKS TO THE NORTHWEST AND THEN NORTH...AS THE DISH POT
LOW WOBBLES/MEANDERS EAST. CHANCE OF SHOWERS TO PERSIST THROUGH
THE DAY ON SATURDAY WITH DEEP CYCLONIC FLOW...THOUGH THE BETTERS
CHANCES WILL BE CLOSER TO THE LOW AND SOUTH ACROSS CENTRAL
ILLINOIS AND WEST CENTRAL INDIANA.
LONG TERM TRENDS STILL INDICATE BIGGER COOL DOWN SUNDAY NIGHT AND
INTO MONDAY. THE DISH POT WILL BE IN THE VICINITY OF THE LOWER
OHIO VALLEY BY THE END OF THE WEEKEND...TURNING ALL FLOW TO THE
NORTH AND NORTHWEST IN THAT TIME FRAME. THE GOOD NEWS IS THAT ANY
STRONG ADVECTION OF COLDER AIR THAT THE SYSTEM MAY HAVE HAD A WEEK
OR SO AGO WHEN IT WAS RAMPING UP...HAS BUT WASHED ITSELF OUT THIS
PAST WEEK. H8 TEMPS ARE PROGGED TO ONLY DIP INTO THE +6 TO +8
REALM WHICH MEANS THAT HIGHS ONLY EXPECTED IN THE LOWER 50S NORTH
OF I-88...TOUCHING 60 WELL SOUTH AND CLOSER TOWARDS ILX/S AREA OF
RESPONSIBILITY.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* OCCASIONAL SHOWERS THROUGH LATE MORNING.
* VARIABLE VSBY/CIGS WITH LOWEST IN/AROUND SHOWERS...BRIEF IFR IN SHRA.
* ORD VSBY LIKELY STAYING MVFR WITH COOLER NORTHEASTERLY WIND FLOW.
* LIGHT NORTHEAST WINDS AT ORD PERSISTING THROUGH MID AFTERNOON.
* LIGHT SOUTHEAST WINDS AT MDW SHOULD BECOME MORE EAST THEN
NORTHEAST INTO EARLY AFTERNOON.
* DECENT CHANCE FOR SCATTERED TS DEVELOPMENT THIS AFTERNOON.
* MAY SEE VARIABLE MVFR/VFR CIG/VSBY AWAY FROM SHRA/TSRA THIS
AFTERNOON.
MDB
//DISCUSSION...UPDATED 16Z...
VARIABLE CONDITIONS REMAIN ACROSS THE TERMINALS WITH EVERYTHING
FROM IFR TO VFR. BANDS OF SHOWERS CONTINUE TO ARC NORTHWARD FROM
UGN TO ORD TO MDW TO LAF. THIS ACTIVITY WILL CONTINUE TO SLOWLY
SHIFT TO THE EAST OVER THE NEXT FEW HOURS BUT WILL BRING PERIODIC
REDUCTIONS TO IFR VSBY. A CORRIDOR OF IFR CIGS HAS DEVELOP NEAR
AND UNDER THE SHOWER ACTIVITY STRETCHING AS FAR WEST AS DPA BUT
THIS SHOULD IMPROVE INTO EARLY THIS AFTERNOON. PREVAILING CIG/VSBY
TRENDS NOT AS CLEAR FOR THE AFTERNOON AS THEY WERE BUT EXPECT THAT
MVFR WILL PREVAIL TO START BUT THERE MAY BE IMPROVEMENT TO MVFR AT
SOME POINT. FLOW OFF THE LAKE ACROSS THE CHI METRO MAY KEEP LOWER
CIGS AND VSBY IN PLACE AT ORD/MDW AND PERHAPS EVENTUALLY GYY
CONFIDENCE IN THE SPECIFICS IS LIMITED. EXPECT THAT ORD WILL KEEP
A NE WIND WITH MDW ON THE FRINGE OF THE LAKE FLOW BUT LIKELY
REMAINING EAST OR EAST-NORTHEAST. DPA WILL LIKELY BE IN THE SAME
SCENARIO...WITH GYY EXPECTED TO FLIP NORTHEAST AT SOME POINT THIS
AFTERNOON. RFD SHOULD STAT MORE SOUTHEAST BEFORE SHIFTING EAST AND
NORTHEAST LATER TODAY.
NEXT CONCERN IS POTENTIAL FOR NEW SHRA/TSRA DEVELOPMENT THIS
AFTERNOON. AM CONCERNED ABOUT NEW DEVELOPMENT IN AN AREA OF
SCATTERED/CLEAR SKIES FROM SQI-RFD-NEAR IKK-PNT WITH SOME
INSTABILITY BUILDING AS A RESULT. THIS DEVELOPMENT MAY OCCUR BY
EARLY AFTERNOON AND LIFT NORTHEAST BUT THIS WILL REMAIN TO BE
SEEN. ANOTHER ROUND OF CONVECTION WILL BE POSSIBLE LATER THIS
EVENING BUT CONFIDENCE IN THIS IS NOT HIGH.
MDB
FROM 12Z...
VERY CHALLENGING AVIATION FORECAST CONTINUES WITH PERIODIC
SHRA/ISO TS. GUIDANCE CONTINUES TO SLIDE THE UPPER LEVEL
DISTURBANCE ACROSS CENTRAL IL. IR IMAGERY INDICATED SOME THINNING
WAS TAKING PLACE ACROSS A NARROW CHANNEL FROM NORTHWEST IL
STRETCHING SOUTHEAST THROUGH CENTRAL IL/SOUTHERN IL. IN THIS
COLUMN CIGS/VSBYS HAVE REDUCED TO MVFR WITH PATCHY IFR. IT DOES
NOT APPEAR THAT THIS WILL IMPACT THE NORTHERN IL AIRFIELDS AT THIS
POINT...HOWEVER SLIGHT REDUCTION IN CIGS/VSBYS MAY OCCUR DUE TO
THE RECENT RAINFALL AND LACK OF MIXING TO SCOUR LLVL MOISTURE.
HAVE HANDLED THIS WITH SLIGHT REDUCTION OF CIGS TO MVFR.
INCREASED INSTABILITY COULD RESULT IN ANOTHER ROUND OF SHRA/TSRA
DURING THE AFTN/EVE HOURS BEFORE COMING TO AN END EARLY SAT
MORNING. HOWEVER...IT APPEARS THAT SOME FG WILL BEGIN TO FORM LATE
FRI NIGHT AND COULD PRODUCE A FEW AREAS OF DENSE FOG GIVEN THE
RECENT RAINFALL.
THE OTHER AVIATION CHALLENGE OVERNIGHT WILL CONTINUE TO REVOLVE
AROUND WIND DIR. WITH THE LACK OF A SOLID GRADIENT TO PRODUCE A
PREVAILING WIND DIR...WINDS CONTINUE TO BE FLUID BETWEEN 040-110
DEG ARND 4 TO 6 KT. EXPECT A SLIGHT INCREASE IN THE GRADIENT OVER
THE NEXT FEW HOURS AND SHUD PROVIDE A MORE DEFINED DIR...HOWEVER
THE UPPER LEVEL DISTURBANCE WILL BE TRAVERSING THE REGION AND
STILL PROVIDE CHANGING WIND DIR FROM THE NE TO SE.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN SHRA CONTINUING FOR SEVERAL HOURS THIS MORNING.
* HIGH CONFIDENCE IN VARIABLE CIG/VSBY THIS MORNING...WITH BRIEF
IFR IN SHRA.
* MEDIUM-HIGH CONFIDENCE IN ORD VSBY REMAINING MVFR OUTSIDE OF
SHRA THIS MORNING.
* MEDIUM CONFIDENCE IN WIND DIRECTION TRENDS AT ORD.
* LOW-MEDIUM CONFIDENCE IN WIND DIRECTION TRENDS AT MDW.
* MEDIUM CONFIDENCE IN SHRA/TSRA DEVELOPMENT THIS AFTERNOON BUT
LOW CONFIDENCE IN TIMING/EXTENT OF IMPACTS AT THE TERMINALS.
* LOW-MEDIUM CONFIDENCE IN CIG/VSBY TRENDS THIS AFTERNOON.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VFR. PSBL FG DEVELOPMENT.
SUNDAY...VFR.
MONDAY...VFR.
TUESDAY...VFR. PSBL MVFR CIGS WITH CHC SHRA/ISO TS.
WEDNESDAY...MVFR EARLY TRENDING VFR. CHC RA/TS EARLY.
THURSDAY...VFR.
BEACHLER
&&
.MARINE...
251 AM CDT
A COUPLE WEATHER FEATURES CONTINUE TO POSE CHALLENGES TO THE
WEATHER ACROSS THE MARINE COMMUNITY...AS AN UPPER LEVEL
DISTURBANCE SLOWLY LIFTS NORTHEAST FROM THE CENTRAL PLAINS TOWARDS
THE SOUTHERN GREAT LAKES TODAY. MEANWHILE A BROAD AREA OF HIGH
PRESSURE OVER NORTHERN MANITOBA WILL DRIFT EAST AND BECOME
CENTERED OVER HUDSON BAY TONIGHT INTO SATURDAY. THIS WILL ALLOW A
GRADIENT TO STEADILY INCREASE ACROSS THE NORTHERN PORTIONS OF THE
LAKE TODAY...WITH WINDS COMING UP TO 15 TO 25 KT. A FEW GUSTS UP
TO 30 KT WILL BE POSSIBLE. ELSEWHERE WITH THE LACK OF A STRONG
GRADIENT...WINDS WILL BE MUCH LIGHTER FROM THE EAST. THIS WILL
ALLOW WAVES TO BE HIGHER ALONG THE WESTERN SIDE OF LAKE MICHIGAN.
AT THIS TIME IT DOES NOT APPEAR WAVES WILL BE LARGE ENOUGH TO
WARRANT ANY HEADLINES IN THE NEARSHORE WATERS FOR
ILLINOIS/NORTHWEST INDIANA. THEN AS THE UPPER LEVEL DISTURBANCE
DRIFTS EAST...A WEAK LOW PRESSURE SYSTEM WILL TRAVERSE LAKE
SUPERIOR. BEHIND THIS SYSTEM ON SUNDAY...A STRONG HIGH PRESSURE
WILL BUILD IN AND TIGHTEN THE GRADIENT YET AGAIN. THIS SHOULD
ALLOW WINDS TO STEADILY INCREASE.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1007 AM CDT FRI MAR 23 2012
.DISCUSSION...
ISSUED 1005 AM CDT FRI MAR 23 2012
LARGE STACKED LOW SPINNING OVER THE SOUTHEAST TIP OF KANSAS PER
WATER VAPOR IMAGERY...WITH SURFACE OBS AND RADAR IMAGERY SHOWING A
SECONDARY LOW PRESSURE AREA OVER CENTRAL MISSOURI. HAD QUITE A BIT
OF FOG DEVELOP OVER THE WESTERN 2/3 OF THE CWA EARLIER...BUT
VISIBILITIES WERE RAPIDLY IMPROVING BY 9 AM AND LATEST
OBSERVATIONS SHOWING MOST SITES ABOVE 4 MILES THIS HOUR. HAVE BEEN
SEEING A RAPID INCREASE IN SHOWERS AND STORMS OVER SOUTHEAST
MISSOURI RECENTLY...WITH A FEW SHOWERS/STORMS NOW MOVING INTO FAR
SOUTHERN PARTS OF OUR CWA. 12Z SOUNDING FROM SPRINGFIELD MO SHOWED
500 MB TEMPERATURES OF -26C ASSOCIATED WITH THE UPPER LOW...WHICH
WILL TRACK EASTWARD ACROSS SOUTHERN MISSOURI THIS AFTERNOON. THIS
WILL ENHANCE MID-LEVEL LAPSE RATES...WITH LATEST RUC MODEL SHOWING
RATES OF AROUND 7.5 TO 8C/KM OVER OUR AREA BY EARLY AFTERNOON
SUPPORTING HAIL DEVELOPMENT WITH THE STRONGER STORMS. SEVERE
WEATHER POTENTIAL STILL EXISTS BECAUSE OF THIS...WITH AREAS
SOUTHEAST OF I-55 MOST AT RISK.
UPDATED GRIDS HAVE BEEN SENT...WITH UPDATED ZONES TO FOLLOW AROUND
1015 AM. MOST CHANGES WERE IN THE PRECIP/WEATHER TYPES...WITH SOME
ADJUSTMENTS TO THE HOURLY GRIDS FOR OTHER ELEMENTS.
GEELHART
&&
.AVIATION...
ISSUED 647 AM CDT FRI MAR 23 2012
COMPLEX AVIATION FORECAST THIS PACKAGE. SITES THAT SAW SOME
CLEARING OVERNIGHT HAVE NOW BEEN REDUCED TO LIFR AND
VLIFR...EITHER DUE TO FOG AND/OR THE LOWER CIGS. THESE CONDITIONS
SHOULD CONTINUE FOR A FEW HOURS THIS MORNING. AS THE SUN COMES UP
AND BURNS SOME OF THE LOWER CIGS AND FOG OFF THIS
MORNING...CONDITIONS SHOULD IMPROVE TO MVFR. IN ADDITION...SHOWERS
WILL MOVE BACK INTO THE AREA AT ALL SITES WITH 5SM BR. BELIEVE
ISOLATED THUNDERSTORMS ARE ALSO POSSIBLE SO WILL HAVE VCTS AT ALL
SITES FOR THE AFTERNOON AND EARLY EVENING HOURS. ONCE THE PCPN
ENDS...CONDITIONS SHOULD IMPROVE TO VFR FOR REST OF THE NIGHT AND
OVERNIGHT. PRESSURE GRADIENT IS VERY WEAK SO EXPECT LIGHT WINDS TO
BECOME SOUTHEAST FOR LATER THIS MORNING...THROUGH THIS AFTERNOON
AND THIS EVENING. THEN LIGHT WINDS ARE EXPECTED AGAIN OVERNIGHT.
AUTEN
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT FRI MAR 23 2012
SHORT TERM...TODAY THROUGH MONDAY NIGHT
00Z MODELS REMAIN IN FAIR AGREEMENT THROUGH THIS WEEKEND AND WILL
USE A BLEND. MET AND MAV GUIDANCE TEMPS SIMILAR THROUGH THIS
WEEKEND AND STAYED CLOSE TOO. GUIDANCE CONTINUES TO GO WARMER ON
SUNDAY AND HAS HIGHS IN THE MID 70S MOST AREAS AND TRENDED THE
FORECAST IN THAT DIRECTION.
COOLER TEMPERATURES EXPECTED LATE THIS WEEK THOUGH STILL 10-15
DEGREES ABOVE NORMAL AND SUNDAY NOW LOOKS WARMER IN THE 70S.
UNSETTLED WEATHER PATTERN EXPECTED THROUGH SAT DUE TO 551 DM 500
MB LOW OVER SOUTHEAST KS THAT SLOWLY WEAKENS IT IT MOVES INTO SE
MO BY SUNSET AND THEN INTO SOUTH CENTRAL KY/MID TN BY SUNSET SAT.
SPC HAS MUCH OF CENTRAL/SE IL INTO THE LOWER OHIO VALLEY IN A
SLIGHT RISK THIS AFTERNOON FOR MAINLY LARGE HAIL (15%) RISK WHILE
WINDS AND ISOLATED TORNADOES ARE JUST 5% RISK.
SHOWERS AND ISOLATED THUNDERSTORMS OVER INDIANA AND NE IL DRIFTING
NNW AROUND THE 551 DM 500 MB LOW OVER SE KS. A SMALL BAND OF
SHOWERS AND A FEW THUNDERSTORMS OVER CENTRAL AND SOUTHCENTRAL MO
CLOSER TO THE UPPER LEVEL LOW. DRY WEDGE INBETWEEN OVER CENTRAL
AND SW IL AND SOME CLEARING FROM LINCOLN SW HAS ALLOWED SOME FOG
TO FORM EARLY THIS MORNING...EVEN DENSE FOG AT MACOMB...KEOKUK AND
PITTSFIELD IN WEST CENTRAL IL. VSBYS GENERALLY 3-5 MILES WEST OF
LINCOLN AND MAY NEED TO ADD FOG TO THE FORECAST FOR THESE AREAS
INTO MID MORNING AND VSBYS LIKELY DROP FURTHER.
EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP BY MIDDAY
AND BECOME MORE WIDESPREAD DURING THE AFTERNOON AS UPPER LEVEL LOW
MOVES INTO SOUTHERN MO AND AIRMASS GETS MORE UNSTABLE AND HAVE
LIKELY TO EVEN CATEGORICAL POPS THIS AFTERNOON OVER SW AREAS. PER
SPC DAY1 OUTLOOK...BAND/ARC OF THUNDERSTORMS IS EXPECTED TO
INCREASE IN COVERAGE/INTENSITY FROM MIDDAY THROUGH AT LEAST MID
AFTERNOON...IN ZONE OF CONVERGENCE LOCATED NE-E OF DEEP- LAYER
LOW. COLD CORE CONVECTIVE REGIME FCST TO SHIFT EWD/NEWD ACROSS
OUTLOOK AREA...WITH DOMINANT THREAT BEING LARGE HAIL...ISOLATED
DAMAGING GUSTS POSSIBLE. TORNADO POTENTIAL APPEARS
CONDITIONAL/MARGINAL ON OUTLOOK SCALE ATTM...BUT MAY BE LOCALLY
ENHANCED BY STORM INTERACTIONS WITH BANNERS OF BOUNDARY- LAYER
VORTICITY. ENHANCED/7.5-8.5 DEG C/KM MID LEVEL LAPSE RATES AND MID
50S TO NEAR 60 F SFC DEW POINTS WILL JUXTAPOSE WITH SURFACE
HEATING TO SUPPORT 600-1200 J/KG MLCAPE...AMIDST 30-45 KT
EFFECTIVE SHEAR MAGNITUDES. THUNDERSTORMS SHOULD DIMINISH DURING
EARLY THIS EVENING WITH LOSS OF DAYTIME HEATING.
SHOWERS TO DIMINISH OVERNIGHT AND THEN INCREASE AGAIN BY SAT
AFTERNOON WITH ISOLATED THUNDERSTORMS POSSIBLE OVER EASTERN/SE IL
SAT AFTEROON ESPECIALLY NEAR THE WABASH RIVER WHERE SHOWERS MAY
LINGER EARLY SAT EVENING BY LAWRENCEVILLE. UPPER LEVEL LOW SLOWLY
WEAKENS AS IT DRIFTS ESE INTO EASTERN TN BY MIDNIGHT SAT NIGHT.
NICE WEATHER EXPECTED EARLY NEXT WEEK WITH UPPER LEVEL LOW
PULLING AWAY INTO THE SE STATES AND STRONG UPPER LEVEL RIDGING
OVER THE GREAT PLAINS SHIFTING EASTWARD INTO THE MS VALLEY BY MON
NIGHT AND INTO IL TUE. 850 MB TEMPS WARM UP SUNDAY TO 10C OR
WARMER SW AREAS AND GIVES HIGHS IN THE LOW TO MID 70S. BACKDOOR
COLD FRONT TO MOVE FROM THE GREAT LAKES REGION THROUGH IL EARLY
NEXT WEEK...COOLING TEMPS MONDAY ESPECIALLY NE AREAS BUT DRY
CONDITIONS EXPECTED SUNDAY THROUGH TUE.
LONG TERM...TUESDAY THROUGH FRIDAY
A PROGRESSIVE NORTHERN STREAM WEATHER SYSTEM TRACKING EAST ALONG
THE US/CANADIAN BORDER TO PUSH A COLD FRONT THROUGH IL TUE NIGHT
AND THEN STALL OUT NEAR THE OHIO RIVER WED BEFORE LIFTING BACK
NORTH LATER NEXT WEEK. THIS TO BRING CHANCES OF
SHOWERS/THUNDERSTORMS BY TUE NIGHT AND MAINLY IN SE IL WED AND
THEN HAVE SLIGHT CHANCES OF CONVECTION LATE NEXT WORK WEEK WITH
FRONT LIFTING BACK NORTH. TEMPS OVERALL TO REMAIN ABOVE NORMAL AND
NO FROST OR FREEZE EXPECTED THROUGH NEXT WEEK.
HUETTL
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1215 AM CDT FRI MAR 23 2012
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TODAY/...
BIGGEST FOCUS TODAY WILL BE ON FOG THIS MORNING...AND THEN CHANCES
FOR SHOWERS ACROSS THE SOUTHERN CWA. FOG HAS DEVELOPED ACROSS MUCH
OF THE CWA...MAINLY NORTH AND EAST OF A LINE FROM OTTUMWA...TO DES
MOINES...TO CARROLL. FOG EXPECTED TO PERSIST ACROSS THE AREA INTO
THE MID MORNING HOURS...WITH WINDS EXPECTED TO REMAIN LIGHT AND
CONTINUE TO HAVE MOISTURE NEAR SURFACE CONDITIONS DUE TO RESIDUAL
MOISTURE FROM RAINFALL OVER THE PAST FEW DAYS. MAJORITY OF VSBYS
RANGING FROM NEAR ZERO TO AROUND ONE QUARTER MILE AND ARE ONLY
EXPECTED TO WORSEN THROUGH SUNRISE...WITH THE HRRR KEEPING VSBYS AT
A QUARTER MILE OR BELOW THROUGH 15Z. THEREFORE HAVE OPTED TO ISSUE A
DENSE FOG ADVISORY FOR MUCH OF THE CWA THROUGH 15Z. FOG SHOULD THEN
LIFT INTO SOME LOW STRATUS AND THEN BREAK UP SOME BY LATE MORNING
INTO THE EARLY AFTERNOON HOURS. WITH THE UPPER LOW CHURNING TO THE
SOUTH OF THE CWA...AND CONTINUED CYCLONIC FLOW OVER THE STATE...DO
NOT EXPECT SKIES TO CLEAR COMPLETELY TODAY...WITH SOME SHOWERS
POSSIBLE ACROSS SOUTHERN CWA THROUGHOUT THE DAY AS BANDS OF LIGHT
SHOWERS CONTINUE TO ROTATE NORTHWARD FROM MISSOURI AROUND MAIN LOW
TO THE SOUTH OF THE CWA. ANY PRECIP ROTATING BACK INTO THE AREA
ACROSS NORTHEASTERN CWA APPEARS TO HOLD OFF UNTIL AFTER 00Z. WITH
H85 TEMPERATURES AROUND +9C...A COOLER START TO THE DAY...AND CLOUD
COVER/LINGERING FOG HAVE TEMPS IN THE UPPER 60S TO AROUND 70.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
THOUGH THE UPPER LOW CENTER IS CURRENTLY OVER FAR SOUTHEAST
KANSAS...THE STRONGEST PV ANOMALY ASSOCIATED WITH THE SYSTEM IS
ROUNDING THROUGH CNTRL ARKANSAS. THIS WILL HELP KEEP THE UPPER LOW
ON A MORE SOUTHERLY TRACK BY THIS EVENING AS IT TRACKS INTO THE
LOWER OHIO VALLEY. ONE FINAL PIECE OF ENERGY WILL WRAP AROUND THE
SYSTEM AND INTO EASTERN AS THE SYSTEM DEPARTS TONIGHT. THIS WILL
BRING ONE LAST CHANCE FOR SHOWERS EAST OF INTERSTATE 35. THE AREA
WILL QUICKLY TRANSITION OUT OF CYCLONIC FLOW ON SATURDAY WITH
RIDGING BUILDING IN FROM THE WEST. DESPITE NW FLOW...SOME SFC WARM
ADVECTION WILL BE TAKING PLACE. THE NW FLOW WILL ALSO AID DESCENT
MIXING AND THERE SHOULD BE AN ABUNDANCE OF SUNSHINE CENTRAL AND WEST
WITH A FEW CLOUDS LINGERING OVER THE EAST. A WEAK FRONTAL BOUNDARY
WILL REACH THE NORTHERN THIRD OF THE STATE SATURDAY NIGHT AND SUNDAY
THOUGH THE GREATEST IMPACTS WILL MOVE THROUGH PORTIONS OF MINNESOTA
AND WISCONSIN. SHOULD BE A PLEASANT DAY OVERALL WITH HIGHS IN THE
60S AND 70S WITH LIGHT WINDS.
THE MONDAY FORECAST CONTINUES TO BECOME MORE COMPLEX. THE
AFOREMENTIONED COLD ADVECTION THROUGH WISCONSIN SUNDAY WILL SHIFT
WEST AS A BACK DOOR COLD FRONT OFF LAKE MICHIGAN SUNDAY NIGHT AND
MONDAY. WARM ADVECTION WILL BE LIFTING INTO WESTERN IOWA BY MONDAY
MORNING HOWEVER ITS EASTWARD ADVANCE WILL LIKELY BE OVERCOME BY THE
COOLER AND MORE DENSE AIR FILTERING IN FROM THE EAST. HIGH
TEMPERATURES AT THIS POINT COULD BE TOO HIGH BY SEVERAL DEGREES IF
THE THIS BOUNDARY COMES IN AS STRONG AS SUGGESTED. DESPITE
THIS...MID LEVEL WARM ADVECTION WILL CONTINUE TO OVERSPREAD THE AREA
MONDAY WITH SOME INSTABILITY DEVELOPING AHEAD OF THE LOW LEVEL JET
AND STRONG THETA E ADVECTION. BEST POTENTIAL FOR THUNDERSTORMS WOULD
BE OVER THE NORTH. ANY THUNDER AT THIS TIME LIKELY WILL BE ELEVATED
THOUGH A MARGINAL SEVERE STORM WOULD BE POSSIBLE. BOWLING BALL UPPER
LOW LIFTING INTO THE NORTHERN PLAINS ON TUESDAY COULD PRODUCE SOME
INTERESTING WEATHER TUESDAY PENDING EXACT TIMING AND PLACEMENT OF
THE SYSTEM. COOLER AIR WILL SINK IN BEHIND THE SYSTEM THOUGH AGAIN
THE GREATEST IMPACT WILL BE TO THE NORTHEAST. TEMPERATURES WILL
REMAIN WELL ABOVE SEASONAL VALUES WITH LOW POTENTIAL FOR
PRECIPITATION WEDNESDAY AND THURSDAY.
&&
.AVIATION...23/18Z
EARLY MORNING FOG HAS LIFTED...WITH A FEW SITES...KOTM/KFOD STILL
EXPERIENCING LOW MVFR CEILINGS. THESE WILL CONTINUE TO LIFT THROUGH
THE EARLY PERIOD...WITH VFR CEILINGS THROUGH 06Z. FOG IS POSSIBLE
AGAIN AT SITES NEAR 12Z...AND HAVE TRENDED VISIBILITIES DOWN.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE
&&
$$
SHORT TERM...BEERENDS
LONG TERM...DONAVON
AVIATION...AWB
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
717 AM CDT FRI MAR 23 2012
.UPDATE...
SUNRISE HAS ALLOWED VISIBILITIES TO SUDDENLY TANK. WEB CAMS SHOW
THE FOG IS NOT CONTINUOUS WITH AREAS OF GOOD VISIBILITY AND FOG
BANKS IN OTHER AREAS. SO...WILL ISSUE A DENSE FOG ADVISORY AND
WORD IT ACCORDINGLY.
..08..
&&
.PREV DISCUSSION... /ISSUED 653 AM CDT FRI MAR 23 2012/
UPDATE...
MONITORING THE FOG FOR THE PAST FEW HOURS. SFC OBS CONTINUE TO
SUGGEST IT IS PATCHY WITH SOME AREAS HAVING GOOD VISIBILITY. WEB
CAMS THAT HAVE ENOUGH LIGHT OR BACKGROUND LIGHT AVAILABLE SUGGEST
THE FOG IS NOT OVERLY THICK IN VERTICAL DEPTH OR WIDESPREAD. THE
IMPENDING SUNRISE WILL PROVIDE MORE LIGHT OVER THE NEXT 30 MINUTES
TO GIVE MORE CLARITY ON THE WEB CAMS.
BASED ON THIS DATA AND RUC TRENDS IT WOULD APPEAR THAT THE FOG IS
IN LOW LYING AREAS AND SOME RIVER VALLEYS. CURRENT PLAN IS TO
CONTINUE WITH THE SPS UNLESS NEW DATA IN THE NEXT 30 MINUTES
SUGGEST OTHERWISE.
.08..
AVIATION...
VFR TO VLIFR CONDITIONS WILL BE SEEN STARTING AT SUNRISE WITH
CONDITIONS IMPROVING TO MVFR OR VFR BY 18Z/23Z. TRENDS WITH THE
RUC MODEL POINT TO AFTERNOON CONVECTION DEVELOPING WITH POTENTIAL
TSRA IMPACTS AT KMLI/KBRL. KCID/KDBQ MY SEE VCSH. AFT 06Z/24
CONDITIONS ARE EXPECTED TO DETERIORATE TO MINIMALLY MVFR WITH THE
POTENTIAL FOR IFR/LIFR CONDITIONS.
.08..
PREV DISCUSSION... /ISSUED 325 AM CDT FRI MAR 23 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS NUMEROUS WEAK LOWS ACROSS THE MIDWEST ALONG
WITH ASSOCIATED TROFS. A WEAK LOW WAS NORTHEAST OF KDSM WITH A TROF
RUNNING SOUTHEAST TO KEVV. ANOTHER TROF RAN FROM CENTRAL INDIANA
NORTHWEST INTO SOUTHERN MINNESOTA. THE OCCLUDED LOW ASSOCIATED WITH
THE UPPER LOW WAS NEAR KCNU WITH TROFS RADIATING OUT FROM IT. DEW
POINTS WERE GENERALLY IN THE 40S AND 50S ACROSS THE MIDWEST.
RADAR TRENDS SHOW THE MAIN PRECIP GENERALLY NORTH OF A LINE FROM
KRST TO KVYS WHICH WAS ASSOCIATED WITH A VORT MAX ROTATING AROUND
THE UPPER LOW.
SHORT TERM...TODAY AND TONIGHT...
A VERY INTERESTING FCST WITH INTERACTIONS BOTH UP AND DOWN ON
VARIOUS SCALES ALONG WITH NONLINEAR PROCESSES. THE RUC WAS VERY
USEFUL IN ESTABLISHING OVERALL NEAR TERM TRENDS.
THE MCS AND LIFT TOOLS ALONG WITH THE HEAVY RAIN TOOL DO A NICE JOB
OF DEPICTING THE CURRENT PRECIPITATION ACROSS THE AREA. THE PRECIP
IS JUST EAST OF THE MAIN THETA E GRADIENT AND THE RUC HAS THIS
GRADIENT SLOWLY MOVING TO THE NORTH AND EAST THROUGH 12Z. THUS THE
CURRENT PRECIP WILL SLOWLY MOVE OUT OF THE AREA. THE PARTIAL
CLEARING THAT HAS OCCURRED IN THE DIRTY DRY SLOT HAS ALLOWED FOG TO
DEVELOP WITH IT LOCALLY THICK IN AN AREA OF WEAK CONVERGENCE ACROSS
SOUTHEAST IOWA. A FEW GROUND TRUTH REPORTS INDICATE IT IS VERY
SHALLOW. SO WILL CONTINUE TO MONITOR FOR TRENDS BUT WILL HIGHLIGHT
FOG THREAT WITH ANOTHER SPS.
ANY PRECIPITATION SHOULD BE CONFINED TO THE FAR NORTHEAST/EAST PARTS
OF THE CWFA THROUGH MID MORNING BEFORE DIFFERENTIAL HEATING BEGINS
TO PRODUCE SOME ISOLD SHRA ACROSS THE REMAINDER OF THE AREA. LIFT
AND HEAVY RAIN TOOLS SUGGEST A CONSIDERABLE AMOUNT OF NEW CONVECTION
SHOULD BE ACROSS NORTHEAST ILLINOIS AT MID DAY WITH ANOTHER VORT
MAX. LIFT TOOL HAS A THETA E GRADIENT ACROSS ROUGHLY THE SOUTHEAST
HALF OF THE CWFA DURING THE AFTERNOON WITH CONVERGENCE INCREASING.
THUS SHOWERS WITH TSRA WILL BE MOST PREVALENT ACROSS ROUGHLY THE
SOUTHERN HALF OF THE CWFA.
CONVECTION WILL CONTINUE INTO THE EVENING HOURS WITH IT MOST
NUMEROUS ACROSS THE SOUTHERN HALF OF THE CWFA. SUNSET WILL ALLOW THE
ATMOSPHERE TO RE-STABILIZE SO CONVECTION WILL DIMINISH DURING THE
EVENING. MCS AND LIFT TOOLS SUGGEST CONVECTION MAY PERSIST OR EVEN
RE-DEVELOP AFTER MIDNIGHT ACROSS THE NORTHWEST THIRD TO HALF OF THE
CWFA WITH CONVERGENCE INCREASING THERE AS ANOTHER VORT MAX ROTATES
AROUND THE UPPER LOW. ..08..
LONG TERM...SATURDAY THROUGH NEXT THURSDAY...
MOSTLY DRY TO DRY WITH TEMPERATURES STILL ABOVE NORMAL BY AT LEAST
SEVERAL DEGREES IF NOT MORE ALL DAYS....THOUGH NOT RECORD WARMTH.
OVERALL...INITIALIZATION GOOD WITH UPSTREAM ENERGY AND VERIFICATION
AND RUN TO RUN CONTINUITY SUPPORTING A 50/50 BLEND OF GFS/HI-RES
ECMWF. LIMITED SENSIBLE IMPACTS WITH SOME LIGHT TO LOCALLY MODERATE
RAIN AMOUNTS POSSIBLY WITH BACKDOOR COLD FRONT MONDAY INTO TUESDAY
AHEAD OF NEXT SHORT WAVE. PERSISTENCE SUGGEST GUIDANCE TEMPS MAY
STILL BE A FEW DEGREES TOO COOL FOR LATER SHIFTS TO CONSIDER MOST
DAYS EXCEPT MONDAY WHEN BACKDOOR FRONT MAY BE COLDER WITH GOOD
ADVECTION FROM NE WINDS OFF LAKE MICHIGAN.
SATURDAY...KEPT LOW POPS WITH CONVECTIVE TEMPERATURE REACHED FOR
MOSTLY PM POPCORN -SHRA. OTHERWISE...PARTLY SUNNY AND MILD WITH
HIGHS MAINLY 70 TO 75 DEGREES WITH LIGHT WINDS. SATURDAY NIGHT...
CLEARING AND A BIT COLDER WITH MINS AROUND 50 DEGREES BUT LIGHT
WIND SUGGEST LATER SHIFTS MAY NEED TO TRIM AT LEAST A FEW DEGREES
WITH GOOD BL DECOUPLING.
SUNDAY...ANOTHER SPLENDID LATE MARCH DAY AHEAD OF BACKDOOR COLD
FRONT WITH HIGHS WELL INTO THE 70S AND LIGHT NORTH WINDS. SUNDAY
NIGHT...BACKDOOR ARRIVES BY LATE EVENING WITH NE WINDS OF 10-20+
MPH SUGGESTED. WENT WITH MINS OF LOWER 40S NE TO LOWER 50S SW BUT
LATER SHIFTS MAY NEED TO TRIM AT LEAST A COUPLE MORE DEGREES MOST
LOCATIONS. WITH OUR EXTENDED MILD WEATHER...THIS WILL FEEL COLDER
THAN ONE WOULD EXPECT FOR LATE MARCH TO MANY.
MONDAY THROUGH TUESDAY...LOCAL TECHNIQUES SUGGEST NE SECTIONS MAY
STRUGGLE WITH IDEAL FETCH OFF LAKE MICHIGAN IN NE 1/2 OF AREA TO
REACH THE MIDDLE 50S WITH GUSTY NE TO E WINDS OF 15-25+ MPH. LOW
CLOUDS ALSO MAY RESULT IN GREATER IMPACT OF A COOL DAY. NEXT SHORT
WAVE MAY SPAWN LIGHT RAIN AND RAIN SHOWERS MONDAY NIGHT INTO TUESDAY.
THE STRENGTH OF FORCING SHOULD BE BETTER ASCERTAINED NEXT 12-24
HOURS. TUESDAY WARM FRONT SHOULD PASS BY MID DAY FOR TEMPERATURES
BACK INTO THE 70S AND MINS TUESDAY NIGHT UPPER 40S TO LOWER 50S WITH
-SHRA/-TSRA ENDING PROBABLY BY MIDNIGHT WITH PASSAGE OF COLD FRONT.
ANY STORMS ATTM PROBABLY NON-SEVERE DUE TO LIMITED FORCING AND
INSTABILITY.
WEDNESDAY AND THURSDAY...MAINLY DRY WITH WEAK HIGH PRESSURE AND ONLY
A BIT COOLER WITH HIGHS IN THE 60S AND MINS IN THE 40S. THIS IS
STILL 10 PLUS DEGREES ABOVE NORMAL AS OUR REMARKABLE EXTENDED PERIOD
OF MARCH WARM SPELL CONTINUES. ..NICHOLS..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR BENTON-
BUCHANAN-CEDAR-DES MOINES-HENRY IA-IOWA-JEFFERSON-JOHNSON-
KEOKUK-LEE-LINN-LOUISA-MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR HANCOCK-
HENDERSON-HENRY IL-MCDONOUGH-MERCER-ROCK ISLAND-WARREN.
MO...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR CLARK-
SCOTLAND.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
655 AM CDT FRI MAR 23 2012
.SHORT TERM /TODAY/...
BIGGEST FOCUS TODAY WILL BE ON FOG THIS MORNING...AND THEN CHANCES
FOR SHOWERS ACROSS THE SOUTHERN CWA. FOG HAS DEVELOPED ACROSS MUCH
OF THE CWA...MAINLY NORTH AND EAST OF A LINE FROM OTTUMWA...TO DES
MOINES...TO CARROLL. FOG EXPECTED TO PERSIST ACROSS THE AREA INTO
THE MID MORNING HOURS...WITH WINDS EXPECTED TO REMAIN LIGHT AND
CONTINUE TO HAVE MOISTURE NEAR SURFACE CONDITIONS DUE TO RESIDUAL
MOISTURE FROM RAINFALL OVER THE PAST FEW DAYS. MAJORITY OF VSBYS
RANGING FROM NEAR ZERO TO AROUND ONE QUARTER MILE AND ARE ONLY
EXPECTED TO WORSEN THROUGH SUNRISE...WITH THE HRRR KEEPING VSBYS AT
A QUARTER MILE OR BELOW THROUGH 15Z. THEREFORE HAVE OPTED TO ISSUE A
DENSE FOG ADVISORY FOR MUCH OF THE CWA THROUGH 15Z. FOG SHOULD THEN
LIFT INTO SOME LOW STRATUS AND THEN BREAK UP SOME BY LATE MORNING
INTO THE EARLY AFTERNOON HOURS. WITH THE UPPER LOW CHURNING TO THE
SOUTH OF THE CWA...AND CONTINUED CYCLONIC FLOW OVER THE STATE...DO
NOT EXPECT SKIES TO CLEAR COMPLETELY TODAY...WITH SOME SHOWERS
POSSIBLE ACROSS SOUTHERN CWA THROUGHOUT THE DAY AS BANDS OF LIGHT
SHOWERS CONTINUE TO ROTATE NORTHWARD FROM MISSOURI AROUND MAIN LOW
TO THE SOUTH OF THE CWA. ANY PRECIP ROTATING BACK INTO THE AREA
ACROSS NORTHEASTERN CWA APPEARS TO HOLD OFF UNTIL AFTER 00Z. WITH
H85 TEMPERATURES AROUND +9C...A COOLER START TO THE DAY...AND CLOUD
COVER/LINGERING FOG HAVE TEMPS IN THE UPPER 60S TO AROUND 70.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
THOUGH THE UPPER LOW CENTER IS CURRENTLY OVER FAR SOUTHEAST
KANSAS...THE STRONGEST PV ANOMALY ASSOCIATED WITH THE SYSTEM IS
ROUNDING THROUGH CNTRL ARKANSAS. THIS WILL HELP KEEP THE UPPER LOW
ON A MORE SOUTHERLY TRACK BY THIS EVENING AS IT TRACKS INTO THE
LOWER OHIO VALLEY. ONE FINAL PIECE OF ENERGY WILL WRAP AROUND THE
SYSTEM AND INTO EASTERN AS THE SYSTEM DEPARTS TONIGHT. THIS WILL
BRING ONE LAST CHANCE FOR SHOWERS EAST OF INTERSTATE 35. THE AREA
WILL QUICKLY TRANSITION OUT OF CYCLONIC FLOW ON SATURDAY WITH
RIDGING BUILDING IN FROM THE WEST. DESPITE NW FLOW...SOME SFC WARM
ADVECTION WILL BE TAKING PLACE. THE NW FLOW WILL ALSO AID DESCENT
MIXING AND THERE SHOULD BE AN ABUNDANCE OF SUNSHINE CENTRAL AND WEST
WITH A FEW CLOUDS LINGERING OVER THE EAST. A WEAK FRONTAL BOUNDARY
WILL REACH THE NORTHERN THIRD OF THE STATE SATURDAY NIGHT AND SUNDAY
THOUGH THE GREATEST IMPACTS WILL MOVE THROUGH PORTIONS OF MINNESOTA
AND WISCONSIN. SHOULD BE A PLEASANT DAY OVERALL WITH HIGHS IN THE
60S AND 70S WITH LIGHT WINDS.
THE MONDAY FORECAST CONTINUES TO BECOME MORE COMPLEX. THE
AFOREMENTIONED COLD ADVECTION THROUGH WISCONSIN SUNDAY WILL SHIFT
WEST AS A BACK DOOR COLD FRONT OFF LAKE MICHIGAN SUNDAY NIGHT AND
MONDAY. WARM ADVECTION WILL BE LIFTING INTO WESTERN IOWA BY MONDAY
MORNING HOWEVER ITS EASTWARD ADVANCE WILL LIKELY BE OVERCOME BY THE
COOLER AND MORE DENSE AIR FILTERING IN FROM THE EAST. HIGH
TEMPERATURES AT THIS POINT COULD BE TOO HIGH BY SEVERAL DEGREES IF
THE THIS BOUNDARY COMES IN AS STRONG AS SUGGESTED. DESPITE
THIS...MID LEVEL WARM ADVECTION WILL CONTINUE TO OVERSPREAD THE AREA
MONDAY WITH SOME INSTABILITY DEVELOPING AHEAD OF THE LOW LEVEL JET
AND STRONG THETA E ADVECTION. BEST POTENTIAL FOR THUNDERSTORMS WOULD
BE OVER THE NORTH. ANY THUNDER AT THIS TIME LIKELY WILL BE ELEVATED
THOUGH A MARGINAL SEVERE STORM WOULD BE POSSIBLE. BOWLING BALL UPPER
LOW LIFTING INTO THE NORTHERN PLAINS ON TUESDAY COULD PRODUCE SOME
INTERESTING WEATHER TUESDAY PENDING EXACT TIMING AND PLACEMENT OF
THE SYSTEM. COOLER AIR WILL SINK IN BEHIND THE SYSTEM THOUGH AGAIN
THE GREATEST IMPACT WILL BE TO THE NORTHEAST. TEMPERATURES WILL
REMAIN WELL ABOVE SEASONAL VALUES WITH LOW POTENTIAL FOR
PRECIPITATION WEDNESDAY AND THURSDAY.
&&
.AVIATION...23/12Z
LIFR VSBYS/CIGS TO LIFT BY MID MORNING ACROSS KFOD...KALO...AND
KOTM. OTHERWISE MAINLY VFR CONDITIONS EXPECTED WITH A MID LEVEL
CLOUD DECK EXPECTED THROUGH THE PERIOD. FOG DEVELOPMENT POSSIBLE AT
KALO AND KMCW LATE TONIGHT. WINDS TO BE OUT OF THE NORTH TO
NORTHWEST AND LIGHT.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR BLACK HAWK-
BOONE-BREMER-BUTLER-CALHOUN-CARROLL-CERRO GORDO-EMMET-FRANKLIN-
GREENE-GRUNDY-HAMILTON-HANCOCK-HARDIN-HUMBOLDT-JASPER-KOSSUTH-
MARSHALL-PALO ALTO-POCAHONTAS-POWESHIEK-SAC-STORY-TAMA-WEBSTER-
WINNEBAGO-WORTH-WRIGHT.
&&
$$
SHORT TERM...BEERENDS
LONG TERM...DONAVON
AVIATION...BEERENDS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
653 AM CDT FRI MAR 23 2012
.UPDATE...
MONITORING THE FOG FOR THE PAST FEW HOURS. SFC OBS CONTINUE TO
SUGGEST IT IS PATCHY WITH SOME AREAS HAVING GOOD VISIBILITY. WEB
CAMS THAT HAVE ENOUGH LIGHT OR BACKGROUND LIGHT AVAILABLE SUGGEST
THE FOG IS NOT OVERLY THICK IN VERTICAL DEPTH OR WIDESPREAD. THE
IMPENDING SUNRISE WILL PROVIDE MORE LIGHT OVER THE NEXT 30 MINUTES
TO GIVE MORE CLARITY ON THE WEB CAMS.
BASED ON THIS DATA AND RUC TRENDS IT WOULD APPEAR THAT THE FOG IS
IN LOW LYING AREAS AND SOME RIVER VALLEYS. CURRENT PLAN IS TO
CONTINUE WITH THE SPS UNLESS NEW DATA IN THE NEXT 30 MINUTES
SUGGEST OTHERWISE.
..08..
&&
.AVIATION...
VFR TO VLIFR CONDITIONS WILL BE SEEN STARTING AT SUNRISE WITH
CONDITIONS IMPROVING TO MVFR OR VFR BY 18Z/23Z. TRENDS WITH THE
RUC MODEL POINT TO AFTERNOON CONVECTION DEVELOPING WITH POTENTIAL
TSRA IMPACTS AT KMLI/KBRL. KCID/KDBQ MY SEE VCSH. AFT 06Z/24
CONDITIONS ARE EXPECTED TO DETERIORATE TO MINIMALLY MVFR WITH THE
POTENTIAL FOR IFR/LIFR CONDITIONS.
..08..
&&
.PREV DISCUSSION... /ISSUED 325 AM CDT FRI MAR 23 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS NUMEROUS WEAK LOWS ACROSS THE MIDWEST ALONG
WITH ASSOCIATED TROFS. A WEAK LOW WAS NORTHEAST OF KDSM WITH A TROF
RUNNING SOUTHEAST TO KEVV. ANOTHER TROF RAN FROM CENTRAL INDIANA
NORTHWEST INTO SOUTHERN MINNESOTA. THE OCCLUDED LOW ASSOCIATED WITH
THE UPPER LOW WAS NEAR KCNU WITH TROFS RADIATING OUT FROM IT. DEW
POINTS WERE GENERALLY IN THE 40S AND 50S ACROSS THE MIDWEST.
RADAR TRENDS SHOW THE MAIN PRECIP GENERALLY NORTH OF A LINE FROM
KRST TO KVYS WHICH WAS ASSOCIATED WITH A VORT MAX ROTATING AROUND
THE UPPER LOW.
SHORT TERM...TODAY AND TONIGHT...
A VERY INTERESTING FCST WITH INTERACTIONS BOTH UP AND DOWN ON
VARIOUS SCALES ALONG WITH NONLINEAR PROCESSES. THE RUC WAS VERY
USEFUL IN ESTABLISHING OVERALL NEAR TERM TRENDS.
THE MCS AND LIFT TOOLS ALONG WITH THE HEAVY RAIN TOOL DO A NICE JOB
OF DEPICTING THE CURRENT PRECIPITATION ACROSS THE AREA. THE PRECIP
IS JUST EAST OF THE MAIN THETA E GRADIENT AND THE RUC HAS THIS
GRADIENT SLOWLY MOVING TO THE NORTH AND EAST THROUGH 12Z. THUS THE
CURRENT PRECIP WILL SLOWLY MOVE OUT OF THE AREA. THE PARTIAL
CLEARING THAT HAS OCCURRED IN THE DIRTY DRY SLOT HAS ALLOWED FOG TO
DEVELOP WITH IT LOCALLY THICK IN AN AREA OF WEAK CONVERGENCE ACROSS
SOUTHEAST IOWA. A FEW GROUND TRUTH REPORTS INDICATE IT IS VERY
SHALLOW. SO WILL CONTINUE TO MONITOR FOR TRENDS BUT WILL HIGHLIGHT
FOG THREAT WITH ANOTHER SPS.
ANY PRECIPITATION SHOULD BE CONFINED TO THE FAR NORTHEAST/EAST PARTS
OF THE CWFA THROUGH MID MORNING BEFORE DIFFERENTIAL HEATING BEGINS
TO PRODUCE SOME ISOLD SHRA ACROSS THE REMAINDER OF THE AREA. LIFT
AND HEAVY RAIN TOOLS SUGGEST A CONSIDERABLE AMOUNT OF NEW CONVECTION
SHOULD BE ACROSS NORTHEAST ILLINOIS AT MID DAY WITH ANOTHER VORT
MAX. LIFT TOOL HAS A THETA E GRADIENT ACROSS ROUGHLY THE SOUTHEAST
HALF OF THE CWFA DURING THE AFTERNOON WITH CONVERGENCE INCREASING.
THUS SHOWERS WITH TSRA WILL BE MOST PREVALENT ACROSS ROUGHLY THE
SOUTHERN HALF OF THE CWFA.
CONVECTION WILL CONTINUE INTO THE EVENING HOURS WITH IT MOST
NUMEROUS ACROSS THE SOUTHERN HALF OF THE CWFA. SUNSET WILL ALLOW THE
ATMOSPHERE TO RE-STABILIZE SO CONVECTION WILL DIMINISH DURING THE
EVENING. MCS AND LIFT TOOLS SUGGEST CONVECTION MAY PERSIST OR EVEN
RE-DEVELOP AFTER MIDNIGHT ACROSS THE NORTHWEST THIRD TO HALF OF THE
CWFA WITH CONVERGENCE INCREASING THERE AS ANOTHER VORT MAX ROTATES
AROUND THE UPPER LOW. ..08..
LONG TERM...SATURDAY THROUGH NEXT THURSDAY...
MOSTLY DRY TO DRY WITH TEMPERATURES STILL ABOVE NORMAL BY AT LEAST
SEVERAL DEGREES IF NOT MORE ALL DAYS....THOUGH NOT RECORD WARMTH.
OVERALL...INITIALIZATION GOOD WITH UPSTREAM ENERGY AND VERIFICATION
AND RUN TO RUN CONTINUITY SUPPORTING A 50/50 BLEND OF GFS/HI-RES
ECMWF. LIMITED SENSIBLE IMPACTS WITH SOME LIGHT TO LOCALLY MODERATE
RAIN AMOUNTS POSSIBLY WITH BACKDOOR COLD FRONT MONDAY INTO TUESDAY
AHEAD OF NEXT SHORT WAVE. PERSISTENCE SUGGEST GUIDANCE TEMPS MAY
STILL BE A FEW DEGREES TOO COOL FOR LATER SHIFTS TO CONSIDER MOST
DAYS EXCEPT MONDAY WHEN BACKDOOR FRONT MAY BE COLDER WITH GOOD
ADVECTION FROM NE WINDS OFF LAKE MICHIGAN.
SATURDAY...KEPT LOW POPS WITH CONVECTIVE TEMPERATURE REACHED FOR
MOSTLY PM POPCORN -SHRA. OTHERWISE...PARTLY SUNNY AND MILD WITH
HIGHS MAINLY 70 TO 75 DEGREES WITH LIGHT WINDS. SATURDAY NIGHT...
CLEARING AND A BIT COLDER WITH MINS AROUND 50 DEGREES BUT LIGHT
WIND SUGGEST LATER SHIFTS MAY NEED TO TRIM AT LEAST A FEW DEGREES
WITH GOOD BL DECOUPLING.
SUNDAY...ANOTHER SPLENDID LATE MARCH DAY AHEAD OF BACKDOOR COLD
FRONT WITH HIGHS WELL INTO THE 70S AND LIGHT NORTH WINDS. SUNDAY
NIGHT...BACKDOOR ARRIVES BY LATE EVENING WITH NE WINDS OF 10-20+
MPH SUGGESTED. WENT WITH MINS OF LOWER 40S NE TO LOWER 50S SW BUT
LATER SHIFTS MAY NEED TO TRIM AT LEAST A COUPLE MORE DEGREES MOST
LOCATIONS. WITH OUR EXTENDED MILD WEATHER...THIS WILL FEEL COLDER
THAN ONE WOULD EXPECT FOR LATE MARCH TO MANY.
MONDAY THROUGH TUESDAY...LOCAL TECHNIQUES SUGGEST NE SECTIONS MAY
STRUGGLE WITH IDEAL FETCH OFF LAKE MICHIGAN IN NE 1/2 OF AREA TO
REACH THE MIDDLE 50S WITH GUSTY NE TO E WINDS OF 15-25+ MPH. LOW
CLOUDS ALSO MAY RESULT IN GREATER IMPACT OF A COOL DAY. NEXT SHORT
WAVE MAY SPAWN LIGHT RAIN AND RAIN SHOWERS MONDAY NIGHT INTO TUESDAY.
THE STRENGTH OF FORCING SHOULD BE BETTER ASCERTAINED NEXT 12-24
HOURS. TUESDAY WARM FRONT SHOULD PASS BY MID DAY FOR TEMPERATURES
BACK INTO THE 70S AND MINS TUESDAY NIGHT UPPER 40S TO LOWER 50S WITH
-SHRA/-TSRA ENDING PROBABLY BY MIDNIGHT WITH PASSAGE OF COLD FRONT.
ANY STORMS ATTM PROBABLY NON-SEVERE DUE TO LIMITED FORCING AND
INSTABILITY.
WEDNESDAY AND THURSDAY...MAINLY DRY WITH WEAK HIGH PRESSURE AND ONLY
A BIT COOLER WITH HIGHS IN THE 60S AND MINS IN THE 40S. THIS IS
STILL 10 PLUS DEGREES ABOVE NORMAL AS OUR REMARKABLE EXTENDED PERIOD
OF MARCH WARM SPELL CONTINUES. ..NICHOLS..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
351 AM CDT FRI MAR 23 2012
.SHORT TERM /TODAY/...
BIGGEST FOCUS TODAY WILL BE ON FOG THIS MORNING...AND THEN CHANCES
FOR SHOWERS ACROSS THE SOUTHERN CWA. FOG HAS DEVELOPED ACROSS MUCH
OF THE CWA...MAINLY NORTH AND EAST OF A LINE FROM OTTUMWA...TO DES
MOINES...TO CARROLL. FOG EXPECTED TO PERSIST ACROSS THE AREA INTO
THE MID MORNING HOURS...WITH WINDS EXPECTED TO REMAIN LIGHT AND
CONTINUE TO HAVE MOISTURE NEAR SURFACE CONDITIONS DUE TO RESIDUAL
MOISTURE FROM RAINFALL OVER THE PAST FEW DAYS. MAJORITY OF VSBYS
RANGING FROM NEAR ZERO TO AROUND ONE QUARTER MILE AND ARE ONLY
EXPECTED TO WORSEN THROUGH SUNRISE...WITH THE HRRR KEEPING VSBYS AT
A QUARTER MILE OR BELOW THROUGH 15Z. THEREFORE HAVE OPTED TO ISSUE A
DENSE FOG ADVISORY FOR MUCH OF THE CWA THROUGH 15Z. FOG SHOULD THEN
LIFT INTO SOME LOW STRATUS AND THEN BREAK UP SOME BY LATE MORNING
INTO THE EARLY AFTERNOON HOURS. WITH THE UPPER LOW CHURNING TO THE
SOUTH OF THE CWA...AND CONTINUED CYCLONIC FLOW OVER THE STATE...DO
NOT EXPECT SKIES TO CLEAR COMPLETELY TODAY...WITH SOME SHOWERS
POSSIBLE ACROSS SOUTHERN CWA THROUGHOUT THE DAY AS BANDS OF LIGHT
SHOWERS CONTINUE TO ROTATE NORTHWARD FROM MISSOURI AROUND MAIN LOW
TO THE SOUTH OF THE CWA. ANY PRECIP ROTATING BACK INTO THE AREA
ACROSS NORTHEASTERN CWA APPEARS TO HOLD OFF UNTIL AFTER 00Z. WITH
H85 TEMPERATURES AROUND +9C...A COOLER START TO THE DAY...AND CLOUD
COVER/LINGERING FOG HAVE TEMPS IN THE UPPER 60S TO AROUND 70.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
THOUGH THE UPPER LOW CENTER IS CURRENTLY OVER FAR SOUTHEAST
KANSAS...THE STRONGEST PV ANOMALY ASSOCIATED WITH THE SYSTEM IS
ROUNDING THROUGH CNTRL ARKANSAS. THIS WILL HELP KEEP THE UPPER LOW
ON A MORE SOUTHERLY TRACK BY THIS EVENING AS IT TRACKS INTO THE
LOWER OHIO VALLEY. ONE FINAL PIECE OF ENERGY WILL WRAP AROUND THE
SYSTEM AND INTO EASTERN AS THE SYSTEM DEPARTS TONIGHT. THIS WILL
BRING ONE LAST CHANCE FOR SHOWERS EAST OF INTERSTATE 35. THE AREA
WILL QUICKLY TRANSITION OUT OF CYCLONIC FLOW ON SATURDAY WITH
RIDGING BUILDING IN FROM THE WEST. DESPITE NW FLOW...SOME SFC WARM
ADVECTION WILL BE TAKING PLACE. THE NW FLOW WILL ALSO AID DESCENT
MIXING AND THERE SHOULD BE AN ABUNDANCE OF SUNSHINE CENTRAL AND WEST
WITH A FEW CLOUDS LINGERING OVER THE EAST. A WEAK FRONTAL BOUNDARY
WILL REACH THE NORTHERN THIRD OF THE STATE SATURDAY NIGHT AND SUNDAY
THOUGH THE GREATEST IMPACTS WILL MOVE THROUGH PORTIONS OF MINNESOTA
AND WISCONSIN. SHOULD BE A PLEASANT DAY OVERALL WITH HIGHS IN THE
60S AND 70S WITH LIGHT WINDS.
THE MONDAY FORECAST CONTINUES TO BECOME MORE COMPLEX. THE
AFOREMENTIONED COLD ADVECTION THROUGH WISCONSIN SUNDAY WILL SHIFT
WEST AS A BACK DOOR COLD FRONT OFF LAKE MICHIGAN SUNDAY NIGHT AND
MONDAY. WARM ADVECTION WILL BE LIFTING INTO WESTERN IOWA BY MONDAY
MORNING HOWEVER ITS EASTWARD ADVANCE WILL LIKELY BE OVERCOME BY THE
COOLER AND MORE DENSE AIR FILTERING IN FROM THE EAST. HIGH
TEMPERATURES AT THIS POINT COULD BE TOO HIGH BY SEVERAL DEGREES IF
THE THIS BOUNDARY COMES IN AS STRONG AS SUGGESTED. DESPITE
THIS...MID LEVEL WARM ADVECTION WILL CONTINUE TO OVERSPREAD THE AREA
MONDAY WITH SOME INSTABILITY DEVELOPING AHEAD OF THE LOW LEVEL JET
AND STRONG THETA E ADVECTION. BEST POTENTIAL FOR THUNDERSTORMS WOULD
BE OVER THE NORTH. ANY THUNDER AT THIS TIME LIKELY WILL BE ELEVATED
THOUGH A MARGINAL SEVERE STORM WOULD BE POSSIBLE. BOWLING BALL UPPER
LOW LIFTING INTO THE NORTHERN PLAINS ON TUESDAY COULD PRODUCE SOME
INTERESTING WEATHER TUESDAY PENDING EXACT TIMING AND PLACEMENT OF
THE SYSTEM. COOLER AIR WILL SINK IN BEHIND THE SYSTEM THOUGH AGAIN
THE GREATEST IMPACT WILL BE TO THE NORTHEAST. TEMPERATURES WILL
REMAIN WELL ABOVE SEASONAL VALUES WITH LOW POTENTIAL FOR
PRECIPITATION WEDNESDAY AND THURSDAY.
&&
.AVIATION...23/06Z
PRIMARY AVN CONCERN WILL BE FOG AND LOW STRATUS
OVERNIGHT...PRODUCING LIFR/VLIFR CONDITIONS AT TIME PRIMARILY AT
KFOD/KMCW/KALO. CURRENTLY VSBYS ARE BOUNCING EVERYWHERE BTWN M1/4SM
AND P6SM HOWEVER SAT IMAGERY INDICATES THAT HIGH CLOUD COVERAGE IS
INCREASING AND BELIEVE THIS WILL TEMPER VSBYS SOMEWHAT LATER
TONIGHT...KEEPING THINGS MAINLY MVFR/IFR. CONFIDENCE IS LOW AND HAVE
USED TEMPOS TO COVER SOME OF THIS UNCERTAINTY AND VSBY BOUNCING AT
KFOD/KMCW. ON FRI MORNING CONDITIONS WILL IMPROVE BY LATE AM AS FOG
DISSIPATES...BUT SOME MVFR CIGS AND ISOLD -SHRA WILL STILL BE
POSSIBLE DURING THE DAY.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR BLACK HAWK-
BOONE-BREMER-BUTLER-CALHOUN-CARROLL-CERRO GORDO-EMMET-FRANKLIN-
GREENE-GRUNDY-HAMILTON-HANCOCK-HARDIN-HUMBOLDT-JASPER-KOSSUTH-
MARSHALL-PALO ALTO-POCAHONTAS-POWESHIEK-SAC-STORY-TAMA-WEBSTER-
WINNEBAGO-WORTH-WRIGHT.
&&
$$
SHORT TERM...BEERENDS
LONG TERM...DONAVON
AVIATION...LEE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
325 AM CDT FRI MAR 23 2012
.SYNOPSIS...
06Z SFC ANALYSIS HAS NUMEROUS WEAK LOWS ACROSS THE MIDWEST ALONG
WITH ASSOCIATED TROFS. A WEAK LOW WAS NORTHEAST OF KDSM WITH A TROF
RUNNING SOUTHEAST TO KEVV. ANOTHER TROF RAN FROM CENTRAL INDIANA
NORTHWEST INTO SOUTHERN MINNESOTA. THE OCCLUDED LOW ASSOCIATED WITH
THE UPPER LOW WAS NEAR KCNU WITH TROFS RADIATING OUT FROM IT. DEW
POINTS WERE GENERALLY IN THE 40S AND 50S ACROSS THE MIDWEST.
RADAR TRENDS SHOW THE MAIN PRECIP GENERALLY NORTH OF A LINE FROM
KRST TO KVYS WHICH WAS ASSOCIATED WITH A VORT MAX ROTATING AROUND
THE UPPER LOW.
&&
.SHORT TERM...TODAY AND TONIGHT...
A VERY INTERESTING FCST WITH INTERACTIONS BOTH UP AND DOWN ON
VARIOUS SCALES ALONG WITH NONLINEAR PROCESSES. THE RUC WAS VERY
USEFUL IN ESTABLISHING OVERALL NEAR TERM TRENDS.
THE MCS AND LIFT TOOLS ALONG WITH THE HEAVY RAIN TOOL DO A NICE JOB
OF DEPICTING THE CURRENT PRECIPITATION ACROSS THE AREA. THE PRECIP
IS JUST EAST OF THE MAIN THETA E GRADIENT AND THE RUC HAS THIS
GRADIENT SLOWLY MOVING TO THE NORTH AND EAST THROUGH 12Z. THUS THE
CURRENT PRECIP WILL SLOWLY MOVE OUT OF THE AREA. THE PARTIAL
CLEARING THAT HAS OCCURRED IN THE DIRTY DRY SLOT HAS ALLOWED FOG TO
DEVELOP WITH IT LOCALLY THICK IN AN AREA OF WEAK CONVERGENCE ACROSS
SOUTHEAST IOWA. A FEW GROUND TRUTH REPORTS INDICATE IT IS VERY
SHALLOW. SO WILL CONTINUE TO MONITOR FOR TRENDS BUT WILL HIGHLIGHT
FOG THREAT WITH ANOTHER SPS.
ANY PRECIPITATION SHOULD BE CONFINED TO THE FAR NORTHEAST/EAST PARTS
OF THE CWFA THROUGH MID MORNING BEFORE DIFFERENTIAL HEATING BEGINS
TO PRODUCE SOME ISOLD SHRA ACROSS THE REMAINDER OF THE AREA. LIFT
AND HEAVY RAIN TOOLS SUGGEST A CONSIDERABLE AMOUNT OF NEW CONVECTION
SHOULD BE ACROSS NORTHEAST ILLINOIS AT MID DAY WITH ANOTHER VORT
MAX. LIFT TOOL HAS A THETA E GRADIENT ACROSS ROUGHLY THE SOUTHEAST
HALF OF THE CWFA DURING THE AFTERNOON WITH CONVERGENCE INCREASING.
THUS SHOWERS WITH TSRA WILL BE MOST PREVALENT ACROSS ROUGHLY THE
SOUTHERN HALF OF THE CWFA.
CONVECTION WILL CONTINUE INTO THE EVENING HOURS WITH IT MOST
NUMEROUS ACROSS THE SOUTHERN HALF OF THE CWFA. SUNSET WILL ALLOW THE
ATMOSPHERE TO RE-STABILIZE SO CONVECTION WILL DIMINISH DURING THE
EVENING. MCS AND LIFT TOOLS SUGGEST CONVECTION MAY PERSIST OR EVEN
RE-DEVELOP AFTER MIDNIGHT ACROSS THE NORTHWEST THIRD TO HALF OF THE
CWFA WITH CONVERGENCE INCREASING THERE AS ANOTHER VORT MAX ROTATES
AROUND THE UPPER LOW. ..08..
.LONG TERM...SATURDAY THROUGH NEXT THURSDAY...
MOSTLY DRY TO DRY WITH TEMPERATURES STILL ABOVE NORMAL BY AT LEAST
SEVERAL DEGREES IF NOT MORE ALL DAYS....THOUGH NOT RECORD WARMTH.
OVERALL...INITIALIZATION GOOD WITH UPSTREAM ENERGY AND VERIFICATION
AND RUN TO RUN CONTINUITY SUPPORTING A 50/50 BLEND OF GFS/HI-RES
ECMWF. LIMITED SENSIBLE IMPACTS WITH SOME LIGHT TO LOCALLY MODERATE
RAIN AMOUNTS POSSIBLY WITH BACKDOOR COLD FRONT MONDAY INTO TUESDAY
AHEAD OF NEXT SHORT WAVE. PERSISTENCE SUGGEST GUIDANCE TEMPS MAY
STILL BE A FEW DEGREES TOO COOL FOR LATER SHIFTS TO CONSIDER MOST
DAYS EXCEPT MONDAY WHEN BACKDOOR FRONT MAY BE COLDER WITH GOOD
ADVECTION FROM NE WINDS OFF LAKE MICHIGAN.
SATURDAY...KEPT LOW POPS WITH CONVECTIVE TEMPERATURE REACHED FOR
MOSTLY PM POPCORN -SHRA. OTHERWISE...PARTLY SUNNY AND MILD WITH
HIGHS MAINLY 70 TO 75 DEGREES WITH LIGHT WINDS. SATURDAY NIGHT...
CLEARING AND A BIT COLDER WITH MINS AROUND 50 DEGREES BUT LIGHT
WIND SUGGEST LATER SHIFTS MAY NEED TO TRIM AT LEAST A FEW DEGREES
WITH GOOD BL DECOUPLING.
SUNDAY...ANOTHER SPLENDID LATE MARCH DAY AHEAD OF BACKDOOR COLD
FRONT WITH HIGHS WELL INTO THE 70S AND LIGHT NORTH WINDS. SUNDAY
NIGHT...BACKDOOR ARRIVES BY LATE EVENING WITH NE WINDS OF 10-20+
MPH SUGGESTED. WENT WITH MINS OF LOWER 40S NE TO LOWER 50S SW BUT
LATER SHIFTS MAY NEED TO TRIM AT LEAST A COUPLE MORE DEGREES MOST
LOCATIONS. WITH OUR EXTENDED MILD WEATHER...THIS WILL FEEL COLDER
THAN ONE WOULD EXPECT FOR LATE MARCH TO MANY.
MONDAY THROUGH TUESDAY...LOCAL TECHNIQUES SUGGEST NE SECTIONS MAY
STRUGGLE WITH IDEAL FETCH OFF LAKE MICHIGAN IN NE 1/2 OF AREA TO
REACH THE MIDDLE 50S WITH GUSTY NE TO E WINDS OF 15-25+ MPH. LOW
CLOUDS ALSO MAY RESULT IN GREATER IMPACT OF A COOL DAY. NEXT SHORT
WAVE MAY SPAWN LIGHT RAIN AND RAIN SHOWERS MONDAY NIGHT INTO TUESDAY.
THE STRENGTH OF FORCING SHOULD BE BETTER ASCERTAINED NEXT 12-24
HOURS. TUESDAY WARM FRONT SHOULD PASS BY MID DAY FOR TEMPERATURES
BACK INTO THE 70S AND MINS TUESDAY NIGHT UPPER 40S TO LOWER 50S WITH
-SHRA/-TSRA ENDING PROBABLY BY MIDNIGHT WITH PASSAGE OF COLD FRONT.
ANY STORMS ATTM PROBABLY NON-SEVERE DUE TO LIMITED FORCING AND
INSTABILITY.
WEDNESDAY AND THURSDAY...MAINLY DRY WITH WEAK HIGH PRESSURE AND ONLY
A BIT COOLER WITH HIGHS IN THE 60S AND MINS IN THE 40S. THIS IS
STILL 10 PLUS DEGREES ABOVE NORMAL AS OUR REMARKABLE EXTENDED PERIOD
OF MARCH WARM SPELL CONTINUES. ..NICHOLS..
&&
.AVIATION...
VFR TO VLIFR CONDITIONS WILL BE SEEN THROUGH SUNRISE WITH CONDITIONS
IMPROVING TO VFR. DAYTIME HEATING WILL ALLOW ANOTHER ROUND OF SHRA
WITH TSRA TO DVLP WITH CONVECTION BEING MOST NUMEROUS DURING THE
AFTERNOON. CONVECTION WILL DISSIPATE WITH SUNSET BUT MAY LINGER
THROUGH THE NIGHT ACROSS EASTERN IOWA. KMLI/KBRL MAY HAVE THE BEST
CHANCE AT SEEING TSRA WITH MVFR CONDITIONS AFT 18Z/23 AND WILL GO
WITH VCTS IN THE 12Z TAFS. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
08/NICHOLS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
917 PM MDT SAT MAR 24 2012
.UPDATE...
ISSUED AT 843 PM MDT SAT MAR 24 2012
JUST COMPLETED AN UPDATE. MAIN CHANGES WERE TO INCREASE COVERAGE
OF THE FOG OVER THE ENTIRE AREA AND ISSUED A DENSE FOG ADVISORY FOR
EAST CENTRAL COLORADO AND MUCH OF NORTHWEST KANSAS UNTIL 15Z SUNDAY
MORNING. 00Z DDC AND LBF SOUNDINGS SHOW LOW LEVEL MOISTURE HAS
INCREASED IN VALUE AND DEPTH FROM 24 HOURS AGO. MOST MODEL OUTPUT IS
UNDERDOING THE LOW LEVEL MOISTURE. HOWEVER...THE RUC AND HRRR HAVE
CAUGHT ONTO THIS HIGHER MOISTURE AND HAVE BEEN CONSISTENT IN
KEEPING AND/OR INCREASING NOT ONLY THE COVERAGE OF THE FOG BUT THE
EXTENT OF THE DENSE FOG. THE 00Z NAM HAS FINALLY CAUGHT ON AS
WELL. ALL THREE MODELS ARE VERY CLOSE IN THEIR DEPICTION OF THE
DENSE FOG AREA.
SO HAD FAIRLY HIGH CONFIDENCE IN ISSUING THE ADVISORY FOR THE
AREA IN QUESTION. OVERNIGHT SHIFT CAN TWEAK THIS FURTHER AS THE
NIGHT PROGRESSES. WITH HIGHER DEWPOINTS ALSO RAISED THE MINS
ACCORDINGLY...ESPECIALLY IN THE SOUTHERN HALF BASED ON
REALITY/LATEST RUC/HRRR. RUC/HRRR WERE DOING WELL ON
DEWPOINTS/WINDS AND USED THEM FOR THE UPDATE AS WELL.
UPDATE ISSUED AT 549 PM MDT SAT MAR 24 2012
DID AN EARLY UPDATE. CURRENT DEWPOINTS OVER THE FORECAST AREA AND
UPSTREAM ARE HIGHER THAN WHAT MOST MODEL OUTPUT INDICATES. THE HRRR
FOOLLOWED BY THE RUC ARE CATCHING THE DEWPOINTS THE BEST AND INCREASE
THE DEWPOINTS OVER THE ENTIRE AREA THROUGH THE NIGHT. USED THE HRRR
FOR THE UPDATE. LATEST RUC AND NAM OUTPUT IS NOT ONLY INCREASING
THE AREAL COVERAGE OF THE FOG BUT ALSO IS DECREASING THE VISIBILITY.
SO INCREASED THE COVERAGE AND ALSO ADDED DENSE WORDING TO THE
GRIDS. WILL CONTINUE TO WATCH THE TRENDS ON THE OBSERVATIONS PLUS
WAIT FOR THE 00Z SOUNDINGS TO SEE IF A DENSE FOG ADVISORY WILL BE
NEEDED BUT CHANCES OF THIS ARE ON THE INCREASE.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 254 PM MDT SAT MAR 24 2012
500 MB RIDGE WILL REMAIN OVER THE FORECAST AREA THROUGH SUNDAY
BEFORE IT SHIFTS EAST SUNDAY NIGHT. SURFACE DEWPOINTS WILL BE IN
THE 40S MOST AREAS TONIGHT...AND DEW POINT DEPRESSIONS WILL BE LOW
AFTER 09Z. WITH LIGHT WINDS AND WEAK SUBSIDENCE...EXPECT PATCHY FOG
TO DEVELOP LATE TONIGHT. FOG MAY BE MORE WIDESPREAD/DENSE THAN LAST
NIGHT GIVEN THE INCREASE OF LOW LEVEL DEW POINTS...BUT WILL MONITOR
THE EVOLUTION OF FOG FORMATION BEFORE HOISTING ANY HIGHLIGHTS. WILL
UPDATE THE HAZARDOUS WEATHER OUTLOOK...HOWEVER...FOR FOG
POSSIBILITIES.
THERMAL RIDGE WILL MOVE ACROSS THE AREA SUNDAY WHICH WILL PRODUCE
HIGH TEMPERATURES IN THE LOWER 80S. A DRY LINE WILL DEVELOP OVER
EASTERN COLORADO DURING THE AFTERNOON...AND IT WILL PUSH EAST DURING
THE AFTERNOON REACHING THE KANSAS BORDER BY 21Z. CONSIDERED
INTRODUCING CONVECTION INTO THE FORECAST EAST OF THE DRY LINE AS
MIXED LAYER CAPES WILL BE DECENT IN THE MOIST AIR. HODOGRAPHS ALSO
SHOW GOOD SHEAR. HOWEVER...WITH THE AMOUNT OF INHIBITION AND LACK OF
DECENT LOW TO MID LEVEL SUPPORT...DECIDED AGAINST THUNDERSTORMS.
WEST OF THE DRY LINE...EXPECT RELATIVE HUMIDITIES TO DROP TO 15
PERCENT IN EASTERN COLORADO MAINLY ACROSS WESTERN KIT CARSON AND
WESTERN CHEYENNE COUNTIES. SURFACE WINDS WILL ONLY BE AROUND 15
MPH...SO WILL NOT MENTION ANY FIRE WEATHER HIGHLIGHTS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 254 PM MDT SAT MAR 24 2012
NUMEROUS CONCERNS FOR FORECAST AREA ON MONDAY INCLUDING POTENTIAL
FOR A FEW RECORD HIGHS (SEE CLIMATE SECTION BELOW), STRONG FIRE
WEATHER POTENTIAL (SEE FIRE WEATHER SECTION BELOW), AND POTENTIAL
FOR CONVECTION DURING THE LATE AFTERNOON AND EVENING HOURS. FAIRLY
POTENT SHORTWAVE TROUGH IS PROGGED TO MOVE OUT OF THE GREAT BASIN
AND INTO THE WESTERN DAKOTAS DURING THE DAY. A DRYLINE WILL SET UP
INITIALLY ALONG THE KS/CO BORDER AND IS PROGGED TO MIX EASTWARD
TOWARD THE HIGHWAY 25 CORRIDOR BY MID AFTERNOON. THERE IS SOME
DEGREE OF UNCERTAINTY WITH REGARD TO THE EXACT PLACEMENT OF THE
DRYLINE AND THIS WILL HAVE AN IMPACT ON THE POTENTIAL FOR
CONVECTION AT ANY ONE LOCATION. ADDITIONALLY, STRONGEST FORCING
FOR ASCENT WILL RESIDE NORTH OF THE FORECAST AREA SO FEEL
CONFIDENT IN KEEPING SLIGHT CHANCE POPS GOING. HAVING SAID
THAT...PARAMETERS WOULD FAVOR STRONG/SEVERE CONVECTION SHOULD
SOMETHING GET GOING. FEEL BEST SHOT FOR CONVECTION IS FURTHER EAST
THAN PREVIOUSLY ADVERTISED SO NUDGED POPS THAT DIRECTION. HAVE
ALSO INSERTED BLOWING DUST MENTION FOR LOCATIONS TO THE WEST OF
THE DRYLINE. DESPITE RECENT PRECIP...SOIL MOISTURE DEFICITS REMAIN
HIGH. ALSO VERY CONCERNED ABOUT BLOWING DUST/SAND ACROSS CENTRAL
PORTIONS OF YUMA COUNTY WHERE A VERY LARGE BURN SCAR FROM A FIRE
LAST SUNDAY WILL ENHANCED POTENTIAL FOR REDUCED VISIBILITIES.
SLIGHTLY COOLER...BUT STILL MUCH ABOVE NORMAL...AIR MOVES INTO
THE CENTRAL HIGH PLAINS ON TUESDAY. GIVEN LATEST PROGS...DID BUMP
MAX TEMPS UP A FEW DEGREES ACROSS THE AREA.
BROAD/FLAT RIDGE BUILDS BACK ACROSS THE CENTRAL HIGH PLAINS
WEDNESDAY WITH A WEAK SHORTWAVE TROUGH PROGGED TO PASS THURSDAY
INTO THURSDAY NIGHT. SLIGHT CHANCE POPS ACROSS THE EAST INITIALLY
IN MOIST SOUTHEAST FLOW BEFORE SPREADING OVER THE REMAINDER OF THE
FORECAST AREA.
MUCH ABOVE NORMAL TEMPS WILL CONTINUE INTO THE WEEKEND WITH TEMPS
REMAINING IN THE 70S TO NEAR 80.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 511 PM MDT SAT MAR 24 2012
POTENTIAL STILL EXISTS FOR FOG TO DEVELOP AT BOTH LOCATIONS SUNDAY
MORNING. THEREFORE...HAVE PLACED IFR CIG/VIS AT BOTH LOCATIONS
11-15Z. AFTERWARDS...WINDS WILL BECOME GUSTY AT BOTH LOCATIONS
FROM THE SOUTHEAST. VFR CONDITIONS WILL EXIST THROUGH 11Z AND
AGAIN AFTER 15Z AT BOTH LOCATIONS.
&&
.FIRE WEATHER...
ISSUED AT 254 PM MDT SAT MAR 24 2012
BORDERLINE FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS EASTERN
COLORADO ON SUNDAY. HOWEVER...WIND SPEEDS ARE EXPECTED TO REMAIN
BELOW CRITERIA NEEDED FOR ISSUANCE OF A RED FLAG WARNING.
A MORE SUBSTANTIAL CRITICAL FIRE WEATHER DAY APPEARS LIKELY ALONG
AND WEST OF HIGHWAY 25 ON MONDAY TO THE WEST OF A FAIRLY STOUT
DRYLINE. GIVEN HIGH CONFIDENCE...WILL GO AHEAD AND ISSUE A FIRE
WEATHER WATCH FOR THESE LOCATIONS. RECENT PRECIP AND THE RESULTANT
GREEN UP MAY HELP MITIGATE THE THREAT BUT SUBSTANTIAL DRY FUELS
REMAIN ACROSS THE TRI-STATE REGION.
RH VALUES WILL BE BELOW 20 PERCENT AGAIN ON TUESDAY...WEDNESDAY
...AND THURSDAY ACROSS WESTERN PORTIONS OF THE AREA BUT CURRENT
INDICATIONS WOULD SHOW THE WIND SPEEDS SHOULD REMAIN LIGHT AT
AROUND 10 MPH OR LESS.
&&
.CLIMATE...
ISSUED AT 254 PM MDT SAT MAR 24 2012
POTENTIAL CONTINUES TO EXIST FOR A FEW RECORD HIGHS TO FALL ON
MONDAY BUT THE BIGGER STORY BY THIS TIME NEXT WEEKEND WILL BE THE
FACT THAT A FEW LOCATIONS WILL HAVE SET AN ALL-TIME RECORD FOR THE
WARMEST AVERAGE TEMPERATURE. CURRENT RECORDS ARE AS FOLLOWS:
GOODLAND - 48.8 DEGREES SET IN 1907 - CURRENT AVERAGE TEMP 48.0
BURLINGTON - 47.7 DEGREES SET IN 1986 - CURRENT AVERAGE TEMP 46.7
MCCOOK - 48.3 DEGREES SET IN 2007 - CURRENT AVERAGE TEMP 49.5
HILL CITY - 54.3 DEGREES SET IN 1910 - CURRENT AVERAGE TEMP 50.8
WITH FORECASTED TEMPS...CONFIDENCE IS HIGH THAT AT LEAST
GOODLAND...BURLINGTON...AND MCCOOK WILL SEE THE WARMEST MARCH ON
RECORD. IT REMAINS TO BE SEEN IF HILL CITY WILL BREAK THE RECORD
AS WELL.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING
FOR COZ252>254.
DENSE FOG ADVISORY FROM 1 AM TO 9 AM MDT SUNDAY FOR COZ090>092.
KS...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING
FOR KSZ001-002-013-014-027-028-041-042.
DENSE FOG ADVISORY FROM 1 AM MDT /2 AM CDT/ TO 9 AM MDT /10 AM
CDT/ SUNDAY FOR KSZ013>016-027>029-041-042.
NE...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING
FOR NEZ079-080.
&&
$$
UPDATE...BULLER
SHORT TERM...MENTZER
LONG TERM....FOLTZ
AVIATION...BAS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
911 PM CDT SAT MAR 24 2012
.UPDATE...
ISSUED AT 903 PM CDT SAT MAR 24 2012
HAVE UPDATED HOURLY DEWPOINT GRIDS BASED OFF THE FACT THAT THE ALL
THE MODELS (GFS, NAM, HRRR) ARE UNDOING SURFACE DEWPOINTS (TD`S).
TD`S HAVE BEEN RUNNING IN THE LOWER 50S DEG F ACROSS KDDC COUNTRY
THIS EVENING. TONIGHTS 00Z RAOB AT THE WFO SHOW THE INCREASING
POTENTIAL FOR DENSE FOG. LAMP GUIDANCE HAS COME IN AT IFR CIGS
FOR KGCK AND KDDC. THE LAST HOUR FROM THE HRRR SHOWS VISIBILITIES
AT 0.25 MILES. CONTINUED UPSLOPE SOUTHEASTERLY WINDS ARE EXPECTED
THROUGH THE OVERNIGHT. AS A RESULT, HAVE ISSUED A DENSE FOG ADVISORY
FOR MY WESTERN COUNTIES. STARTED OUT CONSERVATIVE SINCE THE MID SHIFT
COULD ADD MORE COUNTIES EASTWARD IF NEED BE AND AS SUGGESTED BY LAMP
GUIDANCE AND POSSIBLY LATER MODEL RUNS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 345 PM CDT SAT MAR 24 2012
A GENERAL WARMING TREND IS ANTICIPATED IN THE VERY SHORT TERM
FORECAST. TEMPERATURES WARMED INTO THE LOW TO MID 70S THIS
AFTERNOON AND WERE HEADED TOWARD THE 80 DEGREE MARK IN THE LATE
AFTERNOON. THE AREA WILL REMAIN IN THE WARM SECTOR SOUTH TO SOUTHEAST
FLOW AS WEAK CYCLOGENESIS REMAINS FOCUSED DIURNALLY OVER SOUTHEAST
COLORADO. SURFACE MOISTURE WILL INCREASE ACROSS THE AREA INCREASING
DEW POINTS INTO THE 50S THE NEXT FEW DAYS. THE COMBINATION OF
SOUTHEAST UPSLOPE WINDS AND HIGHER LEVEL MOISTURE AIR, ACROSS THE
AREA WILL BE FAVORABLE FOR DENSE FOG DEVELOPMENT AS TEMPERATURES
FALL OVERNIGHT UNDER A VERY DRY MID AND UPPER LEVEL AIRMASS. THE
RUC AND NAM BOTH INDICATE DENSE FOG DEVELOPMENT, AND ARE NOT IN
AGREEMENT AT ALL ON THE PLACEMENT. HOWEVER THE MOST FAVORABLE
LOCATION FOR WIDESPREAD DENSE FOG DEVELOPMENT WILL BE WHERE THE
WINDS GO LIGHT IN THE ZONE OF SURFACE WIND CONVERGENCE PROBABLY
AFTER 8Z.
DEW POINTS WILL LIKELY MIX OUT TO LOWER VALUES IN THE FAR WESTERN
COUNTIES ON SUNDAY. THE NAM INDICATED THE REAL DRYLINE TO BE
POSITIONED WELL TO THE SOUTHWEST IN NE NEW MEXICO WHERE IT WANTS
TO DEVELOP CONVECTIVE PRECIPITATION IN THE LATE AFTERNOON AS IT IS
RETREATING. HAVING SAID THAT, THE SURFACE POSITIVE BUOYANT ENERGY IS
A RESPECTABLE 1000-2000 J/KG FROM A DIGHTON TO MEADE CORRIDOR AS
MODELED BY THE NAM. HOWEVER, THE ATMOSPHERE ALOFT REMAINS DRY ON
SUNDAY. THE WARM NOSE ON THE 21 UTC NAM SOUNDING SUGGESTS PARCELS
WOULD NEED TO BE LIFTED FROM ABOVE 800 MB WHICH DOESN`T APPEAR
PLAUSIBLE WITH SUCH WEAK SURFACE CONVERGENCE AND DRY AIR.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 256 PM CDT SAT MAR 24 2012
SUNDAY NIGHT WILL SEE AN UPPER LEVEL RIDGE WORK EASTWARD INTO
EASTERN KANSAS. AN UPPER LOW PRESSURE SYSTEM OVER SOUTHERN NEVADA
WILL ALLOW A SOUTHWEST UPPER FLOW TO DEVELOP ACROSS WESTERN KANSAS
MONDAY. A DRY LINE WILL START ADVANCING WEST EARLY IN THE DAY
MONDAY, AND SOUTH WINDS WILL BECOME STRONG, ESPECIALLY IN OUR WEST
ON THE MOIST SIDE OF THE DRY LINE. FOR NOW, GRIDS WILL HAVE
25-35KTS G40KTS IN MY WESTERN 1/2 OF THE CWA, AND 15-25KTS G30KTS IN
THE EASTERN CWA. A WIND ADVISORY WILL LIKELY BE NEEDED FOR MONDAY
AFTERNOON, BUT WILL HOLD OFF ONE OR TWO MORE SHIFTS BEFORE ISSUING
THE NPW PRODUCT. STORMS MAY FIRE IN THE LATE DAY IN OUR WEST NEAR
THE DRY LINE, BUT THE BETTER UPPER LEVEL DYNAMICS ARE TO OUR NORTH.
THE 20 POPS SEEM APPROPRIATE FOR THIS SITUATION, UNLESS LATER MODEL
RUNS SHOW SOMETHING DIFFERENT. FOR WHAT IT IS WORTH, THE GFS BACKED
OFF ON THUNDERSTORMS MONDAY AFTERNOON, KEEPING THE PRECIPITATION FAR
TO OUR NORTH.
MONDAY NIGHT WILL BE PARTLY TO MOSTLY CLOUDY WITH A WEAK UPPER
TROUGH CROSSING JUST TO OUR NORTH. A FAIRLY STRONG COLD FRONT WILL
SLIP INTO OUR NORTHWEST SECTIONS AFTER MIDNIGHT AND BE NEAR OUR
SOUTHERN BORDER BY TUESDAY MORNING. THEN, THE FRONT APPEARS TO
DISSIPATE NEAR THE OKLAHOMA TUESDAY MORNING, BEFORE STARTING TO
ADVANCE BACK NORTH AS A WARM FRONT WEDNESDAY. SINCE THAT FRONT IS
PLOWING THROUGH DECENT LOW LEVEL MOISTURE, 20 PERCENT POPS WILL
START IN THE WEST LATE MONDAY AND TRANSFER TO THE EAST MONDAY
NIGHT. SEEMS THERE WILL BE AT LEAST A SMALL CHANCE FOR SEVERE
STORMS WITH HAIL MONDAY NIGHT, BUT WITH 20 POPS DO NOT PLAN TO
MENTION SEVERE STORMS IN THE GRIDS. WILL UPDATE THE HWO TO AT LEAST
MENTION SEVERE STORMS ARE POSSIBLE. NO PLANS IN OUR 3 WESTERN
COUNTIES FOR POPS MONDAY NIGHT. MIN TEMPS MON NIGHT WILL DEPEND
STRONGLY ON THE COLD FRONT MOVEMENT AND POSITION, AND RANGE FROM THE
LOWER 40S IN OUR EXTREME NORTHWEST COUNTIES SUCH AS HAMILTON TO THE
LOWER 50S FROM HAYS TO DODGE CITY TO NEAR LIBERAL, AND THE MID 50S
IN THE PRATT AND BARBER COUNTY AREAS.
ANY PRECIP SHOULD BE EAST OF OUR CWA BY TUESDAY, WITH MAX TEMPS
BEHIND THE FRONT 10 TO 15 DEGREES COLDER THAN MONDAY, MAXING IN THE
70 DEGREE RANGE IN SCOTT CITY TO NEAR 77 DEGREES IN MEDICINE LODGE.
TUESDAY SHOULD PRODUCE SUNNY SKIES AS WELL. TUESDAY NIGHT WILL BE
MOSTLY CLEAR WITH NO PRECIPITATION, AND MINIMUMS IN THE LOWER 40S IN
OUR NORTHWEST RANGING TO THE MID 50S IN OUR SOUTHEAST. ON
WEDNESDAY, THAT FRONT WILL ADVANCE NORTH AS A WARM FRONT AND MOVE
INTO OUR SOUTHERN CWA. SOUTHERN PARTS OF OUR CWA WILL BECOME PARTLY
CLOUDY WHILE NORTHERN PARTS OF OUR FORECAST CONTINUING TO BE MOSTLY
SUNNY. LATE WEDNESDAY, THERE IS A SLIGHT CHANCE FOR A THUNDERSTORM
IN OUR EXTREME SOUTHEAST, DUE TO DAY TIME HEATING AND DEW POINTS
NEAR 60F DEGREES. EXPECT PARTLY CLOUDY SKIES WEDNESDAY NIGHT, LOW
TEMPS IN THE 50F TO 56F DEGREE RANGE, AND A SLIGHT CHANCE OF STORMS
IN OUR EASTERN 2 COUNTIES OF THE CWA.
ON THURSDAY, THE DRY LINE WILL COME BACK INTO PLAY, MARCHING EAST
ACROSS OUR AREA DURING THE DAY. BY THE TIME OF MAX HEATING, WITH
HIGHS EXPECTED IN THE UPPER 70S TO LOWER 80S, A THUNDERSTORM OR TWO
WILL BE POSSIBLE NEAR THE DRY LINE. THURSDAY NIGHT WILL CONTINUE TO
SEE SLIGHT CHANCES FOR STORMS, WITH THAT CHANCE SPREADING WEST
ACROSS ALL OUR CWA BY FRIDAY. AN UPPER WAVE WILL CROSS JUST NORTH
OF OUR CWA, AND MAY FIRE OFF A FEW STORMS FRIDAY AND FRIDAY NIGHT.
MAX TEMPS EXPECTED FRIDAY ARE IN THE MID 70S, WITH MIN TEMPS FROM
46F TO 54F DEGREES FRIDAY NIGHT, AND MAXIMUM TEMPERATURES ON
SATURDAY RANGING IN THE MID TO UPPER 70S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 606 PM CDT SAT MAR 24 2012
FRCST CONCERN FOR THE 00Z TAFS IS THE POTENTIAL FOR FOG. SREF SHOWS
LOW PROBS FOR +FG ACROSS FAR SW KS. BUFKIT SND`S SHOW A VERY SHALLOW
RADIATIVE FG PROFILE. THE MOST AGGRESSIVE MOS...GFS LAV...SHOWS ABOUT
4 MI AT KGCK/KDDC. NAM IS RUNNING A LITTLE LOW W/ TD`S AT 22Z. WITH
TD`S IN THE LOW 50SF AND UPSLOPE SE WINDS OVERNIGHT, DID NOT WANT TO
DEVIATE THAT MUCH FROM PREVIOUS SHIFT FOR FG BUT NOT READY TO GO 1/4
MILE SINCE MOST OF THE MODELS SUGGESTS OTHERWISE. AS A RESULT, TRENDED
TAFS TO LOWER VIS WITH 1 MI AT KGCK AND 2 MI AT KDDC BY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 50 81 57 82 / 0 0 0 20
GCK 50 82 56 83 / 0 0 0 20
EHA 48 85 55 85 / 0 0 0 10
LBL 49 84 56 83 / 0 0 0 20
HYS 48 80 57 82 / 0 0 0 10
P28 50 81 57 82 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY FROM 2 AM CDT /1 AM MDT/ TO 9 AM CDT /8 AM
MDT/ SUNDAY FOR KSZ030-043>045-061>063-074-075-084-085.
&&
$$
UPDATE...SUGDEN
SHORT TERM...RUSSELL
LONG TERM....BURKE
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
602 PM MDT SAT MAR 24 2012
.UPDATE...
ISSUED AT 549 PM MDT SAT MAR 24 2012
DID AN EARLY UPDATE. CURRENT DEWPOINTS OVER THE FORECAST AREA AND
UPSTREAM ARE HIGHER THAN WHAT MOST MODEL OUTPUT INDICATES. THE HRRR
FOOLLOWED BY THE RUC ARE CATCHING THE DEWPOINTS THE BEST AND INCREASE
THE DEWPOINTS OVER THE ENTIRE AREA THROUGH THE NIGHT. USED THE HRRR
FOR THE UPDATE. LATEST RUC AND NAM OUTPUT IS NOT ONLY INCREASING
THE AREAL COVERAGE OF THE FOG BUT ALSO IS DECREASING THE VISIBILITY.
SO INCREASED THE COVERAGE AND ALSO ADDED DENSE WORDING TO THE
GRIDS. WILL CONTINUE TO WATCH THE TRENDS ON THE OBSERVATIONS PLUS
WAIT FOR THE 00Z SOUNDINGS TO SEE IF A DENSE FOG ADVISORY WILL BE
NEEDED BUT CHANCES OF THIS ARE ON THE INCREASE.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 254 PM MDT SAT MAR 24 2012
500 MB RIDGE WILL REMAIN OVER THE FORECAST AREA THROUGH SUNDAY
BEFORE IT SHIFTS EAST SUNDAY NIGHT. SURFACE DEWPOINTS WILL BE IN
THE 40S MOST AREAS TONIGHT...AND DEW POINT DEPRESSIONS WILL BE LOW
AFTER 09Z. WITH LIGHT WINDS AND WEAK SUBSIDENCE...EXPECT PATCHY FOG
TO DEVELOP LATE TONIGHT. FOG MAY BE MORE WIDESPREAD/DENSE THAN LAST
NIGHT GIVEN THE INCREASE OF LOW LEVEL DEW POINTS...BUT WILL MONITOR
THE EVOLUTION OF FOG FORMATION BEFORE HOISTING ANY HIGHLIGHTS. WILL
UPDATE THE HAZARDOUS WEATHER OUTLOOK...HOWEVER...FOR FOG
POSSIBILITIES.
THERMAL RIDGE WILL MOVE ACROSS THE AREA SUNDAY WHICH WILL PRODUCE
HIGH TEMPERATURES IN THE LOWER 80S. A DRY LINE WILL DEVELOP OVER
EASTERN COLORADO DURING THE AFTERNOON...AND IT WILL PUSH EAST DURING
THE AFTERNOON REACHING THE KANSAS BORDER BY 21Z. CONSIDERED
INTRODUCING CONVECTION INTO THE FORECAST EAST OF THE DRY LINE AS
MIXED LAYER CAPES WILL BE DECENT IN THE MOIST AIR. HODOGRAPHS ALSO
SHOW GOOD SHEAR. HOWEVER...WITH THE AMOUNT OF INHIBITION AND LACK OF
DECENT LOW TO MID LEVEL SUPPORT...DECIDED AGAINST THUNDERSTORMS.
WEST OF THE DRY LINE...EXPECT RELATIVE HUMIDITIES TO DROP TO 15
PERCENT IN EASTERN COLORADO MAINLY ACROSS WESTERN KIT CARSON AND
WESTERN CHEYENNE COUNTIES. SURFACE WINDS WILL ONLY BE AROUND 15
MPH...SO WILL NOT MENTION ANY FIRE WEATHER HIGHLIGHTS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 254 PM MDT SAT MAR 24 2012
NUMEROUS CONCERNS FOR FORECAST AREA ON MONDAY INCLUDING POTENTIAL
FOR A FEW RECORD HIGHS (SEE CLIMATE SECTION BELOW), STRONG FIRE
WEATHER POTENTIAL (SEE FIRE WEATHER SECTION BELOW), AND POTENTIAL
FOR CONVECTION DURING THE LATE AFTERNOON AND EVENING HOURS. FAIRLY
POTENT SHORTWAVE TROUGH IS PROGGED TO MOVE OUT OF THE GREAT BASIN
AND INTO THE WESTERN DAKOTAS DURING THE DAY. A DRYLINE WILL SET UP
INITIALLY ALONG THE KS/CO BORDER AND IS PROGGED TO MIX EASTWARD
TOWARD THE HIGHWAY 25 CORRIDOR BY MID AFTERNOON. THERE IS SOME
DEGREE OF UNCERTAINTY WITH REGARD TO THE EXACT PLACEMENT OF THE
DRYLINE AND THIS WILL HAVE AN IMPACT ON THE POTENTIAL FOR
CONVECTION AT ANY ONE LOCATION. ADDITIONALLY, STRONGEST FORCING
FOR ASCENT WILL RESIDE NORTH OF THE FORECAST AREA SO FEEL
CONFIDENT IN KEEPING SLIGHT CHANCE POPS GOING. HAVING SAID
THAT...PARAMETERS WOULD FAVOR STRONG/SEVERE CONVECTION SHOULD
SOMETHING GET GOING. FEEL BEST SHOT FOR CONVECTION IS FURTHER EAST
THAN PREVIOUSLY ADVERTISED SO NUDGED POPS THAT DIRECTION. HAVE
ALSO INSERTED BLOWING DUST MENTION FOR LOCATIONS TO THE WEST OF
THE DRYLINE. DESPITE RECENT PRECIP...SOIL MOISTURE DEFICITS REMAIN
HIGH. ALSO VERY CONCERNED ABOUT BLOWING DUST/SAND ACROSS CENTRAL
PORTIONS OF YUMA COUNTY WHERE A VERY LARGE BURN SCAR FROM A FIRE
LAST SUNDAY WILL ENHANCED POTENTIAL FOR REDUCED VISIBILITIES.
SLIGHTLY COOLER...BUT STILL MUCH ABOVE NORMAL...AIR MOVES INTO
THE CENTRAL HIGH PLAINS ON TUESDAY. GIVEN LATEST PROGS...DID BUMP
MAX TEMPS UP A FEW DEGREES ACROSS THE AREA.
BROAD/FLAT RIDGE BUILDS BACK ACROSS THE CENTRAL HIGH PLAINS
WEDNESDAY WITH A WEAK SHORTWAVE TROUGH PROGGED TO PASS THURSDAY
INTO THURSDAY NIGHT. SLIGHT CHANCE POPS ACROSS THE EAST INITIALLY
IN MOIST SOUTHEAST FLOW BEFORE SPREADING OVER THE REMAINDER OF THE
FORECAST AREA.
MUCH ABOVE NORMAL TEMPS WILL CONTINUE INTO THE WEEKEND WITH TEMPS
REMAINING IN THE 70S TO NEAR 80.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 511 PM MDT SAT MAR 24 2012
POTENTIAL STILL EXISTS FOR FOG TO DEVELOP AT BOTH LOCATIONS SUNDAY
MORNING. THEREFORE...HAVE PLACED IFR CIG/VIS AT BOTH LOCATIONS
11-15Z. AFTERWARDS...WINDS WILL BECOME GUSTY AT BOTH LOCATIONS
FROM THE SOUTHEAST. VFR CONDITIONS WILL EXIST THROUGH 11Z AND
AGAIN AFTER 15Z AT BOTH LOCATIONS.
&&
.FIRE WEATHER...
ISSUED AT 254 PM MDT SAT MAR 24 2012
BORDERLINE FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS EASTERN
COLORADO ON SUNDAY. HOWEVER...WIND SPEEDS ARE EXPECTED TO REMAIN
BELOW CRITERIA NEEDED FOR ISSUANCE OF A RED FLAG WARNING.
A MORE SUBSTANTIAL CRITICAL FIRE WEATHER DAY APPEARS LIKELY ALONG
AND WEST OF HIGHWAY 25 ON MONDAY TO THE WEST OF A FAIRLY STOUT
DRYLINE. GIVEN HIGH CONFIDENCE...WILL GO AHEAD AND ISSUE A FIRE
WEATHER WATCH FOR THESE LOCATIONS. RECENT PRECIP AND THE RESULTANT
GREEN UP MAY HELP MITIGATE THE THREAT BUT SUBSTANTIAL DRY FUELS
REMAIN ACROSS THE TRI-STATE REGION.
RH VALUES WILL BE BELOW 20 PERCENT AGAIN ON TUESDAY...WEDNESDAY
...AND THURSDAY ACROSS WESTERN PORTIONS OF THE AREA BUT CURRENT
INDICATIONS WOULD SHOW THE WIND SPEEDS SHOULD REMAIN LIGHT AT
AROUND 10 MPH OR LESS.
&&
.CLIMATE...
ISSUED AT 254 PM MDT SAT MAR 24 2012
POTENTIAL CONTINUES TO EXIST FOR A FEW RECORD HIGHS TO FALL ON
MONDAY BUT THE BIGGER STORY BY THIS TIME NEXT WEEKEND WILL BE THE
FACT THAT A FEW LOCATIONS WILL HAVE SET AN ALL-TIME RECORD FOR THE
WARMEST AVERAGE TEMPERATURE. CURRENT RECORDS ARE AS FOLLOWS:
GOODLAND - 48.8 DEGREES SET IN 1907 - CURRENT AVERAGE TEMP 48.0
BURLINGTON - 47.7 DEGREES SET IN 1986 - CURRENT AVERAGE TEMP 46.7
MCCOOK - 48.3 DEGREES SET IN 2007 - CURRENT AVERAGE TEMP 49.5
HILL CITY - 54.3 DEGREES SET IN 1910 - CURRENT AVERAGE TEMP 50.8
WITH FORECASTED TEMPS...CONFIDENCE IS HIGH THAT AT LEAST
GOODLAND...BURLINGTON...AND MCCOOK WILL SEE THE WARMEST MARCH ON
RECORD. IT REMAINS TO BE SEEN IF HILL CITY WILL BREAK THE RECORD
AS WELL.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING
FOR COZ252>254.
KS...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING
FOR KSZ001-002-013-014-027-028-041-042.
NE...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING
FOR NEZ079-080.
&&
$$
UPDATE...BULLER
SHORT TERM...MENTZER
LONG TERM....FOLTZ
AVIATION...BAS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
526 AM MDT FRI MAR 23 2012
.UPDATE...
ISSUED AT 407 AM MDT FRI MAR 23 2012
SHALLOW FOG HAS PRODUCED VISIBILITIES OF 1 TO 5 MILES...WITH LOWER
VISIBILITIES IN THE VALLEYS AND RIVER BOTTOMS AS OVERHEAD CLOUDS
HAVE DISSIPATED. FOGGY CONDITIONS SHOULD START TO IMPROVE AFTER
6AM MDT/ 7AM CDT AS TEMPERATURES BEGIN TO WARM...WITH THE FOG
COMPLETELY DISSIPATED BY MID MORNING.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 319 AM MDT FRI MAR 23 2012
SOME PATCHY FOG WILL BE POSSIBLE ACROSS THE AREA THIS MORNING DUE TO
THE MOIST GROUND CONDITIONS FROM YESTERDAY/S RAINFALL. THE FOG
SHOULD DISSIPATE BY MID MORNING.
THE CLOSED UPPER LEVEL LOW THAT BROUGHT RAIN TO THE REGION YESTERDAY
WILL CONTINUE TO MOVE EAST TODAY. AN UPPER LEVEL RIDGE WILL MOVE
INTO THE AREA BEHIND THE CLOSED LOW TODAY. AS A RESULT WINDS WILL
BE LIGHT. AS THE CLOSED LOW MOVES EAST...WARMER AIR WILL MOVE IN
FROM THE WEST. WITH 850MB TEMPS AROUND 15C...TEMPS AROUND 70 WILL
BE POSSIBLE. TONIGHT LOWS WILL DIP TO THE UPPER 30S TO AROUND 40.
RELATIVE HUMIDITIES WILL BE NEAR 100 PERCENT OVERNIGHT...HOWEVER
WILL HOLD OFF PLACING FOG IN THE FORECAST AS POINT SOUNDINGS SHOW A
VERY SHALLOW SATURATED LAYER AT THE SURFACE.
SATURDAY THE UPPER LEVEL RIDGE WILL CONTINUE TO MOVE OVER THE AREA.
AT THE SURFACE A TROUGH OF LOW PRESSURE WILL MOVE IN FROM THE WEST
DURING THE MORNING THEN MOVE NORTH DURING THE AFTERNOON AS A WARM
FRONT. 850MB TEMPS OF 20C WILL MOVE OVER THE AREA BEHIND THE
FRONT...ALLOWING HIGHS TO WARM TO NEAR 80 DEGREES DURING THE AFTERNOON.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 319 AM MDT FRI MAR 23 2012
SATURDAY NIGHT LOWS WILL DIP INTO THE MID TO UPPER 40S. PATCHY FOG
WILL BE POSSIBLE GENERALLY ALONG AND EAST OF THE COLORADO BORDER
THROUGH MID MORNING SUNDAY.
SUNDAY SOUTH WINDS WILL INCREASE AS THE SURFACE PRESSURE GRADIENT
TIGHTENS AND THE 850MB WINDS STRENGTHEN. WIND GUSTS OF 35 MPH WILL BE
POSSIBLE DURING THE AFTERNOON. DURING THE AFTERNOON CAPE VALUES OF
500-1500J/KG WILL DEVELOP OVER NORTHWEST KANSAS AND SOUTHWEST
NEBRASKA AS DEW POINTS MOISTEN INTO THE 50S. WILL HOLD OFF PLACING
THUNDERSTORMS IN THE FORECAST AS POINT SOUNDINGS SHOW LARGE DEW
POINT DEPRESSIONS THROUGH THE COLUMN. THE GUSTY SOUTH WINDS AND
850MB TEMPS OF 20C WILL HELP TEMPERATURES TO WARM INTO THE UPPER 70S
AND LOWER 80S.
MONDAY-THURSDAY...MEDIUM RANGE MODELS REMAIN IN REASONABLE AGREEMENT
WITH RESPECT TO LARGE SCALE PATTERN WITH SOME ACTIVE WEATHER
POSSIBLE ON MONDAY AS STRONG SHORT WAVE TROUGH LIFTS ACROSS THE
NORTHERN PLAINS...FORCING COLD FRONT ACROSS THE CWA. LATEST
OPERATIONAL GUIDANCE AND ENSEMBLE DATA CONTINUE TO SUPPORT AT LEAST
A SMALL THREAT FOR THUNDERSTORMS ACROSS EASTERN CWA AND DO NOT SEE
MUCH OF A REASON TO DEVIATE FROM THAT. AFTER THIS INITIAL
SYSTEM...SOMEWHAT AMPLIFIED YET PROGRESSIVE FLOW ALOFT IS EXPECTED
THROUGH THE END OF THE PERIOD WITH SOME WEAK TROUGHING EXPECTED BY
THURSDAY. OVERALL...WOULD NOT BE SURPRISED TO SEE SOME SCATTERED
SHOWERS AND THUNDERSTORMS IN A FEW OF THE PERIODS...BUT OVERALL
THINK PROBABILITIES TO LOW TO REALLY TRY TO PIN DOWN GIVEN OVERALL
WEAK EXPECTED FORCING.
THINK BIGGEST CONCERN OF THE EXTENDED PERIOD WILL BE MONDAY...WITH
POSITION OF UPPER TROUGH LOOKS LIKE STRONG JET OF LOW LEVEL WINDS
WILL DEVELOP ACROSS MUCH OF THE AREA WITH H7 FLOW INCREASING TO 45
TO 50 KTS. IN ADDITION TO THE STRONG WINDS...TEMPERATURES WELL INTO
THE 80S AND MUCH DRIER AIR MOVING INTO THE AREA BEHIND A DRYLINE
WILL ONCE AGAIN INCREASE THE FIRE DANGER TO POTENTIALLY CRITICAL
LEVELS. WILL NEED TO SEE WHAT IMPACT THE WIDESPREAD RAIN HAD ON
FUELS...BUT WILL HAVE TO WATCH THIS PERIOD CLOSELY THE NEXT SEVERAL
DAYS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 517 AM MDT FRI MAR 23 2012
IFR TO VFR CONDITIONS WILL BE POSSIBLE FOR THE TAFS. LATEST
OBSERVATIONS REPORT SHALLOW FOG AT KGLD...WITH VIS VARYING FROM 1SM
TO 10SM. SATELLITE IMAGERY SHOWS A DECK OF LOW CLOUDS MOVING SOUTH
TOWARD KGLD. LATEST REPORT FROM ST. FRANCIS HAS CEILINGS OF
3500FT...SO CEILINGS SHOULD REMAIN ABOVE MVFR. FOR KMCK VIS HAVE
BEEN SLOWLY FALLING OVER THE LAST HOUR OR SO. RUC AND NAM POINT
SOUNDINGS SHOW A SHALLOW SATURATED LAYER AT THE SURFACE. THIS MAY
CAUSE THE VIS TO VARY SO HAVE PLACED A TEMPO GROUP FOR VFR VIS AND
A PREVAILING MVFR VIS. CONDITIONS SHOULD IMPROVE AROUND 15Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
KS...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...JTL
LONG TERM....JRM
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1230 AM CDT FRI MAR 23 2012
...UPDATED AVIATION SECTION...
.UPDATE...
ISSUED AT 741 PM CDT THU MAR 22 2012
HAVE PULLED POPS AND WX OUT OF THE GRIDS AS KDDC WSR-88D IS NOT INDICATING
ANY RETURNED POWER AT 0.50 DEG AND HIGHER. CLOUD TOPS PER IR SATELLITE
CHANNEL HAVE BEEN WARMING ACROSS THE CENTRAL AND EASTERN SECTIONS OF
THE CWFA AS WELL. LASTLY, THE 00Z KDDC RAOB SHOWED WARMING AND DRYING
THROUGH THE ATMOSPHERIC COLUMN WITH THE PWAT AT 0.51 INCHES NOW. AM
WATCHING A BAND OF PRECIPITATION ACROSS EASTERN COLORADO ASSOCIATED
WITH THE MAIN UPPER LEVEL LOW FURTHER TO THE SE. THE HRRR HAS PICKED
UP WELL ON THIS FEATURE. HAVE DOUBTS ANY PRECIPITATION WILL REACH THE
GROUND ACROSS FAR WESTERN KANSAS AS THIS MOISTURE LOOKS CONFINED MAINLY
TO THE LOWER TO MID LEVELS AROUND 700 TO 500 HPA.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 343 PM CDT THU MAR 22 2012
MAIN SHORT TERM CHALLENGES TONIGHT WILL BE THE TIMING OF THE END OF
PRECIPITATION. INDICATIONS FROM THE RUC, HRRR, AND NAM12 WOULD SEEM
TO INDICATE THAT THE SHOWER ACTIVITY WILL BE WANING OVER THE NEXT
COUPLE OF HOURS. POPS WILL BE RAPIDLY DECREASING IN THE GRIDS WITH
SLIGHT CHANCE POPS GONE BY 01-02Z OR SO IN THE SOUTHEAST ZONES. THE
FOCUS THEN WILL TURN TO THE FOG DEVELOPMENT. SKIES ARE EXPECTED TO
CLEAR (OR AT LEAST BECOME MOSTLY CLEAR)...ESPECIALLY AFTER 06Z
TONIGHT...AND WITH LIGHT WINDS AT 6 KNOTS OR LESS AND SATURATED
GROUNDS...THE STAGE WILL BE SET FOR FOG FORMATION AS TEMPERATURES
FALL INTO THE MID TO UPPER 30S. WILL BE ADDING AREAS OF FOG TO THE
GRIDS FOR THE 09-14Z TIME FRAME. ON FRIDAY...ONCE THE FOG CLEARS
(IF IT DEVELOPS AS FORECAST) SHORTWAVE RIDGING WILL ADVANCE ON THE
WESTERN PLAINS FROM THE ROCKIES. THE LOW LEVEL RIDGE AXIS WILL
REMAIN OVER WESTERN KANSAS THROUGH THE DAY FRIDAY AND THIS WILL
YIELD LIGHT WINDS ALL DAY AT 6 KNOTS OR LESS. LOW LEVEL THICKNESSES
WILL STILL BE FAIRLY LOW WITH THE UPPER LOW NOT ALL THAT FAR REMOVED
FROM THE PLAINS...SO TEMPERATURES WILL MAX OUT IN THE MID 60S FOR
MOST LOCATIONS...AND LOWER 70S ACROSS FAR SOUTHWEST ZONES WHERE
THICKNESSES WILL BE INCREASING AT A QUICKER RATE WITH THE SHORTWAVE
RIDGE APPROACHING.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 131 PM CDT THU MAR 22 2012
MUCH WARMER AIR WILL RETURN TO WESTERN KANSAS FRIDAY AS THE
UPPER-LEVEL LOW DISCUSSED IN THE SHORT TERM DISCUSSION MOVES INTO
MISSOURI AND SUNSHINE RETURNS. HIGHS SHOULD WARM INTO THE LOWER
TO MID 70S. THE WARM TEMPERATURES WILL PERSIST THROUGH NEXT WEEK
AS UPPER-LEVEL TROUGHING DEVELOPS ACROSS THE WESTERN UNITED
STATES, AND SURFACE LEE TROUGHING DEVELOPS ACROSS THE HIGH PLAINS.
A SHORTWAVE TROUGH WILL PASS ACROSS THE NORTHERN PLAINS BY MONDAY
NIGHT AND TUESDAY. THE GFS/GEM AND ECMWF WERE GENERALLY FOLLOWED
WITH THIS SYSTEM. DESPITE SOME SUBTLE MODEL DIFFERENCES, THE
BOTTOM LINE IS THAT THE UPPER-LEVEL SYSTEM WILL PASS TO OUR NORTH,
WITH LITTLE IN THE WAY OF SYNOPTIC SCALE LIFT OVER WESTERN KANSAS.
TEMPERATURES COULD POSSIBLY REACH INTO THE MID 80S BEHIND THE
DRYLINE IN FAR WESTERN KANSAS MONDAY. RICH LOW-LEVEL MOISTURE
WILL BE DRAWN NORTHWARD ALONG AND EAST OF THE 100TH MERIDIAN IN
ADVANCE OF THE SYSTEM. OFTENTIMES IN MARCH, STRONG FRONTS PUSH THE
LOW-LEVEL MOISTURE DEEP INTO THE TROPICS. BUT SO FAR THIS MARCH WE
HAVE HAD NO PROBLEM GETTING RICH MOISTURE BACK FROM THE GULF IN
THE ABSENCE OF STRONG FRONTAL PASSAGES. A DRYLINE WILL SET UP
ACROSS WESTERN KANSAS MONDAY, WITH AN UNSTABLE AIRMASS DEVELOPING
IMMEDIATELY AHEAD OF IT. HOWEVER, THUNDERSTORMS MAY NOT DEVELOP
SINCE THE ASSOCIATED UPPER-LEVEL JET AND MID-LEVEL COOLING WILL
PASS TO OUR NORTH. BUT AN ISOLATED LATE DAY THUNDERSTORM CANNOT BE
COMPLETELY RULED OUT. AFTER THIS SYSTEM PASSES, THE ASSOCIATED
WEAK COLD FRONT WILL MOVE THROUGH SOUTHWEST KANSAS, KNOCKING
TEMPERATURES DOWN ONLY A FEW DEGREES. IN FACT, TEMPERATURES OUGHT
TO REMAIN ABOVE CLIMATOLOGICAL AVERAGES ALL WEEK AS LEE TROUGHING
QUICKLY REDEVELOPS GIVEN THE FAIRLY ZONAL MID-LEVEL FLOW. A
THUNDERSTORM OR TWO COULD DEVELOP ALONG THE TRAILING COLD FRONT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1220 AM CDT FRI MAR 23 2012
NORTHERLY WINDS WILL BECOME LIGHT AND VARIABLE EARLY THIS MORNING
AS AN UPPER LEVEL SYSTEM MOVES INTO THE MISSISSIPPI VALLEY. VFR
CONDITIONS WILL PREVAIL WITH CLOUDS AOA050 DISSIPATING BEFORE
SUNRISE. LIGHT AND VARIABLE WINDS CONTINUE THROUGH THE AFTERNOON
WITH MOSTLY CLEAR SKIES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 41 74 48 78 / 0 0 0 0
GCK 40 76 48 79 / 0 0 0 0
EHA 42 77 48 80 / 0 0 0 0
LBL 41 77 48 79 / 0 0 0 0
HYS 41 76 48 77 / 0 0 0 0
P28 43 74 48 77 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...UMSCHEID
LONG TERM....FINCH
AVIATION...HOVORKA 42
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1010 PM MDT THU MAR 22 2012
.UPDATE...
ISSUED AT 932 PM MDT THU MAR 22 2012
NUDGED POPS UP TO CHANCE CATEGORY ALONG AND WEST OF THE CO/KS
STATE LINE...MAINLY NORTH OF THE INTERSTATE...PER RADAR IMAGES
AND LATEST HRRR WHICH HAS A GOOD HANDLE ON CURRENT LOCATION OF
PRECIPITATION. NO OTHER CHANGES MADE.
UPDATE ISSUED AT 830 PM MDT THU MAR 22 2012
UPDATED TONIGHT THROUGH FRIDAY PERIODS. MAIN ADJUSTMENT WAS TO
INCREASE CLOUD COVER AROUND AN UPPER LOW PRESSURE CENTER CURRENTLY
OVER NORTH CENTRAL OKLAHOMA. AS THIS LOW MOVES EAST-NORTHEAST
TOWARD SOUTHERN MISSOURI FRIDAY CONSIDERABLE WRAPAROUND
CLOUDINESS WILL IMPACT THE WESTERN 1/2-1/3 OF THE AREA THROUGH
FRIDAY MORNING BEFORE DECREASING IN COVERAGE DURING THE AFTERNOON
AS AVAILABLE MOISTURE DECREASES.
AT 0230Z RADAR STILL SHOWING A FEW ECHOES ACROSS FAR WESTERN YUMA
AND KIT CARSON COUNTIES WHERE SOME LIGHT RAIN SHOWERS ARE FALLING.
THIS AREA OF PRECIPITATION CONTINUES TO SLOWLY LOSE ITS INTENSITY
AND AM THINKING THAT BY 06Z OR 09Z AT THE LATEST IT SHOULD BE WEAK
ENOUGH TO REMOVE POP MENTION.
NO CHANGES MADE TO THE FOG FORECAST EARLY FRIDAY MORNING THROUGH
MID MORNING. WINDS LIGHT THROUGH THE NEXT 36 HOURS OR SO. HIGH
TEMPERATURES STILL LOOK TO WARM CLOSE TO 70 DEGREES FOR MANY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 232 PM MDT THU MAR 22 2012
VISIBLE SATELLITE IMAGERY SHOWS CENTER OF LOW JUST SOUTHEAST OF
KP28. A BAND OF LIGHT SHOWERS ON THE NORTHWEST SIDE OF LOW WILL
PERSIST ACROSS THE EASTERN COLORADO COUNTIES THROUGH THE EVENING. AS
THE LOW SLOWLY MOVES EAST...MOISTURE ADVECTION/SHOWERS WILL END. LOW
WILL BE FAR ENOUGH EAST BY 12Z FRIDAY THAT CLOUDS WILL BE ALSO
DECREASE. HOWEVER...THE BOUNDARY LAYER IS QUITE MOIST AFTER
WIDESPREAD RAIN LAST NIGHT...SO AS CLEARING/SURFACE COOLING TAKES
PLACE...FOG WILL FORM. HARD TO PINPOINT EXACTLY WHERE FOG IS MOST
LIKELY TO DEVELOP...BUT WILL BEGIN BY INTRODUCING IT ACROSS THE
WESTERN HALF OF FORECAST AREA AROUND 08Z. EXPECT TEMPERATURES TO
DROP INTO THE MID 30S MOST AREAS TONIGHT.
MODELS AGREE THAT 500 MB RIDGE WILL BUILD OVER THE HIGH PLAINS
FRIDAY AFTERNOON. WARM AIR ADVECTION WILL BEGIN AFTER 18Z...WITH 850
MB TEMPERATURES REACHING 16-18 DEGREES CELSIUS. THUS...EXPECT
MAXIMUM TEMPERATURES TO REACH INTO THE UPPER 60S UNDER MOSTLY SUNNY
SKIES. THERE MAY BE FOG AGAIN FRIDAY NIGHT...BUT WILL SEE HOW FOG
FORMS TONIGHT BEFORE INTRODUCING IT AGAIN.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 232 PM MDT THU MAR 22 2012
A HIGHLY AMPLIFIED RIDGE WILL BE IN PLACE ACROSS THE CENTRAL US
SATURDAY THROUGH MONDAY WITH VERY WARM TEMPERATURES AND DRY
CONDITIONS EXPECTED. HIGH TEMPERATURES WILL GENERALLY RANGE
FROM THE UPPER 70S TO LOW 80S...WITH AFTERNOON TEMPERATURES POSSIBLY
WARMING INTO THE MIDDLE 80S ON MONDAY.
BY MONDAY NIGHT A SHORTWAVE TROUGH WILL PASS ACROSS THE
NORTHERN PLAINS...WITH AN ASSOCIATED COLD FRONT DROPPING SOUTH OVER
THE CWA LATE MONDAY NIGHT. WITH A DRY LINE LINGERING OVER THE CWA AND
DECENT INSTABILITY EAST OF THIS FEATURE MONDAY AFTERNOON THROUGH
MONDAY NIGHT...A FEW THUNDERSTORMS COULDNT BE RULED OUT OVER EASTERN
LOCATIONS. I STILL HAVE CONCERNS THAT A STRONG CAP IN PLACE ACROSS
OUR CWA WILL LIMIT CONVECTIVE POTENTIAL...AND THE OVERALL TREND WITH
GUIDANCE HAS BEEN TO PUSH THE BEST CHANCES FURTHER EAST. OVERALL THE
SYNOPTIC PATTERN HAS BEEN FAIRLY CONSISTENT...SO I DECIDED TO KEEP
SLIGHT CHANCE POPS IN THE EXTREME EASTERN PART OF OUR CWA FOR
ANOTHER FORECAST CYCLE. IF CURRENT TRENDS HOLD THESE POPS COULD
PROBABLY BE REMOVED.
TUESDAY THROUGH THURSDAY...A MORE PROGRESSIVE PATTERN SETS IN BY THE
MIDDLE OF NEXT WEEK. HOWEVER...THE MAIN STORM TRACK REMAINS FAR TO
THE NORTH...SO DRY CONDITIONS SHOULD CONTINUE ACROSS THE
TRI-STATE REGION. TEMPERATURES OVER THE CWA WILL BE SLIGHTLY COOLER
AFTER THE RIDGE BREAKS DOWN MONDAY NIGHT...HOWEVER THEY WILL REMAIN
ABOVE NORMAL WITH HIGHS GENERALLY IN THE UPPER 60S/LOW 70S ACROSS
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1010 PM MDT THU MAR 22 2012
VFR EXPECTED THROUGH THE PERIOD AT KGLD AND KMCK. VARIABLE WINDS
6 KTS OR LESS EXPECTED THROUGH 00Z BEFORE BECOMING S/SE AROUND
7KTS. MAY SEE SOME FOG AND CIGS 1500-2500 FT AT KGLD EARLY FRIDAY
MORNING GIVEN THE LIGHT WINDS AND RECENT RAINFALL. OTHERWISE...AT
KGLD EXPECTING CLOUDS BETWEEN 5-10K FT AS WRAPAROUND CLOUDINESS ON
THE BACK SIDE OF AN UPPER LEVEL LOW PRESSURE AREA MOVES ACROSS THE
AREA TONIGHT THROUGH FRIDAY MORNING.
&&
.FIRE WEATHER...
ISSUED AT 232 PM MDT THU MAR 22 2012
RH VALUES WILL APPROACH CRITICAL LEVELS EACH AFTERNOON FROM SATURDAY
THROUGH NEXT WEDNESDAY...PRIMARILY OVER WESTERN PARTS OF OUR
FORECAST AREA. THERE ARE STILL QUESTIONS REGARDING WHETHER WINDS
WILL FALL WITHIN RED FLAG CRITERIA EACH AFTERNOON. THE GUSTIEST
WINDS ARE CURRENTLY EXPECTED SUNDAY AND MONDAY. AT THIS TIME THE
THE BEST CHANCE FOR RED FLAG CRITERIA TO BE MET STILL LOOKS TO BE ON
MONDAY AFTERNOON...WITH WITH WIND GUSTS AROUND 30 MPH AND RH VALUES
IN THE 15-20 PERCENT RANGE. ANOTHER FACTOR TO CONSIDER WILL BE THE
EFFECT OF OUR RECENT RAINFALL ON FUELS. AFTER SEVERAL VERY WARM/DRY
AFTERNOONS FUELS WILL LIKELY BE FAVORABLE...ESPECIALLY BY
SUNDAY/MONDAY AFTERNOONS. IT IS STILL TOO EARLY TO ISSUE A
WATCH/WARNING FOR THESE PERIODS...SO THE SITUATION WILL CONTINUE TO
BE MONITORED.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
KS...NONE.
NE...NONE.
&&
$$
UPDATE...007
SHORT TERM...MENTZER
LONG TERM....DR
AVIATION...007
AREA FORECAST DISCUSSION
NWS PADUCAH KY
939 PM CDT SAT MAR 24 2012
.UPDATE...
ISSUED AT 930 PM CDT SAT MAR 24 2012
NEEDED TO UPDATE NEAR TERM RAIN CHCS /TONIGHT/ FOR PERSISTENT
BAND/CLUSTER OF SHOWERS HEADING SOUTH THROUGH THE WABASH RIVER
VALLEY. ALSO...STILL STUBBORN ACTIVITY FROM TIME TO TIME IN SE MO.
HRRR/4.0 KM WRF HAVE CAUGHT ONTO THESE TRENDS. HOWEVER...THE 12Z
WRF MODEL TAKES THAT WABASH RIVER VALLEY ACTIVITY A BIT FURTHER
WEST INTO OUR FA OVERNIGHT AS OPPOSED TO THE HRRR RUN. WILL TRY TO
SPLIT THE DIFFERENCE AND GO WITH LIKELY POPS FOR LOW QPF AMOUNTS UP
IN SW INDIANA AND ALONG THE WABASH RIVER...THEN CONTINUE HIGH CHC
POPS SOUTHWARD INTO THE NRN PENNYRILE OF KY BEFORE SLOWLY
DIMINISHING AFTER 07-09Z.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 258 PM CDT SAT MAR 24 2012
ANY LINGERING SHOWERS ACROSS SOUTHEAST AND SOUTHERN PORTIONS OF
THE PAH FORECAST AREA SHOULD TAPER OFF AND MOVE OUT OF THE REGION
BY SUNSET WITH THE UPPER LOW FINALLY MAKING ITS WAY FARTHER EAST.
CLOUDS WILL SLOWLY DECREASE FROM WEST TO EAST TONIGHT. A UPPER
LEVEL RIDGE OF HIGH PRESSURE WILL BUILD INTO THE SOUTHERN PLAINS
INTO EARLY NEXT WEEK. DESPITE NORTH TO NORTHEAST WINDS...PLENTY OF
SUNSHINE ON SUNDAY AND MONDAY WILL HELP TEMPERATURES REACH THE
LOWER TO MIDDLE 70S ON SUNDAY AND MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 258 PM CDT SAT MAR 24 2012
GFS AND ECMWF SHOW THE UPPER LEVEL RIDGE SLIDING EAST AND GRADUALLY
BREAKING DOWN BY MID WEEK. WINDS WILL BECOME SOUTHERLY BY
TUESDAY...AND THE ALREADY ABOVE NORMAL TEMPERATURES WILL GET A
EVEN WARMER FOR TUESDAY AND WEDNESDAY.
GFS AND ECMWF ARE IN PRETTY DECENT AGREEMENT BRINGING A COLD FRONT
DOWN TO THE OHIO RIVER BY 18Z WEDNESDAY. SLIGHT TO LOW CHANCE
POPS LATE TUESDAY NIGHT ACROSS THE NORTHERN THIRD OF THE PAH FA
WILL SPREAD SOUTH ACROSS THE ENTIRE AREA WEDNESDAY. THE FRONT WILL
SLIDE A LITTLE FARTHER SOUTH...THEN IT WILL MEANDER ACROSS OR JUST
SOUTH OF THE AREA INTO THURSDAY. BY THURSDAY NIGHT...GFS TAKES THE
FRONT EVEN FARTHER SOUTH...REMOVING ANY QPF FROM THE
REGION...WHILE ECMWF BRINGS THE FRONT BACK NORTH...WHICH KEEPS
SHOWER AND THUNDERSTORM CHANCES GOING INTO FRIDAY AND SATURDAY AS
ANOTHER LOW PRESSURE SYSTEM MOVES UP FROM THE SOUTHERN PLAINS.
BOTH MODELS HAVE BEEN ALTERNATELY SHOWING THESE TYPES OF
SOLUTIONS...AND FOR NOW WE WILL KEEP SLIGHT TO LOW CHANCE POPS
GOING THROUGH THE END OF THE FORECAST PERIOD. THOUGH THE
POSITIONING OF THE FRONT MAKES TEMPERATURES A LITTLE MORE
UNCERTAIN...CONDITIONS WILL REMAIN UNSEASONABLY WARM.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY)
ISSUED AT 651 PM CDT SAT MAR 24 2012
TAF SITES SHOULD REMAIN VFR TONIGHT WITH LIGHT NNW WINDS BECOMING
VARIABLE OR CALM AFTER SUNSET. WILL SEE PATCHY LOW VFR CIGS 4-5
KFT AR TIMES...ESP AT KEVV/KOWB SITES. CIGS COULD FALL INTO THE
MVFR CATEGORY DURING THE DAY SUNDAY AS ANOTHER BAND OF MOISTURE
WRAPS AROUND THE STRONG UPPER LOW MOVING OFF INTO THE SE UNITED
STATES REGION. THINKING IS THAT THE CIGS WILL STAY AOA 2 KFT THO.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...GM
SHORT TERM...RST
LONG TERM....RST
AVIATION...CW
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
1231 AM CDT FRI MAR 23 2012
.UPDATE...
ISSUED AT 1158 PM CDT THU MAR 22 2012
MAIN CHALLENGE THIS EVENING AND INTO THE OVERNIGHT HOURS HAS BEEN
THE THE VARIABILITY OF CLOUD COVER BETWEEN THE CONVECTIVE BANDS
ROTATING AROUND THE CLOSED COLD CORE UPPER LOW MOVING INTO
SOUTHWEST MO. THE SHORT TERM NUMERICAL MODEL SUITE /4KM NAM-WRF
ARW AND NMM...AS WELL AS THE 3KM HRRR AND 12KM NAM-WRF/ STILL
SUGGEST THAT MOST OF THE WFO PAH FORECAST AREA WILL REMAIN OUT OF
THE PRECIPITATION...WITH THE EXCEPTION OF SOUTHEAST MO BETWEEN
09-12Z FRIDAY.
WITH THE CLEAR SKIES...FOG WILL BE AN INTERMITTENT PROBLEM
OVERNIGHT. SOME OF THE FOG WILL REMAIN QUITE SHALLOW /GROUND
FOG/...WHILE DEEPER MORE PERSISTENT FOG WILL DEVELOP LATER TONIGHT
ALONG THE EDGE OF THE RECEDING OPAQUE CLOUD COVER. THE GRIDDED
FORECAST HINTS AT THE AREAS WITH THE GREATER POTENTIAL FOR DENSE
FOG...BUT LIGHT FOG AND/OR GROUND FOG WILL BE POSSIBLE ACROSS MOST
AREAS UNDER THE CLEARING SKIES OVERNIGHT. A SPECIAL WEATHER
STATEMENT WAS ISSUED FOR PARTS OF SOUTHEAST MISSOURI AND ALL OF
SOUTHERN ILLINOIS FOR FOG DEVELOPMENT.
AN INITIAL LOOK AT THE FRIDAY CONVECTIVE ACTIVITY SUGGESTS A FAIR
AMOUNT OF MULTICELL DEVELOPMENT WITH THE MAIN ROTATING SHEAR AXES
AHEAD OF THE COLD CORE LOW CIRCULATION. THE NAM-WRF SUGGESTS A
QUICK TURNAROUND IN THE EXPENDITURE OF CAPE...WITH BANDING OF
PRECIPITATION A LIKELY SCENARIO. THE BIG KEY WILL BE THE AMOUNT OF
DESTABILIZATION OF THE BOUNDARY LAYER DURING THE MORNING HOURS.
THIS MAY SLOW THE ONSET OF SIGNIFICANT PARCEL MIXING OVER SOUTHERN
IL/WESTERN KY UNTIL LATER IN THE MORNING /POSSIBLY AFTER 16Z/. BY
THAT TIME...SUFFICIENT SHEAR AND SHARPER LAPSE RATES SHOULD LEAD
TO BETTER UPDRAFTS CAPABLE OF HAIL. I WOULD NOT BE SURPRISED TO
SEE SOME 1-1.5 INCH HAIL IN LOCAL CASES...BUT MOST HAIL SHOULD
REMAIN IN THE 0.25-0.75 INCH SIZE CATEGORY. THE 4KM NAM-WRF /ARW
VERSION/ HINTED THAT SERN IL AN SWRN IN COULD SEE BETTER UPDRAFT
FOR SEVERE CRITERIA WIND/HAIL IN THE 17Z-22Z TIME FRAME. WILL JUST
HAVE TO WAIT AND SEE. AGAIN...THE KEY WILL BE THE DEGREE OF
INSOLATION /SUNSHINE/ AND LACK OF CLOUD COVER TO SUPPORT SURFACE-
BASED PARCEL LIFT.
UPDATE ISSUED AT 710 PM CDT THU MAR 22 2012
MINOR VORTICITY LOBE/CENTER APPEARED TO BE GENERATED OVER
SOUTHWEST KY/EXTREME SOUTHERN IL NEAR KPAH BETWEEN 5-6 PM CDT.
THIS FEATURE...WELL DEPICTED BY THE 3KM HRRR 1KM AGL REFLECTIVITY
SHOULD CONTINUE TO MOVE NORTHEAST THROUGH 10 PM ACROSS SOUTHERN
IL. THERE MAY BE SOME REGENERATION OF PRECIPITATION AS THIS
FEATURE MOVE NEAR THE CONFLUENCE OF THE WABASH/OHIO RIVERS NEAR
SOUTHWEST INDIANA EARLY THIS EVENING. KEPT A MENTION OF
POP/WEATHER IN THIS AREA...BUT MAY NEED TO RE-ADJUST AS THE
BOUNDARY LAYER STABILIZES AND A WEAK LLJ SET UP.
ABUNDANT MOISTURE NEAR THE SURFACE AND A STABILIZING BOUNDARY
LAYER WILL LIKELY LEAD TO SOME FOG GENERATION AFTER MIDNIGHT. AT
THE CURRENT TIME...THE MENTION OF FOG IS WELL COVERED...BUT PLAN
TO SEE WHERE THE GREATEST VISIBILITY RESTRICTIONS WILL BE FOR THE
MID-EVENING UPDATE.
WITH THE UPPER LOW AND SHARPER LAPSE RATES APPROACHING WITH THE
SOUTHWEST MO CONVECTIVE ACTIVITY...KEPT A NARROW BAND OF ISOLATED
TO SCATTERED THUNDERSTORMS MENTIONED OVER THE WESTERN FOUR COUNTIES
OF SOUTHEAST MO THIS EVENING /MAINLY POPLAR BLUFF-GREENVILLE
WESTWARD/.
PLAN TO HAVE A LITTLE MORE DETAILED LOOK AT THUNDERSTORM/HAIL/WIND
POTENTIAL FOR FRIDAY. THE CURRENT SPC OUTLOOK AREA FOR DAY 2 LOOKS
FAIRLY GOOD...WITH THE TIME OF GREATEST CONCERN LIKELY RANGE
BETWEEN 16Z-22Z /11 AM -5 PM CDT/ ALONG AND EAST OF A KPAH-KSAR-
KMVN LINE.
&&
.SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT)
N-S BAND OF SHOWERS SHIFTING SLOWLY TO THE EAST...A LITTLE FASTER
THAN ORIGINALLY EXPECTED...SO FRONTAL BOUNDARY OBVIOUSLY ON THE
MOVE. SOME DEVELOPMENT WEST OF THE MAIN BAND...BUT NOT FILLING IN TOO
WELL AT THE MOMENT.
MAIN BAND OF PRECIP SHOULD CONTINUE ITS EASTWARD MOVEMENT OVERNIGHT...
HOWEVER BY LATE TONIGHT THE LEADING EDGE OF PRECIP ASSOCIATED WITH
THE PARENT UPPER LOW IS EXPECTED TO BE MOVING INTO THE WESTERN
SECTIONS OF OUR CWA. IF SKIES REMAIN CLEAR TO MOSTLY CLEAR OVERNIGHT
BETWEEN THE TWO AREAS OF PRECIP...WITH WET SOIL AND LIGHT TO CALM
WINDS...AREAS OF FOG WILL LIKELY DEVELOP...SO ADDED IT.
THE COMBINATION OF THE PARENT UPPER LOW MOVING ACROSS OUR CWA
FRIDAY...STEEP MID LEVEL LAPSE RATES...AND COLD AIR ALOFT WILL
LIKELY GENERATE THUNDERSTORM DEVELOPMENT...WITH THERE BEING A
THREAT FOR LARGE HAIL PRODUCTION...ESPECIALLY ACROSS THE NORTHERN
HALF OF THE CWA.
FRIDAY NIGHT PRECIP CHANCES WILL DIMINISH FROM WEST TO EAST AS THE
UPPER MOVES FARTHER AWAY FROM OUR CWA.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
SHOWERS WILL LINGER ACROSS THE LOWER OHIO VALLEY ON SATURDAY AS THE
UPPER LOW SLIDES SOUTHEAST ACROSS NORTHEAST PORTIONS OF THE PADUCAH
FORECAST AREA. DUE TO THE PROXIMITY OF THE LOW...THUNDERSTORMS WILL
REMAIN POSSIBLE ACROSS THE EASTERN THIRD OF THE FA...WITH SOME SMALL
HAIL NOT OUT OF THE QUESTION. BY SATURDAY NIGHT...JUST A FEW
SHOWERS WILL BE POSSIBLE ACROSS EASTERN THIRD OF THE FA.
AN UPPER LEVEL RIDGE WILL BUILD ACROSS THE SOUTHERN PLAINS SUNDAY
AND SLIDE EAST INTO EARLY NEXT WEEK. THIS WILL KEEP CONDITIONS DRY
WITH TEMPERATURES 10 TO 15 DEGREES ABOVE NORMAL.
GFS AND ECMWF SHOW A LOW PRESSURE SYSTEM SLIDING FROM THE NORTHERN
PLAINS INTO THE NORTHERN GREAT LAKES REGION LATE TUESDAY INTO
WEDNESDAY. THIS LOW WILL BRING A COLD FRONT INTO THE AREA TUESDAY
NIGHT INTO THURSDAY. BOTH MODELS PRODUCE QPF...THOUGH GFS PRODUCES
MORE SIGNIFICANT QPF TUESDAY NIGHT INTO WEDNESDAY NIGHT...WHILE THE
ECMWF HOLDS OFF ON A LITTLE MORE SUBSTANTIAL QPF UNTIL THURSDAY WHEN
IT BRINGS THE FRONT BACK NORTH. IN EITHER CASE...AT LEAST SOME
CHANCE POPS LOOK REASONABLE ACROSS NORTHERN PORTIONS OF THE FA
TUESDAY NIGHT...AND ACROSS THE ENTIRE FA WEDNESDAY INTO WEDNESDAY
NIGHT. WENT WITH JUST SOME SMALL POPS ACROSS NORTHEAST AND SOUTHERN
PORTIONS ON THURSDAY FOR NOW UNTIL MODELS BECOME MORE DEFINITIVE
WITH TIMING AND FRONTAL PLACEMENT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1158 PM CDT THU MAR 22 2012
MAIN CHALLENGE WITH THE 06Z TAF ISSUANCE HAS BEEN THE ONSET OF
VLIFR TO IFR CEILINGS AND VISIBILITIES ASSOCIATED WITH THE
RECEDING OPAQUE CLOUD COVER. I HAVE ADJUSTED THE KCGI/KPAH TAF
SITES TO ADDRESS PREVAILING HIGHER VISIBILITIES WITH INTERMITTENT
GROUND FOG /MIFG/. FOR THE MAIN CONVECTIVE ACTIVITY ACROSS THE TAF
SITES ON FRIDAY...ADDRESSED THESE INSTANCES WITH VFR CEILINGS AND
VISIBILITIES...AS WELL AS VICINITY THUNDERSTORM CHANCES. GIVEN THE
BANDED NATURE OF THE EXPECTED CONVECTION...IT WILL BE HARD TO TIME
VISIBILITY AND CEILING RESTRICTIONS BEYOND 1-2 HOURS AT A TIME.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...SMITH
SHORT TERM...JP
LONG TERM....RST
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
720 PM CDT SAT MAR 24 2012
.UPDATE...
00Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
SEVERAL FEATURES OF INTEREST WILL IMPACT THE REGION OVER THE
COMING WEEK... ALTHOUGH AT THIS POINT NO PARTICULARLY SIGNIFICANT
WEATHER APPEARS LIKELY. IN THE BIG PICTURE... THE LARGE SCALE
UPPER FLOW WILL BECOME LESS AMPLIFIED AND HENCE MORE
PROGRESSIVE AND SLIGHTLY MORE SEASONABLE IN OUR NECK OF THE WOODS.
THIS MEANS THAT INSTEAD OF SEEING TEMPERATURES OF 20-30 DEGREES
ABOVE NORMAL... THEY MAY BE MORE ON THE ORDER OF 10-15 DEGREES
ABOVE NORMAL FOR A GOOD PART OF THE UPCOMING WEEK. ONE MAJOR
CONCERN COULD BE THE POTENTIAL FOR FREEZING TEMPERATURES IN THE
UPCOMING WEEK... SINCE SOME OF THE CALENDAR-DEFICIENT PLANTS HAVE
DECIDED IT/S ALREADY TIME TO START GROWING. IT DOESN/T APPEAR AS
THOUGH ANY WIDESPREAD FREEZING TEMPERATURES WILL OCCUR THROUGH THE
UPCOMING WEEK... BUT PORTIONS OF THE AREA COULD SEE READINGS DIP
NEAR OR BELOW FREEZING ON A COUPLE OF MORNINGS. THE GFS AND ECMWF
ARE IN DECENT AGREEMENT THROUGH MOST OF THE WEEK... SO GENERALLY
FOLLOWED A BLEND OF THEIR GUIDANCE... INCREASINGLY BLENDING IT
WITH THE PREVIOUS FORECAST IN THE LATER PERIODS.
VISIBLE IMAGERY SHOWS THIS MORNING/S LOW CLOUDS AND FOG HAVE
FINALLY BURNED OFF OVER MOST OF THE AREA. TEMPERATURES ARE
RESPONDING QUICKLY TO THE SUNSHINE... WITH READINGS CLIMBING
THROUGH THE 60S TO AROUND 70. SHOULD CONTINUE TO SEE READINGS WORK
UPWARD THE NEXT COUPLE OF HOURS... THEN THINGS WILL COOL OFF BOTH
IN RESPONSE TO DARKNESS AND THE COLD FRONT MARCHING SOUTHEAST
THROUGH THE AREA. THE FRONT CURRENTLY STRETCHES FROM NEAR
INTERNATIONAL FALLS SOUTHWEST INTO EASTERN SOUTH DAKOTA.
TEMPERATURES DROP OFF BEHIND THE FRONT... WITH A BIG DROP IN
DEWPOINTS NOTED AS WELL. A FEW SHRA COULD DEVELOP IN NORTHEAST
MINNESOTA AND NORTHWEST WISCONSIN AS THE FRONT MOVES THROUGH THIS
AFTERNOON AND EVENING... BUT AT THIS POINT IT LOOKS LIKE ANY OF
THAT ACTIVITY SHOULD STAY NORTH OF OUR AREA. THE HRRR AND LOCAL
4KM WRF-ARW DO MANAGE TO PRODUCE SOME LIGHT SHRA INTO THE
NORTHEAST PART OF OUR AREA... BUT AT THIS POINT WOULD RATHER SEE
MORE GOING ON IN THE REAL WORLD TO INCLUDE A MENTION. AS
MENTIONED... THE FRONT WILL SLIDE THROUGH TONIGHT... WITH RIDGING
AND COOLER/DRIER AIR ARRIVING FOR OVERNIGHT THROUGH THE DAY ON
SUNDAY. BUT... GIVEN THE MORE PROGRESSIVE FLOW... THIS CHANGE WILL
BE SHORT-LIVED... WITH RETURN FLOW SETTING UP QUICKLY SUNDAY
NIGHT. ISENTROPIC LIFT SUNDAY NIGHT INTO MONDAY IS IMPRESSIVE AS
THE ELEVATED WARM FRONT LIFTS BACK NORTHEAST ACROSS THE AREA. IN
ADDITION TO THE ISENTROPIC LIFT... FAIRLY SUBSTANTIAL LOW-MID
LEVEL FRONTOGENESIS IS PROGGED FROM LATE SUNDAY NIGHT THROUGH THE
DAY ON MONDAY AS THE BOUNDARY SLOWLY LIFTS NORTHEAST ACROSS THE
AREA. A LOOK AT ELEVATED INSTABILITY... PER 850-500MB DIFFERENTIAL
THETA-E VALUES... SHOWS SOME POTENTIAL FOR THUNDER CREEPING IN
FROM WEST TO EAST LATE SUNDAY NIGHT INTO MONDAY NIGHT... WITH A
CHANCE FOR SOME THUNDER ACROSS THE ENTIRE AREA BY LATER MONDAY
NIGHT AS THE WARM SECTOR FULLY ESTABLISHES ITSELF OVER SOUTHERN
MINNESOTA INTO WEST CENTRAL WISCONSIN. EXPECT AN INITIAL ARC OF
PCPN ASSOCIATED WITH ELEVATED WARM ADVECTION TO LIFT INTO THE AREA
LATE SUNDAY NIGHT INTO MONDAY MORNING... THEN A SECONDARY
DEVELOPMENT OF PCPN BEHIND THAT OWING TO INCREASING ISENTROPIC
LIFT ALONG WITH FRONTOGENESIS AND THE ARRIVAL OF ELEVATED
INSTABILITY. IN ADDITION... SOME POTENT STORMS MAY DEVELOP TO OUR
WEST MONDAY AFTERNOON INTO MONDAY EVENING... AND WHAT IS LEFT OF
THOSE COULD WORK INTO THE AREA MONDAY NIGHT.
LOW PRESSURE IS EXPECTED TO LIFT NORTHEAST INTO NORTHWEST
MINNESOTA BY TUESDAY AFTERNOON... WORKING TO DRAG A COLD FRONT
EAST THROUGH OUR AREA SOMEWHAT EARLY IN THE DAY. THE FRONT LOOKS
TO GET ACROSS MOST OF THE MINNESOTA CWFA BY 18Z... AND THROUGH THE
WISCONSIN PORTION OF THE AREA BY MID AFTERNOON. ALTHOUGH DEEP
LAYER SHEAR SHOULD STILL BE QUITE STRONG ON TUESDAY... LOW LEVEL
SHEAR DOES NOT LOOK TO BE AS IMPRESSIVE AS IT DID YESTERDAY...
MAINLY DUE TO THE EARLIER PROGGED ARRIVAL OF THE FRONT. THE
EARLIER FROPA WOULD ALSO LIMIT INSTABILITY INTO THE AREA... WHICH
IS A NEGATIVE TOWARD THE SEVERE WEATHER POSSIBILITIES. SO... AT
THIS POINT... THE OVERALL SEVERE WEATHER CHANCES FROM MONDAY NIGHT
THROUGH TUESDAY DO NOT APPEAR PARTICULARLY HIGH ACROSS THE AREA.
BUT... IT IS STILL A FEW DAYS AWAY... SO ANY CHANGES IN THE TIMING
AND POSITION OF FEATURES COULD STILL CHANGE THINGS A BIT... SO IT
IS WORTH KEEPING AN EYE ON THE SITUATION. STRONG WESTERLY WINDS
WILL USHER IN DRIER AIR BEHIND THE FRONT LATE TUESDAY AFTERNOON
INTO TUESDAY NIGHT... WITH 850MB TEMPERATURES OF BELOW ZERO
ACTUALLY MAKING IT INTO THE AREA FOR A TIME ON WEDNESDAY INTO
WEDNESDAY NIGHT. HOWEVER... THIS CHANGE WILL BE SHORTLIVED ONCE
AGAIN... WITH RETURN FLOW AND WARMER AIR WORKING BACK INTO THE
REGION BY LATER THURSDAY AND INTO FRIDAY. CHANCES FOR SHOWERS AND
A FEW THUNDERSTORMS WILL ACCOMPANY THE RETURN OF WARMER
TEMPERATURES THURSDAY INTO FRIDAY WITH PERHAPS SOME SHOWER CHANCES
LINGERING INTO SATURDAY AS A SHORTWAVE MOVES BY TO OUR NORTH.
&&
.AVIATION.../00Z TAF ISSUANCE/
COLD FRONT NEAR A STC TO RWF TO SUPERIOR LINE AT 00Z WILL BE SOUTH
AND EAST OF THE AREA BY 12Z. MAIN CONCERN WITH THE FRONT ARE THE
LOW MVFR CIGS COMING DOWN IN STRONG LOW LEVEL COLD ADVECTION
BEHIND IT. CLOUDS HAVE HELD STRONG ON SATELLITE...SO HAVE BEEFED
UP THERE APPEARANCE IN TAFS. BOTH THE RUC AND LOCAL WRF SHOW A
BAND OF LOWER CLOUDS WORKING ACROSS THE AREA THIS EVENING...SO
USED THESE MODELS TO TIME THE CLOUDS IN THE TAFS. ONLY CONCERN WITH
THE CLOUDS FOR TONIGHT COMES FROM THE HRRR...WHICH DOES NOT BRING
CLOUDS MUCH FURTHER SOUTH THAN THEIR CURRENT POSITION...BUT GIVEN
DEGREE OF COLD ADVECTION...SIDED WITH THE RUC/WRF. IN
ADDITION...NW WINDS BEHIND THE FRONT HAVE BEEN FAIRLY STRONG AS
WELL...SO BUMPED POST FRONTAL SPEEDS UP A BIT AT ALL TERMINALS.
FOR MUCH OF THE DAY SUNDAY...SKIES WILL BE CLEAR...THOUGH STRONG
WARM ADVECTION WILL START TAKING SHAPE TO THE SOUTHWEST DURING THE
AFTERNOON...WITH CLOUDS BEGINNING TO INCREASE LATE IN THE PERIOD.
KMSP...GIVEN PERSISTENCE OF POST FRONTAL CLOUDS AND LAST SEVERAL
RUC FORECASTS...BROUGHT IN A TEMPO GROUP FOR SUB 017 CIGS. IF THE
RUC IS RIGHT...THIS WOULD END UP BEING A PREVAILING CIG. STRONG
DRYING DEPICTED AT 925 MB BEHIND THE BAND...SO DO EXPECT SKC
CONDITIONS AT ALL BUT POSSIBLY EAU BY 12Z. OTHER THAN THAT...NW
WINDS WILL SLOWLY VEER TOWARD THE EAST...WITH HIGH CLOUDS SLOWLY
DESCENDING TOWARD THE MID LEVELS BY THE END OF THE TAF.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
TRH/MPG
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
116 PM CDT FRI MAR 23 2012
.UPDATE...HAVE ALLOWED THE DFA TO EXPIRE AS VISIBILITY HAS IMPROVED
SOMEWHAT AROUND SWRN CWA. TWIN PORTS REGION STILL LOCALLY DENSE.
MNDOT WEBCAMS SHOW LOW VISIBILITY IN SOME LOCATIONS WHILE OTHERS HAVE
CLEARLY IMPROVED VISIBILITY COMPARED TO EARLIER IMAGES. MAY NEED
TO REISSUE DFA FOR LATER TODAY/OVERNIGHT BASED ON SATURATED NEAR
SFC PROFILE/NOCTURNAL COOLING/PROXIMITY OF LAKE COLD WEDGE.
LOWERED MAX TEMPS EARLIER BASED ON CLOUID COVER/PRECIP/FOG.
&&
.PREV DISCUSSION... /ISSUED 1246 PM CDT FRI MAR 23 2012/
AVIATION...18Z TAF ISSUANCE...
LIFR VSBYS AND CIGS ARE EXPECTED TO CONTINUE THROUGH TOMORROW
MORNING AS A STREAM OF LOW LEVEL MOISTURE CONTINUES TO GET PUMPED
IN FROM THE SE AROUND THE NRN EDGE OF A CUT OFF UPPER LOW OVER THE
LOWER MS VALLEY. THE ADDED INFLUENCE OF LAKE SUPERIOR IS ALSO
HELPING TO INCREASE NEAR SFC MOISTURE AND AIDING IN THE FOG
PERSISTENCE. COULD SEE A COUPLE HOURS THIS AFTERNOON WHERE CIGS
LIFT SLIGHTLY TO LOW-END MVFR AND VSBYS IMPROVE TO GT 3SM. THE
BEST CHANCE WILL BE AROUND HYR AND BRD. A FEW LIGHT RAIN SHOWERS
WILL BE LINGERING AROUND INL EARLY THIS AFTERNOON...WITH MOST OF
THE WIDESPREAD PRECIP ENDING BY MID AFTERNOON. FOG RETURNS TONIGHT
TO MOST TERMINALS...WITH THE BEST CHANCE OF 1/4SM OR LESS AT DLH
AND HIB. SHOULD SEE RAPID IMPROVEMENT IN VSBYS BY LATE SAT
MORNING.
PREV DISCUSSION... /ISSUED 859 AM CDT FRI MAR 23 2012/
UPDATE...ISSUED DFA AS LATEST SFC OBS/WEBCAMS SHOW EXTENSIVE
AREA OF DENSE FOG ACROSS NSHORE...TWIN PORTS...SOUTH
SHORE...BRAINERD LAKES/CASS LAKE VICINITY. RUC13 SNDGS SUPPORT
CONTINUATION OF MOIST INVERSION PROFILE THROUGH AT LEAST
MIDDAY...IF NOT LONGER. GIVEN THE DIFFICULT NATURE OF FORECASTING
THIS PARTICULAR ELEMENT...WILL NEED TO MONITOR THROUGH NEXT FEW
HRS FOR UPDATES TO AREAL COVERAGE/TIMING.
PREV DISCUSSION... /ISSUED 638 AM CDT FRI MAR 23 2012/
AVIATION...12Z TAF ISSUANCE...
WIDESPREAD LIFR/IFR CONDITIONS ARE LIKELY THROUGH LATE THIS
MORNING ACROSS THE REGION DUE TO VERY LOW CIGS AND FG/BR/-RA.
CONDITIONS ARE PROJECTED TO IMPROVE LATE THIS MORNING AND THIS
AFTERNOON TO MORE IFR/MVFR CONDITIONS...BUT BE PREPARED FOR SOME
AREAS TO HAVE LINGERING LIFR CONDITIONS. CONDITIONS SHOULD THEN
WORSEN AGAIN TONIGHT TO LIFR/IFR CONDITIONS DUE TO VERY LOW CIGS
AND FG.
PREV DISCUSSION... /ISSUED 335 AM CDT FRI MAR 23 2012/
SHORT TERM....TODAY THROUGH SATURDAY.
CURRENT RADAR IMAGERY AND SFC ANALYSIS SHOWS WEAK EAST/SOUTHEAST FLOW
WITH SCT RAIN SHOWERS OVER THE CWA. A CORRIDOR OF MODERATE TO
HEAVY RAIN IS FOUND ALONG THE INTERNATIONAL BORDER NEAR THE
OCCLUDED FRONT THAT HAS NOW PUSHED NORTH INTO CANADA. RADAR
ESTIMATED RAINFALL OVER THE PAST 48 HRS RANGES FROM A QUARTER OF
AN INCH IN MOST AREAS...TO HIGHER AMOUNTS OF A HALF TO ONE INCH IN
THE IRON RANGE/ARROWHEAD REGION. AT 300 AM...THE HEAVIEST AMOUNTS
WERE ACROSS NORTHERN ST LOUIS/LAKE COUNTIES WHERE RADAR ESTIMATED
VALUES WERE AROUND AN INCH AND A HALF.
A WELL DEFINED CUT OFF LOW IS CURRENTLY SEEN ON SAT IMAGERY ROTATING
OVER THE CENTRAL PLAINS...CONTINUING TO WRAP WARM HUMID AIR FROM THE
GULF NORTH INTO THE WESTERN GREAT LAKES REGION. WINDS WILL REMAIN
NORTHEAST OVER LAKE SUPERIOR TODAY RESULTING IN COOLER TEMPERATURES
AROUND 45-50 DEGREES LAKESIDE. ELSEWHERE...ANOTHER MILD MARCH DAY
IN THE 60S WITH RAIN SHOWERS/DRIZZLE WILL PREVAIL.
THE LOW WILL GRADUALLY PUSH EAST INTO THE SRN INDIANA/KENTUCKY
REGION THROUGH SATURDAY...ALLOWING FOR UPPER LEVEL RIDING TO BUILD
INTO THE NRN PLAINS. SHORT RANGE MODELS IN AGREEMENT CLOUDS AND
HIGH HUMIDITIES LINGER OVER THE NORTHLAND THROUGH SATURDAY
MORNING...GRADUALLY ERODING IN THE WRN ZONES SAT AFTN. HAVE
INTRODUCED FOG AND DRIZZLE TO ERN HALF OF CWA OVERNIGHT WHERE
SFC-H85 PROFILES REMAIN SATURATED BUT LACK FORCING FOR
SHOWERS/MEASURABLE RAINFALL.
LONG TERM [SATURDAY NIGHT - THURSDAY]...
THE MODELS ARE IN FAIRLY GOOD AGREEMENT...SO LEANED ON A BLEND. THE
MODEL CONSENSUS IS FOR A PASSING COLD FRONT SATURDAY
NIGHT...BRINGING THE NORTHLAND AND MUCH COOLER AND DRIER SUNDAY.
HIGH PRESSURE SHOULD KEEP MOST OF THE REGION DRY MONDAY...BUT HAD TO
INCLUDE SOME LOW POPS FOR SHOWERS AND THUNDERSTORMS ACROSS THE
WESTERN AND SOUTHERN FA DUE TO THE MODELS INDICATING PCPN IN THE
PLAINS FROM ORGANIZING LOW PRESSURE. THAT LOW PRESSURE SYSTEM SHOULD
THEN MOVE ACROSS THE DAKOTAS INTO CENTRAL/NORTHERN MINNESOTA THROUGH
TUESDAY....AND THEN OVER THE GREAT LAKES THROUGH WEDNESDAY. THE
PASSAGE OF THE SYSTEM COULD BRING SHOWERS AND STORMS TO THE
NORTHLAND. HIGH PRESSURE SHOULD THEN PROVIDE DRY WEATHER THURSDAY.
TEMPERATURES WILL GENERALLY REMAIN ABOVE NORMAL THROUGH THE LONG
TERM PERIOD.
&&
.POINT TEMPS/POPS...
DLH 42 62 35 50 / 20 10 10 10
INL 46 66 27 43 / 10 10 10 10
BRD 47 70 35 55 / 10 10 10 10
HYR 47 68 40 57 / 20 10 10 10
ASX 42 60 37 48 / 30 10 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...DENSE FOG ADVISORY UNTIL 10 AM CDT SATURDAY FOR LSZ121-140>148.
&&
$$
SHORT TERM...CANNON
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1246 PM CDT FRI MAR 23 2012
.AVIATION...18Z TAF ISSUANCE...
LIFR VSBYS AND CIGS ARE EXPECTED TO CONTINUE THROUGH TOMORROW
MORNING AS A STREAM OF LOW LEVEL MOISTURE CONTINUES TO GET PUMPED
IN FROM THE SE AROUND THE NRN EDGE OF A CUT OFF UPPER LOW OVER THE
LOWER MS VALLEY. THE ADDED INFLUENCE OF LAKE SUPERIOR IS ALSO
HELPING TO INCREASE NEAR SFC MOISTURE AND AIDING IN THE FOG
PERSISTENCE. COULD SEE A COUPLE HOURS THIS AFTERNOON WHERE CIGS
LIFT SLIGHTLY TO LOW-END MVFR AND VSBYS IMPROVE TO GT 3SM. THE
BEST CHANCE WILL BE AROUND HYR AND BRD. A FEW LIGHT RAIN SHOWERS
WILL BE LINGERING AROUND INL EARLY THIS AFTERNOON...WITH MOST OF
THE WIDESPREAD PRECIP ENDING BY MID AFTERNOON. FOG RETURNS TONIGHT
TO MOST TERMINALS...WITH THE BEST CHANCE OF 1/4SM OR LESS AT DLH
AND HIB. SHOULD SEE RAPID IMPROVEMENT IN VSBYS BY LATE SAT
MORNING.
&&
.PREV DISCUSSION... /ISSUED 859 AM CDT FRI MAR 23 2012/
UPDATE...ISSUED DFA AS LATEST SFC OBS/WEBCAMS SHOW EXTENSIVE
AREA OF DENSE FOG ACROSS NSHORE...TWIN PORTS...SOUTH
SHORE...BRAINERD LAKES/CASS LAKE VICINITY. RUC13 SNDGS SUPPORT
CONTINUATION OF MOIST INVERSION PROFILE THROUGH AT LEAST
MIDDAY...IF NOT LONGER. GIVEN THE DIFFICULT NATURE OF FORECASTING
THIS PARTICULAR ELEMENT...WILL NEED TO MONITOR THROUGH NEXT FEW
HRS FOR UPDATES TO AREAL COVERAGE/TIMING.
PREV DISCUSSION... /ISSUED 638 AM CDT FRI MAR 23 2012/
AVIATION...12Z TAF ISSUANCE...
WIDESPREAD LIFR/IFR CONDITIONS ARE LIKELY THROUGH LATE THIS
MORNING ACROSS THE REGION DUE TO VERY LOW CIGS AND FG/BR/-RA.
CONDITIONS ARE PROJECTED TO IMPROVE LATE THIS MORNING AND THIS
AFTERNOON TO MORE IFR/MVFR CONDITIONS...BUT BE PREPARED FOR SOME
AREAS TO HAVE LINGERING LIFR CONDITIONS. CONDITIONS SHOULD THEN
WORSEN AGAIN TONIGHT TO LIFR/IFR CONDITIONS DUE TO VERY LOW CIGS
AND FG.
PREV DISCUSSION... /ISSUED 335 AM CDT FRI MAR 23 2012/
SHORT TERM....TODAY THROUGH SATURDAY.
CURRENT RADAR IMAGERY AND SFC ANALYSIS SHOWS WEAK EAST/SOUTHEAST FLOW
WITH SCT RAIN SHOWERS OVER THE CWA. A CORRIDOR OF MODERATE TO
HEAVY RAIN IS FOUND ALONG THE INTERNATIONAL BORDER NEAR THE
OCCLUDED FRONT THAT HAS NOW PUSHED NORTH INTO CANADA. RADAR
ESTIMATED RAINFALL OVER THE PAST 48 HRS RANGES FROM A QUARTER OF
AN INCH IN MOST AREAS...TO HIGHER AMOUNTS OF A HALF TO ONE INCH IN
THE IRON RANGE/ARROWHEAD REGION. AT 300 AM...THE HEAVIEST AMOUNTS
WERE ACROSS NORTHERN ST LOUIS/LAKE COUNTIES WHERE RADAR ESTIMATED
VALUES WERE AROUND AN INCH AND A HALF.
A WELL DEFINED CUT OFF LOW IS CURRENTLY SEEN ON SAT IMAGERY ROTATING
OVER THE CENTRAL PLAINS...CONTINUING TO WRAP WARM HUMID AIR FROM THE
GULF NORTH INTO THE WESTERN GREAT LAKES REGION. WINDS WILL REMAIN
NORTHEAST OVER LAKE SUPERIOR TODAY RESULTING IN COOLER TEMPERATURES
AROUND 45-50 DEGREES LAKESIDE. ELSEWHERE...ANOTHER MILD MARCH DAY
IN THE 60S WITH RAIN SHOWERS/DRIZZLE WILL PREVAIL.
THE LOW WILL GRADUALLY PUSH EAST INTO THE SRN INDIANA/KENTUCKY
REGION THROUGH SATURDAY...ALLOWING FOR UPPER LEVEL RIDING TO BUILD
INTO THE NRN PLAINS. SHORT RANGE MODELS IN AGREEMENT CLOUDS AND
HIGH HUMIDITIES LINGER OVER THE NORTHLAND THROUGH SATURDAY
MORNING...GRADUALLY ERODING IN THE WRN ZONES SAT AFTN. HAVE
INTRODUCED FOG AND DRIZZLE TO ERN HALF OF CWA OVERNIGHT WHERE
SFC-H85 PROFILES REMAIN SATURATED BUT LACK FORCING FOR
SHOWERS/MEASURABLE RAINFALL.
LONG TERM [SATURDAY NIGHT - THURSDAY]...
THE MODELS ARE IN FAIRLY GOOD AGREEMENT...SO LEANED ON A BLEND. THE
MODEL CONSENSUS IS FOR A PASSING COLD FRONT SATURDAY
NIGHT...BRINGING THE NORTHLAND AND MUCH COOLER AND DRIER SUNDAY.
HIGH PRESSURE SHOULD KEEP MOST OF THE REGION DRY MONDAY...BUT HAD TO
INCLUDE SOME LOW POPS FOR SHOWERS AND THUNDERSTORMS ACROSS THE
WESTERN AND SOUTHERN FA DUE TO THE MODELS INDICATING PCPN IN THE
PLAINS FROM ORGANIZING LOW PRESSURE. THAT LOW PRESSURE SYSTEM SHOULD
THEN MOVE ACROSS THE DAKOTAS INTO CENTRAL/NORTHERN MINNESOTA THROUGH
TUESDAY....AND THEN OVER THE GREAT LAKES THROUGH WEDNESDAY. THE
PASSAGE OF THE SYSTEM COULD BRING SHOWERS AND STORMS TO THE
NORTHLAND. HIGH PRESSURE SHOULD THEN PROVIDE DRY WEATHER THURSDAY.
TEMPERATURES WILL GENERALLY REMAIN ABOVE NORMAL THROUGH THE LONG
TERM PERIOD.
&&
.POINT TEMPS/POPS...
DLH 49 42 62 35 / 50 20 10 10
INL 58 46 66 27 / 80 10 10 10
BRD 62 47 70 35 / 40 10 10 10
HYR 64 47 68 40 / 60 20 10 10
ASX 50 42 60 37 / 60 30 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR MNZ020-021-
025-026-033>037.
WI...DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR WIZ001>003.
LS...DENSE FOG ADVISORY UNTIL 10 AM CDT SATURDAY FOR LSZ121-140>148.
&&
$$
AVIATION...TENTINGER
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
859 AM CDT FRI MAR 23 2012
.UPDATE...ISSUED DFA AS LATEST SFC OBS/WEBCAMS SHOW EXTENSIVE
AREA OF DENSE FOG ACROSS NSHORE...TWIN PORTS...SOUTH
SHORE...BRAINERD LAKES/CASS LAKE VICINITY. RUC13 SNDGS SUPPORT
CONTINUATION OF MOIST INVERSION PROFILE THROUGH AT LEAST
MIDDAY...IF NOT LONGER. GIVEN THE DIFFICULT NATURE OF FORECASTING
THIS PARTICULAR ELEMENT...WILL NEED TO MONITOR THROUGH NEXT FEW
HRS FOR UPDATES TO AREAL COVERAGE/TIMING.
&&
.PREV DISCUSSION... /ISSUED 638 AM CDT FRI MAR 23 2012/
AVIATION...12Z TAF ISSUANCE...
WIDESPREAD LIFR/IFR CONDITIONS ARE LIKELY THROUGH LATE THIS
MORNING ACROSS THE REGION DUE TO VERY LOW CIGS AND FG/BR/-RA.
CONDITIONS ARE PROJECTED TO IMPROVE LATE THIS MORNING AND THIS
AFTERNOON TO MORE IFR/MVFR CONDITIONS...BUT BE PREPARED FOR SOME
AREAS TO HAVE LINGERING LIFR CONDITIONS. CONDITIONS SHOULD THEN
WORSEN AGAIN TONIGHT TO LIFR/IFR CONDITIONS DUE TO VERY LOW CIGS
AND FG.
PREV DISCUSSION... /ISSUED 335 AM CDT FRI MAR 23 2012/
SHORT TERM....TODAY THROUGH SATURDAY.
CURRENT RADAR IMAGERY AND SFC ANALYSIS SHOWS WEAK EAST/SOUTHEAST FLOW
WITH SCT RAIN SHOWERS OVER THE CWA. A CORRIDOR OF MODERATE TO
HEAVY RAIN IS FOUND ALONG THE INTERNATIONAL BORDER NEAR THE
OCCLUDED FRONT THAT HAS NOW PUSHED NORTH INTO CANADA. RADAR
ESTIMATED RAINFALL OVER THE PAST 48 HRS RANGES FROM A QUARTER OF
AN INCH IN MOST AREAS...TO HIGHER AMOUNTS OF A HALF TO ONE INCH IN
THE IRON RANGE/ARROWHEAD REGION. AT 300 AM...THE HEAVIEST AMOUNTS
WERE ACROSS NORTHERN ST LOUIS/LAKE COUNTIES WHERE RADAR ESTIMATED
VALUES WERE AROUND AN INCH AND A HALF.
A WELL DEFINED CUT OFF LOW IS CURRENTLY SEEN ON SAT IMAGERY ROTATING
OVER THE CENTRAL PLAINS...CONTINUING TO WRAP WARM HUMID AIR FROM THE
GULF NORTH INTO THE WESTERN GREAT LAKES REGION. WINDS WILL REMAIN
NORTHEAST OVER LAKE SUPERIOR TODAY RESULTING IN COOLER TEMPERATURES
AROUND 45-50 DEGREES LAKESIDE. ELSEWHERE...ANOTHER MILD MARCH DAY
IN THE 60S WITH RAIN SHOWERS/DRIZZLE WILL PREVAIL.
THE LOW WILL GRADUALLY PUSH EAST INTO THE SRN INDIANA/KENTUCKY
REGION THROUGH SATURDAY...ALLOWING FOR UPPER LEVEL RIDING TO BUILD
INTO THE NRN PLAINS. SHORT RANGE MODELS IN AGREEMENT CLOUDS AND
HIGH HUMIDITIES LINGER OVER THE NORTHLAND THROUGH SATURDAY
MORNING...GRADUALLY ERODING IN THE WRN ZONES SAT AFTN. HAVE
INTRODUCED FOG AND DRIZZLE TO ERN HALF OF CWA OVERNIGHT WHERE
SFC-H85 PROFILES REMAIN SATURATED BUT LACK FORCING FOR
SHOWERS/MEASURABLE RAINFALL.
LONG TERM [SATURDAY NIGHT - THURSDAY]...
THE MODELS ARE IN FAIRLY GOOD AGREEMENT...SO LEANED ON A BLEND. THE
MODEL CONSENSUS IS FOR A PASSING COLD FRONT SATURDAY
NIGHT...BRINGING THE NORTHLAND AND MUCH COOLER AND DRIER SUNDAY.
HIGH PRESSURE SHOULD KEEP MOST OF THE REGION DRY MONDAY...BUT HAD TO
INCLUDE SOME LOW POPS FOR SHOWERS AND THUNDERSTORMS ACROSS THE
WESTERN AND SOUTHERN FA DUE TO THE MODELS INDICATING PCPN IN THE
PLAINS FROM ORGANIZING LOW PRESSURE. THAT LOW PRESSURE SYSTEM SHOULD
THEN MOVE ACROSS THE DAKOTAS INTO CENTRAL/NORTHERN MINNESOTA THROUGH
TUESDAY....AND THEN OVER THE GREAT LAKES THROUGH WEDNESDAY. THE
PASSAGE OF THE SYSTEM COULD BRING SHOWERS AND STORMS TO THE
NORTHLAND. HIGH PRESSURE SHOULD THEN PROVIDE DRY WEATHER THURSDAY.
TEMPERATURES WILL GENERALLY REMAIN ABOVE NORMAL THROUGH THE LONG
TERM PERIOD.
&&
.POINT TEMPS/POPS...
DLH 54 42 61 38 / 50 10 10 10
INL 60 46 63 31 / 80 10 20 10
BRD 66 47 69 38 / 40 10 10 10
HYR 64 47 68 42 / 60 10 10 10
ASX 51 42 59 39 / 60 10 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR MNZ020-021-
025-026-033>037.
WI...DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR WIZ001>003.
LS...NONE.
&&
$$
SHORT TERM...CANNON
AREA FORECAST DISCUSSION
NWS HASTINGS NE
354 PM CDT FRI MAR 23 2012
.SHORT TERM...THROUGH SATURDAY AFTERNOON. NEEDLESS TO SAY...THE
NEXT 24 HOURS CONTINUE THE RETURN TO INCREDIBLY NICE LATE MARCH
WEATHER...WITH HIGH TEMPS ON SATURDAY FORECAST TO BE RIGHT AROUND
CLIMATOLOGICAL NORMALS FOR LATE MAY/EARLY JUNE.
STARTING OFF AT 20Z THIS AFTERNOON...A LIGHT AND SOMEWHAT VARIABLE
WIND REGIME IS IN PLACE ACROSS THE CWA...THANKS TO A BROAD DIFFUSE
RIDGE AXIS. THE COMBINATION OF MODEST BOUNDARY LAYER
MOISTURE...ALONG WITH SOME COOLER MID LEVEL AIR ON THE BACK SIDE
OF THE DEPARTING CLOSED LOW OVER SOUTH CENTRAL MISSOURI...HAS
RESULTED IN A LEGITIMATE SCATTERED FAIR WEATHER CUMULUS FIELD
ESPECIALLY ACROSS THE EASTERN HALF OF THE CWA. ALTHOUGH THIS
SCATTERED TO LOCALLY BROKEN DECK WAS A BIT MORE CLOUD COVER THAN
EARLIER EXPECTED...TEMPS HAVE HAD STILL HAD NO PROBLEMS MAKING IT
INTO AT LEAST THE MID-UPPER 60S AT THIS HOUR...WITH SOME PLACES
POSSIBLY TOUCHING 70 BY DAYS END. AS MENTIONED...WATER VAPOR
IMAGERY AND SHORT TERM MODEL DATA CLEARLY REVEAL THE DEPARTING
CLOSED LOW AS THE MAIN MID/UPPER FEATURE OF INTEREST...WITH
SHORTWAVE RIDGING NOW BUILDING ALONG AN AXIS FROM THE SOUTHERN
ROCKIES TO NORTHERN PLAINS...AND THE NEXT LOW PRESSURE SYSTEM OF
INTEREST STILL WELL OFF THE PACIFIC COAST.
FOR LATE THIS AFTERNOON...HAVE KEPT THE FORECAST DRY...ALTHOUGH
THE HRRR CONTINUES TO INSIST THAT A FEW SPRINKLES COULD FLIRT WITH
FAR SOUTHEAST EDGES OF THE CWA. BASED ON LATEST VIS SATELLITE
TRENDS...ANY SLIGHTLY ENHANCED CUMULUS GROWTH POTENTIALLY
CONDUCIVE TO SPRINKLES/LIGHT RAIN SHOULD REMAIN JUST EAST OF THESE
COUNTIES.
THIS EVENING/TONIGHT...BOUNDARY LAYER CUMULUS DEVELOPMENT SHOULD
QUICKLY FADE AWAY...RESULTING IN ESSENTIALLY CLEAR SKIES AS
SHORTWAVE RIDGING CONTINUES TO NOSE OVERHEAD IN THE WAKE OF THE
DEPARTING LOW...WHICH WILL BE NEAR THE IL/IN/KY BORDER AREA BY
12Z. BREEZES WILL REMAIN LIGHT OVERNIGHT...BUT THE DIRECTION WILL
PREVAIL FROM THE WEST/SOUTHWEST. ONLY POTENTIAL ISSUE IS FOG
DEVELOPMENT OVERNIGHT. VARIOUS MODEL BOUNDARY LAYER RELATIVE
HUMIDITY PROGS...ALONG WITH MET/MAV VISIBILITY GUIDANCE...SUGGEST
THAT THIS LIGHT WESTERLY LOW LEVEL FLOW WILL NOT BE VERY CONDUCIVE
TO FOG DEVELOPMENT. THAT BEING SAID...AT LEAST LIGHT FOG HAS
DEVELOPED HERE AND THERE ACROSS THE CWA THE PAST FEW NIGHTS
LARGELY DUE TO MOIST GROUND IN THE WAKE OF RECENT RAINFALL. GIVEN
THAT PATCHY FOG WORDING HAS ALREADY BEEN IN THE FORECAST FOR OVER
24 HOURS NOW IN SOME AREAS...WILL LET IT RIDE...BUT WOULD BE VERY
SURPRISED TO SEE MORE THAN PATCHY LIGHT VISIBILITY RESTRICTIONS.
FOR LOW TEMPS...KEPT SIMILAR TO PREVIOUS FORECAST IN EASTERN
ZONES...BUT BUMPED DOWNWARD A FEW DEGREES IN THE WEST...RESULTING
IN A RANGE FROM MID-UPPER 30S WEST...LOW 40S CENTRAL...MID 40S
SOUTHEAST. BASED ON WHAT HAPPENED THIS MORNING WITH LOWS TUMBLING
INTO THE LOW 30S WEST...WOULD NOT BE SURPRISED IF TONIGHTS LOWS
END UP A BIT LOWER THAN FORECAST. HOWEVER...THE LIGHT WESTERLY
BREEZES SHOULD HELP HOLD THINGS UP A BIT VERSUS LAST NIGHT.
SATURDAY...THE MID/UPPER PATTERN REMAINS QUITE TRANQUIL...AS THE
HEART OF THE 700-500MB RIDGE BUILDS OVER THE PLAINS...WELL TO THE
EAST OF THE DEEP TROUGH AXIS OFF THE PACIFIC COAST...AND THE
PRIMARY 300MB JET AXIS SNAKING FROM NORTHERN CA THEN EASTWARD
ACROSS SOUTHERN CANADA. AS A SURFACE HIGH PRESSURE SYSTEM WORKS
INTO SOUTHERN CANADA INTO THE DAKOTAS...A VERY WEAK COLD FRONT
WILL PUSH SOUTHWARD TOWARD/INTO THE NORTHWEST CWA DURING THE
AFTERNOON. OTHERWISE...LIGHT SOUTHWEST BREEZES WILL PREVAIL ACROSS
MOST OF THE CWA FOR THE MAJORITY OF THE DAY. WITH FORECAST
SOUNDINGS A BIT DRIER IN THE BOUNDARY LAYER COMPARED TO
TODAY...NOT ANTICIPATING MUCH CUMULUS DEVELOPMENT...AND IN FACT
VERY LITTLE CLOUD COVER. TEMP WISE...GIVEN THE WIDESPREAD SUN AND
850MB TEMPS CLIMBING WELL INTO THE 14-17C RANGE...A NOTABLE JUMP
IN AFTERNOON HIGHS IN LIKELY. DIDN/T GET TOO CARRIED AWAY...BUT
NUDGED UP PREVIOUS FORECAST TOWARD HIGHER END OF MET/MAV GUIDANCE
CONSENSUS...WITH MOST OF THE CWA INTO THE 78-80 RANGE.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY. WE KICK THINGS OFF
SATURDAY NIGHT WITH A PROMINENT UPPER RIDGE OVER THE PLAINS AND A
HIGHLY AMPLIFIED TROUGH ON ENTERING THE WEST COAST OF THE UNITED
STATES. WEATHER SHOULD REMAIN DRY INTO SUNDAY THANKS TO BEING
UNDER THE INFLUENCE OF NOT ONLY THE UPPER LEVEL RIDGE BUT A
SURFACE RIDGE AS WELL. THERE WILL BE A SURFACE TROUGH DEVELOPING
IN THE LEE OF THE ROCKIES BY SUNDAY NIGHT WITH A HEALTHY FAIRLY
STRONG LOW-LEVEL JET INCREASING OVER PARTS OF WESTERN AND CENTRAL
KANSAS...WITH THE NOSE OF THE JET MAKING ITS WAY INTO SOUTHERN AND
CENTRAL PARTS OF THE CWA BY LATE SUNDAY NIGHT...WITH THE NAM A BIT
STRONGER HERE...INDICATING A 50 KT JET...AS OPPOSED TO NEAR 40 KTS
FOR THE GFS AND ECMWF. AT THIS POINT...THERE DOES NOT APPEAR TO BE
ENOUGH MOISTURE TO GET ANY CONVECTION GOING...BUT IF THERE
WERE...STRONG TO SEVERE THUNDERSTORMS WOULD CERTAINLY NOT BE OUT
OF THE QUESTION. CONFIDENCE IS NOT HIGH ENOUGH TO INTRODUCE
CHANCES OF RAIN AT THIS POINT.
A POTENT NEGATIVELY TILTED SHORTWAVE TROUGH WILL EJECT NORTHEAST OUT
OF THE CENTRAL ROCKIES MONDAY NIGHT AND HAS BEEN PROJECTED TO DO SO
FOR SOME TIME. THERE ARE SOME STRENGTH AND TIMING DIFFERENCES
BETWEEN MEDIUM TO LONG RANGE MODELS...BUT THE GENERAL SCENARIO IS
SIMILAR. THE ECMWF CONTINUES TO PROJECT A STRONGER WAVE THAT EJECTS
INTO THE PLAINS SOONER THAN THE GFS SOLUTION. SURFACE PRESSURE
GRADIENTS WILL INCREASE ALONG WITH INCREASED MIXING AND WE COULD BE
GETTING CLOSE TO WIND ADVISORY WITH HEALTHY WIND FROM THE
SOUTH...ESPECIALLY IN THE WESTERN CWA. MODELS GENERALLY PRODUCE THE
NOSE OF THE LOW-LEVEL JET WELL NORTH OF THE CWA...ALONG WITH THE
BEST MID TO UPPER LEVEL FORCING TO THE NORTH AS WELL. AT THE
SURFACE...BY MONDAY EVENING...THE DRY LINE SHOULD STILL BE WELL TO
THE WEST OF THE CWA...WHILE A WARM FRONT IS EXPECTED TO HAVE PASSED
TO THE NORTHEAST OF THE CWA BY THEN. SEVERE PARAMETERS SUGGEST
POSSIBLE SEVERE WEATHER NEAR THESE BOUNDARIES...BUT WE MAY WIGGLE
OUT OF MOST OF THE SEVERE WEATHER BY BEING BETWEEN THESE BOUNDARIES
WHILE SEVERE WEATHER INITIATES TOWARD EVENING...GIVEN THAT SOUNDINGS
SUGGEST WE WILL BE TOO CAPPED TO PRODUCED MUCH OF ANYTHING IN THE
REGION UNTIL LATE AFTERNOON AND QUITE LIKELY IN THE EVENING...AND
FOR THIS REASON...I HAVE ALL BUT PULLED CHANCES OF PRECIPITATION
FROM MONDAY AFTERNOON...SAVE PERHAPS THE FAR NORTHEASTERN CORNER OF
THE CWA IF THE WARM FRONT DOES NOT GET OUT OF THE CWA FAST
ENOUGH...AND HAVE LIMITED THAT SMALL AREA TO LATE
AFTERNOON...DESPITE THE FACT THAT THE LATEST ECMWF PAINTS SOME QPF
OVER THE NORTHWEST. THIS DOES NOT LOOK PROBABLE AS IT APPEARS THAT
THE WARM FRONT SHOULD CLEAR THE CWA BEFORE CONVECTION BEGINS AND
THERE IS NO OTHER FOCUS FOR CONVECTION IN THE AFTERNOON TO REALLY
GET THINGS GOING FROM WHAT IT LOOKS LIKE FOR NOW. THIS LOOKS LIKE A
SCENARIO WHERE WE MAY WIND UP GETTING SOME NOCTURNAL HIGH PLAINS
CONVECTION AS THE THETA E AXIS WILL MOVE FROM WEST TO EAST ACROSS
THE CWA BETWEEN 03Z AND 08Z TUESDAY (MONDAY EVENING)...BUT THIS MAY
BE MORE OF A WEAKER LEFTOVER EVENT...GIVING US ELEVATED
STRONGER/HEAVY RAINER STORMS...BUT PERHAPS NO LONGER SEVERE. I AM
NOT CONFIDENT ENOUGH TO PULL SEVERE POTENTIAL OUT OF THE HWO...AS
TIMING DIFFERENCES COULD MAKE A HUGE DIFFERENCE...AND BEING SO FAR
OUT IN THE FORECAST...IT WOULD BE PRUDENT TO KEEP SEVERE POTENTIAL
MENTIONED IN THE HWO.
AFTER THE WAVE PASSES MONDAY NIGHT...THERE WILL BE LITTLE MORE
CHANCE OF PRECIPITATION FOR A COUPLE OF DAYS WITH RIDGING TAKING
PLACE. TUESDAY COULD BE GETTING CLOSE TO RED FLAG POTENTIAL IN THE
FAR WESTERN CWA WITH RELATIVE HUMIDITY POSSIBLY GETTING NEAR 20
PERCENT AND WEST WINDS APPROACHING SUSTAINED 20 MPH. THE ECMWF
INDICATES A SMALL PERTURBATION RIDING THE RIDGE BY WEDNESDAY NIGHT
ALONG OUR SOUTHERN FRINGE WITH PERHAPS THE AID OF SOME CONVERGENCE
AT 850 MB...BUT EVEN WITH QPF ADVERTISED BY THE ECMWF...PROBABILITY
OF PRECIPITATION FOR RUSSEL AND CONCORDIA ARE AROUND 20
PERCENT...AND LOWER THAN THIS IN OUR CWA TO THE NORTH. FOR THE REST
OF THE EXTENDED...I LEFT LOW CHANCES OF PRECIPITATION AS FLOW COULD
CONTAIN POTENTIAL SMALL WAVES OF ENERGY...ALTHOUGH TEMPERATURES WILL
REMAIN WELL ABOVE NORMAL.
&&
.PREV DISCUSSION... /ISSUED 1237 PM CDT FRI MAR 23 2012/
AVIATION...18Z KGRI TAF. A VERY QUIET 24 HOURS ANTICIPATED
AVIATION WISE...WITH SURFACE BREEZES REMAINING LIGHT AND VARIABLE
THROUGH THIS EVENING AND THEN TRANSITIONING TO LIGHT AND
SOUTHWESTERLY INTO SATURDAY MORNING.
CLOUD WISE...COULD EASILY SEE A FEW HOURS OF SCATTERED CUMULUS
BASED IN THE 4000-5000 FT AGL RANGE THIS AFTERNOON...BUT THIS
SHOULD DISSIPATE BY SUNSET. ONLY MINOR CONCERN IS POSSIBILITY OF
LIGHT FOG DEVELOPMENT MAINLY A FEW HOURS EITHER SIDE OF SUNRISE
SATURDAY MORNING...BUT THE SETUP FOR WIDESPREAD FOG DOES NOT
APPEAR THAT FAVORABLE. CONFIDENCE IS LOW ENOUGH IN FOG FORMATION
TO LEAVE PREVAILING VISIBILITY VFR AT THIS TIME...BUT SUPPOSE A
BRIEF PERIOD OF MVFR IS NOT COMPLETELY OUT OF THE QUESTION.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/AVIATION...PFANNKUCH
LONG TERM...HEINLEIN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1237 PM CDT FRI MAR 23 2012
.UPDATE...MADE VERY LITTLE CHANGE TO AFTERNOON FORECAST...MAINLY
JUST THE USUAL MINOR TWEAKS TO WIND/SKY/DEWPOINT TRENDS. GAVE HIGH
TEMPS A VERY SLIGHT NUDGE UPWARD ACROSS MOST OF THE CWA...WITH A
BIT MORE COVERAGE OF READINGS AT/JUST ABOVE 70 ANTICIPATED BY MID
AFTERNOON. JUST STARTING TO SEE THE FIRST SIGNS OF SHALLOW
BOUNDARY LOWER CUMULUS DEVELOPMENT ACROSS MAINLY CENTRAL/SOUTHEAST
PORTIONS OF THE CWA...BUT ANTICIPATE MOST AREAS TO SEE NO MORE
THAN SCATTERED COVERAGE OF THESE CLOUDS...ALTHOUGH FAR SOUTHEAST
AREAS AROUND BELOIT/HEBRON COULD POTENTIALLY AVERAGE PARTLY TO
MOSTLY CLOUDY FOR AT LEAST A FEW HOURS WITH GREATER CUMULUS
DEVELOPMENT DOWN THAT WAY. LAST FEW HRRR RUNS HAVE ACTUALLY HINTED
AT SOME SPRINKLE POTENTIAL DOWN IN THESE SOUTHEAST AREAS THIS
AFTERNOON...BUT AT THIS POINT EXPECTING CUMULUS TO REMAIN SHALLOW
ENOUGH TO KEEP THIS AT BAY.
&&
.AVIATION...18Z KGRI TAF. A VERY QUIET 24 HOURS ANTICIPATED
AVIATION WISE...WITH SURFACE BREEZES REMAINING LIGHT AND VARIABLE
THROUGH THIS EVENING AND THEN TRANSITIONING TO LIGHT AND
SOUTHWESTERLY INTO SATURDAY MORNING.
CLOUD WISE...COULD EASILY SEE A FEW HOURS OF SCATTERED CUMULUS
BASED IN THE 4000-5000 FT AGL RANGE THIS AFTERNOON...BUT THIS
SHOULD DISSIPATE BY SUNSET. ONLY MINOR CONCERN IS POSSIBILITY OF
LIGHT FOG DEVELOPMENT MAINLY A FEW HOURS EITHER SIDE OF SUNRISE
SATURDAY MORNING...BUT THE SETUP FOR WIDESPREAD FOG DOES NOT
APPEAR THAT FAVORABLE. CONFIDENCE IS LOW ENOUGH IN FOG FORMATION
TO LEAVE PREVAILING VISIBILITY VFR AT THIS TIME...BUT SUPPOSE A
BRIEF PERIOD OF MVFR IS NOT COMPLETELY OUT OF THE QUESTION.
&&
.PREV DISCUSSION... /ISSUED 450 AM CDT FRI MAR 23 2012/
SHORT TERM...TODAY THROUGH 12Z MONDAY...A PLEASANT END OF THE
WEEK AND UPCOMING WEEKEND ARE IN STORE FOR THE LOCAL AREA AS AN
UPPER LEVEL RIDGE OF HIGH PRESSURE IS EXPECTED TO BUILD ACROSS THE
CENTRAL AND NORTHERN PLAINS BEHIND THE DEPARTING UPPER LEVEL LOW.
IN THE NEAR TERM...EXPECT A FEW LIGHT SHOWERS OR SPRINKLES TO
CONTINUE ACROSS THE EASTERN FRINGES OF THE FORECAST AREA THROUGH
THE EARLY MORNING HOURS...WITH LITTLE TO NO ADDITIONAL
ACCUMULATION EXPECTED. THIS FINAL BAND OF PRECIPITATION HAS BEEN
WEAKENING FOR THE PAST SEVERAL HOURS...AND IS EXPECTED TO
COMPLETELY DISSIPATE OVER THE NEXT HOUR OR TWO...WITH CLEARING
SKIES EXPECTED ACROSS THE LOCAL AREA BY MID MORNING. IN THE
MEANTIME...EXPECT PATCHY FOG DEVELOPMENT TO CONTINUE AHEAD OF
SUNRISE...AS LIGHT WINDS AND MOIST SOILS HAVE ALREADY RESULTED IN
SEVERAL OBSERVATION SITES TEMPORARILY FALLING TO BELOW 5 MILES
VISIBILITY THE PAST FEW HOURS. WHILE WIDESPREAD DENSE FOG IS NOT
EXPECTED...WOULD NOT BE SURPRISED TO SEE SOME PATCHY DENSE
FOG...ESPECIALLY IN LOW LYING AREAS...TOWARDS SUNRISE. THE GOOD
NEWS...HOWEVER...IS THAT ANY FOG THAT DOES DEVELOP IS EXPECTED TO
BE SHORT LIVED...WITH A BEAUTIFUL AFTERNOON EXPECTED ACROSS THE
REGION. WITH LIGHT WINDS...AMPLE SUNSHINE...AND REBOUNDING TEMPS
ALOFT...WENT AHEAD AND NUDGED UP AFTERNOON HIGHS A COUPLE OF
DEGREES...WITH MOST LOCATIONS EXPECTED TO TOP OUT NEAR 70
DEGREES...OR NEARLY 15 DEGREES ABOVE THE NORMAL HIGH FOR MID/LATE
MARCH.
WINDS WILL BEGIN TO SHIFT SOUTHERLY...ALBEIT REMAIN LIGHT ON
SATURDAY...AS THE SURFACE RIDGE OF HIGH PRESSURE ACROSS THE REGION
THIS MORNING CONTINUES TO PUSH FURTHER EAST. THIS SOUTHERLY WIND
COMPONENT WILL AID IN POTENTIAL MORNING FOG DEVELOPMENT THE NEXT
COUPLE OF MORNINGS...AND OPTED TO INCREASE COVERAGE OF PATCHY
MORNING FOG COVERAGE FOR THE UPCOMING WEEKEND. EVEN
SO...TEMPERATURES ALOFT WILL CONTINUE TO WARM...AND WITH AMPLE
SUNSHINE AND GOOD MIXING EXPECTED DURING THE AFTERNOON HOURS...
EXPECT HIGH TEMPERATURES TO TOP OUT NEAR 80 DEGREES BOTH
AFTERNOONS. WINDS ARE NOT EXPECTED TO BE AN ISSUE ON
SATURDAY...BUT DO INCREASE A BIT SUNDAY AFTERNOON IN RESPONSE TO A
TROUGH OF LOW PRESSURE BUILDING TO OUR WEST. EVEN SO...RELATIVE
HUMIDITIES APPEAR TO REMAIN HIGH ENOUGH THAT FIRE WEATHER
CONDITIONS DO NOT APPEAR TO BE A MAJOR CONCERN AT THIS POINT IN
TIME.
LONG TERM...12Z MONDAY THROUGH THURSDAY.
STARTING OFF THE LONG TERM...THE GFS AND THE ECMWF ARE IN FAIRLY
GOOD AGREEMENT MONDAY MORNING WITH THE POSITION OF AN UPPER LEVEL
TROUGH ACROSS QUEBEC AND THE EAST COAST...A RIDGE ACROSS THE CENTRAL
CONUS...AND A SECONDARY TROUGH AXIS STRETCHING FROM WASHINGTON TO
NEVADA. AT THE SURFACE...HIGH PRESSURE BUILDS ACROSS ONTARIO...WHILE
A LOW PRESSURE SYSTEM DEVELOPS ACROSS THE NORTHERN ROCKIES.
AS THE SURFACE LOW SLIDES NORTHEAST...A TIGHT PRESSURE GRADIENT WILL
FORM ACROSS THE PLAINS. WITH MODELS HINTING AT SUCH A TIGHT
GRADIENT...AND TO COLLABORATE WITH NEIGHBORING OFFICES...DECIDED TO
INCREASE WINDS ON MONDAY AFTERNOON TO JUST NEAR WIND ADVISORY
CRITERIA.
BY MONDAY NIGHT...THE SECONDARY TROUGH AXIS WILL BEGIN TO SLIDE INTO
THE REGION. THE LATEST RUN OF THE ECMWF HAS NOW COME INTO AGREEMENT
WITH THE GFS...POSITIONING THE CLOSED OFF 500 MB LOW OVER WESTERN
SOUTH DAKOTA BY MONDAY NIGHT. THUNDERSTORMS WILL REMAIN POSSIBLE
DURING THE AFTERNOON AND EVENING HOURS ON MONDAY AS AMPLE MOISTURE
AND MUCAPE VALUES NEAR 1500 TO 2000 J/KG REMAIN OVER THE FORECAST
AREA. POSITIONING OF THE DRY LINE WILL COME INTO QUESTION AS BOTH
THE GFS AND THE ECMWF KEEP THE DRY LINE TO THE WEST UNTIL AT LEAST
0Z. DECIDED TO GO WITH A MENTION OF THUNDERSTORMS DURING THE
AFTERNOON HOURS...BUT THE BULK OF THE PRECIPITATION LOOKS TO ARRIVE
DURING THE OVERNIGHT HOURS.
BY TUESDAY...UPPER LEVEL RIDGING WILL RETURN TO THE PLAINS...AND DRY
AIR WILL MOVE INTO THE REGION. FIRE WEATHER MIGHT BE A CONCERN ON
TUESDAY...DEPENDING ON THE LOCATION AND MAGNITUDE OF ANY
PRECIPITATION THAT FALLS MONDAY NIGHT. CURRENTLY...MODELS SOUNDINGS
INDICATE GOOD BOUNDARY LAYER MIXING DURING THE DAY ON TUESDAY TO AT
LEAST 850 MB...ALSO HELPING DRY THINGS OUT. WITH THIS
SOLUTION...DEWPOINTS NEED TO BE LOWERED BY AS MUCH AS 5 TO 10
DEGREES IN SOME LOCATIONS. FOR NOW DECIDED AGAINST LOWERING DEWPOINTS
BY THIS MUCH...AS IT REMAINS DAY 4 AND PRECIPITATION CHANCES ON
MONDAY WILL GREATLY AFFECT DEWPOINTS ON TUESDAY. HOWEVER...THAT
BEING SAID...SHOULD THE GFS SOLUTION VERIFY...RELATIVE HUMIDITY
VALUES ACROSS THE WESTERN PORTION OF THE CWA...WILL LIKELY BE WELL
BELOW 20 PERCENT.
TOWARDS THE END OF THE LONG TERM...BOTH THE GFS AND THE ECMWF
SUGGEST A MID LEVEL SHORT WAVE AND WEAK SURFACE LOW PRESSURE SYSTEM
WILL PUSH ACROSS CENTRAL PLAINS...CREATING A CHANCE FOR
PRECIPITATION THURSDAY NIGHT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE/AVIATION...PFANNKUCH
SHORT TERM...ROSSI
LONG TERM...SALTZMAN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1038 PM EDT SAT MAR 24 2012
.SYNOPSIS...
AN UPPER LEVEL LOW PASSING TO OUR SOUTH...WILL SPREAD SHOWERS
ACROSS THE REGION THIS EVENING AND CONTINUE THROUGH THE OVERNIGHT
PERIOD. SHOWERS WILL DIMINISH SUNDAY MORNING...BUT MOSTLY CLOUDY
SKIES WILL PERSIST. A COLD FRONT WILL PASS SUNDAY NIGHT...YIELDING
MUCH COOLER WEATHER FOR EARLY IN THE WORK WEEK...INCLUDING
TEMPERATURES WELL BELOW FREEZING AREA WIDE MONDAY NIGHT AND
TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
.1035 PM UPDATE...
AS WAS THE CASE BEFORE...LARGE SCALE DEFORMATION ZONE STILL
SPRAWLING OVER THE FORECAST REGION THIS EVENING. IN FACT...FEATURE
IS SHOWING UP BEAUTIFULLY IN BOTH IR AND WATER VAPOR SATELLITE
IMAGES AS A SHEARING AREA OF CLOUDS OVER UPSTATE NY. IN ANY
EVENT...THERE ARE TWO MAIN AREAS OF PRECIP WORTH WATCHING THIS
HOUR WITH THE FIRST RESIDING ACROSS THE NORTHERN CWA WHICH APPEARS
TO BE THE DIRECT RESULT OF THE PREVIOUSLY MENTIONED LOW/MID-LEVEL
DEFORMATION ZONE. THE NEXT AREA OF PRECIP IS BEGINNING TO WORK
NORTH FROM EASTERN PA/WESTERN NJ WHICH APPEARS TO BE IN RESPONSE
TO A STRENGTHENING LOW-LEVEL JET AHEAD OF THE SOUTHWARD SAGGING
CUTOFF LOW WHICH CONTINUES TO DIG SOUTHEAST TOWARDS THE
CAROLINAS. THE LOW LEVEL JET WAS NOTED ON BOTH THE KBGM AND KDIX
RADAR VAD WIND PROFILES AS 30-40 KTS MAXIMUMS CENTERED BETWEEN 3
AND 4 KFT RESPECTIVELY. DESPITE THE INTIMIDATING APPEARANCE ON
RADAR...ANY PRECIP ACROSS THE AREA CONTINUES TO BATTLE LOW-LEVEL
DRY AIR WITH THE LATEST AVP OBSERVATION SHOWING A DEWPOINT
DEPRESSION OF 30 DEGREES. WITH MODEL GUIDANCE CONTINUING TO
SUGGEST WIDESPREAD SHOWERS ACROSS THE AREA OVERNIGHT...CURRENT
OBSERVATION AND RADAR TRENDS SUPPORT DROPPING POPS INTO THE CHANCE
CATEGORY FOR THE NEXT FEW HRS AS MUCH OF THIS ACTIVITY IS NOT
HITTING THE GROUND. EXPECT PROSPECTS FOR RA TO INCREASE ACROSS THE
NORTHERN CWA OVERNIGHT AS DEFORMATION AXIS BEGINS TO PIVOT TOWARDS
THE SOUTHWEST IN ADVANCE OF EASTWARD ADVANCING SHORTWAVE
APPROACHING FROM WESTERN ONTARIO.
BASED ON LOW-LEVEL DRY AIR IN PLACE...HAVE ADDED DZ MENTION AREA
WIDE THROUGH THE REMAINDER OF THE OVERNIGHT HRS IN ADDITION TO THE RA
MENTION. HAVE ALSO HAD TO BUMP OVERNIGHT LOWS UP A FEW DEGREES AS
WARM THERMAL ADVECTION COMBINED WITH ABUNDANT CLOUD COVER IS
PREVENTING TEMPS FROM FALLING AS QUICKLY AS PREVIOUSLY FORECAST.
.7 PM UPDATE...
PRECIP HAVING A VERY DIFFICULT TIME MAINTAINING ITSELF THIS
EVENING AS LOW/MID-LEVEL DEFORMATION ESSENTIALLY SHEARS OUT ANYTHING
TRYING TO DEVELOP. LATEST WATER VAPOR IMAGES SHOW THIS SHEARING
ZONE QUITE WELL WITH RUC H70 STREAMLINES DEPICTING A WELL DEFINED
COL APPROACHING OUR AREA FROM THE NORTHWEST. IN
ADDITION...ANYTHING TRYING TO FALL IS STILL BATTLING LOW-LEVEL DRY
AIR WITH 20+ DEGREE DEW POINT DEPRESSIONS NOTED ACROSS PORTIONS OF
THE AREA. BASED ON LATEST RADAR TRENDS AND THE FACTS LISTED
ABOVE...WE HAVE NO CHOICE BUT TO DECREASE POPS FROM LIKELY TO
CHANCE FOR THE NEXT FEW HOURS AND THAT/S EVEN A STRETCH.
AS THE EVENING HOURS CONTINUE ON...SHOWER ACTIVITY OVER WESTERN
NY/SOUTHERN ONTARIO WILL BEGIN TO MOVE SOUTHEAST AS SHEAR AXIS
SINKS SOUTH IN ADVANCE OF APPROACHING COL/SHORTWAVE OVER WESTERN
ONTARIO. AS THIS OCCURS THOUGH...ONGOING PRECIP WILL AGAIN MOVE
INTO A DRIER AIRMASS WHICH WILL LIKELY CURTAIL ONGOING ACTIVITY TO
SOME DEGREE...AND LATEST HRRR SIMULATED REFLECTIVITY TRENDS
SUPPORT THIS LINE OF THINKING. ALL IN ALL...HAVE NOT MADE ANY
LARGE WHOLESALE CHANGES JUST YET AS WE/D LIKE TO CONTINUE TO
MONITOR RADAR/SATELLITE TRENDS BEFORE DOING SO. IN ANY
EVENT...THIS FEATURE IS TURING OUT TO BE A DUD FOR HOPEFUL/NEEDED
RAINFALL. WILL CONTINUE TO MONITOR.
.PREVIOUS NEAR TERM DISCUSSION...
AT 4 PM...LOCAL RADARS SHOW WIDESPREAD LIGHT SHOWERS ACROSS
NORTHERN/CENTRAL PENNSYLVANIA WITH SCATTERED ACTIVITY OVER CENTRAL
NEW YORK. H5 UPPER LEVEL LOW OVER TN WILL CONTINUE TO DROP
SOUTHEAST OVERNIGHT AND BE NEAR NORTH CAROLINA/SOUTH CAROLINA BY
MORNING. SO FAR THE SHOWERS HAVE HAD A DIFFICULT TIME MOVING NORTH
DUE TO LARGE TEMP/DEW POINT DEPRESSIONS. THIS EVENING LOW LEVELS
WILL CONTINUE TO SATURATE UNDER MOIST SOUTHEAST FLOW AND
INCREASING ISENTROPIC LIFT. EXPECT SHOWERS TO BECOME WIDESPREAD
THIS EVENING FROM SOUTH TO NORTH, INCREASED POPS TO LIKELY ALL
AREAS.
LOW TEMPS OVERNIGHT WILL RANGE FROM THE MID TO UPPER 40S.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...UPPER LEVEL FEATURE WILL CONTINUE DROPPING SOUTHEAST AND
RESIDE OFF THE SOUTH CAROLINA COAST BY AFTERNOON. MODELS INDICATE
A WEAK SFC REFLECTION WILL RESIDE OVER CENTRAL NEW YORK DURING THE
MORNING HOURS THEN LIFT EAST WITH A DRIER WESTERLY FLOW DEVELOPING
DURING THE AFTERNOON. WILL CONTINUE WITH LIKELY POPS FOR THE
MORNING HOURS ACROSS THE NRN/FAR EASTERN CWA WHERE BETTER
MOISTURE AND SFC CONVERGENCE MAY ENHANCE ACTIVITY. REST OF AREA
JUST CHC POPS WITH POPS OVERALL DECREASING RAPIDLY DURING THE
AFTERNOON UNDER NORTHWEST FLOW. SKIES WILL REMAIN MOSTLY CLOUDY
FOR MUCH OF THE AFTERNOON AS LOW LEVEL MOISTURE LINGERS. MAX TEMPS
WILL RANGE FROM THE UPPER 50S TO LOWER 60S.
SUNDAY NIGHT/MONDAY...H5 SHORT WAVE TROF WILL MOVE THROUGH EASTERN
CANADA DRAGGING A SIGNIFICANT COLD FRONT THROUGH THE REGION LATE
SUNDAY NIGHT. BOUNDARY IS MOISTURE STARVED SO NO PRECIP EXPECTED
WITH FROPA BUT A SIGNIFICANT CHANGE IN AIRMASS WILL OCCUR AS T85
PLUMMETS TO -10C BY 12Z MONDAY. ON MONDAY, SFC HIGH PRES NEAR JAMES
BAY WILL GRADUALLY BUILD SOUTH BRINGING MOSTLY SUNNY SKIES BUT
MAXES ONLY IN THE UPPER 30S TO MID 40S. MONDAY AFTERNOON, DUE TO
LOW LEVEL INSTABILITY AND STRONG PRES GRADIENT GUSTY WINDS ARE
EXPECTED WITH GUSTS AROUND 40 MPH POSSIBLE IN THE HIGHER TERRAIN
OF THE WESTERN CATSKILLS.
MONDAY NIGHT/TUESDAY...MONDAY NIGHT, HIGH PRES WILL BUILD SOUTH
OVER THE REGION RESULTING IN MAINLY CLEAR SKIES AND DIMINISHING
WINDS. TEMPS WILL DROP INTO THE MIDDLE TEENS TO THE LOWERS 20S.
LAKE RESPONSE NOT EXPECTED DUE TO SHORT FETCH AND EXTREMELY DRY
AIRMASS. ON TUESDAY THE SFC HIGH WILL BE OVER CENTRAL NY WITH
LIGHT WINDS AND MOSTLY SUNNY SKIES. MAXES WILL RANGE IN THE MID TO
UPPER 40S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
3 PM SAT UPDATE... ON THE LARGE-SCALE...THE PATN ACROSS NORTH
AMERICA THIS PD WILL FEATURE AN ERN PACIFIC TROUGH...FRONT
RANGE/CNTRL CONUS RIDGE...AND A CANADIAN MARITIME/WRN ATLANTIC
TROUGH AXIS. THIS WILL KEEP NY/PA WITHIN A W TO NW FLOW PATN
ALOFT...FEATURING NEAR NORMAL TEMPS FOR LATE MAR (HIGHS MOSTLY IN
THE 40S AND 50S)...AND FRNTL PASSAGES/SHOWERY PDS ABT EVERY 2-3
DAYS...WITH GENERALLY DRY CONDS OTHERWISE.
SENSIBLE WX-WISE...AN APPROACHING FRNTL COMPLEX WILL BRING OUR FIRST
EPISODE OF -SHRA LATE TUE NGT AND WED (MAYBE EVEN A BIT OF
-SHSN/--SHSN AT THE START). THIS SYSTEM WILL MOVE OFF TO THE E BY
LATE WED NGT/EARLY THU...WITH MAINLY DRY WX ANTICIPATED FOR THE
SECOND HALF OF THE WORK WEEK (THU AND FRI). NEXT WEEKEND...ANOTHER
UPR-LVL DISTURBANCE/WARM FRNTL BNDRY IN THE LWR LVLS WILL BRING IN
THE POTENTIAL FOR -SHRA.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
7 PM SAT UPDATE... VFR CONDS AREA-WIDE THIS EVE...COULD
DETERIORATE A BIT INTO THE MVFR CAT AFTER 06Z...IN --SHRA/LWR
CIGS...SPCLY AT KELM/KAVP/KBGM. THAT BEING SAID...ALMOST ALL
AVAILABLE CIG/VSBY GUIDANCE IS MUCH LWR DURING THE
NGT...INDICATING THE POTENTIAL FOR IFR. HOWEVER...GIVEN THE AMT OF
DRY AIR IN THE BLYR THAT STILL HAS TO BE OVERCOME...AND ALSO THE
FACT THAT THE BEST FORCING MECHANISMS TO GENERATE LGT RAIN ARE
PROGGED TO TRACK MOSTLY S OF OUR FCST AREA LTR TNT AND EARLY
SUN...WE FEEL THE GUIDANCE IS TOO PESSIMISTIC. DEFINITELY A LOW
CONFIDENCE FCST...THOUGH. KSYR AND KRME SEEM THE MOST PROBABLE
SITES TO REMAIN VFR.
CONDS SHOULD SLOWLY IMPROVE DURING THE DAY SUN...AS A WEAKENING
COLD FRNT PUSHES SEWD THROUGH THE RGN...AND DRIER AIR FILTERS IN
FROM THE NW.
LGT WINDS IN THE DEEPER VLYS (KELM/KAVP)...AND E TO SE WINDS 5-10
KT ELSEWHERE DURG THE NGT AND EARLY SUN...SHOULD SHIFT INTO THE W
AND NW BY MIDDAY.
.OUTLOOK...
SUN NGT TO TUE NGT...VFR. MAYBE MVFR CIGS AT KSYR KITH KELM MONDAY...
DUE TO LAKE EFFECT MOISTURE AND NNW FLOW.
WED TO THU...MVFR IN SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RRM
NEAR TERM...CMG/RRM
SHORT TERM...RRM
LONG TERM...MLJ
AVIATION...MLJ/TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
750 PM EDT SAT MAR 24 2012
.SYNOPSIS...
AN UPPER LEVEL LOW PASSING TO OUR SOUTH...WILL SPREAD SHOWERS
ACROSS THE REGION THIS EVENING AND CONTINUE THROUGH THE OVERNIGHT
PERIOD. SHOWERS WILL DIMINISH SUNDAY MORNING...BUT MOSTLY CLOUDY
SKIES WILL PERSIST. A COLD FRONT WILL PASS SUNDAY NIGHT...YIELDING
MUCH COOLER WEATHER FOR EARLY IN THE WORK WEEK...INCLUDING
TEMPERATURES WELL BELOW FREEZING AREA WIDE MONDAY NIGHT AND
TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
.7 PM UPDATE...
PRECIP HAVING A VERY DIFFICULT TIME MAINTAINING ITSELF THIS
EVENING AS LOW/MID-LEVEL DEFORMATION ESSENTIALLY SHEARS OUT ANYTHING
TRYING TO DEVELOP. LATEST WATER VAPOR IMAGES SHOW THIS SHEARING
ZONE QUITE WELL WITH RUC H70 STREAMLINES DEPICTING A WELL DEFINED
COL APPROACHING OUR AREA FROM THE NORTHWEST. IN
ADDITION...ANYTHING TRYING TO FALL IS STILL BATTLING LOW-LEVEL DRY
AIR WITH 20+ DEGREE DEW POINT DEPRESSIONS NOTED ACROSS PORTIONS OF
THE AREA. BASED ON LATEST RADAR TRENDS AND THE FACTS LISTED
ABOVE...WE HAVE NO CHOICE BUT TO DECREASE POPS FROM LIKELY TO
CHANCE FOR THE NEXT FEW HOURS AND THAT/S EVEN A STRETCH.
AS THE EVENING HOURS CONTINUE ON...SHOWER ACTIVITY OVER WESTERN
NY/SOUTHERN ONTARIO WILL BEGIN TO MOVE SOUTHEAST AS SHEAR AXIS
SINKS SOUTH IN ADVANCE OF APPROACHING COL/SHORTWAVE OVER WESTERN
ONTARIO. AS THIS OCCURS THOUGH...ONGOING PRECIP WILL AGAIN MOVE
INTO A DRIER AIRMASS WHICH WILL LIKELY CURTAIL ONGOING ACTIVITY TO
SOME DEGREE...AND LATEST HRRR SIMULATED REFLECTIVITY TRENDS
SUPPORT THIS LINE OF THINKING. ALL IN ALL...HAVE NOT MADE ANY
LARGE WHOLESALE CHANGES JUST YET AS WE/D LIKE TO CONTINUE TO
MONITOR RADAR/SATELLITE TRENDS BEFORE DOING SO. IN ANY
EVENT...THIS FEATURE IS TURING OUT TO BE A DUD FOR HOPEFUL/NEEDED
RAINFALL. WILL CONTINUE TO MONITOR.
.PREVIOUS NEAR TERM DISCUSSION...
AT 4 PM...LOCAL RADARS SHOW WIDESPREAD LIGHT SHOWERS ACROSS
NORTHERN/CENTRAL PENNSYLVANIA WITH SCATTERED ACTIVITY OVER CENTRAL
NEW YORK. H5 UPPER LEVEL LOW OVER TN WILL CONTINUE TO DROP
SOUTHEAST OVERNIGHT AND BE NEAR NORTH CAROLINA/SOUTH CAROLINA BY
MORNING. SO FAR THE SHOWERS HAVE HAD A DIFFICULT TIME MOVING NORTH
DUE TO LARGE TEMP/DEW POINT DEPRESSIONS. THIS EVENING LOW LEVELS
WILL CONTINUE TO SATURATE UNDER MOIST SOUTHEAST FLOW AND
INCREASING ISENTROPIC LIFT. EXPECT SHOWERS TO BECOME WIDESPREAD
THIS EVENING FROM SOUTH TO NORTH, INCREASED POPS TO LIKELY ALL
AREAS.
LOW TEMPS OVERNIGHT WILL RANGE FROM THE MID TO UPPER 40S.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...UPPER LEVEL FEATURE WILL CONTINUE DROPPING SOUTHEAST AND
RESIDE OFF THE SOUTH CAROLINA COAST BY AFTERNOON. MODELS INDICATE
A WEAK SFC REFLECTION WILL RESIDE OVER CENTRAL NEW YORK DURING THE
MORNING HOURS THEN LIFT EAST WITH A DRIER WESTERLY FLOW DEVELOPING
DURING THE AFTERNOON. WILL CONTINUE WITH LIKELY POPS FOR THE
MORNING HOURS ACROSS THE NRN/FAR EASTERN CWA WHERE BETTER
MOISTURE AND SFC CONVERGENCE MAY ENHANCE ACTIVITY. REST OF AREA
JUST CHC POPS WITH POPS OVERALL DECREASING RAPIDLY DURING THE
AFTERNOON UNDER NORTHWEST FLOW. SKIES WILL REMAIN MOSTLY CLOUDY
FOR MUCH OF THE AFTERNOON AS LOW LEVEL MOISTURE LINGERS. MAX TEMPS
WILL RANGE FROM THE UPPER 50S TO LOWER 60S.
SUNDAY NIGHT/MONDAY...H5 SHORT WAVE TROF WILL MOVE THROUGH EASTERN
CANADA DRAGGING A SIGNIFICANT COLD FRONT THROUGH THE REGION LATE
SUNDAY NIGHT. BOUNDARY IS MOISTURE STARVED SO NO PRECIP EXPECTED
WITH FROPA BUT A SIGNIFICANT CHANGE IN AIRMASS WILL OCCUR AS T85
PLUMMETS TO -10C BY 12Z MONDAY. ON MONDAY, SFC HIGH PRES NEAR JAMES
BAY WILL GRADUALLY BUILD SOUTH BRINGING MOSTLY SUNNY SKIES BUT
MAXES ONLY IN THE UPPER 30S TO MID 40S. MONDAY AFTERNOON, DUE TO
LOW LEVEL INSTABILITY AND STRONG PRES GRADIENT GUSTY WINDS ARE
EXPECTED WITH GUSTS AROUND 40 MPH POSSIBLE IN THE HIGHER TERRAIN
OF THE WESTERN CATSKILLS.
MONDAY NIGHT/TUESDAY...MONDAY NIGHT, HIGH PRES WILL BUILD SOUTH
OVER THE REGION RESULTING IN MAINLY CLEAR SKIES AND DIMINISHING
WINDS. TEMPS WILL DROP INTO THE MIDDLE TEENS TO THE LOWERS 20S.
LAKE RESPONSE NOT EXPECTED DUE TO SHORT FETCH AND EXTREMELY DRY
AIRMASS. ON TUESDAY THE SFC HIGH WILL BE OVER CENTRAL NY WITH
LIGHT WINDS AND MOSTLY SUNNY SKIES. MAXES WILL RANGE IN THE MID TO
UPPER 40S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
3 PM SAT UPDATE... ON THE LARGE-SCALE...THE PATN ACROSS NORTH
AMERICA THIS PD WILL FEATURE AN ERN PACIFIC TROUGH...FRONT
RANGE/CNTRL CONUS RIDGE...AND A CANADIAN MARITIME/WRN ATLANTIC
TROUGH AXIS. THIS WILL KEEP NY/PA WITHIN A W TO NW FLOW PATN
ALOFT...FEATURING NEAR NORMAL TEMPS FOR LATE MAR (HIGHS MOSTLY IN
THE 40S AND 50S)...AND FRNTL PASSAGES/SHOWERY PDS ABT EVERY 2-3
DAYS...WITH GENERALLY DRY CONDS OTHERWISE.
SENSIBLE WX-WISE...AN APPROACHING FRNTL COMPLEX WILL BRING OUR FIRST
EPISODE OF -SHRA LATE TUE NGT AND WED (MAYBE EVEN A BIT OF
-SHSN/--SHSN AT THE START). THIS SYSTEM WILL MOVE OFF TO THE E BY
LATE WED NGT/EARLY THU...WITH MAINLY DRY WX ANTICIPATED FOR THE
SECOND HALF OF THE WORK WEEK (THU AND FRI). NEXT WEEKEND...ANOTHER
UPR-LVL DISTURBANCE/WARM FRNTL BNDRY IN THE LWR LVLS WILL BRING IN
THE POTENTIAL FOR -SHRA.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
7 PM SAT UPDATE... VFR CONDS AREA-WIDE THIS EVE...COULD
DETERIORATE A BIT INTO THE MVFR CAT AFTER 06Z...IN --SHRA/LWR
CIGS...SPCLY AT KELM/KAVP/KBGM. THAT BEING SAID...ALMOST ALL
AVAILABLE CIG/VSBY GUIDANCE IS MUCH LWR DURING THE
NGT...INDICATING THE POTENTIAL FOR IFR. HOWEVER...GIVEN THE AMT OF
DRY AIR IN THE BLYR THAT STILL HAS TO BE OVERCOME...AND ALSO THE
FACT THAT THE BEST FORCING MECHANISMS TO GENERATE LGT RAIN ARE
PROGGED TO TRACK MOSTLY S OF OUR FCST AREA LTR TNT AND EARLY
SUN...WE FEEL THE GUIDANCE IS TOO PESSIMISTIC. DEFINITELY A LOW
CONFIDENCE FCST...THOUGH. KSYR AND KRME SEEM THE MOST PROBABLE
SITES TO REMAIN VFR.
CONDS SHOULD SLOWLY IMPROVE DURING THE DAY SUN...AS A WEAKENING
COLD FRNT PUSHES SEWD THROUGH THE RGN...AND DRIER AIR FILTERS IN
FROM THE NW.
LGT WINDS IN THE DEEPER VLYS (KELM/KAVP)...AND E TO SE WINDS 5-10
KT ELSEWHERE DURG THE NGT AND EARLY SUN...SHOULD SHIFT INTO THE W
AND NW BY MIDDAY.
.OUTLOOK...
SUN NGT TO TUE NGT...VFR. MAYBE MVFR CIGS AT KSYR KITH KELM MONDAY...
DUE TO LAKE EFFECT MOISTURE AND NNW FLOW.
WED TO THU...MVFR IN SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RRM
NEAR TERM...CMG/RRM
SHORT TERM...RRM
LONG TERM...MLJ
AVIATION...MLJ/TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
729 PM EDT SAT MAR 24 2012
.SYNOPSIS...
AN UPPER LEVEL LOW PASSING TO OUR SOUTH...WILL SPREAD SHOWERS
ACROSS THE REGION THIS EVENING AND CONTINUE THROUGH THE OVERNIGHT
PERIOD. SHOWERS WILL DIMINISH SUNDAY MORNING...BUT MOSTLY CLOUDY
SKIES WILL PERSIST. A COLD FRONT WILL PASS SUNDAY NIGHT...YIELDING
MUCH COOLER WEATHER FOR EARLY IN THE WORK WEEK...INCLUDING
TEMPERATURES WELL BELOW FREEZING AREA WIDE MONDAY NIGHT AND
TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
.7 PM UPDATE...
PRECIP HAVING A VERY DIFFICULT TIME MAINTAINING ITSELF THIS
EVENING AS LOW/MID-LEVEL DEFORMATION ESSENTIALLY SHEARS OUT ANYTHING
TRYING TO DEVELOP. LATEST WATER VAPOR IMAGES SHOW THIS SHEARING
ZONE QUITE WELL WITH RUC H70 STREAMLINES DEPICTING A WELL DEFINED
COL APPROACHING OUR AREA FROM THE NORTHWEST. IN
ADDITION...ANYTHING TRYING TO FALL IS STILL BATTLING LOW-LEVEL DRY
AIR WITH 20+ DEGREE DEWPOINT DEPRESSIONS NOTED ACROSS PORTIONS OF
THE AREA. BASED ON LATEST RADAR TRENDS AND THE FACTS LISTED
ABOVE...WE HAVE NO CHOICE BUT TO DECREASE POPS FROM LIKELY TO
CHANCE FOR THE NEXT FEW HOURS AND THAT/S EVEN A STRETCH.
AS THE EVENING HOURS CONTINUE ON...SHOWER ACTIVITY OVER WESTERN
NY/SOUTHERN ONTARIO WILL BEGIN TO MOVE SOUTHEAST AS SHEAR AXIS
SINKS SOUTH IN ADVANCE OF APPROACHING COL/SHORTWAVE OVER WESTERN
ONTARIO. AS THIS OCCURS THOUGH...ONGOING PRECIP WILL AGAIN MOVE
INTO A DRIER AIRMASS WHICH WILL LIKELY CURTAIL ONGOING ACTIVITY TO
SOME DEGREE...AND LATEST HRRR SIMULATED REFLECTIVITY TRENDS
SUPPORT THIS LINE OF THINKING. ALL IN ALL...HAVE NOT MADE ANY
LARGE WHOLESALE CHANGES JUST YET AS WE/D LIKE TO CONTINUE TO
MONITOR RADAR/SATELLITE TRENDS BEFORE DOING SO. IN ANY
EVENT...THIS FEATURE IS TURING OUT TO BE A DUD FOR HOPEFUL/NEEDED
RAINFALL. WILL CONTINUE TO MONITOR.
.PREVIOUS NEAR TERM DISCUSSION...
AT 4 PM...LOCAL RADARS SHOW WIDESPREAD LIGHT SHOWERS ACROSS
NORTHERN/CENTRAL PENNSYLVANIA WITH SCATTERED ACTIVITY OVER CENTRAL
NEW YORK. H5 UPPER LEVEL LOW OVER TN WILL CONTINUE TO DROP
SOUTHEAST OVERNIGHT AND BE NEAR NORTH CAROLINA/SOUTH CAROLINA BY
MORNING. SO FAR THE SHOWERS HAVE HAD A DIFFICULT TIME MOVING NORTH
DUE TO LARGE TEMP/DEW POINT DEPRESSIONS. THIS EVENING LOW LEVELS
WILL CONTINUE TO SATURATE UNDER MOIST SOUTHEAST FLOW AND
INCREASING ISENTROPIC LIFT. EXPECT SHOWERS TO BECOME WIDESPREAD
THIS EVENING FROM SOUTH TO NORTH, INCREASED POPS TO LIKELY ALL
AREAS.
LOW TEMPS OVERNIGHT WILL RANGE FROM THE MID TO UPPER 40S.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...UPPER LEVEL FEATURE WILL CONTINUE DROPPING SOUTHEAST AND
RESIDE OFF THE SOUTH CAROLINA COAST BY AFTERNOON. MODELS INDICATE
A WEAK SFC REFLECTION WILL RESIDE OVER CENTRAL NEW YORK DURING THE
MORNING HOURS THEN LIFT EAST WITH A DRIER WESTERLY FLOW DEVELOPING
DURING THE AFTERNOON. WILL CONTINUE WITH LIKELY POPS FOR THE
MORNING HOURS ACROSS THE NRN/FAR EASTERN CWA WHERE BETTER
MOISTURE AND SFC CONVERGENCE MAY ENHANCE ACTIVITY. REST OF AREA
JUST CHC POPS WITH POPS OVERALL DECREASING RAPIDLY DURING THE
AFTERNOON UNDER NORTHWEST FLOW. SKIES WILL REMAIN MOSTLY CLOUDY
FOR MUCH OF THE AFTERNOON AS LOW LEVEL MOISTURE LINGERS. MAX TEMPS
WILL RANGE FROM THE UPPER 50S TO LOWER 60S.
SUNDAY NIGHT/MONDAY...H5 SHORT WAVE TROF WILL MOVE THROUGH EASTERN
CANADA DRAGGING A SIGNIFICANT COLD FRONT THROUGH THE REGION LATE
SUNDAY NIGHT. BOUNDARY IS MOISTURE STARVED SO NO PRECIP EXPECTED
WITH FROPA BUT A SIGNIFICANT CHANGE IN AIRMASS WILL OCCUR AS T85
PLUMMETS TO -10C BY 12Z MONDAY. ON MONDAY, SFC HIGH PRES NEAR JAMES
BAY WILL GRADUALLY BUILD SOUTH BRINGING MOSTLY SUNNY SKIES BUT
MAXES ONLY IN THE UPPER 30S TO MID 40S. MONDAY AFTERNOON, DUE TO
LOW LEVEL INSTABILITY AND STRONG PRES GRADIENT GUSTY WINDS ARE
EXPECTED WITH GUSTS AROUND 40 MPH POSSIBLE IN THE HIGHER TERRAIN
OF THE WESTERN CATSKILLS.
MONDAY NIGHT/TUESDAY...MONDAY NIGHT, HIGH PRES WILL BUILD SOUTH
OVER THE REGION RESULTING IN MAINLY CLEAR SKIES AND DIMINISHING
WINDS. TEMPS WILL DROP INTO THE MIDDLE TEENS TO THE LOWERS 20S.
LAKE RESPONSE NOT EXPECTED DUE TO SHORT FETCH AND EXTREMELY DRY
AIRMASS. ON TUESDAY THE SFC HIGH WILL BE OVER CENTRAL NY WITH
LIGHT WINDS AND MOSTLY SUNNY SKIES. MAXES WILL RANGE IN THE MID TO
UPPER 40S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
3 PM SAT UPDATE... ON THE LARGE-SCALE...THE PATN ACROSS NORTH
AMERICA THIS PD WILL FEATURE AN ERN PACIFIC TROUGH...FRONT
RANGE/CNTRL CONUS RIDGE...AND A CANADIAN MARITIME/WRN ATLANTIC
TROUGH AXIS. THIS WILL KEEP NY/PA WITHIN A W TO NW FLOW PATN
ALOFT...FEATURING NEAR NORMAL TEMPS FOR LATE MAR (HIGHS MOSTLY IN
THE 40S AND 50S)...AND FRNTL PASSAGES/SHOWERY PDS ABT EVERY 2-3
DAYS...WITH GENERALLY DRY CONDS OTHERWISE.
SENSIBLE WX-WISE...AN APPROACHING FRNTL COMPLEX WILL BRING OUR FIRST
EPISODE OF -SHRA LATE TUE NGT AND WED (MAYBE EVEN A BIT OF
-SHSN/--SHSN AT THE START). THIS SYSTEM WILL MOVE OFF TO THE E BY
LATE WED NGT/EARLY THU...WITH MAINLY DRY WX ANTICIPATED FOR THE
SECOND HALF OF THE WORK WEEK (THU AND FRI). NEXT WEEKEND...ANOTHER
UPR-LVL DISTURBANCE/WARM FRNTL BNDRY IN THE LWR LVLS WILL BRING IN
THE POTENTIAL FOR -SHRA.
&&
.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
130 PM UPDATE...
VFR CONDITIONS ARE EXPECTED TODAY INTO THIS EVENING THEN FALLING
TO MVFR. MVFR LAST TO AT LEAST MIDDAY SUNDAY. ISOLATED TO
SCATTERED FOR THE MOST PART NOW, BUT TWO BANDS OF STEADIER SHOWERS
NOW TO KAVP AND MOVING NE INTO THE REST OF THE SITES THIS AFTN.
WITH THE STEADY SHOWERS LATE AFTN AND EVENING CIGS AND VSBYS WILL
FALL TO MVFR FROM SW TO NE BETWEEN 3 AND 6Z. CONDITIONS WORSEN
FURTHER LATE TONIGHT. MODEL GUIDANCE HAS IFR VSBYS AND CIGS LATE
TONIGHT BUT HAVE HEDGED HIGHER. MODEL GUIDANCE IS TYPICALLY ON THE
LOW SIDE. CONFIDENCE LOW. UNDER STEADIEST SHOWERS THEN JUST AHEAD
OF SLOW MOVING OCCLUDED FRONT SO THIS MAY HAVE TO BE ADJUSTED
DOWN. SLOW RECOVERY LATE MORNING AS SHOWERS MOVE OUT TO THE NE AND
FRONT GOES THROUGH. CIGS WILL RISE BUT THINK IT WILL REMAIN MVFR.
VSBYS SHOULD RISE TO VFR EXCEPT AT ITH BECAUSE OF THE LAKE.
EAST TO SE WINDS AT 5 TO 10 KTS THIS AFTN. TONIGHT WINDS DROP TO 5
KTS. LATE SUNDAY MORNING WINDS SHIFT TO WEST TO NW AT 5 TO 8 KTS.
.OUTLOOK...
SUN AFTN...MVFR CONDITIONS CONTINUING.
SUN NGT TO TUE NGT...VFR. MAYBE MVFR CIGS AT SYR ITH ELM MONDAY
DUE TO LAKE EFFECT MOISTURE AND NNW FLOW.
WED TO THU...MVFR IN SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RRM
NEAR TERM...CMG/RRM
SHORT TERM...RRM
LONG TERM...MLJ
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1045 PM EDT SAT MAR 24 2012
.SYNOPSIS...
A STRONG UPPER LEVEL LOW WILL MOVE ACROSS THE SOUTHERN APPALACHIANS
TONIGHT AND OFF THE CAROLINA COAST SUNDAY NIGHT. A RIDGE OF HIGH
PRESSURE ALOFT WILL BUILD INTO THE REGION ON TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
AS OF 1045 PM SATURDAY...
RECENT SFC ANALYSIS SHOWS A LOW PRESSURE SYSTEM CENTERED OVER THE
FOOTHILLS NEAR HICKORY. CONVECTION EARLIER THIS EVENING HAS LARGELY
WEAKENED AND SHIFTED NORTHEAST INTO VA. STABLE OUTFLOW FROM THE
LARGE LINEAR CONVECTIVE COMPLEX HAS OVERSPREAD NEARLY ALL OF THE
PIEDMONT AND INTO THE NORTHERN COASTAL PLAIN. LATEST MESOANALYSIS
AND RUC PROXIMITY SOUNDINGS INDICATE THE BOUNDARY LAYER HAS
STABILIZED BUT ELEVATED INSTABILITY WITH MUCAPE VALUES OF ~500 J/KG
REMAIN. WITH 0-6KM BULK SHEAR VALUES OF 30-40KTS...ELEVATED
ORGANIZED CONVECTION IS POSSIBLE OVERNIGHT. EXPECT THE CONVECTIVE
COVERAGE TO BE SOMEWHAT LIMITED BUT WILL MAINTAIN SLIGHT CHANCE AND
CHANCE POPS FOR THE OVERNIGHT. WITH THIS IN MIND...WILL CLEAR THE
TORNADO WATCH FOR ALL LOCATIONS WHILE ACKNOWLEDGING THAT A STRONGER
STORM WHILE NOT ROOTED IN THE BOUNDARY LAYER COULD STILL PRODUCE
SOME HAIL...WITH THE WIND THREAT AND ESPECIALLY THE TORNADO THREAT
MINIMAL.
THE SURFACE LOW IS EXPECTED TO SHIFT SLOWLY EAST OVERNIGHT AND BE
CENTERED NEAR KFAY BY DAYBREAK SUNDAY. HAVE ADJUSTED WIND FORECAST
OVERNIGHT ACCORDINGLY. LOWS OVERNIGHT WILL RANGE FROM THE LOWER 50S
IN THE WEST/NW PIEDMONT TO THE UPPER 50S IN THE COASTAL PLAIN. -BLAES
FOR SUNDAY AND SUNDAY NIGHT...IF THERE IS A LULL IN SHOWER ACTIVITY
SUNDAY MORNING...INSTABILITY SHOWERS AND THUNDERSTORMS ARE EXPECTED
TO RE-DEVELOP SUNDAY AFTERNOON UNDERNEATH THE -20 TO 21C H5 COLD
CORE...ESPECIALLY IN THE WARM SECTOR EAST OF THE SFC COLD FRONT
WHERE STRONGER HEATING WITHIN THE LINGERING LOW-LEVEL MOISTURE
TONGUE SHOULD SUPPORT MARGINAL INSTABILITY BETWEEN 500 TO 1000 J/KG
OF MUCAPE. HOWEVER...VERY WEAK FLOW BENEATH THE UPPER-LEVEL LOW WILL
FAVOR PULSE AS THE MAIN CONVECTIVE MODE WITH THE WIND DAMAGE AND
HAIL THREATS LIKELY REMAINING MARGINAL.
WILL CONTINUE TO MENTION THE THREAT OF SMALL TO MARGINALLY
SEVERE HAIL FOR SUNDAY IN THE HWO.
HIGHS SUNDAY AFTERNOON RANGING FROM LOWER 70S NW TO MID/UPPER 70S IN
THE EAST. LOWS SUNDAY NIGHT WILL DEPEND ON THE TIMING OF THE SYSTEM
EXITING...WITH DRIER AIR/CLEARING FILTERING INTO THE WESTERN
PIEDMONT AOA DAYBREAK. LOWS RANGING FROM LOWER TO MID 50S NORTHWEST
TO MID/UPPER 50S SOUTHEAST.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SATURDAY...
ON MONDAY THE UPPER LEVEL LOW WILL EXIT OFF THE ATLANTIC COAST AND
AN H500 RIDGE WILL MOVE EAST TO TAKE ITS PLACE. AT THE SURFACE THE
PARENT HIGH WILL MOVE INTO WESTERN ONTARIO. LOW LEVEL FLOW WILL BE
OUT OF THE NORTH ON MONDAY AND CONDITIONS MAY BECOME GUSTY BY
AFTERNOON IN A WELL MIXED LAYER...15-20 KNOTS. THE ONSET OF COLD AIR
ADVECTION WILL BE GENERALLY WEAK DURING THE AFTERNOON BUT WILL
INCREASE OVERNIGHT. THIS WILL LEAVE ONE MORE DAY OF HIGH
TEMPERATURES CLOSE TO 80 DEGREES. WITH DEWPOINTS RUNNING IN THE
40S...DRY AND PLEASANT CONDITIONS WILL PREVAIL THROUGHOUT THE DAY.
HIGHS NEAR 80 WITH LOWS TUESDAY MORNING IN THE MID 40S.
STRONGER COLD AIR ADVECTION WILL BEGIN OVERNIGHT MONDAY AND EARLY
TUESDAY MORNING AS THE UPPER LEVEL FLOW TURNS NORTHWESTERLY. THE DAY
WILL ONCE AGAIN BE DRY AS HIGH PRESSURE MOVES OVER THE REGION WITH
LIGHT EASTERLY WINDS AT THE SURFACE. HIGHS WILL BE ON THE ORDER OF
15 DEGREES COOLER THAN MONDAY AS THICKNESSES DROP 40-50 METERS.
HIGHS IN THE MID 60S...LOWS IN THE UPPER 40S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 300 PM SATURDAY...
ON WEDNESDAY THE SURFACE HIGH MOVES OFF THE CAROLINA COAST. A
SURFACE LOW WILL TRACK OVER THE GREAT LAKES WITH ITS ASSOCIATED
SHORTWAVE TROUGH. EXPECT SOUTHWESTERLY FLOW ON WEDNESDAY AS CENTRAL
NC WILL BE STUCK BETWEEN THE DEPARTING HIGH AND THE APPROACHING LOW.
ANY PRECIPITATION WITH THE FRONT SHOULD STAY WELL NORTH OF THE AREA
ON WEDNESDAY...KEEPING CONDITIONS WARM AND DRY. HIGH TEMPERATURES
WILL RECOVER ABOUT 10 DEGREES FROM TUESDAY AND MOISTURE ADVECTION
WILL BEGIN FROM THE SOUTH AS DEWPOINTS WILL RISE INTO THE 50S BY THE
END OF THE DAY. HIGHS MID TO UPPER 70S WITH LOWS THURSDAY MORNING IN
THE LOWER 50S.
THURSDAY IS THE MOST UNCERTAIN DAY IN THE LONG TERM WITH REGARDS TO
WHETHER OR NOT THE FRONT DROPPING DOWN FROM THE NORTH WILL FOR ONE
MAKE IT COMPLETELY THROUGH THE CWA...AND TWO IF IT WILL BRING
PRECIPITATION OR NOT. AT CURRENT TIME THE ECMWF BRINGS IT THROUGH AS
A DRY FRONT BY 12Z THURSDAY...WHILE THE GFS IS A LITTLE BIT MORE
ROBUST BRINGING SOME SHOWERS THROUGH AT LEAST THE NORTHERN PORTION
OF THE CWA AND THEN DRIES OUT WHILE LINGERING ACROSS THE SOUTH
THROUGH 18Z OR SO. FOR THIS FORECAST PACKAGE...WILL INTRODUCE SLIGHT
CHANCE OF POPS IN THE NORTH AND KEEP THE SOUTHERN PORTION OF THE CWA
DRY...SOUTH OF HIGHWAY 64. WITH THE FRONT LINGERING...TEMPERATURES
WILL STILL MAKE IT UP INTO THE UPPER 70S TO LOWER 80S WITH A LITTLE
BIT COOLER ACROSS THE NORTH. WINDS WILL BE LIGHT AND GRADUALLY VEER
TO NORTHWESTERLY AS THE FRONT MOVES SOUTH. LOWS THURSDAY NIGHT UPPER
40S TO LOW 50S.
FRIDAY AND SATURDAY WILL BE GENERALLY DRY BEHIND THE FRONT ALTHOUGH
THERE IS SOME UNCERTAINTY ON SATURDAY AS A WEAK FRONTAL SYSTEM
APPROACHES FROM THE WEST. THE ECMWF KEEPS THE AREA DRY...HOLDING OFF
PRECIPITATION UNTIL SUNDAY WHEREAS THE GFS BRINGS IN SCATTERED
SHOWERS BY SATURDAY AFTERNOON. SINCE THIS SYSTEM APPEARS WEAK
AT THIS TIME...TIMING OF THE ONSET OF PRECIPITATION MAY BE LARGELY
DETERMINED BY HOW FAR OFF OF THE COAST THE SURFACE HIGH SETTLES ON
SATURDAY. WITH LIGHT UPPER LEVEL FLOW...WILL GO WITH THE ECMWF AT
THIS TIME WHICH KEEPS THE HIGH CLOSER TO SHORE AND THUS DRY
CONDITIONS FOR SATURDAY. HIGHS DURING THIS PERIOD WILL BE IN THE
UPPER 60S TO LOW 70S WITH LOWS IN THE UPPER 40S TO LOWER 50S.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 800 PM SATURDAY...
MULTIPLE AREAS OF CONVECTION WILL MOVE ACROSS CENTRAL NC FROM WEST
TO EAST THIS EVENING INTO THE EARLY OVERNIGHT HOURS. THE CONVECTION
WILL RESULT IN BRIEF PERIODS OF LIFR/IFR CIGS AND VSBYS ALONG WITH
GUSTS TO 40KTS OR MORE AND SMALL HAIL. THREAT OF CONVECTION WILL
DIMINISH ACROSS KINT/KGSO BY 01Z. MAIN THREAT OF CONVECTION AT KRDU
WILL END BY 02-03Z AND AT KFAY/KRWI BY 04Z.
A COLD FRONT WILL SLOWLY SHIFT ACROSS CENTRAL NC FROM 06-15Z.
SCT SHOWERS ARE EXPECTED TO PERSIST OVERNIGHT WITH PERIODS OF MVFR
CIGS. AHEAD OF THE FRONT THERE IS THE POTENTIAL FOR SOME FOG TOWARD
DAYBREAK ...MAINLY ACROSS KFAY AND KRWI. LIGHT SOUTHEAST TO
SOUTHERLY SFC WINDS TONIGHT WILL VEER AROUND TO WEST AND NORTHWEST
ON SUNDAY MORNING. VFR/MVFR CONDITIONS ARE EXPECTED ON SUNDAY WITH
SCT SHOWERS THAT MAY REDUCE CIGS AND VSBYS BRIEFLY.
LOOKING FURTHER AHEAD...FAIR WEATHER WITH VFR CONDITIONS WILL RETURN
SUNDAY NIGHT WITH WEST TO EAST CLEARING. VFR CONDITIONS WILL
DOMINATE THROUGH THE MIDDLE OF NEXT WEEK AS A RIDGE BUILDS OVER THE
AREA FROM THE WEST IN THE WAKE OF THE UPPER LEVEL LOW. -BLAES/CBL
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...BLAES/CBL
SHORT TERM...RTE
LONG TERM...RTE
AVIATION...BLAES/CBL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
323 PM CDT FRI MAR 23 2012
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT...
NO SIGNIFICANT DIFFERENCE IN MODEL SOLUTIONS IN THE SHORT TERM
PERIODS AND USED A BLEND OF THE MODELS FOR THE GRIDS.
BIGGEST CONCERN IN EARLY FORECAST PERIODS IS POSSIBLY OF FOG REDEVELOPING
RAPDILY TONIGHT SHORTLY AFTER SUNDOWN. HRRR AND LAMP DATA
INDICATES A VERY SHARP LINE OF STRATUS AND FOG DEVELOPING ACROSS
SOUTH CENTRAL AND EAST CENTRAL NORTH DAKOTA BUT DREW THE
LINE SOMEWHAT FARTHER WEST AND INCLUDED BISMARCK...MANDAN AND MINOT
IN THE FOG. NO ADVISORY AT THIS TIME AS A COLD FRONT WILL PUSH
THROUGH THE AREA FROM WEST TO EAST BY MORNING PROMOTING MIXING.
SURFACE LOW WILL MOVE EAST OF AREA ON SATURDAY WITH NORTHWEST
WINDS DEVELOPING ACROSS THE REGION. RELATIVE HUMIDITIES SHOULD NOT
DECREASE TO POINT OF CAUSING FIRE WEATHER ISSUES. SATURDAY HIGH
PRESSURE MOVES EAST ACROSS SOUTH CENTRAL CANADA WITH COOL
NORTHERLY FLOW OVER THE AREA.
.LONG TERM...SUNDAY THROUGH FRIDAY...
THE HIGHLIGHT OF THE EXTENDED FORECAST IS THE STORM SYSTEM FORECAST
TO IMPACT THE NORTHERN PLAINS LATE MONDAY INTO TUESDAY...AND A BREAK
FROM FIRE WEATHER HEADLINES WITH SLIGHTLY COOLER
TEMPERATURES...ALBEIT STILL ABOVE NORMAL READINGS.
IN REGARDS TO THE DETAILS...A RELATIVELY COOL SUNDAY IS FORECAST
ACROSS WESTERN AND CENTRAL NORTH DAKOTA WITH EASTERLY SURFACE FLOW
RESULTING STRONG SURFACE HIGH PRESSURE NEAR HUDSON BAY AND LEE SIDE
LOW PRESSURE. HIGHS ON SUNDAY SHOULD RANGE FROM THE MID TO UPPER 40S
ACROSS THE TURTLE MOUNTAINS THROUGH THE JAMES RIVER VALLEY...WITH
HIGHS NEAR 60 ACROSS THE SOUTHWEST. DESPITE EASTERLY WINDS OF 20 TO
30 MPH...CRITICAL FIRE WEATHER CONDITIONS ARE NOT ANTICIPATED AS A
RESULT OF COOLER TEMPERATURES YIELDING AFTERNOON MINIMUM RH VALUES
IN THE 30 TO 40 PERCENT RANGE.
LEE SIDE CYCLOGENESIS INCREASES LATE MONDAY AFTERNOON AND INTO THE
NIGHT AS THE STRONG UPPER LEVEL WAVE FORECAST TO COME ON SHORE INTO
CALIFORNIA SUNDAY NIGHT PROPAGATES NORTHEAST TOWARDS THE NORTHERN
PLAINS. SOUTH-EASTERLY LOW LEVEL FLOW IS ALSO FORECAST TO INCREASE
DURING THIS TIMEFRAME AS A RESULT OF THE CYCLOGENESIS WITH GULF
MOISTURE TRANSPORT INTO THE NORTHERN PLAINS AS PWATS CLIMB INTO THE
0.75 TO 1.0 INCH RANGE BY MONDAY NIGHT. GIVEN THE LOW LEVEL WARM AIR
ADVECTION REGIME ASSOCIATED WITH THE SOUTHERLY FLOW...CAPPING SHOULD
PREVENT CONVECTIVE INITIATION THROUGH THE AFTERNOON...WITH A MORE
FAVORED AREA FOR DEVELOPMENT DURING THE AFTERNOON AND EARLY EVENING
CLOSER TO THE SURFACE WARM FRONT ACROSS SOUTH DAKOTA.
HOWEVER...CONVECTIVE CHANCES DO INCREASE MONDAY NIGHT AS THE MAIN
UPPER LEVEL WAVE APPROACHES WITH A STRENGTHENING LOW LEVEL JET AND
STEEP MID LEVEL LAPSE RATES. OVERALL ELEVATED CAPE IS LESS AND
FURTHER SOUTH TODAY COMPARED TO YESTERDAY. HOWEVER...ISOLATED
MARGINAL SEVERE HAIL WITH ELEVATED STORMS MONDAY NIGHT IS POSSIBLE
GIVEN THE AMPLE SHEAR PROFILES AND MID LEVEL LAPSE RATES.
THE UPPER LEVEL LOW IS FORECAST TO CLOSE OFF ACROSS NORTHEAST SOUTH
DAKOTA TUESDAY MORNING WITH WRAP AROUND PRECIPITATION ASSOCIATED
WITH THE TROWAL/DEFORMATION ZONE CONTINUING ACROSS MUCH OF WESTERN
AND CENTRAL NORTH DAKOTA DURING THE DAY ON TUESDAY. AT THIS TIME ALL
PRECIPITATION APPEARS TO BE RAIN...WITH A SLIGHT CHANCE FOR SOME
FLAKES TO MIX IN LATE TUESDAY EVENING AS COLDER AIR IS DRAWN INTO
THE SYSTEM. TUESDAY ALSO LOOKS TO BE WINDY...ESPECIALLY ACROSS THE
SOUTHWEST AND SOUTH CENTRAL GIVEN STRONG ISALLOBARIC FORCING ON THE
BACKSIDE OF THE LOW COUPLED WITH COLD AIR ADVECTION AND GOOD LOW
LEVEL MIXING. GIVEN THE STRENGTH OF THE WIND FIELD TUESDAY AFTERNOON
INTO THE EVENING...THE UPCOMING MODEL CYCLES WILL HAVE TO BE
MONITORED CLOSELY IF ANY SNOW WILL BE ABLE TO COUPLE WITH THE WINDS
TO CREATE POSSIBLE TRAVEL PROBLEMS. HOWEVER...THE 23/12 UTC
DETERMINISTIC SUITE IS SLIGHTLY COOLER COMPARED TO YESTERDAY...YET
WOULD STILL FAVOR ALL RAIN. IN THE WAKE OF THE TUESDAY SYSTEM...THE
UPPER LEVEL CENTRAL CONUS RIDGE IS FORECAST TO RE-AMPLIFY WITH ABOVE
NORMAL TEMPERATURES FAVORED FOR THE REMAINDER OF THE EXTENDED.
&&
.AVIATION...
THE LOW LEVEL STRATUS FIELD THAT WAS IN PLACE ACROSS MUCH OF WESTERN
AND CENTRAL NORTH DAKOTA THIS MORNING HAS ERODED AND LIFTED AS A
STRATOCUMULUS FIELD THIS AFTERNOON. HOWEVER...HIGH RESOLUTION MODEL
GUIDANCE IS SUGGESTING THE STRATUS FIELD TO FILL IN AND THE FOG TO
RETURN AFTER SUNSET THIS EVENING. THIS SEEMS PLAUSIBLE WITH LITTLE
AIRMASS CHANGE ACROSS MUCH OF THE AREA TONIGHT UNTIL COLD FRONT
PUSHES THROUGH THE AREA BETWEEN 10-15 UTC SATURDAY MORNING.
THEREFORE...HAVE INCLUDED STRATUS REFORMATION AND POSSIBLE FOG
DEVELOPMENT INTO THE KMOT...KBIS AND KJMS TAF SITES....WHILE THE
WESTERN TAF SITES OF KDIK AND KISN MAY REMAIN WEST OF THE STRATUS
FIELD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HW
LONG TERM....PJA
AVIATION...PJA
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
132 PM EDT FRI MAR 23 2012
.SYNOPSIS...
A SLOW MOVING UPPER LEVEL LOW PRESSURE SYSTEM WILL PUSH INTO THE
REGION BY SATURDAY. THIS LOW WILL THEN SLIDE OFF TO THE SOUTHEAST
SUNDAY WITH HIGH PRESSURE BUILDING BACK IN EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LEVEL LOW IS EVIDENT ON WATER VAPOR IMAGERY SPINNING ACROSS
SOUTHEAST MISSOURI THIS MORNING. AS THE LOW PUSHES SLOWLY EAST
THROUGH THE DAY...BANDS OF SHOWERS ROTATING UP THROUGH THE MID
OHIO VALLEY WILL ALSO SLOWLY WORK THEIR WAY EAST ACROSS MUCH OF
OUR AREA. THE EASTWARD PROGRESSION HAS BEEN RATHER SLOW THOUGH AND
THE LATEST RUC SEEMS TO BE PICKING UP ON THIS. WILL THEREFORE KEEP
HIGHEST POPS MAINLY ACROSS OUR WEST THROUGH A GOOD PART OF THE
DAY. LIGHTNING HAS BEEN FAIRLY SPOTTY SO FAR AND THINK CLOUDS WILL
HELP KEEP INSTABILITY SOMEWHAT MARGINAL...SO EXPECT MAINLY SHOWERS
WITH JUST A CHANCE OF THUNDER. CLOUDS AND PCPN SHOULD HELP KEEP
TEMPS FROM GETTING TOO OUT OF HAND WITH TEMPERATURES GENERALLY IN
THE UPPER 60S TO NEAR 70. OUR FAR NORTHEAST SHOULD SEE A LITTLE
MORE SUN THIS MORNING AND THIS MAY ALLOW THEM TO GET A BIT WARMER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
UPR LVL CLOSED LOW WILL CONTINUE TO SLOWLY INCH ITS WAY EAST
OVERNIGHT. COLD FRONT AHEAD OF THIS FEATURE WILL OCCLUDE AND WILL
MOVE ENE THROUGH THE AREA. BEST CHANCES FOR PCPN WILL BE ACRS
THE ERN ZONES EARLY ON. SOME OF THE MESOSCALE MODELS INDICATE THAT
LIKELY POPS MAY OCCUR ACRS THE SWRN SECTIONS THIS EVENING/OVERNIGHT AS
OCCLUDED FRONT PUSHES THROUGH. HAVE DECIDED TO LEAVE HIGH CHANCE
IN THIS AREA ATTM GIVEN LOW CONFIDENCE. HAVE USED A BLEND OF RAW
MODEL DATA TO COME UP WITH OVERNIGHT LOWS...WHICH SHOULD RANGE
FROM THE LOWER 50S SW TO THE UPPER 50S NE.
FOR SATURDAY INTO SATURDAY NIGHT...UPR LVL CLOSED LOW IS FORECAST
TO PIVOT ESE THROUGH THE OHIO VALLEY. ATTM...A WEAK SFC TROF AND
SFC LOW WILL TREK ACRS THE REGION. LOW LEVEL FORCING WILL BE WEAK
AT BEST...BUT MODELS INDICATE THAT A ROTATING VORT LOBE MAY
PROVIDE THE BEST UPR LVL SUPPORT ACRS THE SWRN ZONES. THUS...HAVE
GONE WITH CHANCE POPS EXCEPT ACRS THE SWRN ZONES WHERE LIKELY POPS
WILL BE USED. BEST CHANCE OF THUNDER WILL OCCUR DURING THE HEAT OF
THE DAY WHEN LOW LEVEL LAPSE RATES WILL BE THE GREATEST. PCPN
SHOULD DECREASE SATURDAY EVENING AS UPR LVL PULLS AWAY AND
INSTABILITY DROPS OFF. TEMPERATURES...ALTHOUGH COOLER...WILL STILL
BE ABOVE NORMAL DESPITE THE UPR LVL CLOSED LOW. HIGHS WILL RANGE
FROM THE MID TO UPPER 60S. LOWS WILL DROP INTO THE UPPER 40S TO
THE LOWER 50S.
FOR SUNDAY INTO SUNDAY NIGHT...ECMWF AND GFS DEPICT A DIGGING MID
LVL TROF WHICH WILL PUSH INTO SE CANADA/NRN NEW ENGLAND BY MONDAY
MORNING. THIS SYSTEM WILL PUSH A COLD FRONT SOUTH THROUGH THE
REGION SUNDAY/SUNDAY EVENING. WILL HOLD ON TO LOW CHANCES POPS
WITH FRONTAL PASSAGE. DRIER AIR AND CLEARING SKIES LATE SUNDAY
NIGHT WILL MARK THE BEGINNING OF A COOLING TREND.
FOR MONDAY INTO MONDAY NIGHT...CANADIAN HIGH PRESSURE WILL BUILD
SOUTHWARD INTO THE GREAT LAKES AND OHIO VALLEY. CAA WILL BRING
TEMPERATURES DOWN CLOSER TO NORMALS FOR LATE MARCH. WITH CLEAR
SKIES MONDAY NIGHT...SOME GUIDANCE SUGGESTS THAT LOWS MAY DROP
BELOW FREEZING...ESPECIALLY ACRS NRN AND ERN SECTIONS. THIS COULD
POSE A PROBLEM GIVEN THAT VEGETATION IS WELL AHEAD OF SCHEDULE DUE
TO THE VERY UNSEASONABLY WARM WEATHER THAT WE HAVE EXPERIENCED.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS THE REGION THROUGH
TUESDAY. THE NEXT SYSTEM WILL BEGIN TO BRING SHOWERS AND
THUNDERSTORMS INTO WESTERN PORTIONS OF THE FA LATE TUESDAY NIGHT
WITH A BETTER CHANCE OF THUNDERSTORM ACTIVITY ON WEDNESDAY. A COLD
FRONT WILL MOVE THROUGH WEDNESDAY NIGHT AND PRECIPITATION WILL END
ACROSS THE FA BY THURSDAY MORNING.
TEMPERATURES WILL WARM ONCE AGAIN BY WEDNESDAY WITH 70S EXPECTED.
TEMPERATURES WILL COOL BEHIND THE FRONT ON THURSDAY.
&&
.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
UPPER LEVEL LOW OVER SOUTHERN MISSOURI WILL PUSH SLOWLY EAST
ACROSS THE LOWER OHIO VALLEY THROUGH SATURDAY. AHEAD OF
THIS...BANDS OF SHOWERS AND PERHAPS A FEW THUNDERSTORMS WILL
ROTATE UP ACROSS OUR REGION. THE INITIAL BAND IS CONTINUING TO
AFFECT MAINLY THE WESTERN PORTIONS OF OUR AREA AND WILL CONTINUE
TO DO SO THROUGH THE AFTERNOON. AS IT PROGRESSES SLOWLY EAST...IT
SHOULD EVENTUALLY REACH CENTRAL OHIO TOWARD LATE AFTERNOON.
INSTABILITY REMAINS MARGINAL WITHIN THIS BAND SO THINK THUNDER
WILL REMAIN FAIRLY ISOLATED.
BETTER INSTABILITY BACK TO OUR SOUTHWEST IS LEADING TO MORE
WIDESPREAD THUNDERSTORM ACTIVITY ACROSS SOUTHERN ILLINOIS AND WESTERN
KENTUCKY. THIS WAVE SHOULD EVENTUALLY PUSH EAST INTO OUR AREA
LATER TONIGHT BUT BY THAT TIME...INSTABILITY SHOULD ONCE AGAIN BE
MARGINAL AND WILL THEREFORE HOLD OFF ON MENTIONING THUNDER LATER
TONIGHT. JUST AHEAD OF THE LOW...THERE WERE SOME LOW CLOUDS AND
FOG THIS MORNING AND SOME OF THIS MAY REDEVELOP ACROSS OUR AREA
LATE TONIGHT. ANY FOG/LOWER CLOUDS SHOULD DISSIPATE THROUGH LATE
MORNING. EXPECT WIDESPREAD CU TO DEVELOP FROM LATE MORNING INTO
EARLY AFTERNOON AS UPPER LEVEL LOW APPROACHES. WILL ALSO LIKELY
SEE SOME SCATTERED SHOWER/THUNDERSTORM DEVELOPMENT TOWARD THE END
OF THE TAF PERIOD.
OUTLOOK...MVFR CEILINGS POSSIBLE AT TIMES THROUGH SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...JGL
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
955 AM EDT FRI MAR 23 2012
.SYNOPSIS...
A SLOW MOVING UPPER LEVEL LOW PRESSURE SYSTEM WILL PUSH INTO THE
REGION BY SATURDAY. THIS LOW WILL THEN SLIDE OFF TO THE SOUTHEAST
SUNDAY WITH HIGH PRESSURE BUILDING BACK IN EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LEVEL LOW IS EVIDENT ON WATER VAPOR IMAGERY SPINNING ACROSS
SOUTHEAST MISSOURI THIS MORNING. AS THE LOW PUSHES SLOWLY EAST
THROUGH THE DAY...BANDS OF SHOWERS ROTATING UP THROUGH THE MID
OHIO VALLEY WILL ALSO SLOWLY WORK THEIR WAY EAST ACROSS MUCH OF
OUR AREA. THE EASTWARD PROGRESSION HAS BEEN RATHER SLOW THOUGH AND
THE LATEST RUC SEEMS TO BE PICKING UP ON THIS. WILL THEREFORE KEEP
HIGHEST POPS MAINLY ACROSS OUR WEST THROUGH A GOOD PART OF THE
DAY. LIGHTNING HAS BEEN FAIRLY SPOTTY SO FAR AND THINK CLOUDS WILL
HELP KEEP INSTABILITY SOMEWHAT MARGINAL...SO EXPECT MAINLY SHOWERS
WITH JUST A CHANCE OF THUNDER. CLOUDS AND PCPN SHOULD HELP KEEP
TEMPS FROM GETTING TOO OUT OF HAND WITH TEMPERATURES GENERALLY IN
THE UPPER 60S TO NEAR 70. OUR FAR NORTHEAST SHOULD SEE A LITTLE
MORE SUN THIS MORNING AND THIS MAY ALLOW THEM TO GET A BIT WARMER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
UPR LVL CLOSED LOW WILL CONTINUE TO SLOWLY INCH ITS WAY EAST
OVERNIGHT. COLD FRONT AHEAD OF THIS FEATURE WILL OCCLUDE AND WILL
MOVE ENE THROUGH THE AREA. BEST CHANCES FOR PCPN WILL BE ACRS
THE ERN ZONES EARLY ON. SOME OF THE MESOSCALE MODELS INDICATE THAT
LIKELY POPS MAY OCCUR ACRS THE SWRN SECTIONS THIS EVENING/OVERNIGHT AS
OCCLUDED FRONT PUSHES THROUGH. HAVE DECIDED TO LEAVE HIGH CHANCE
IN THIS AREA ATTM GIVEN LOW CONFIDENCE. HAVE USED A BLEND OF RAW
MODEL DATA TO COME UP WITH OVERNIGHT LOWS...WHICH SHOULD RANGE
FROM THE LOWER 50S SW TO THE UPPER 50S NE.
FOR SATURDAY INTO SATURDAY NIGHT...UPR LVL CLOSED LOW IS FORECAST
TO PIVOT ESE THROUGH THE OHIO VALLEY. ATTM...A WEAK SFC TROF AND
SFC LOW WILL TREK ACRS THE REGION. LOW LEVEL FORCING WILL BE WEAK
AT BEST...BUT MODELS INDICATE THAT A ROTATING VORT LOBE MAY
PROVIDE THE BEST UPR LVL SUPPORT ACRS THE SWRN ZONES. THUS...HAVE
GONE WITH CHANCE POPS EXCEPT ACRS THE SWRN ZONES WHERE LIKELY POPS
WILL BE USED. BEST CHANCE OF THUNDER WILL OCCUR DURING THE HEAT OF
THE DAY WHEN LOW LEVEL LAPSE RATES WILL BE THE GREATEST. PCPN
SHOULD DECREASE SATURDAY EVENING AS UPR LVL PULLS AWAY AND
INSTABILITY DROPS OFF. TEMPERATURES...ALTHOUGH COOLER...WILL STILL
BE ABOVE NORMAL DESPITE THE UPR LVL CLOSED LOW. HIGHS WILL RANGE
FROM THE MID TO UPPER 60S. LOWS WILL DROP INTO THE UPPER 40S TO
THE LOWER 50S.
FOR SUNDAY INTO SUNDAY NIGHT...ECMWF AND GFS DEPICT A DIGGING MID
LVL TROF WHICH WILL PUSH INTO SE CANADA/NRN NEW ENGLAND BY MONDAY
MORNING. THIS SYSTEM WILL PUSH A COLD FRONT SOUTH THROUGH THE
REGION SUNDAY/SUNDAY EVENING. WILL HOLD ON TO LOW CHANCES POPS
WITH FRONTAL PASSAGE. DRIER AIR AND CLEARING SKIES LATE SUNDAY
NIGHT WILL MARK THE BEGINNING OF A COOLING TREND.
FOR MONDAY INTO MONDAY NIGHT...CANADIAN HIGH PRESSURE WILL BUILD
SOUTHWARD INTO THE GREAT LAKES AND OHIO VALLEY. CAA WILL BRING
TEMPERATURES DOWN CLOSER TO NORMALS FOR LATE MARCH. WITH CLEAR
SKIES MONDAY NIGHT...SOME GUIDANCE SUGGESTS THAT LOWS MAY DROP
BELOW FREEZING...ESPECIALLY ACRS NRN AND ERN SECTIONS. THIS COULD
POSE A PROBLEM GIVEN THAT VEGETATION IS WELL AHEAD OF SCHEDULE DUE
TO THE VERY UNSEASONABLY WARM WEATHER THAT WE HAVE EXPERIENCED.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS THE REGION THROUGH
TUESDAY. THE NEXT SYSTEM WILL BEGIN TO BRING SHOWERS AND
THUNDERSTORMS INTO WESTERN PORTIONS OF THE FA LATE TUESDAY NIGHT
WITH A BETTER CHANCE OF THUNDERSTORM ACTIVITY ON WEDNESDAY. A COLD
FRONT WILL MOVE THROUGH WEDNESDAY NIGHT AND PRECIPITATION WILL END
ACROSS THE FA BY THURSDAY MORNING.
TEMPERATURES WILL WARM ONCE AGAIN BY WEDNESDAY WITH 70S EXPECTED.
TEMPERATURES WILL COOL BEHIND THE FRONT ON THURSDAY.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
THE OVERALL WEATHER CONDITIONS TODAY WILL FEATURE OCCASIONAL RAIN
SHOWERS...AND POSSIBLY SOME THUNDERSTORMS (ESPECIALLY IN THE
AFTERNOON). THE WEATHER SYSTEM CAUSING THIS ACTIVITY IS MOVING
ONLY VERY SLOWLY EASTWARD...WITH ALL OF THE INDIVIDUAL BANDS OF
PRECIPITATION MOVING ALMOST DUE NORTH. THIS MAKES IT MORE
DIFFICULT THAN NORMAL TO PROVIDE EXACT TIMING IN THE FORECAST FOR
EACH INDIVIDUAL BATCH OF SHOWERS MORE THAN A FEW HOURS IN ADVANCE.
MVFR (AND POSSIBLY IFR) CONDITIONS WILL BE POSSIBLE IN THE HEAVIER
SHOWERS...WHICH WOULD OF COURSE BE ESPECIALLY TRUE IN
THUNDERSTORMS.
CHANCES OF HEAVIER PRECIPITATION WILL END BY EVENING. AS AN UPPER
LEVEL LOW PRESSURE SYSTEM MOVES INTO THE REGION...DISORGANIZED
SHOWERS WILL CONTINUE TO BE POSSIBLE THROUGH SATURDAY AND BEYOND.
THE MOISTURE WITH THIS SYSTEM IS NOT ESPECIALLY DEEP SO OCCASIONAL
MVFR CONDITIONS SEEM TO BE THE WORST OF WHAT IS EXPECTED AT THIS
TIME.
OUTLOOK...MVFR CEILINGS POSSIBLE EARLY ON SATURDAY AND AT TIMES
THROUGH SUNDAY. THUNDERSTORMS POSSIBLE ON SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...JGL
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/NOVAK
AVIATION...HATZOS
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1047 PM CDT SAT MAR 24 2012
.DISCUSSION.../ISSUED AT 900 PM CDT/
BACKDOOR COLD FRONT HAS JUST PUSHED THROUGH SIOUX FALLS AND
CONTINUES TO MOVE SOUTH. MAIN UPDATE WAS JUST TO ADJUST TIMING OF
THIS FRONT MOVING ACROSS THE CWA TONIGHT. WINDS WILL PICK UP FROM
THE NORTH NORTHEAST BEHIND IT...GUSTING 20 TO 30 MPH. ADJUSTED LOW
TEMPERATURES DOWN A FEW DEGREES TONIGHT...GIVEN THE QUICK DROP
BEHIND THE FRONT AND THE CONTINUED LOW LEVEL CAA EXPECTED THROUGH
THE NIGHT. WENT WITH VALUES CLOSER TO THE RUC AND HRRR...AS THEY
APPEAR TO BE HANDLING THE FRONTAL PASSAGE FAIRLY WELL. NEXT
CHALLENGE TONIGHT IS POSSIBLE STRATUS DEVELOPMENT. SEEING SOME
STRATUS ON SATELLITE ALREADY MAKING IT DOWN INTO BROOKINGS AND
LINCOLN COUNTIES. THIS IS SHOWN WELL ON NAM 925MB RH AND HRRR CLOUD
COVER PRODUCTS. EXPECT THIS TO CONTINUE TO SLOWLY MOVE
SOUTH...THOUGH IT SHOULD ALSO BEGIN TO DISSIPATE...BEFORE
POTENTIALLY REFORMING CLOSER TO THE MISSOURI RIVER...WHERE LOW LEVEL
DEWPOINTS WILL REMAIN HIGHER. HOWEVER...LATER TONIGHT...WINDS TURN
SOUTHWESTERLY AROUND 800MB...WITH INCREASING MOISTURE IN THAT LAYER.
THUS WILL LIKELY SEE STRATUS BEGIN TO DEVELOP THERE AS WELL. SO IN
GENERALLY...EXPECT A GRADUAL INCREASE IN STRATUS TONIGHT ACROSS THE
CWA...WITH MUCH OF THE AREA POTENTIALLY BEING MOSTLY CLOUDY BY
MORNING. /CHENARD
.PREVIOUS DISCUSSION.../ISSUED AT 345 PM CDT
TONIGHTS FORECAST CHALLENGE INCLUDE STRATUS POTENTIAL AND LOW
TEMPERATURES. FRONTAL PASSAGE FINALLY COMES DOWN IN EARNEST THIS
EVENING...WHICH WILL INCREASE THE NORTHERLY SURFACE FLOW AFTER
EVENING AND OVERNIGHT. ONE THING TO NOTE IS THE STRATUS IN EASTERN
ND IS EDGING SOUTHWARD. THIS POST FRONTAL STRATUS IS MORE ORGANIZED
THEN THE STRATUS IN CENTRAL SD...WHICH IS MIXING OUT AT THIS TIME.
THEREFORE HEDGED SOME STRATUS COMING DOWN FIRST IN OUR NORTHEAST
ZONES...THEN SOUTHWARD TOWARD I 90 AS THE OVERNIGHT PROGRESSES. THE
SURFACE WINDS BECOME EASTERLY TONIGHT...AND MY INITIAL WORRY WAS
STRATUS BACKING IN FROM MINNESOTA. HOWEVER THAT STRATUS IS ALSO
MIXING OUT SO IT MAY NOT BE A PROBLEM. WITH THE STRATUS COOLED
TEMPERATURES TO THE NORTH OF OUR FORECAST AREA...AND WITH THE WINDS
BECOMING NE AND E...COOLED OFF LOWS A LITTLE BIT TONIGHT IN OUR
NORTHERN AND WESTERN ZONES. STRATUS MAY ALSO DEVELOP IN OUR S
CENTRAL SD ZONES LATE TONIGHT AS THE AIR MASS REACHES SATURATION IN
THAT AREA. ON SUNDAY...THE LOW LEVEL BOUNDARY WITH THE BACK DOOR
COLD FRONT IS EXTREMELY STRONG IN THIS AREA. THEREFORE BACKED OFF ON
TEMPERATURES ACROSS OUR NORTHERN FORECAST AREA AS THEY MAY ALSO BE
HINDERED BY A CLOUD DECK IN THE 4500 TO 6500 FOOT RANGE MUCH OF THE
DAY. BUT SOUTH OF THE BOUNDARY...SIOUX CITY MAY HIT THE UPPER 70S
WHICH GIVES ALMOST A 20 DEGREE TEMPERATURE DIFFERENCE FROM NORTH TO
SOUTH IN OUR AREA. /MJF
MAY GENERATE SOME CONVECTION IN OUR NORTH EARLY ON SUNDAY NIGHT AS
THE 925 MB FRONT BEGINS TO LIFT NORTHWARD...A MID LEVEL WAVE TRACKS
INTO THE WEST...AND THE LOW LEVEL JET BEGINS TO STRENGTHEN. THEN MAY
SEE ADDITIONAL DEVELOPMENT ALONG THE MISSOURI RIVER LATER IN THE
NIGHT ALONG THE BETTER ELEVATED INSTABILITY AXIS/THETA E
ADVECTION/AND LOWER LEVEL CONVERGENCE ON THE NOSE OF THE
STRENGTHENING LOW LEVEL JET. COULD HAVE A COUPLE OF SEVERE STORMS
WITH ELEVATED CAPE VALUES BETWEEN 1000 TO 1500 J/KG AND EFFECTIVE
SHEAR OF 35 TO 40 KTS. THIS FORCING WILL LIFT NORTH AND EAST THROUGH
THE EARLY PART OF MONDAY...SO FOLLOWED SUIT WITH POPS TAKING THEM
ACROSS OUR NORTH AND EAST INTO EARLY AFTERNOON. CANNOT COMPLETELY
RULE OUT ISOLATED CONVECTION BACK TO THE WEST ON MONDAY MORNING WITH
THE MOISTURE TRANSPORT AND INSTABILITY...THOUGH HARD TO PIN
POINT...AND THE ATMOSPHERE WILL BECOME INCREASINGLY STABLE THROUGH
THE MORNING HOURS AND BECOME MORE CAPPED FROM THE SOUTHWEST DURING
THE EARLY PART OF THE DAY. DID KEEP A CHANCE OF POPS IN OUR
NORTHEAST THROUGH THE LATER AFTERNOON WITH THE 925 MB FRONT
REMAINING OVER THAT AREA. TIGHT THERMAL GRADIENT WILL LINGER OVER
THE AREA ON MONDAY AFTERNOON...WITH HIGHS AROUND 60 IN MARSHALL TO
THE LOWER 80S THROUGH THE MISSOURI RIVER CORRIDOR. WILL ALSO BE A
WINDY DAY WITH A TIGHTENING GRADIENT AND HIGHER WINDS ALOFT.
THE MAIN UPPER LEVEL SHORTWAVE WILL TRACK ACROSS THE REGION ON
MONDAY NIGHT AS THE SURFACE COLD FRONT EXTENDING FROM THE PARENT LOW
OVER NORTH DAKOTA BEGINS TO PUSH THROUGH THE AREA. WITH
THIS...EXPECT SCATTERED CONVECTION TO PUSH FROM WEST TO EAST ACROSS
THE CWA DURING THE NIGHT...AND CANNOT RULE OUT A COUPLE OF SEVERE
STORMS IN OUR WEST DURING THE EVENING. WILL BE A VERY MILD NIGHT
WITH THE WINDS AND A SOUTHERLY COMPONENT FLOW...WITH TEMPERATURES
ONLY DROPPING INTO THE LOWER 50S NORTH TO UPPER 50S FAR SOUTH.
TUESDAY WILL SEE THE SYSTEM RETREATING FROM THE AREA...AND MODELS
NOW INDICATING A DRY DAY WITH ANY WRAP AROUND PRECIPITATION
REMAINING TO OUR NORTH. IT WILL BE A VERY WINDY DAY HOWEVER WITH THE
TIGHT GRADIENT AND WINDS AT THE TOP OF THE MIXED LAYER RUNNING
BETWEEN 35 TO 40 KTS. WITH THE WINDS AND AFTERNOON TEMPERATURES IN
THE LOWER 70S ACROSS OUR SOUTH...IN ADDITION TO RH VALUES IN THE
LOWER TO MID 20S OVER THAT AREA...WILL MOST LIKELY HAVE SOME FIRE
WEATHER ISSUES FOR THAT DAY.
IN THE EXTENDED...WEDNESDAY THROUGH SATURDAY...MODELS IN DECENT ON
AGREEMENT ON UPPER LEVEL RIDGING BUILDING INTO THE REGION ON
WEDNESDAY AND EARLY THURSDAY...BEFORE A SHORTWAVE OVER THE PACIFIC
NORTHWEST TOPS THE RIDGE LATER ON THURSDAY INTO FRIDAY BRINGING OUR
NEXT CHANCE OF PRECIPITATION DURING THAT TIME FRAME. LOOKS TO BE A
GENERAL WARMING TREND THROUGH THE PERIOD...WITH 925 MB TEMPERATURES
GOING FROM THE SINGLE DIGITS AND LOW TEENS C ON WEDNESDAY...TO MID
TEENS TO POSSIBLY MID 20S C BY SATURDAY. /JM
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
BAND OF MVFR TO IFR CEILINGS NEAR OVC010 WILL SPREAD SOUTH ALONG THE
INTERSTATE 29 CORRIDOR THROUGH 12Z SUNDAY AND THEN GRADUALLY BECOME
VFR DURING THE MORNING. OTHERWISE WILL BE VFR THROUGH MOST OF THE
CWA AFTER 15Z SUNDAY THROUGH 06Z MONDAY. THERE WILL BE A SLIGHT
CHANCE OF THUNDERSTORM NORTH OF A HON-MML LINE SUNDAY EVENING WITH A
BETTER CHANCE SOUTH OF I90 AND WEST OF I29 LATE SUNDAY NIGHT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
900 PM CDT SAT MAR 24 2012
.DISCUSSION.../ISSUED AT 900 PM CDT/
BACKDOOR COLD FRONT HAS JUST PUSHED THROUGH SIOUX FALLS AND
CONTINUES TO MOVE SOUTH. MAIN UPDATE WAS JUST TO ADJUST TIMING OF
THIS FRONT MOVING ACROSS THE CWA TONIGHT. WINDS WILL PICK UP FROM
THE NORTH NORTHEAST BEHIND IT...GUSTING 20 TO 30 MPH. ADJUSTED LOW
TEMPERATURES DOWN A FEW DEGREES TONIGHT...GIVEN THE QUICK DROP
BEHIND THE FRONT AND THE CONTINUED LOW LEVEL CAA EXPECTED THROUGH
THE NIGHT. WENT WITH VALUES CLOSER TO THE RUC AND HRRR...AS THEY
APPEAR TO BE HANDLING THE FRONTAL PASSAGE FAIRLY WELL. NEXT
CHALLENGE TONIGHT IS POSSIBLE STRATUS DEVELOPMENT. SEEING SOME
STRATUS ON SATELLITE ALREADY MAKING IT DOWN INTO BROOKINGS AND
LINCOLN COUNTIES. THIS IS SHOWN WELL ON NAM 925MB RH AND HRRR CLOUD
COVER PRODUCTS. EXPECT THIS TO CONTINUE TO SLOWLY MOVE
SOUTH...THOUGH IT SHOULD ALSO BEGIN TO DISSIPATE...BEFORE
POTENTIALLY REFORMING CLOSER TO THE MISSOURI RIVER...WHERE LOW LEVEL
DEWPOINTS WILL REMAIN HIGHER. HOWEVER...LATER TONIGHT...WINDS TURN
SOUTHWESTERLY AROUND 800MB...WITH INCREASING MOISTURE IN THAT LAYER.
THUS WILL LIKELY SEE STRATUS BEGIN TO DEVELOP THERE AS WELL. SO IN
GENERALLY...EXPECT A GRADUAL INCREASE IN STRATUS TONIGHT ACROSS THE
CWA...WITH MUCH OF THE AREA POTENTIALLY BEING MOSTLY CLOUDY BY
MORNING. /CHENARD
.PREVIOUS DISCUSSION.../ISSUED AT 345 PM CDT
TONIGHTS FORECAST CHALLENGE INCLUDE STRATUS POTENTIAL AND LOW
TEMPERATURES. FRONTAL PASSAGE FINALLY COMES DOWN IN EARNEST THIS
EVENING...WHICH WILL INCREASE THE NORTHERLY SURFACE FLOW AFTER
EVENING AND OVERNIGHT. ONE THING TO NOTE IS THE STRATUS IN EASTERN
ND IS EDGING SOUTHWARD. THIS POST FRONTAL STRATUS IS MORE ORGANIZED
THEN THE STRATUS IN CENTRAL SD...WHICH IS MIXING OUT AT THIS TIME.
THEREFORE HEDGED SOME STRATUS COMING DOWN FIRST IN OUR NORTHEAST
ZONES...THEN SOUTHWARD TOWARD I 90 AS THE OVERNIGHT PROGRESSES. THE
SURFACE WINDS BECOME EASTERLY TONIGHT...AND MY INITIAL WORRY WAS
STRATUS BACKING IN FROM MINNESOTA. HOWEVER THAT STRATUS IS ALSO
MIXING OUT SO IT MAY NOT BE A PROBLEM. WITH THE STRATUS COOLED
TEMPERATURES TO THE NORTH OF OUR FORECAST AREA...AND WITH THE WINDS
BECOMING NE AND E...COOLED OFF LOWS A LITTLE BIT TONIGHT IN OUR
NORTHERN AND WESTERN ZONES. STRATUS MAY ALSO DEVELOP IN OUR S
CENTRAL SD ZONES LATE TONIGHT AS THE AIR MASS REACHES SATURATION IN
THAT AREA. ON SUNDAY...THE LOW LEVEL BOUNDARY WITH THE BACK DOOR
COLD FRONT IS EXTREMELY STRONG IN THIS AREA. THEREFORE BACKED OFF ON
TEMPERATURES ACROSS OUR NORTHERN FORECAST AREA AS THEY MAY ALSO BE
HINDERED BY A CLOUD DECK IN THE 4500 TO 6500 FOOT RANGE MUCH OF THE
DAY. BUT SOUTH OF THE BOUNDARY...SIOUX CITY MAY HIT THE UPPER 70S
WHICH GIVES ALMOST A 20 DEGREE TEMPERATURE DIFFERENCE FROM NORTH TO
SOUTH IN OUR AREA. /MJF
MAY GENERATE SOME CONVECTION IN OUR NORTH EARLY ON SUNDAY NIGHT AS
THE 925 MB FRONT BEGINS TO LIFT NORTHWARD...A MID LEVEL WAVE TRACKS
INTO THE WEST...AND THE LOW LEVEL JET BEGINS TO STRENGTHEN. THEN MAY
SEE ADDITIONAL DEVELOPMENT ALONG THE MISSOURI RIVER LATER IN THE
NIGHT ALONG THE BETTER ELEVATED INSTABILITY AXIS/THETA E
ADVECTION/AND LOWER LEVEL CONVERGENCE ON THE NOSE OF THE
STRENGTHENING LOW LEVEL JET. COULD HAVE A COUPLE OF SEVERE STORMS
WITH ELEVATED CAPE VALUES BETWEEN 1000 TO 1500 J/KG AND EFFECTIVE
SHEAR OF 35 TO 40 KTS. THIS FORCING WILL LIFT NORTH AND EAST THROUGH
THE EARLY PART OF MONDAY...SO FOLLOWED SUIT WITH POPS TAKING THEM
ACROSS OUR NORTH AND EAST INTO EARLY AFTERNOON. CANNOT COMPLETELY
RULE OUT ISOLATED CONVECTION BACK TO THE WEST ON MONDAY MORNING WITH
THE MOISTURE TRANSPORT AND INSTABILITY...THOUGH HARD TO PIN
POINT...AND THE ATMOSPHERE WILL BECOME INCREASINGLY STABLE THROUGH
THE MORNING HOURS AND BECOME MORE CAPPED FROM THE SOUTHWEST DURING
THE EARLY PART OF THE DAY. DID KEEP A CHANCE OF POPS IN OUR
NORTHEAST THROUGH THE LATER AFTERNOON WITH THE 925 MB FRONT
REMAINING OVER THAT AREA. TIGHT THERMAL GRADIENT WILL LINGER OVER
THE AREA ON MONDAY AFTERNOON...WITH HIGHS AROUND 60 IN MARSHALL TO
THE LOWER 80S THROUGH THE MISSOURI RIVER CORRIDOR. WILL ALSO BE A
WINDY DAY WITH A TIGHTENING GRADIENT AND HIGHER WINDS ALOFT.
THE MAIN UPPER LEVEL SHORTWAVE WILL TRACK ACROSS THE REGION ON
MONDAY NIGHT AS THE SURFACE COLD FRONT EXTENDING FROM THE PARENT LOW
OVER NORTH DAKOTA BEGINS TO PUSH THROUGH THE AREA. WITH
THIS...EXPECT SCATTERED CONVECTION TO PUSH FROM WEST TO EAST ACROSS
THE CWA DURING THE NIGHT...AND CANNOT RULE OUT A COUPLE OF SEVERE
STORMS IN OUR WEST DURING THE EVENING. WILL BE A VERY MILD NIGHT
WITH THE WINDS AND A SOUTHERLY COMPONENT FLOW...WITH TEMPERATURES
ONLY DROPPING INTO THE LOWER 50S NORTH TO UPPER 50S FAR SOUTH.
TUESDAY WILL SEE THE SYSTEM RETREATING FROM THE AREA...AND MODELS
NOW INDICATING A DRY DAY WITH ANY WRAP AROUND PRECIPITATION
REMAINING TO OUR NORTH. IT WILL BE A VERY WINDY DAY HOWEVER WITH THE
TIGHT GRADIENT AND WINDS AT THE TOP OF THE MIXED LAYER RUNNING
BETWEEN 35 TO 40 KTS. WITH THE WINDS AND AFTERNOON TEMPERATURES IN
THE LOWER 70S ACROSS OUR SOUTH...IN ADDITION TO RH VALUES IN THE
LOWER TO MID 20S OVER THAT AREA...WILL MOST LIKELY HAVE SOME FIRE
WEATHER ISSUES FOR THAT DAY.
IN THE EXTENDED...WEDNESDAY THROUGH SATURDAY...MODELS IN DECENT ON
AGREEMENT ON UPPER LEVEL RIDGING BUILDING INTO THE REGION ON
WEDNESDAY AND EARLY THURSDAY...BEFORE A SHORTWAVE OVER THE PACIFIC
NORTHWEST TOPS THE RIDGE LATER ON THURSDAY INTO FRIDAY BRINGING OUR
NEXT CHANCE OF PRECIPITATION DURING THAT TIME FRAME. LOOKS TO BE A
GENERAL WARMING TREND THROUGH THE PERIOD...WITH 925 MB TEMPERATURES
GOING FROM THE SINGLE DIGITS AND LOW TEENS C ON WEDNESDAY...TO MID
TEENS TO POSSIBLY MID 20S C BY SATURDAY. /JM
&&
.AVIATION.../FOR THE 00Z TAF ISSUANCE/
MAIN SURGE OF GUSTY NORTH WINDS JUST NORTH OF I90 AT 23Z WITH LOW
LEVEL FLOW BECOMING MORE NORTH TO NORTHEAST DURING THE NIGHT AND
THEN TO THE EAST ON SUNDAY. SHOULD REMAIN VFR THROUGH 04Z AND THEN
EXPECT MVFR CEILINGS TO DROP SOUTHEAST INTO SOUTHWEST MINNESOTA AND
PORTIONS OF NORTHWEST IOWA AND PERSIST INTO SUNDAY MORNING BEFORE
BECOMING VFR AGAIN. REST OF CWA SHOULD REMAIN VFR THROUGH 00Z
MONDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1254 PM CDT FRI MAR 23 2012
.DISCUSSION...
DENSE FOG VERY SLOWLY DECREASING THIS MORNING. WILL LET THE ADVISORY
EXPIRE AT 1000 AM...BUT STILL PLAN ON SOME DENSE FOG IN MAINLY NW IA
AND SW MN FOR AN HOUR OR TWO LONGER. OTHERWISE...ANOTHER
UNSEASONABLY WARM DAY AHEAD WITH VERY LITTLE WIND...SO VERY
PLEASANT. HIGHS FROM THE UPPER 60S TO LOWER 70S STILL LOOKS ON
TARGET. /08
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
OTHER THAN A SMALL PATCH OF IFR CEILINGS EAST OF THE BUFFALO RIDGE
VFR CONDITIONS ARE EXPECTED THROUGH ABOUT 6Z THIS EVENING. MAINLY
MVFR TYPE FOG IS ANTICIPATED TONIGHT HOWEVER NEAR AND EAST OF THE
BUFFALO RIDGE THERE WILL BE A BETTER CHANCE FOR THE DEVELOPMENT OF
IFR OR LIFR VISIBILITIES IN FOG WITH LIGHT WINDS AND RESIDUAL LOW
LEVEL MOISTURE. OTHERWISE...FROM ABOUT 15Z SATURDAY ON VFR
CONDITIONS WILL AGAIN PREVAIL. /08
&&
.PREV DISCUSSION.../ISSUED AT 416 AM CDT/
INITIAL CONCERN IS DENSE FOG WHICH HAS DEVELOPED ACROSS EASTERN
PORTIONS OF THE FORECAST AREA. HRRR HAD A DECENT HANDLE ON THE
DEVELOPMENT AREA THROUGH THE EARLY MORNING AND TRIES TO EXPAND THE
WESTERN EDGE OF THE FOG WESTWARD TO THE JAMES VALLEY THROUGH 13Z
BEFORE RAPID IMPROVEMENT IN VISIBILITY BETWEEN 15Z AND 17Z. NOT YET
SEEING ANY INDICATION OF MUCH WESTWARD PUSH INTO SOMEWHAT DRIER LOW
LEVEL AIR THOUGH...SO WILL LET DENSE FOG ADVISORY ISSUED EARLIER FOR
AREAS ALONG/EAST OF HURON-SALEM-AKRON LINE STAND. FOG EXPECTED TO
LIFT DURING THE LATE MORNING...THOUGH MAY SEE SOME LINGERING STRATUS
IN EASTERN AREAS INTO THE EARLY AFTERNOON. BETWEEN THAT AND MID-UPPER
LEVEL CLOUDS CONTINUING TO WRAP AROUND SLOWLY DEPARTING UPPER LOW...
EASTERN COUNTIES SHOULD BE PARTLY SUNNY THROUGH THE AFTERNOON WITH
MORE SUNSHINE EXPECTED ALONG/WEST OF I-29. LIGHT WIND FLOW TODAY WILL
LIKELY NOT SCOUR OUT RESIDUAL LOW LEVEL MOISTURE IN THE EAST THOUGH
AND COULD SEE SOME REDEVELOPMENT OF FOG LATE TONIGHT/EARLY SATURDAY
AND HAVE ADDED PATCHY FOG TO AREAS ALONG/EAST OF THE BUFFALO RIDGE
AND IOWA GREAT LAKES.
OTHERWISE BUILDING UPPER RIDGE STILL ON TRACK TO BRING DRY WEATHER
FOR THE WEEKEND. GFS/NAM NOW STRONGER THAN THEIR RUNS FROM 24 HOURS
AGO WITH NORTHERN STREAM WAVE TRACKING ACROSS CANADA THIS WEEKEND.
THIS ALLOWS FRONT AND TRAILING RELATIVELY COOLER AIRMASS TO PUSH
FARTHER SOUTH THROUGH THE UPPER MIDWEST...SIMILAR TO WHAT ECMWF/GEM
WERE SHOWING YESTERDAY MORNING. SATURDAY SHOULD BE QUITE MILD OVER
THE ENTIRE CWA WITH HIGHS IN THE 70S...POSSIBLY HITTING 80 IN PARTS
OF THE MISSOURI VALLEY. FRONTAL BOUNDARY THEN SETS UP NORTHWEST TO
SOUTHEAST ACROSS THE CWA...MAKING TEMPERATURES A LITTLE MORE TRICKY
FOR SUNDAY INTO MONDAY. BOUNDARY WILL SEPARATE 50S AND LOWER 60S IN
MINNESOTA...FROM UPPER 70S-LOWER 80S IN NEBRASKA AND SOUTHWEST SOUTH
DAKOTA...AND THE GRADIENT LIKELY TO BE SOMEWHERE IN OUR CWA. FOR NOW
HAVE COOLED NORTHEAST AREAS FROM PREVIOUS FORECAST FOR SUNDAY/MONDAY
BUT GRADIENT MAY HAVE TO BE TIGHTENED FURTHER IF 925MB TEMPS...WHICH
RANGE FROM 7-9C IN SOUTHWEST MN TO THE LOWER 20S IN SOUTH CENTRAL
SD...PAN OUT FOR MONDAY AFTERNOON.
BOUNDARY COULD ALSO BE FOCUS FOR A FEW SHOWERS OR THUNDERSTORMS LATE
SUNDAY NIGHT AND MONDAY AS LOW LEVEL JET INCREASES AHEAD OF THE NEXT
SYSTEM. INSTABILITY ON THE WEAK SIDE ALONG/NORTHEAST OF THE BOUNDARY
WITH MORE FAVORABLE CAPE BUILDING INTO WARM SECTOR ACROSS SOUTHWEST
CWA MONDAY AFTERNOON...THOUGH PRETTY STOUT CAP REMAINS IN PLACE
THROUGH THE AFTERNOON SO KEEPING POPS ON THE LOW SIDE FOR DAYTIME
HOURS. BETTER CHANCE LOOKS TO BE MONDAY NIGHT AS BOTH GFS/ECMWF SHOW
POTENT MID-UPPER LEVEL WAVE CRASHING INTO THE RIDGE OVER THE EASTERN
DAKOTAS. WITH STRONG DYNAMIC LIFT AND VERY STRONG LOW-MID LEVEL WINDS
AROUND SOUTH SIDE OF DEEP LOW...MAY NOT TAKE MUCH TO PRODUCE DAMAGING
WIND GUSTS WITH ANY STORMS THAT DEVELOP/MOVE INTO THE MORE UNSTABLE
AIR ACROSS THE SOUTHWEST CWA MONDAY NIGHT.
QUICK MOVING COMPACT SYSTEM WILL SHIFT EAST OF THE AREA TUESDAY...
THOUGH COULD SEE SOME SHOWERS WRAP AROUND INTO MAINLY NORTHERN PARTS
OF THE AREA TUESDAY BEFORE DRIER AIR BUILDS IN AND PRECIP THREAT
SHIFTS EAST OF THE AREA TUESDAY NIGHT. WITH STRONG SURFACE LOW
PASSING TO OUR NORTH TUESDAY...LIKELY TO SEE STRONG SYNOPTIC SCALE
FLOW DEVELOP IN WELL-MIXED DEEP WESTERLY FLOW BEHIND THE FRONT.
UPPER RIDGING WILL BRING DRY WEATHER BACK TO THE AREA FOR WEDNESDAY
AND WEDNESDAY NIGHT...WITH UPPER TROUGH SET TO MOVE INTO THE NORTHERN
PLAINS LATE IN THE WEEK. DIFFERENCES IN TIMING AMONG THE MODELS SO
WILL HAVE JUST A SLIGHT CHANCE OF THUNDERSTORMS IN THE WESTERN CWA
THURSDAY...WITH BETTER CHANCE HOLDING OFF UNTIL THURSDAY NIGHT OR
FRIDAY...DEPENDING ON EVENTUAL TIMING. TEMPERATURES WILL REMAIN ON
THE MILD SIDE OF NORMAL...THOUGH LATTER PART OF THE FORECAST PERIOD
SHOULD BE COOLER THAN THE NEXT FEW DAYS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
945 AM CDT FRI MAR 23 2012
.DISCUSSION...
DENSE FOG VERY SLOWLY DECREASING THIS MORNING. WILL LET THE ADVISORY
EXPIRE AT 1000 AM...BUT STILL PLAN ON SOME DENSE FOG IN MAINLY NW IA
AND SW MN FOR AN HOUR OR TWO LONGER. OTHERWISE...ANOTHER
UNSEASONABLY WARM DAY AHEAD WITH VERY LITTLE WIND...SO VERY
PLEASANT. HIGHS FROM THE UPPER 60S TO LOWER 70S STILL LOOKS ON
TARGET. /08
&&
.PREV DISCUSSION.../ISSUED AT 416 AM CDT/
INITIAL CONCERN IS DENSE FOG WHICH HAS DEVELOPED ACROSS EASTERN
PORTIONS OF THE FORECAST AREA. HRRR HAD A DECENT HANDLE ON THE
DEVELOPMENT AREA THROUGH THE EARLY MORNING AND TRIES TO EXPAND THE
WESTERN EDGE OF THE FOG WESTWARD TO THE JAMES VALLEY THROUGH 13Z
BEFORE RAPID IMPROVEMENT IN VISIBILITY BETWEEN 15Z AND 17Z. NOT YET
SEEING ANY INDICATION OF MUCH WESTWARD PUSH INTO SOMEWHAT DRIER LOW
LEVEL AIR THOUGH...SO WILL LET DENSE FOG ADVISORY ISSUED EARLIER FOR
AREAS ALONG/EAST OF HURON-SALEM-AKRON LINE STAND. FOG EXPECTED TO
LIFT DURING THE LATE MORNING...THOUGH MAY SEE SOME LINGERING STRATUS
IN EASTERN AREAS INTO THE EARLY AFTERNOON. BETWEEN THAT AND MID-UPPER
LEVEL CLOUDS CONTINUING TO WRAP AROUND SLOWLY DEPARTING UPPER LOW...
EASTERN COUNTIES SHOULD BE PARTLY SUNNY THROUGH THE AFTERNOON WITH
MORE SUNSHINE EXPECTED ALONG/WEST OF I-29. LIGHT WIND FLOW TODAY WILL
LIKELY NOT SCOUR OUT RESIDUAL LOW LEVEL MOISTURE IN THE EAST THOUGH
AND COULD SEE SOME REDEVELOPMENT OF FOG LATE TONIGHT/EARLY SATURDAY
AND HAVE ADDED PATCHY FOG TO AREAS ALONG/EAST OF THE BUFFALO RIDGE
AND IOWA GREAT LAKES.
OTHERWISE BUILDING UPPER RIDGE STILL ON TRACK TO BRING DRY WEATHER
FOR THE WEEKEND. GFS/NAM NOW STRONGER THAN THEIR RUNS FROM 24 HOURS
AGO WITH NORTHERN STREAM WAVE TRACKING ACROSS CANADA THIS WEEKEND.
THIS ALLOWS FRONT AND TRAILING RELATIVELY COOLER AIRMASS TO PUSH
FARTHER SOUTH THROUGH THE UPPER MIDWEST...SIMILAR TO WHAT ECMWF/GEM
WERE SHOWING YESTERDAY MORNING. SATURDAY SHOULD BE QUITE MILD OVER
THE ENTIRE CWA WITH HIGHS IN THE 70S...POSSIBLY HITTING 80 IN PARTS
OF THE MISSOURI VALLEY. FRONTAL BOUNDARY THEN SETS UP NORTHWEST TO
SOUTHEAST ACROSS THE CWA...MAKING TEMPERATURES A LITTLE MORE TRICKY
FOR SUNDAY INTO MONDAY. BOUNDARY WILL SEPARATE 50S AND LOWER 60S IN
MINNESOTA...FROM UPPER 70S-LOWER 80S IN NEBRASKA AND SOUTHWEST SOUTH
DAKOTA...AND THE GRADIENT LIKELY TO BE SOMEWHERE IN OUR CWA. FOR NOW
HAVE COOLED NORTHEAST AREAS FROM PREVIOUS FORECAST FOR SUNDAY/MONDAY
BUT GRADIENT MAY HAVE TO BE TIGHTENED FURTHER IF 925MB TEMPS...WHICH
RANGE FROM 7-9C IN SOUTHWEST MN TO THE LOWER 20S IN SOUTH CENTRAL
SD...PAN OUT FOR MONDAY AFTERNOON.
BOUNDARY COULD ALSO BE FOCUS FOR A FEW SHOWERS OR THUNDERSTORMS LATE
SUNDAY NIGHT AND MONDAY AS LOW LEVEL JET INCREASES AHEAD OF THE NEXT
SYSTEM. INSTABILITY ON THE WEAK SIDE ALONG/NORTHEAST OF THE BOUNDARY
WITH MORE FAVORABLE CAPE BUILDING INTO WARM SECTOR ACROSS SOUTHWEST
CWA MONDAY AFTERNOON...THOUGH PRETTY STOUT CAP REMAINS IN PLACE
THROUGH THE AFTERNOON SO KEEPING POPS ON THE LOW SIDE FOR DAYTIME
HOURS. BETTER CHANCE LOOKS TO BE MONDAY NIGHT AS BOTH GFS/ECMWF SHOW
POTENT MID-UPPER LEVEL WAVE CRASHING INTO THE RIDGE OVER THE EASTERN
DAKOTAS. WITH STRONG DYNAMIC LIFT AND VERY STRONG LOW-MID LEVEL WINDS
AROUND SOUTH SIDE OF DEEP LOW...MAY NOT TAKE MUCH TO PRODUCE DAMAGING
WIND GUSTS WITH ANY STORMS THAT DEVELOP/MOVE INTO THE MORE UNSTABLE
AIR ACROSS THE SOUTHWEST CWA MONDAY NIGHT.
QUICK MOVING COMPACT SYSTEM WILL SHIFT EAST OF THE AREA TUESDAY...
THOUGH COULD SEE SOME SHOWERS WRAP AROUND INTO MAINLY NORTHERN PARTS
OF THE AREA TUESDAY BEFORE DRIER AIR BUILDS IN AND PRECIP THREAT
SHIFTS EAST OF THE AREA TUESDAY NIGHT. WITH STRONG SURFACE LOW
PASSING TO OUR NORTH TUESDAY...LIKELY TO SEE STRONG SYNOPTIC SCALE
FLOW DEVELOP IN WELL-MIXED DEEP WESTERLY FLOW BEHIND THE FRONT.
UPPER RIDGING WILL BRING DRY WEATHER BACK TO THE AREA FOR WEDNESDAY
AND WEDNESDAY NIGHT...WITH UPPER TROUGH SET TO MOVE INTO THE NORTHERN
PLAINS LATE IN THE WEEK. DIFFERENCES IN TIMING AMONG THE MODELS SO
WILL HAVE JUST A SLIGHT CHANCE OF THUNDERSTORMS IN THE WESTERN CWA
THURSDAY...WITH BETTER CHANCE HOLDING OFF UNTIL THURSDAY NIGHT OR
FRIDAY...DEPENDING ON EVENTUAL TIMING. TEMPERATURES WILL REMAIN ON
THE MILD SIDE OF NORMAL...THOUGH LATTER PART OF THE FORECAST PERIOD
SHOULD BE COOLER THAN THE NEXT FEW DAYS.
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
DENSE VLIFR FOG WILL CONTINUE AT KFSD UNTIL AT LEAST 15Z...THEN
SHOULD GRADUALLY LIFT BETWEEN 15Z-17Z. KHON AND KSUX HAVE REMAINED
JUST WEST OF THE DENSE FOG...AND SOME IFR VISIBILITIES AND CEILINGS
MAY BE BRIEFLY POSSIBLE AT THESE LOCATIONS BEFORE 15Z. BY 18Z...ALL
TAF SITES SHOULD IMPROVE TO VFR...HOWEVER SOME LIGHT FOG MAY BE
POSSIBLE AGAIN AFTER MIDNIGHT SATURDAY AT KFSD AND KSUX. /LAFLIN
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR IAZ001>003-
012>014-020>022.
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ071-072-
080-081-089-090-097-098.
NE...NONE.
SD...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR SDZ038>040-
054>056-061-062-067.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
642 AM CDT FRI MAR 23 2012
.DISCUSSION.../ISSUED AT 416 AM CDT/
INITIAL CONCERN IS DENSE FOG WHICH HAS DEVELOPED ACROSS EASTERN
PORTIONS OF THE FORECAST AREA. HRRR HAD A DECENT HANDLE ON THE
DEVELOPMENT AREA THROUGH THE EARLY MORNING AND TRIES TO EXPAND THE
WESTERN EDGE OF THE FOG WESTWARD TO THE JAMES VALLEY THROUGH 13Z
BEFORE RAPID IMPROVEMENT IN VISIBILITY BETWEEN 15Z AND 17Z. NOT YET
SEEING ANY INDICATION OF MUCH WESTWARD PUSH INTO SOMEWHAT DRIER LOW
LEVEL AIR THOUGH...SO WILL LET DENSE FOG ADVISORY ISSUED EARLIER FOR
AREAS ALONG/EAST OF HURON-SALEM-AKRON LINE STAND. FOG EXPECTED TO
LIFT DURING THE LATE MORNING...THOUGH MAY SEE SOME LINGERING STRATUS
IN EASTERN AREAS INTO THE EARLY AFTERNOON. BETWEEN THAT AND MID-UPPER
LEVEL CLOUDS CONTINUING TO WRAP AROUND SLOWLY DEPARTING UPPER LOW...
EASTERN COUNTIES SHOULD BE PARTLY SUNNY THROUGH THE AFTERNOON WITH
MORE SUNSHINE EXPECTED ALONG/WEST OF I-29. LIGHT WIND FLOW TODAY WILL
LIKELY NOT SCOUR OUT RESIDUAL LOW LEVEL MOISTURE IN THE EAST THOUGH
AND COULD SEE SOME REDEVELOPMENT OF FOG LATE TONIGHT/EARLY SATURDAY
AND HAVE ADDED PATCHY FOG TO AREAS ALONG/EAST OF THE BUFFALO RIDGE
AND IOWA GREAT LAKES.
OTHERWISE BUILDING UPPER RIDGE STILL ON TRACK TO BRING DRY WEATHER
FOR THE WEEKEND. GFS/NAM NOW STRONGER THAN THEIR RUNS FROM 24 HOURS
AGO WITH NORTHERN STREAM WAVE TRACKING ACROSS CANADA THIS WEEKEND.
THIS ALLOWS FRONT AND TRAILING RELATIVELY COOLER AIRMASS TO PUSH
FARTHER SOUTH THROUGH THE UPPER MIDWEST...SIMILAR TO WHAT ECMWF/GEM
WERE SHOWING YESTERDAY MORNING. SATURDAY SHOULD BE QUITE MILD OVER
THE ENTIRE CWA WITH HIGHS IN THE 70S...POSSIBLY HITTING 80 IN PARTS
OF THE MISSOURI VALLEY. FRONTAL BOUNDARY THEN SETS UP NORTHWEST TO
SOUTHEAST ACROSS THE CWA...MAKING TEMPERATURES A LITTLE MORE TRICKY
FOR SUNDAY INTO MONDAY. BOUNDARY WILL SEPARATE 50S AND LOWER 60S IN
MINNESOTA...FROM UPPER 70S-LOWER 80S IN NEBRASKA AND SOUTHWEST SOUTH
DAKOTA...AND THE GRADIENT LIKELY TO BE SOMEWHERE IN OUR CWA. FOR NOW
HAVE COOLED NORTHEAST AREAS FROM PREVIOUS FORECAST FOR SUNDAY/MONDAY
BUT GRADIENT MAY HAVE TO BE TIGHTENED FURTHER IF 925MB TEMPS...WHICH
RANGE FROM 7-9C IN SOUTHWEST MN TO THE LOWER 20S IN SOUTH CENTRAL
SD...PAN OUT FOR MONDAY AFTERNOON.
BOUNDARY COULD ALSO BE FOCUS FOR A FEW SHOWERS OR THUNDERSTORMS LATE
SUNDAY NIGHT AND MONDAY AS LOW LEVEL JET INCREASES AHEAD OF THE NEXT
SYSTEM. INSTABILITY ON THE WEAK SIDE ALONG/NORTHEAST OF THE BOUNDARY
WITH MORE FAVORABLE CAPE BUILDING INTO WARM SECTOR ACROSS SOUTHWEST
CWA MONDAY AFTERNOON...THOUGH PRETTY STOUT CAP REMAINS IN PLACE
THROUGH THE AFTERNOON SO KEEPING POPS ON THE LOW SIDE FOR DAYTIME
HOURS. BETTER CHANCE LOOKS TO BE MONDAY NIGHT AS BOTH GFS/ECMWF SHOW
POTENT MID-UPPER LEVEL WAVE CRASHING INTO THE RIDGE OVER THE EASTERN
DAKOTAS. WITH STRONG DYNAMIC LIFT AND VERY STRONG LOW-MID LEVEL WINDS
AROUND SOUTH SIDE OF DEEP LOW...MAY NOT TAKE MUCH TO PRODUCE DAMAGING
WIND GUSTS WITH ANY STORMS THAT DEVELOP/MOVE INTO THE MORE UNSTABLE
AIR ACROSS THE SOUTHWEST CWA MONDAY NIGHT.
QUICK MOVING COMPACT SYSTEM WILL SHIFT EAST OF THE AREA TUESDAY...
THOUGH COULD SEE SOME SHOWERS WRAP AROUND INTO MAINLY NORTHERN PARTS
OF THE AREA TUESDAY BEFORE DRIER AIR BUILDS IN AND PRECIP THREAT
SHIFTS EAST OF THE AREA TUESDAY NIGHT. WITH STRONG SURFACE LOW
PASSING TO OUR NORTH TUESDAY...LIKELY TO SEE STRONG SYNOPTIC SCALE
FLOW DEVELOP IN WELL-MIXED DEEP WESTERLY FLOW BEHIND THE FRONT.
UPPER RIDGING WILL BRING DRY WEATHER BACK TO THE AREA FOR WEDNESDAY
AND WEDNESDAY NIGHT...WITH UPPER TROUGH SET TO MOVE INTO THE NORTHERN
PLAINS LATE IN THE WEEK. DIFFERENCES IN TIMING AMONG THE MODELS SO
WILL HAVE JUST A SLIGHT CHANCE OF THUNDERSTORMS IN THE WESTERN CWA
THURSDAY...WITH BETTER CHANCE HOLDING OFF UNTIL THURSDAY NIGHT OR
FRIDAY...DEPENDING ON EVENTUAL TIMING. TEMPERATURES WILL REMAIN ON
THE MILD SIDE OF NORMAL...THOUGH LATTER PART OF THE FORECAST PERIOD
SHOULD BE COOLER THAN THE NEXT FEW DAYS.
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
DENSE VLIFR FOG WILL CONTINUE AT KFSD UNTIL AT LEAST 15Z...THEN
SHOULD GRADUALLY LIFT BETWEEN 15Z-17Z. KHON AND KSUX HAVE REMAINED
JUST WEST OF THE DENSE FOG...AND SOME IFR VISIBILITIES AND CEILINGS
MAY BE BRIEFLY POSSIBLE AT THESE LOCATIONS BEFORE 15Z. BY 18Z...ALL
TAF SITES SHOULD IMPROVE TO VFR...HOWEVER SOME LIGHT FOG MAY BE
POSSIBLE AGAIN AFTER MIDNIGHT SATURDAY AT KFSD AND KSUX. /LAFLIN
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR IAZ001>003-
012>014-020>022.
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ071-072-
080-081-089-090-097-098.
NE...NONE.
SD...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR SDZ038>040-
054>056-061-062-067.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
416 AM CDT FRI MAR 23 2012
.DISCUSSION.../ISSUED AT 416 AM CDT/
INITIAL CONCERN IS DENSE FOG WHICH HAS DEVELOPED ACROSS EASTERN
PORTIONS OF THE FORECAST AREA. HRRR HAD A DECENT HANDLE ON THE
DEVELOPMENT AREA THROUGH THE EARLY MORNING AND TRIES TO EXPAND THE
WESTERN EDGE OF THE FOG WESTWARD TO THE JAMES VALLEY THROUGH 13Z
BEFORE RAPID IMPROVEMENT IN VISIBILITY BETWEEN 15Z AND 17Z. NOT YET
SEEING ANY INDICATION OF MUCH WESTWARD PUSH INTO SOMEWHAT DRIER LOW
LEVEL AIR THOUGH...SO WILL LET DENSE FOG ADVISORY ISSUED EARLIER FOR
AREAS ALONG/EAST OF HURON-SALEM-AKRON LINE STAND. FOG EXPECTED TO
LIFT DURING THE LATE MORNING...THOUGH MAY SEE SOME LINGERING STRATUS
IN EASTERN AREAS INTO THE EARLY AFTERNOON. BETWEEN THAT AND MID-UPPER
LEVEL CLOUDS CONTINUING TO WRAP AROUND SLOWLY DEPARTING UPPER LOW...
EASTERN COUNTIES SHOULD BE PARTLY SUNNY THROUGH THE AFTERNOON WITH
MORE SUNSHINE EXPECTED ALONG/WEST OF I-29. LIGHT WIND FLOW TODAY WILL
LIKELY NOT SCOUR OUT RESIDUAL LOW LEVEL MOISTURE IN THE EAST THOUGH
AND COULD SEE SOME REDEVELOPMENT OF FOG LATE TONIGHT/EARLY SATURDAY
AND HAVE ADDED PATCHY FOG TO AREAS ALONG/EAST OF THE BUFFALO RIDGE
AND IOWA GREAT LAKES.
OTHERWISE BUILDING UPPER RIDGE STILL ON TRACK TO BRING DRY WEATHER
FOR THE WEEKEND. GFS/NAM NOW STRONGER THAN THEIR RUNS FROM 24 HOURS
AGO WITH NORTHERN STREAM WAVE TRACKING ACROSS CANADA THIS WEEKEND.
THIS ALLOWS FRONT AND TRAILING RELATIVELY COOLER AIRMASS TO PUSH
FARTHER SOUTH THROUGH THE UPPER MIDWEST...SIMILAR TO WHAT ECMWF/GEM
WERE SHOWING YESTERDAY MORNING. SATURDAY SHOULD BE QUITE MILD OVER
THE ENTIRE CWA WITH HIGHS IN THE 70S...POSSIBLY HITTING 80 IN PARTS
OF THE MISSOURI VALLEY. FRONTAL BOUNDARY THEN SETS UP NORTHWEST TO
SOUTHEAST ACROSS THE CWA...MAKING TEMPERATURES A LITTLE MORE TRICKY
FOR SUNDAY INTO MONDAY. BOUNDARY WILL SEPARATE 50S AND LOWER 60S IN
MINNESOTA...FROM UPPER 70S-LOWER 80S IN NEBRASKA AND SOUTHWEST SOUTH
DAKOTA...AND THE GRADIENT LIKELY TO BE SOMEWHERE IN OUR CWA. FOR NOW
HAVE COOLED NORTHEAST AREAS FROM PREVIOUS FORECAST FOR SUNDAY/MONDAY
BUT GRADIENT MAY HAVE TO BE TIGHTENED FURTHER IF 925MB TEMPS...WHICH
RANGE FROM 7-9C IN SOUTHWEST MN TO THE LOWER 20S IN SOUTH CENTRAL
SD...PAN OUT FOR MONDAY AFTERNOON.
BOUNDARY COULD ALSO BE FOCUS FOR A FEW SHOWERS OR THUNDERSTORMS LATE
SUNDAY NIGHT AND MONDAY AS LOW LEVEL JET INCREASES AHEAD OF THE NEXT
SYSTEM. INSTABILITY ON THE WEAK SIDE ALONG/NORTHEAST OF THE BOUNDARY
WITH MORE FAVORABLE CAPE BUILDING INTO WARM SECTOR ACROSS SOUTHWEST
CWA MONDAY AFTERNOON...THOUGH PRETTY STOUT CAP REMAINS IN PLACE
THROUGH THE AFTERNOON SO KEEPING POPS ON THE LOW SIDE FOR DAYTIME
HOURS. BETTER CHANCE LOOKS TO BE MONDAY NIGHT AS BOTH GFS/ECMWF SHOW
POTENT MID-UPPER LEVEL WAVE CRASHING INTO THE RIDGE OVER THE EASTERN
DAKOTAS. WITH STRONG DYNAMIC LIFT AND VERY STRONG LOW-MID LEVEL WINDS
AROUND SOUTH SIDE OF DEEP LOW...MAY NOT TAKE MUCH TO PRODUCE DAMAGING
WIND GUSTS WITH ANY STORMS THAT DEVELOP/MOVE INTO THE MORE UNSTABLE
AIR ACROSS THE SOUTHWEST CWA MONDAY NIGHT.
QUICK MOVING COMPACT SYSTEM WILL SHIFT EAST OF THE AREA TUESDAY...
THOUGH COULD SEE SOME SHOWERS WRAP AROUND INTO MAINLY NORTHERN PARTS
OF THE AREA TUESDAY BEFORE DRIER AIR BUILDS IN AND PRECIP THREAT
SHIFTS EAST OF THE AREA TUESDAY NIGHT. WITH STRONG SURFACE LOW
PASSING TO OUR NORTH TUESDAY...LIKELY TO SEE STRONG SYNOPTIC SCALE
FLOW DEVELOP IN WELL-MIXED DEEP WESTERLY FLOW BEHIND THE FRONT.
UPPER RIDGING WILL BRING DRY WEATHER BACK TO THE AREA FOR WEDNESDAY
AND WEDNESDAY NIGHT...WITH UPPER TROUGH SET TO MOVE INTO THE NORTHERN
PLAINS LATE IN THE WEEK. DIFFERENCES IN TIMING AMONG THE MODELS SO
WILL HAVE JUST A SLIGHT CHANCE OF THUNDERSTORMS IN THE WESTERN CWA
THURSDAY...WITH BETTER CHANCE HOLDING OFF UNTIL THURSDAY NIGHT OR
FRIDAY...DEPENDING ON EVENTUAL TIMING. TEMPERATURES WILL REMAIN ON
THE MILD SIDE OF NORMAL...THOUGH LATTER PART OF THE FORECAST PERIOD
SHOULD BE COOLER THAN THE NEXT FEW DAYS.
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
FOG HAS BEGUN TO DEVELOP ACROSS NORTHWEST IOWA AND IS EXPECTED TO
BECOME MORE WIDESPREAD OVER THE NEXT FEW HOURS. FOG APPEARS TO BE
DEVELOPING A FEW HOURS FASTER THAN THE HRRR OUTPUT. APPEARS AS
THOUGH CLOUD COVER WILL KEEP FOG POTENTIAL AT BAY FOR A FEW HOURS AT
KHON...BUT FOG IS EXPECTED TO IMPACT KFSD TERMINAL FIRST...THEN
EXPANDING TO KHON AND EVENTUALLY DOWN THE RIVER VALLEY IN NORTHWEST
IOWA. HAVE LOWERED EXPECTED VISIBILITIES IN THE TAFS...BUT HAVE NOT
MENTIONED QUARTER MILE YET EVEN THOUGH IT IS POSSIBLE. OVERNIGHT
CREW WILL HAVE TO WATCH THIS CLOSELY. WITH VERY WEAK WINDS ACROSS
THE AREA...FOG WILL LIKELY STICK AROUND THROUGH THE 15-17 TIME
FRAME...WHEN IT WILL GRADUALLY MIX OUT. THEREAFTER...LIGHT WINDS
AND MOSTLY CLEAR SKIES ARE EXPECTED.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR IAZ001>003-
012>014-020>022.
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ071-072-
080-081-089-090-097-098.
NE...NONE.
SD...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR SDZ038>040-
054>056-061-062-067.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1148 PM CDT THU MAR 22 2012
.UPDATE...FOR 06Z AVIATION DISCUSSION.
&&
.AVIATION...06Z AVIATION DISCUSSION.
UNCERTAINTIES...ACTUAL UPPER LEVEL LOW MOVEMENT/INFLUENCES AND
SHWR/TSTM DEVELOPMENT LENGTH AND COVERAGE. SEVERAL ADMS POSSIBLE
THRU 24/06Z. SOME GENERAL UNCERTAINTY WITH ACTUAL CLOUD COVERAGE
TRENDS...WITH POTENTIAL DRY SLOT DEVELOPMENT LEADING TO MVFR FOG
DEVELOPMENT 23/06Z-23/12Z. SHWRS/TSTMS SHOULD REDEVELOP PER
PROXIMITY OF UPPER LEVEL LOW AND DIURNAL HEATING INFLUENCES BY 23/17Z...
WITH VFR CU CEILINGS PREDOMINATE. PER QUESTIONS OF ACTUAL UPPER
LEVEL LOW PROXIMITY...WILL MENTION ONLY VCTS IN TAFS AFTER 24/00Z.
&&
.PREV DISCUSSION.../ISSUED 1022 PM CDT THU MAR 22 2012/
UPDATE...
CONVECTION ACROSS THE PLATEAU HAS NEARLY MOVED OUT OF THE AREA
LEAVING THE MID STATE VIRTUALLY PRECIP FREE RIGHT NOW.
HOWEVER...LATEST RUC AND NAM SOLUTIONS CONTINUE TO SHOW THAT SOME
LATE NIGHT UPPER LEVEL ENERGY COULD GET CONVECTION GOING ONCE
AGAIN. WILL GO AHEAD AND DROP POPS DOWN TO THE CHC CATEGORY ACROSS
OUR EAST.
PREV DISCUSSION... /ISSUED 651 PM CDT THU MAR 22 2012/
UPDATE...FOR 00Z AVIATION DISCUSSION.
AVIATION...00Z AVIATION DISCUSSION.
UNCERTAINTIES...ACTUAL UPPER LEVEL LOW MOVEMENT/INFLUENCES AND SHWR/TSTM
DEVELOPMENT. SEVERAL ADMS POSSIBLE THRU 23/24Z. SOME GENERAL
UNCERTAINTY WITH ACTUAL CLOUD COVERAGE TRENDS...ALONG WITH MVFR
FOG DEVELOPMENT 23/06Z-23/12Z CKV/BNA. THUS...DIMINISH LIGHT SHWRS
AND ERODE CEILINGS BY 23/03Z CKV/BNA...WITH REDEVELOPING
SHWRS/TSTMS PER DIURNAL INFLUENCES AND APPROACHING UPPER LEVEL LOW
BY 23/24Z...WITH VFR CEILINGS. PER BETTER OVERALL MOISTURE...CSV
MVFR CEILINGS WITH LIGHT SHWRS TRANISTIONING TO TSTMS FROM 23/14Z-23/24Z.
PREV DISCUSSION.../ISSUED 632 PM CDT THU MAR 22 2012/
UPDATE...
SFC BOUNDARY ACROSS WESTERN MIDDLE TN CONTINUES TO DECREASE IN
STRENGTH IN TERMS OF THE FORCING ASSOCIATED WITH IT. ACTIVITY
ACROSS OUR EASTERN ZONES IS IN RESPONSE TO AN UPPER IMPULSE WITHIN
THE SOUTHERLY FLOW ALOFT. REDEVELOPMENT ACROSS WESTERN ZONES IS
STILL EXPECTED AS ADDITIONAL UPPER LEVEL ENERGY IS EXPECTED TO LIFT
NORTHWARD OVERNIGHT. LATEST NAM12 AND RUC SOLUTIONS ARE IN FAVOR OF
REDEVELOPMENT. HOWEVER...ADDITIONAL QPF AMOUNTS ARE NOT
SIGNIFICANT AND LOOK TO BE ONLY AROUND ONE QUARTER INCH OR SO.
FOR TONIGHT...I WILL BE LEANING TOWARD LOWERING THE POPS AS THE
FUTURE CONVECTION IS DEPENDENT UPON REDEVELOPMENT AS OPPOSED TO
MIGRATION.
OTW...LOW TEMPS LOOK TO BE IN GOOD SHAPE. THE LOWER DEW POINTS ARE
WAY BACK TOWARD FAR WESTERN TN. STILL THOUGH...FOR LOW TEMPS WE SHOULD
SEE UPPER 50S WESTERN AREAS BY SUNRISE WITH NEAR 60 ELSEWHERE. A
GENERALLY LIGHT S/SE WIND FLOW SHOULD CONTINUE.
UPDATED GIRDS/ZONES OUT SHORTLY.
PREV DISCUSSION... /ISSUED 339 PM CDT THU MAR 22 2012/
SHORT TERM...BAND OF SHOWERS AND ISOLATED THUNDERSTORMS CONTINUES
TO MOVE SLOWLY EASTWARD ACROSS THE MID STATE THIS AFTERNOON. BY
MID-AFTERNOON, THE BAND WAS CENTERED NEAR THE I-65 CORRIDOR.
AFTERNOON TEMPERATURES WERE MAINLY IN THE 70S WHERE RAIN HAD NOT YET
ARRIVED, BUT WERE IN THE UPPER 50S TO UPPER 60S IN THE RAIN-COOLED
AIR.
MODEL SOLUTIONS ARE STILL QUITE SIMILAR WITH THEIR HANDLING OF
SLOW-MOVING CLOSED UPPER LOW OVER THE NEXT FEW DAYS. THE MAIN
FORECAST DIFFICULTY WILL BE THE EXACT LOCATION OF THE DRY SLOT
ON FRIDAY AND THE RESULTING SHOWER/THUNDERSTORM PATTERN TO THE EAST.
RIGHT NOW IT LOOKS LIKE BAND OF PRECIP WILL CONTINUE SLOGGING
EASTWARD OVERNIGHT, BUT WILL PROBABLY SLOW SOMEWHAT AS IT PUSHES
TOWARD THE PLATEAU LATER TONIGHT.
DEEPEST MOISTURE SHOULD BE OVER EASTERN MIDDLE TENNESSEE FRIDAY,
WHERE DAYTIME INSTABILITY WILL BE GREATEST, ALONG WITH AT LEAST A
SLIGHT CHANCE FOR SEVERE THUNDERSTORMS (ATTENDED BY HAIL AND DAMAGING
STRAIGHT LINE WINDS). MEANWHILE, EXPECT WESTERN AREAS TO DRY OUT
DURING THE DAY.
AS CLOSED UPPER LOW PUSHES TO THE OHIO RIVER ON FRIDAY NIGHT, IT
SHOULD BE ACCOMPANIED BY A CIRCULAR AREA OF CLOUDS SIMILAR TO WHAT
WE`VE OBSERVED OVER THE PLAINS STATES TODAY. AS A RESULT EXPECT CLOUDS,
ALONG WITH A CHANCE OF SHOWERS AND THUNDERSTORMS, TO BE PRESENT
IN A RELATIVELY BROAD SWATH TO THE SOUTH AND EAST OF THE LOW PRESSURE
CENTER.
ON SATURDAY, AS COLD CORE LOW DROPS EAST-SOUTHEASTWARD ACROSS THE
TENNESSEE VALLEY, WE WILL SEE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS IN MIDDLE TENNESSEE. WITH COLDER AIR ALOFT, WOULD
NOT BE SURPRISED TO SEE SOME "HAILERS" ON SATURDAY.
SHOWERS FINALLY PULL EAST OF OUR AREA BY SUNDAY, AND GIVE WAY TO
A SPELL OF DRY WEATHER SUNDAY THROUGH TUESDAY. A RIDGE OF HIGH
PRESSURE BUILDS IN FROM THE WEST, ACCOMPANIED BY A WARMING TREND.
FOLLOWING WEEKEND HIGH TEMPERATURES IN THE UPPER 60S TO LOWER 70S
AT NASHVILLE, HIGHS WILL LIKELY PUSH BACK TO NEAR 80 DEGREES BY
TUESDAY.
LONG TERM...A SHORTWAVE WILL PUSH IN AND DAMPEN OUR FRIENDLY RIDGE
BY THE MIDDLE-TO-LATTER PART OF NEXT WEEK, BRINGING ALONG ANOTHER
CHANCE FOR SHOWERS AND THUNDERSTORMS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1046 PM CDT SAT MAR 24 2012
.UPDATE...
TEMPERATURES WERE RUNNING A BIT WARMER THAN PREVIOUSLY FORECAST
OVER AREAS NORTHEAST OF THE DALLAS FORT WORTH METROPLEX. WILL
INCREASE OVERNIGHT LOWS BY A FEW DEGREES IN THESE AREAS BASED ON
TRENDS AND NEW GUIDANCE. OTHERWISE PATCHY FOG STILL LOOKS LIKE A
POSSIBILITY PRIMARILY SOUTH OF I 20 BY SUNRISE.
30
&&
.AVIATION...
FOR THE 00Z TAFS...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH
THE VALID FORECAST PERIOD EXCEPT FOR THE POSSIBILITY OF SOME EARLY
MORNING FOG AROUND WACO.
A SURFACE RIDGE OF HIGH PRESSURE IN PLACE OVER NORTH TX WILL SLIDE
SLOWLY OFF TO THE NORTHEAST THROUGH THE OVERNIGHT HRS. THIS WILL
ALLOW FOR A RETURN OF SHALLOW MOISTURE TO THE AREA SOUTHWEST OF
THE RIDGE AXIS BY SUNRISE. LATEST GUIDANCE INDICATES THAT THIS
RETURN OF SHALLOW MOISTURE WILL REMAIN SOUTHWEST OF METROPLEX AREA
TAF SITES...BUT WILL END UP AFFECTING THE WACO AREA JUST BEFORE
SUNRISE. BASED ON LATEST RUC FORECAST SOUNDINGS DECIDED TO INCLUDE
A FEW HRS OF IFR VSBYS AT KACT IN THE 11 TO 15Z TIMEFRAME AS A
SHALLOW INVERSION OF TEMPERATURE AND MOISTURE IS INDICATED. WITH
CLEAR SKIES AND LIGHT WIND IN PLACE THIS SET-UP SHOULD RESULT IN
AREAS OF GROUND FOG WITHIN THIS TIMEFRAME. AFTER A COUPLE OF HOURS
OF HEATING...EXPECT THIS SHALLOW INVERSION TO MIX OUT RESULTING IN
A QUICK DISPERSION OF ANY GROUND FOG NEAR KACT. VFR CONDITIONS ARE
EXPECTED FOR THE REMAINDER OF THE FORECAST PERIOD.
CAVANAUGH
&&
.PREV DISCUSSION... /ISSUED 336 PM CDT SAT MAR 24 2012/
SURFACE RIDGE AXIS REMAINS OVER THE EASTERN CWA WITH WEAK
SOUTHERLY FLOW OVER THE WESTERN ZONES BEGINNING TO BRING HIGHER
GULF MOISTURE NORTHWARD. DENSE FOG DEVELOPED OVER THE HILL CENTRAL
AND SOUTHEAST TEXAS LAST NIGHT. EXPECT FOG TO DEVELOP AGAIN
TONIGHT...THIS TIME A LITTLE FARTHER NORTH...PRIMARILY ALONG AND
WEST OF THE BRAZOS RIVER VALLEY WHERE TONGUE OF HIGHER SURFACE
MOISTURE WILL SET UP. ASIDE FROM ANY FOG...A GENERALLY
CLEAR...CALM...AND COMFORTABLE NIGHT IS IN STORE. ANOTHER MILD AND
PLEASANT DAY IS EXPECTED SUNDAY WITH HIGHS IN THE LOWER 80S.
SURFACE RIDGE WILL SHIFT TO THE EAST BY SUNDAY NIGHT AND SOUTHERLY
WINDS WILL GRADUALLY INCREASE TO 10-15 MPH BY MONDAY. AS A RESULT
GULF MOISTURE AND OVERNIGHT LOW TEMPS SLOWLY INCREASE EARLY NEXT
WEEK...BUT HIGH TEMPS REMAIN MILD.
CLOUD COVER IS EXPECTED TO ARRIVE MONDAY NIGHT AND TUESDAY AS A
SHORTWAVE TRACKS ACROSS COLORADO AND INTO THE NORTHERN PLAINS. A
FEW STORMS MAY FIRE ALONG THE DRY LINE IN THE TX PANHANDLE MONDAY
EVENING BUT THE FORCING REMAINS WELL NORTHWEST OF OUR AREA FOR ANY
RAIN CHANCES HERE. MID-HIGH CLOUD COVER WILL BE MOST ABUNDANT ON
TUESDAY WHICH MAY HOLD AFTERNOON HIGHS DOWN A DEGREE OR TWO FROM
MONDAY/S READINGS. OTHERWISE WITH SOUTHERLY FLOW CONTINUING...
EXPECT MORNING STRATUS AND AFTERNOON SUN WITH HIGHS NEAR 80 AND
LOWS NEAR 60 FOR THE MIDWEEK PERIOD.
MODELS ARE IN DECENT AGREEMENT IN THE SYNOPTIC PATTERN BY THE END
OF THE WEEK. THE WESTERLIES ARE EXPECTED TO WEAKEN ACROSS THE
REGION AS THE POLAR JET SETS UP OVER THE CANADIAN BORDER AND THE
SUBTROPICAL JET BECOMES SITUATED ACROSS CENTRAL MEXICO. IN THE VOID
BETWEEN THE TWO...IT APPEARS THE SYNOPTIC ENVIRONMENT WILL BE
FAVORABLE FOR A SHORTWAVE TO INTENSIFY INTO A SLOW MOVING UPPER
LOW OVER TEXAS BY FRIDAY. THE INTENSIFICATION OF THE SHORTWAVE
INTO AN UPPER LOW RESULTS PRIMARILY FROM AN ATMOSPHERIC CONVECTIVE
FEEDBACK...WHERE THE RELEASE OF LATENT HEAT FROM CONVECTION /NOT
THERMAL GRADIENTS/ STRENGTHEN THE VORTEX. GFS/ECMWF/GEM ALL SHOW
THIS UPPER LOW BECOMING A VERTICALLY STACKED AND WARM-CORE
SYSTEM...WITH THE CYCLONIC CIRCULATION EXTENDING DOWN TO THE
SURFACE. CYCLONES OF THIS NATURE ARE NOT UNCOMMON IN THE SUMMER
MONTHS AND ARE NOTORIOUS FOR HEAVY RAIN. HOWEVER...SINCE THIS IS
OCCURRING SO EARLY IN THE YEAR...MOISTURE/INSTABILITY CONTENT IS
PROBABLY NOT HIGH ENOUGH TO RESULT IN SIGNIFICANT CONVECTION OR
HEAVY RAINS. THE BEST CHANCES OF RAIN WILL PROBABLY OCCUR ON
FRIDAY WHEN THE LOW IS OVERHEAD...BUT WILL BE CONSERVATIVE WITH
POPS FOR NOW. HIGH TEMPS SHOULD COOL INTO THE 70S DUE TO CLOUD
COVER AND SCATTERED RAIN SHOWERS...WITH LOWS IN THE LOW-MID 60S.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 57 83 59 83 61 / 0 0 0 0 10
WACO, TX 55 82 56 83 58 / 0 0 0 0 5
PARIS, TX 52 80 53 82 57 / 0 0 0 0 5
DENTON, TX 51 83 56 83 59 / 0 0 0 0 10
MCKINNEY, TX 50 81 53 81 57 / 0 0 0 0 10
DALLAS, TX 58 83 60 83 61 / 0 0 0 0 10
TERRELL, TX 51 82 55 82 58 / 0 0 0 0 5
CORSICANA, TX 57 83 56 82 58 / 0 0 0 0 5
TEMPLE, TX 56 83 56 83 57 / 0 0 0 0 5
MINERAL WELLS, TX 57 84 55 83 57 / 0 0 0 0 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
69/30
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1000 PM CDT SAT MAR 24 2012
.DISCUSSION...CURRENT OBS AND MSAS DATA INDICATE HIGHER SWATH OF
MOISTURE LOCATED ALONG AND OFFSHORE OF THE SOUTHERN COASTAL BEND
AND LOWER TEXAS COAST. THIS MOISTURE...ALBEIT SHALLOW...WILL
CONTINUE TO ADVECT INLAND OVERNIGHT WITH STRATUS LIKELY TO DEVELOP
ALONG WITH SOME FOG. NAM AND RUC PROG GREATEST FOG POTENTIAL TO BE
LOCATED INLAND ALONG AND IN BETWEEN THE HWY 281 AND 77 CORRIDORS.
CHANGES TO THE FORECAST WERE TO ALTER DIURNAL DROP OF HOURLY
TEMPS ACROSS THE REGION TO SHOW MORE TEMPERATE COOLING THIS
EVENING AND TO CHANGE DEWPOINTS TO REFLECT HIGHER MOISTURE VALUES
MOVING ONSHORE. ALSO ENHANCED FOG WORKING SLIGHTLY FOR AREAS
MENTIONED ABOVE. UPDATED PRODUCTS WILL BE OUT SHORTLY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 65 84 64 83 66 / 0 0 10 0 10
VICTORIA 61 83 60 84 62 / 0 0 10 0 10
LAREDO 68 91 68 90 69 / 0 10 10 10 10
ALICE 65 86 65 86 64 / 0 0 10 10 10
ROCKPORT 67 80 67 80 68 / 0 0 10 0 10
COTULLA 62 86 63 86 64 / 0 10 10 10 10
KINGSVILLE 65 83 65 85 65 / 0 0 10 0 10
NAVY CORPUS 68 79 66 79 69 / 0 0 10 0 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
UPDATE...HART/79
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
703 PM CDT SAT MAR 24 2012
.AVIATION...
FOR THE 00Z TAFS...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH
THE VALID FORECAST PERIOD EXCEPT FOR THE POSSIBILITY OF SOME EARLY
MORNING FOG AROUND WACO.
A SURFACE RIDGE OF HIGH PRESSURE IN PLACE OVER NORTH TX WILL SLIDE
SLOWLY OFF TO THE NORTHEAST THROUGH THE OVERNIGHT HRS. THIS WILL
ALLOW FOR A RETURN OF SHALLOW MOISTURE TO THE AREA SOUTHWEST OF
THE RIDGE AXIS BY SUNRISE. LATEST GUIDANCE INDICATES THAT THIS
RETURN OF SHALLOW MOISTURE WILL REMAIN SOUTHWEST OF METROPLEX AREA
TAF SITES...BUT WILL END UP AFFECTING THE WACO AREA JUST BEFORE
SUNRISE. BASED ON LATEST RUC FORECAST SOUNDINGS DECIDED TO INCLUDE
A FEW HRS OF IFR VSBYS AT KACT IN THE 11 TO 15Z TIMEFRAME AS A
SHALLOW INVERSION OF TEMPERATURE AND MOISTURE IS INDICATED. WITH
CLEAR SKIES AND LIGHT WIND IN PLACE THIS SET-UP SHOULD RESULT IN
AREAS OF GROUND FOG WITHIN THIS TIMEFRAME. AFTER A COUPLE OF HOURS
OF HEATING...EXPECT THIS SHALLOW INVERSION TO MIX OUT RESULTING IN
A QUICK DISPERSION OF ANY GROUND FOG NEAR KACT. VFR CONDITIONS ARE
EXPECTED FOR THE REMAINDER OF THE FORECAST PERIOD.
CAVANAUGH
&&
.PREV DISCUSSION... /ISSUED 336 PM CDT SAT MAR 24 2012/
SURFACE RIDGE AXIS REMAINS OVER THE EASTERN CWA WITH WEAK
SOUTHERLY FLOW OVER THE WESTERN ZONES BEGINNING TO BRING HIGHER
GULF MOISTURE NORTHWARD. DENSE FOG DEVELOPED OVER THE HILL CENTRAL
AND SOUTHEAST TEXAS LAST NIGHT. EXPECT FOG TO DEVELOP AGAIN
TONIGHT...THIS TIME A LITTLE FARTHER NORTH...PRIMARILY ALONG AND
WEST OF THE BRAZOS RIVER VALLEY WHERE TONGUE OF HIGHER SURFACE
MOISTURE WILL SET UP. ASIDE FROM ANY FOG...A GENERALLY
CLEAR...CALM...AND COMFORTABLE NIGHT IS IN STORE. ANOTHER MILD AND
PLEASANT DAY IS EXPECTED SUNDAY WITH HIGHS IN THE LOWER 80S.
SURFACE RIDGE WILL SHIFT TO THE EAST BY SUNDAY NIGHT AND SOUTHERLY
WINDS WILL GRADUALLY INCREASE TO 10-15 MPH BY MONDAY. AS A RESULT
GULF MOISTURE AND OVERNIGHT LOW TEMPS SLOWLY INCREASE EARLY NEXT
WEEK...BUT HIGH TEMPS REMAIN MILD.
CLOUD COVER IS EXPECTED TO ARRIVE MONDAY NIGHT AND TUESDAY AS A
SHORTWAVE TRACKS ACROSS COLORADO AND INTO THE NORTHERN PLAINS. A
FEW STORMS MAY FIRE ALONG THE DRY LINE IN THE TX PANHANDLE MONDAY
EVENING BUT THE FORCING REMAINS WELL NORTHWEST OF OUR AREA FOR ANY
RAIN CHANCES HERE. MID-HIGH CLOUD COVER WILL BE MOST ABUNDANT ON
TUESDAY WHICH MAY HOLD AFTERNOON HIGHS DOWN A DEGREE OR TWO FROM
MONDAY/S READINGS. OTHERWISE WITH SOUTHERLY FLOW CONTINUING...
EXPECT MORNING STRATUS AND AFTERNOON SUN WITH HIGHS NEAR 80 AND
LOWS NEAR 60 FOR THE MIDWEEK PERIOD.
MODELS ARE IN DECENT AGREEMENT IN THE SYNOPTIC PATTERN BY THE END
OF THE WEEK. THE WESTERLIES ARE EXPECTED TO WEAKEN ACROSS THE
REGION AS THE POLAR JET SETS UP OVER THE CANADIAN BORDER AND THE
SUBTROPICAL JET BECOMES SITUATED ACROSS CENTRAL MEXICO. IN THE VOID
BETWEEN THE TWO...IT APPEARS THE SYNOPTIC ENVIRONMENT WILL BE
FAVORABLE FOR A SHORTWAVE TO INTENSIFY INTO A SLOW MOVING UPPER
LOW OVER TEXAS BY FRIDAY. THE INTENSIFICATION OF THE SHORTWAVE
INTO AN UPPER LOW RESULTS PRIMARILY FROM AN ATMOSPHERIC CONVECTIVE
FEEDBACK...WHERE THE RELEASE OF LATENT HEAT FROM CONVECTION /NOT
THERMAL GRADIENTS/ STRENGTHEN THE VORTEX. GFS/ECMWF/GEM ALL SHOW
THIS UPPER LOW BECOMING A VERTICALLY STACKED AND WARM-CORE
SYSTEM...WITH THE CYCLONIC CIRCULATION EXTENDING DOWN TO THE
SURFACE. CYCLONES OF THIS NATURE ARE NOT UNCOMMON IN THE SUMMER
MONTHS AND ARE NOTORIOUS FOR HEAVY RAIN. HOWEVER...SINCE THIS IS
OCCURRING SO EARLY IN THE YEAR...MOISTURE/INSTABILITY CONTENT IS
PROBABLY NOT HIGH ENOUGH TO RESULT IN SIGNIFICANT CONVECTION OR
HEAVY RAINS. THE BEST CHANCES OF RAIN WILL PROBABLY OCCUR ON
FRIDAY WHEN THE LOW IS OVERHEAD...BUT WILL BE CONSERVATIVE WITH
POPS FOR NOW. HIGH TEMPS SHOULD COOL INTO THE 70S DUE TO CLOUD
COVER AND SCATTERED RAIN SHOWERS...WITH LOWS IN THE LOW-MID 60S.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 56 83 59 83 61 / 0 0 0 0 10
WACO, TX 55 82 56 83 58 / 0 0 0 0 5
PARIS, TX 49 80 53 82 57 / 0 0 0 0 5
DENTON, TX 51 83 56 83 59 / 0 0 0 0 10
MCKINNEY, TX 49 81 53 81 57 / 0 0 0 0 10
DALLAS, TX 57 83 60 83 61 / 0 0 0 0 10
TERRELL, TX 51 82 55 82 58 / 0 0 0 0 5
CORSICANA, TX 55 83 56 82 58 / 0 0 0 0 5
TEMPLE, TX 57 83 56 83 57 / 0 0 0 0 5
MINERAL WELLS, TX 53 84 55 83 57 / 0 0 0 0 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
152 PM EDT FRI MAR 23 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL TRACK EAST OUT OF THE MID MISSISSIPPI
VALLEY TODAY...THEN SOUTHEAST ACROSS THE TENNESSEE VALLEY ON
SATURDAY. BY MONDAY THE SYSTEM WILL BE OFF THE EAST COAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 130 PM EDT FRIDAY...
CONVECTION DEVELOPING IN UNSTABLE AIR THIS AFTERNOON ACROSS THE
WESTERN MOUNTAINS. ADJUSTED POPS AND TEMPERATURES FOR LATEST TRENDS.
AS OF 1140 AM EDT FRIDAY...
ADJUSTED THE ONSET OF CONVECTION AND RAISED TEMPERATURES A FEW
DEGREES THIS AFTERNOON. PLAYED EARLY POPS CLOSE TO HRRR THIS AFTERNOON.
ADJUSTMENTS MADE IN CLOUD COVER THIS AFTERNOON INTO TONIGHT.
AS OF 925 AM EDT FRIDAY...
THE UPPER LOW OVER THE PLAINS WILL MOVE SLOWLY EASTWARD THIS
AFTERNOON AND TONIGHT...THIS WILL PUSH AN OCCLUDED SURFACE FRONT
AND ASSOCIATED MOISTURE EASTWARD. THIS MORNING WRFARW-RNK AND NAM
BRINGS SOME CONVECTION INTO THE WEST THIS AFTERNOON AND SPREAD
STORMS EAST TONIGHT. EXPECT ISOLATED TO SCATTERED THUNDERSTORMS
IN THE AFTERNOON MAINLY WEST OF I77...THEN BETTER COVERAGE ANTICIPATED
AFTER 8PM/00Z TONIGHT. AS PREVIOUS SHIFT POINT OUT...THE THREAT
OF SEVERE THUNDERSTORMS...ESPECIALLY HAIL...INCREASES BY THIS
EVENING INTO SATURDAY AS THE UPPER LOW AND COLD POOL GET CLOSER. THE DAY2
CONVECTIVE OUTLOOK PLACES EAST OF THE MOUNTAINS IN A SLIGHT RISK
ON SATURDAY. MADE SOME MINOR ADJUSTMENTS IN ISC GRIDS FOR
TEMPERATURES...AND POPS FOR THIS AFTERNOON.
AS OF 400 AM EDT FRIDAY...
MODELS SIMILAR WITH TIMING OF APPROACHING OCCLUDED FRONT AND
ASSOCIATED PRECIPITATION. THERE MAY BE ISOLATED TO SCATTERED
THUNDERSTORMS IN THE AFTERNOON BUT THE BETTER PROBABILITY AND
COVERAGE OF PRECIPITATION WILL BE AFTER 8PM/00Z TONIGHT. THE
THREAT OF SEVERE THUNDERSTORMS...ESPECIALLY HAIL...INCREASES BY
THIS EVENING AS THE UPPER LOW AND COLD POOL GET CLOSER.
MADE ONLY MINOR ADJUSTMENTS FOR HIGHS TODAY. STAYED CLOSE TO LAMP
GUIDANCE. MILD DEW POINTS AND CLOUDS COVER WILL HOLD TEMPERATURES
UP TONIGHT. USED A BLEND OF BIAS CORRECTED MET/MAV GUIDANCE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 400 AM EDT FRIDAY...
STRONG CYCLONE WHICH HAS BEEN QUASI-STATIONARY OVER THE SOUTHERN
PLAINS WILL FINALLY TRACK EAST AND ACROSS THE MID ATLANTIC REGION
THIS WEEKEND. THIS FEATURE IS EXPECTED TO SLOWLY TREK ACROSS THE
AREA SATURDAY AND SUNDAY WITH SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS. INITIAL WAVE OF PRECIP SHOULD HAVE PASSED THROUGH THE
CWA BY 12 UTC...8AM SATURDAY...ASSOCIATED WITH THE OCCLUDED SURFACE
FRONT. WITH PASSAGE OF OCCLUSION...SHOULD SEE A BREAK IN THE PRECIP
WITH STRONG INDICATION THAT A DRY SLOT WILL WORK ACROSS THE FCST
AREA PRIOR TO ARRIVAL OF PRECIP UNDERNEATH THE UPPER LOW. IF THIS
BREAK IN PRECIP ASSOCIATED WITH THE DRY SLOT REVEALS ANY
CLEARING...THEN SOLAR INSOLATION LIKELY TO INCREASE INSTABILITY
ACROSS THE CWA INCREASING POTENTIAL FOR SEVERE STORMS. IF THIS TURNS
OUT TO BE THE CASE...WILL THEN NEED TO ENTERTAIN POSSIBILITY OF
SUPERCELLS PER INCREASING DEEP LAYER SHEAR AHEAD OF THE APPROACHING
UPPER VORTEX.
WILL DEFER TO THE STORM PREDICTION CENTER FOR GUIDANCE ON THIS
DEVELOPING SITUATION...BUT IT APPEARS THE GREATEST THREAT FOR SEVERE
WEATHER MAY RESIDE JUST SOUTH OF THE FCST AREA.
FOR SATURDAY NIGHT AND SUNDAY THE UPPER LOW IS PROGGED TO PASS
DIRECTLY OVER THE MID ATLANTIC REGION...THE CENTER OF THE LOW
SPIRALING EAST AND OFF THE COAST SUNDAY NIGHT. FOCUS SATURDAY NIGHT
THROUGH SUNDAY WILL BE FOR SCATTERED TO NUMEROUS SHOWERS AND
EMBEDDED THUNDERSTORMS...THE THREAT FOR PRECIP PERSISTING UNTIL THE
STORM SYSTEM PASSES EAST OF THE REGION SUNDAY NIGHT.
TEMPERATURES WILL TREND DOWNWARD OVER THE WEEKEND...SATURDAY BEING
THE WARMER OF THE TWO DAYS WITH READINGS IN THE 70S PENDING A BIT OF
SUN. SHAVE ABOUT 10 DEGREES OFF THE TMAX FOR SUNDAY COMPARED TO
SATURDAY...SUNDAY STILL TOPPING OUT 4-8 DEGREES ABOVE THE NORM.
QPF FOR THE ENTIRE EVENT...NOON FRIDAY THROUGH MIDNIGHT SUNDAY NIGHT
LOOKS TO BE ON THE ORDER OF ONE TO TWO INCHES...THE HIGHER AMOUNTS
FAVORING CONVEYOR BELT OF DEEPER MOISTURE THAT WILL RESIDE ON THE
NORTH SIDE OF THE CYCLONE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 400 AM EDT FRIDAY...
CYCLONE IS PROGGED TO BE WELL EAST OF THE AREA BY 12Z MONDAY...
BOOTED OUT TO SEA BY A STRONG NORTHERN STREAM TROF THAT WILL DIVE
SOUTHEAST ACROSS NEW ENGLAND FROM EASTERN CANADA. THE COMBINATION OF
THE EXITING CYCLONE AND TROF OVER NEW ENGLAND WILL BRING BREEZY
CONDITIONS TO THE AREA MONDAY AND MONDAY NIGHT...FOLLOWED BY A SUNNY
DRY DAY FOR TUESDAY. TEMPERATURES WILL BEGIN TO MODERATE
TUESDAY...WITH A MORE SIGNIFICANT REBOUND WEDNESDAY AS THE LOW LEVEL
FLOW BECOMES SOUTHWESTERLY. ATTM WILL MAINTAIN A DRY FORECAST FOR
MIDWEEK BUT WILL HAVE TO KEEP EYES ON FAST MOVING FRONT WHICH IS
PROGGED TO MOVE ACROSS THE OHIO VALLEY WEDNESDAY...POSSIBLY ARRIVING
ACROSS OUR THE MTNS AS EARLY AS WEDNESDAY AFTERNOON. THIS SOLUTION
IS ABOUT 12-18 HOURS FASTER THAN PREVIOUS MODEL RUNS.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1140 AM EDT FRIDAY...
THIS MORNING PATCHY FOG DISSIPATED QUICKLY...LEAVING PLENTY OF
SUNSHINE. CLOUDS WILL FILL IN FROM WEST TO EAST THIS AFTERNOON INTO
TONIGHT WITH CEILINGS LOWERING TONIGHT. MODERATE CONFIDENCE THAT
CEILINGS WILL REMAIN VFR AS THE PRECIPITATION BEGINS. AFTER 00Z
TONIGHT...THERE IS A CHANCE THAT BLF AND LWB MAY HAVE MVFR/IFR CEILINGS
AND VISIBILITIES WITH CONVECTION AND LOW CLOUDS.
MODELS BRING PRECIPITATION ASSOCIATED WITH THE CLOSED UPPER LOW
OVER THE MIDWEST INTO THE FORECAST AREA AFTER 00Z. MORE WIDESPREAD
RAIN IS EXPECTED SATURDAY THROUGH SUNDAY AS THE LOW MOVES EAST
THEN SOUTHEAST.
DRIER WEATHER AND VFR CONDITIONS ARE EXPECTED BEHIND THE SYSTEM
SUNDAY NIGHT THROUGH TUESDAY.
&&
.CLIMATE...
RECORD HIGH TEMPS FOR TODAY...
3/23
ROANOKE 82 IN 2007
LYNCHBURG 91 IN 2007
DANVILLE 86 IN 1966
BLUEFIELD 77 IN 2007
BLACKSBURG 80 IN 1966
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/KK
SHORT TERM...PM
LONG TERM...WP
AVIATION...AMS
CLIMATE...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1147 AM EDT FRI MAR 23 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL TRACK EAST OUT OF THE MID MISSISSIPPI
VALLEY TODAY...THEN SOUTHEAST ACROSS THE TENNESSEE VALLEY ON
SATURDAY. BY MONDAY THE SYSTEM WILL BE OFF THE EAST COAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1140 AM EDT FRIDAY...
ADJUSTED THE ONSET OF CONVECTION AND RAISED TEMPERATURES A FEW
DEGREES THIS AFTERNOON. PLAYED EARLY POPS CLOSE TO HRRR THIS AFTERNOON.
ADJUSTMENTS MADE IN CLOUD COVER THIS AFTERNOON INTO TONIGHT.
AS OF 925 AM EDT FRIDAY...
THE UPPER LOW OVER THE PLAINS WILL MOVE SLOWLY EASTWARD THIS
AFTERNOON AND TONIGHT...THIS WILL PUSH AN OCCLUDED SURFACE FRONT
AND ASSOCIATED MOISTURE EASTWARD. THIS MORNING WRFARW-RNK AND NAM
BRINGS SOME CONVECTION INTO THE WEST THIS AFTERNOON AND SPREAD
STORMS EAST TONIGHT. EXPECT ISOLATED TO SCATTERED THUNDERSTORMS
IN THE AFTERNOON MAINLY WEST OF I77...THEN BETTER COVERAGE ANTICIPATED
AFTER 8PM/00Z TONIGHT. AS PREVIOUS SHIFT POINT OUT...THE THREAT
OF SEVERE THUNDERSTORMS...ESPECIALLY HAIL...INCREASES BY THIS
EVENING INTO SATURDAY AS THE UPPER LOW AND COLD POOL GET CLOSER. THE DAY2
CONVECTIVE OUTLOOK PLACES EAST OF THE MOUNTAINS IN A SLIGHT RISK
ON SATURDAY. MADE SOME MINOR ADJUSTMENTS IN ISC GRIDS FOR
TEMPERATURES...AND POPS FOR THIS AFTERNOON.
AS OF 400 AM EDT FRIDAY...
MODELS SIMILAR WITH TIMING OF APPROACHING OCCLUDED FRONT AND
ASSOCIATED PRECIPITATION. THERE MAY BE ISOLATED TO SCATTERED
THUNDERSTORMS IN THE AFTERNOON BUT THE BETTER PROBABILITY AND
COVERAGE OF PRECIPITATION WILL BE AFTER 8PM/00Z TONIGHT. THE
THREAT OF SEVERE THUNDERSTORMS...ESPECIALLY HAIL...INCREASES BY
THIS EVENING AS THE UPPER LOW AND COLD POOL GET CLOSER.
MADE ONLY MINOR ADJUSTMENTS FOR HIGHS TODAY. STAYED CLOSE TO LAMP
GUIDANCE. MILD DEW POINTS AND CLOUDS COVER WILL HOLD TEMPERATURES
UP TONIGHT. USED A BLEND OF BIAS CORRECTED MET/MAV GUIDANCE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 400 AM EDT FRIDAY...
STRONG CYCLONE WHICH HAS BEEN QUASI-STATIONARY OVER THE SOUTHERN
PLAINS WILL FINALLY TRACK EAST AND ACROSS THE MID ATLANTIC REGION
THIS WEEKEND. THIS FEATURE IS EXPECTED TO SLOWLY TREK ACROSS THE
AREA SATURDAY AND SUNDAY WITH SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS. INITIAL WAVE OF PRECIP SHOULD HAVE PASSED THROUGH THE
CWA BY 12 UTC...8AM SATURDAY...ASSOCIATED WITH THE OCCLUDED SURFACE
FRONT. WITH PASSAGE OF OCCLUSION...SHOULD SEE A BREAK IN THE PRECIP
WITH STRONG INDICATION THAT A DRY SLOT WILL WORK ACROSS THE FCST
AREA PRIOR TO ARRIVAL OF PRECIP UNDERNEATH THE UPPER LOW. IF THIS
BREAK IN PRECIP ASSOCIATED WITH THE DRY SLOT REVEALS ANY
CLEARING...THEN SOLAR INSOLATION LIKELY TO INCREASE INSTABILITY
ACROSS THE CWA INCREASING POTENTIAL FOR SEVERE STORMS. IF THIS TURNS
OUT TO BE THE CASE...WILL THEN NEED TO ENTERTAIN POSSIBILITY OF
SUPERCELLS PER INCREASING DEEP LAYER SHEAR AHEAD OF THE APPROACHING
UPPER VORTEX.
WILL DEFER TO THE STORM PREDICTION CENTER FOR GUIDANCE ON THIS
DEVELOPING SITUATION...BUT IT APPEARS THE GREATEST THREAT FOR SEVERE
WEATHER MAY RESIDE JUST SOUTH OF THE FCST AREA.
FOR SATURDAY NIGHT AND SUNDAY THE UPPER LOW IS PROGGED TO PASS
DIRECTLY OVER THE MID ATLANTIC REGION...THE CENTER OF THE LOW
SPIRALING EAST AND OFF THE COAST SUNDAY NIGHT. FOCUS SATURDAY NIGHT
THROUGH SUNDAY WILL BE FOR SCATTERED TO NUMEROUS SHOWERS AND
EMBEDDED THUNDERSTORMS...THE THREAT FOR PRECIP PERSISTING UNTIL THE
STORM SYSTEM PASSES EAST OF THE REGION SUNDAY NIGHT.
TEMPERATURES WILL TREND DOWNWARD OVER THE WEEKEND...SATURDAY BEING
THE WARMER OF THE TWO DAYS WITH READINGS IN THE 70S PENDING A BIT OF
SUN. SHAVE ABOUT 10 DEGREES OFF THE TMAX FOR SUNDAY COMPARED TO
SATURDAY...SUNDAY STILL TOPPING OUT 4-8 DEGREES ABOVE THE NORM.
QPF FOR THE ENTIRE EVENT...NOON FRIDAY THROUGH MIDNIGHT SUNDAY NIGHT
LOOKS TO BE ON THE ORDER OF ONE TO TWO INCHES...THE HIGHER AMOUNTS
FAVORING CONVEYOR BELT OF DEEPER MOISTURE THAT WILL RESIDE ON THE
NORTH SIDE OF THE CYCLONE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 400 AM EDT FRIDAY...
CYCLONE IS PROGGED TO BE WELL EAST OF THE AREA BY 12Z MONDAY...
BOOTED OUT TO SEA BY A STRONG NORTHERN STREAM TROF THAT WILL DIVE
SOUTHEAST ACROSS NEW ENGLAND FROM EASTERN CANADA. THE COMBINATION OF
THE EXITING CYCLONE AND TROF OVER NEW ENGLAND WILL BRING BREEZY
CONDITIONS TO THE AREA MONDAY AND MONDAY NIGHT...FOLLOWED BY A SUNNY
DRY DAY FOR TUESDAY. TEMPERATURES WILL BEGIN TO MODERATE
TUESDAY...WITH A MORE SIGNIFICANT REBOUND WEDNESDAY AS THE LOW LEVEL
FLOW BECOMES SOUTHWESTERLY. ATTM WILL MAINTAIN A DRY FORECAST FOR
MIDWEEK BUT WILL HAVE TO KEEP EYES ON FAST MOVING FRONT WHICH IS
PROGGED TO MOVE ACROSS THE OHIO VALLEY WEDNESDAY...POSSIBLY ARRIVING
ACROSS OUR THE MTNS AS EARLY AS WEDNESDAY AFTERNOON. THIS SOLUTION
IS ABOUT 12-18 HOURS FASTER THAN PREVIOUS MODEL RUNS.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
AS OF 1140 AM EDT FRIDAY...
THIS MORNING PATCHY FOG DISSIPATED QUICKLY...LEAVING PLENTY OF
SUNSHINE. CLOUDS WILL FILL IN FROM WEST TO EAST THIS AFTERNOON INTO
TONIGHT WITH CEILINGS LOWERING TONIGHT. MODERATE CONFIDENCE THAT
CEILINGS WILL REMAIN VFR AS THE PRECIPITATION BEGINS. AFTER 00Z
TONIGHT...THERE IS A CHANCE THAT BLF AND LWB MAY HAVE MVFR CEILINGS
AND VISIBILITIES WITH CONVECTION AND LOW CLOUDS.
MODELS BRING PRECIPITATION ASSOCIATED WITH THE CLOSED UPPER LOW
OVER THE MIDWEST INTO THE FORECAST AREA AFTER 00Z. MORE WIDESPREAD
RAIN IS EXPECTED SATURDAY THROUGH SUNDAY AS THE LOW MOVES EAST
THEN SOUTHEAST.
DRIER WEATHER AND VFR CONDITIONS ARE EXPECTED BEHIND THE SYSTEM
SUNDAY NIGHT THROUGH TUESDAY.
&&
.CLIMATE...
RECORD HIGH TEMPS FOR TODAY...
3/23
ROANOKE 82 IN 2007
LYNCHBURG 91 IN 2007
DANVILLE 86 IN 1966
BLUEFIELD 77 IN 2007
BLACKSBURG 80 IN 1966
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/KK
SHORT TERM...PM
LONG TERM...WP
AVIATION...AMS
CLIMATE...
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1054 PM CDT SAT MAR 24 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A LARGE CUT-OFF
LOW PRESSURE SYSTEM MOVING SE OVER KENTUCKY AND TENNESSEE EARLY THIS
AFTERNOON...WHILE A SHORTWAVE OVER LAKE WINNIPEG IS DRIVING A COLD
FRONT OVER THE NORTHERN MISSISSIPPI VALLEY. BETWEEN THESE
FEATURES...CYCLONIC FLOW IS MAINTAINING A FAIRLY EXPANSIVE STRATO-CU
DECK OVER THE WESTERN GREAT LAKES. SOME BREAKS IN THE STRATUS ARE
GROWING LARGER OVER NW WISCONSIN WHERE A DRIER AIRMASS EXISTS
ALOFT. AS THE COLD FRONT MOVES ACROSS THE REGION LATE TONIGHT INTO
SUNDAY MORNING...CLOUDS AND FOG ARE THE MAIN FORECAST CONCERNS.
TONIGHT...LOW CLOUDS SHOULD BE HANGING AROUND MUCH OF NORTHEAST AND
INTO CENTRAL WISCONSIN FOR THE EARLY PART OF THE EVENING...WHERE
MOISTURE IS DEEPER THROUGH THE COLUMN AND WEAK LOW LEVEL CONVERGENCE
LINGERS. EVENTUALLY THOUGH...UPSTREAM DRIER AIR WILL MAKE INROADS
OVER NORTH-CENTRAL WISCONSIN INTO NORTHEAST WISCONSIN THROUGH THE
EVENING. HAVE LEFT SKY CONDITIONS SCATTERED-WEST TO BROKEN-EAST
WITH THE UNCERTAINTY OF COVERAGE. COLD FRONT OVER THE NORTHERN
MISSISSIPPI VALLEY WILL MOVE ACROSS THE AREA AFTER MIDNIGHT. FAIRLY
WIDESPREAD STRATUS DECK BEHIND THE FRONT SO WILL SHOW SKIES
RETURNING TO BROKEN AS THE BOUNDARY WORKS THROUGH. THE PRESSURE
GRADIENT WILL TIGHTEN UP BEHIND THE FRONT AS WELL...WHICH WILL HELP
DISSIPATE ANY FOG. LOWS RANGING FROM THE UPPER 30S NORTH TO THE
UPPER 40S SOUTH.
SUNDAY...THE COLD FRONT WILL MOVE SOUTHEAST ACROSS CENTRAL AND
NORTHEAST WISCONSIN DURING THE MORNING...THEN CLEAR THE REGION FOR
THE AFTERNOON. A VERY DRY AIRMASS WILL BE ARRIVING BEHIND THE COLD
FRONT...SO WILL SEE AMPLE SUNSHINE MOVING IN BEHIND THE STRATUS
ALONG THE FRONT. LOWERED DEWPOINTS OVER N-C WISCONSIN FOR THE
AFTERNOON WHERE TEMPS WILL ONLY REACH INTO THE LOWER AND MIDDLE
50S. CENTRAL AND EAST-CENTRAL WISCONSIN SHOULD SEE HIGHS IN THE
LOWER TO MIDDLE 60S.
.LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY. THE WARM PATTERN
WILL CONTINUE NEXT WEEK...THOUGH NOT QUITE AS WARM AS THE LAST FEW
WEEKS. LOWS AND HIGHS OF 5 TO 10 DEGREES ABOVE NORMAL ARE EXPECTED
ON MOST DAYS BUT THAT WILL LIKELY FEEL CHILLY AFTER TEMPERATURES
IN THE 70S AND 80S EARLIER THIS WEEK. NOT MUCH IN THE WAY OF
PRECIPITATION IS EXPECTED AND ALL OR NEARLY ALL WILL BE RAIN. THE
FIRST CHANCE OF PRECIPITATION IS MONDAY AS MID LEVEL WARM
ADVECTION MOVES ACROSS THE AREA. WHATEVER FALLS SHOULD BE MOSTLY
IN CENTRAL WISCONSIN AND BE MOSTLY SPRINKLES OR VERY LIGHT
SHOWERS. BETTER CHANCE OF SHOWERS AND THUNDERSTORMS MONDAY NIGHT
AND TUESDAY AS DECENT UPPER LOW LIFTS NORTHEAST FROM THE PLAINS.
THERE MAY BE ENOUGH COLD AIR NEAR THE GROUND FOR THE PRECIPITATION
TO FALL AS SLEET IN NORTHCENTRAL WISCONSIN LATE MONDAY NIGHT AND
EARLY TUESDAY. ANOTHER CHANCE OF SHOWERS THURSDAY NIGHT AND FRIDAY
AS A WEAK SYSTEM PASSES BY TO THE NORTH. OTHERWISE GENERALLY MILD
AND DRY WEATHER. A FROST OR FREEZE IS LIKELY SUNDAY NIGHT. WHILE
THIS IS USUALLY NOT NOTEWORTHY AT THIS TIME OF THE YEAR...IT MAY
BE A CONCERN FOR ORCHARD OWNERS AS SOEM TREES HAVE BEGUN FLOWERING
DUE TO THE RECENT RECORD WARMTH.
&&
.AVIATION...SCT-OVC STRATOCUMULUS WITH BASES IN THE 4-6K FT
RANGE WERE OBSERVED ACROSS THE FORECAST AREA LATE THIS EVENING.
WHERE SKIES HAD TEMPORARILY CLEARED...PATCHY FOG DEVELOPED. THE
FOG WAS LOCALLY DENSE. THE PATCHY FOG SHOULD CONTINUE UNTIL THE
WINDS PICK UP AND DRIER AIR ARRIVES IN THE WAKE OF A COLD FRONT
LATER TONIGHT. LOW CLOUDS OVER NE MN HAVE BEEN SLOW TO MOVE TOWARD
THE AREA THIS EVENING...BUT STILL THINK THEY MAKE IT INTO AT LEAST
PART OF THE FORECAST AREA LATER TONIGHT. WILL MENTION SCT-BKN015
IN THE TAFS LATE TONIGHT INTO EARLY SUNDAY. DRY AIR BEHIND THE
FRONT SHOULD ERODE ANY MVFR CIGS BY MID-MORNING SUNDAY...LEAVING
VFR CONDITIONS FOR THE REMAINDER OF THE DAY. GUSTY NE WINDS MAY
DEVELOP IN THE FOX VALLEY/LAKESHORE AREAS LATE SUNDAY AFTERNOON
AND EVENING.
KIECKBUSCH
&&
.MARINE...
A COLD FRONT MOVING ACROSS THE AREA WILL BRING GUSTY NORTHEAST
WINDS TO THE AREA SUNDAY NIGHT AND EARLY MONDAY. FUNNELING DOWN THE
BAY COULD PRODUCE GUSTS TO 25 TO 30 KNOTS NEAR GREEN BAY. A WARM
FRONT WILL PUSH NORTHWARD ACROSS THE AREA TUESDAY. GUSTS TO NEAR
GALE FORCE FROM THE SOUTHEAST ARE POSSIBLE ON TUESDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
653 PM CDT SAT MAR 24 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A LARGE CUT-OFF
LOW PRESSURE SYSTEM MOVING SE OVER KENTUCKY AND TENNESSEE EARLY THIS
AFTERNOON...WHILE A SHORTWAVE OVER LAKE WINNIPEG IS DRIVING A COLD
FRONT OVER THE NORTHERN MISSISSIPPI VALLEY. BETWEEN THESE
FEATURES...CYCLONIC FLOW IS MAINTAINING A FAIRLY EXPANSIVE STRATO-CU
DECK OVER THE WESTERN GREAT LAKES. SOME BREAKS IN THE STRATUS ARE
GROWING LARGER OVER NW WISCONSIN WHERE A DRIER AIRMASS EXISTS
ALOFT. AS THE COLD FRONT MOVES ACROSS THE REGION LATE TONIGHT INTO
SUNDAY MORNING...CLOUDS AND FOG ARE THE MAIN FORECAST CONCERNS.
TONIGHT...LOW CLOUDS SHOULD BE HANGING AROUND MUCH OF NORTHEAST AND
INTO CENTRAL WISCONSIN FOR THE EARLY PART OF THE EVENING...WHERE
MOISTURE IS DEEPER THROUGH THE COLUMN AND WEAK LOW LEVEL CONVERGENCE
LINGERS. EVENTUALLY THOUGH...UPSTREAM DRIER AIR WILL MAKE INROADS
OVER NORTH-CENTRAL WISCONSIN INTO NORTHEAST WISCONSIN THROUGH THE
EVENING. HAVE LEFT SKY CONDITIONS SCATTERED-WEST TO BROKEN-EAST
WITH THE UNCERTAINTY OF COVERAGE. COLD FRONT OVER THE NORTHERN
MISSISSIPPI VALLEY WILL MOVE ACROSS THE AREA AFTER MIDNIGHT. FAIRLY
WIDESPREAD STRATUS DECK BEHIND THE FRONT SO WILL SHOW SKIES
RETURNING TO BROKEN AS THE BOUNDARY WORKS THROUGH. THE PRESSURE
GRADIENT WILL TIGHTEN UP BEHIND THE FRONT AS WELL...WHICH WILL HELP
DISSIPATE ANY FOG. LOWS RANGING FROM THE UPPER 30S NORTH TO THE
UPPER 40S SOUTH.
SUNDAY...THE COLD FRONT WILL MOVE SOUTHEAST ACROSS CENTRAL AND
NORTHEAST WISCONSIN DURING THE MORNING...THEN CLEAR THE REGION FOR
THE AFTERNOON. A VERY DRY AIRMASS WILL BE ARRIVING BEHIND THE COLD
FRONT...SO WILL SEE AMPLE SUNSHINE MOVING IN BEHIND THE STRATUS
ALONG THE FRONT. LOWERED DEWPOINTS OVER N-C WISCONSIN FOR THE
AFTERNOON WHERE TEMPS WILL ONLY REACH INTO THE LOWER AND MIDDLE
50S. CENTRAL AND EAST-CENTRAL WISCONSIN SHOULD SEE HIGHS IN THE
LOWER TO MIDDLE 60S.
.LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY. THE WARM PATTERN
WILL CONTINUE NEXT WEEK...THOUGH NOT QUITE AS WARM AS THE LAST FEW
WEEKS. LOWS AND HIGHS OF 5 TO 10 DEGREES ABOVE NORMAL ARE EXPECTED
ON MOST DAYS BUT THAT WILL LIKELY FEEL CHILLY AFTER TEMPERATURES
IN THE 70S AND 80S EARLIER THIS WEEK. NOT MUCH IN THE WAY OF
PRECIPITATION IS EXPECTED AND ALL OR NEARLY ALL WILL BE RAIN. THE
FIRST CHANCE OF PRECIPITATION IS MONDAY AS MID LEVEL WARM
ADVECTION MOVES ACROSS THE AREA. WHATEVER FALLS SHOULD BE MOSTLY
IN CENTRAL WISCONSIN AND BE MOSTLY SPRINKLES OR VERY LIGHT
SHOWERS. BETTER CHANCE OF SHOWERS AND THUNDERSTORMS MONDAY NIGHT
AND TUESDAY AS DECENT UPPER LOW LIFTS NORTHEAST FROM THE PLAINS.
THERE MAY BE ENOUGH COLD AIR NEAR THE GROUND FOR THE PRECIPITATION
TO FALL AS SLEET IN NORTHCENTRAL WISCONSIN LATE MONDAY NIGHT AND
EARLY TUESDAY. ANOTHER CHANCE OF SHOWERS THURSDAY NIGHT AND FRIDAY
AS A WEAK SYSTEM PASSES BY TO THE NORTH. OTHERWISE GENERALLY MILD
AND DRY WEATHER. A FROST OR FREEZE IS LIKELY SUNDAY NIGHT. WHILE
THIS IS USUALLY NOT NOTEWORTHY AT THIS TIME OF THE YEAR...IT MAY
BE A CONCERN FOR ORCHARD OWNERS AS SOEM TREES HAVE BEGUN FLOWERING
DUE TO THE RECENT RECORD WARMTH.
&&
.AVIATION...ALTHOUGH SOME CLEARING OCCURRED OVER NE/EC WI LATE
THIS AFTERNOON...SOME MVFR CIGS LINGERED OVER MUCH OF C/NC WI.
EXPECT THE MVFR CIGS TO GRADUALLY BREAK UP EARLY THIS EVENING.
WITH DEW POINTS STILL IN THE MID 40S TO LOWER 50S...PARTIAL
CLEARING AND LIGHT WINDS COULD LEAD TO SOME PATCHY FOG DEVELOPMENT
BY MID TO LATE EVENING. HAVE OPTED TO LEAVE THIS OUT OF THE TAFS
FOR NOW...AND WATCH THE OBSERVATIONS THIS EVENING. UPSTREAM COLD
FRONT OVER NW WI WILL MOVE ACROSS THE AREA DURING THE LATE EVENING
AND OVERNIGHT HOURS. EXPECT MVFR AND LOCAL IFR CIGS TO ARRIVE
A FEW HOURS AFTER THE FRONTAL PASSAGE...WITH WINDS GRADUALLY PICKING
UP FROM THE NORTH. AMPLE DRY AIR BEHIND THE FRONT WILL ERODE THE
MVFR CIGS LATE TONIGHT INTO MID-MORNING SUNDAY...LEAVING VFR
CONDITIONS FOR THE REMAINDER OF THE DAY.
KIECKBUSCH
&&
.MARINE...
A COLD FRONT MOVING ACROSS THE AREA WILL BRING GUSTY NORTHEAST
WINDS TO THE AREA SUNDAY NIGHT AND EARLY MONDAY. FUNNELING DOWN THE
BAY COULD PRODUCE GUSTS TO 25 TO 30 KNOTS NEAR GREEN BAY. A WARM
FRONT WILL PUSH NORTHWARD ACROSS THE AREA TUESDAY. GUSTS TO NEAR
GALE FORCE FROM THE SOUTHEAST ARE POSSIBLE ON TUESDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1104 PM MDT SAT MAR 24 2012
.AVIATION...
VFR CONDITIONS EXPECTED AT TAF SITES OVER NEXT 24 HOURS. LOW LEVEL
MOISTURE ADVECTING INTO EASTERN CO MAY RESULT IN SOME IFR-LIFR
CIGS/VIS IN FOG EAST OF KLHX AFTER 08Z. WITH LIGHT NORTH TO
NORTHWEST WINDS EXPECTED AT KCOS AND KPUB...LOW CIGS/FOG SHOULD
STAY EAST OF BOTH TERMINALS...HOWEVER EACH MODEL RUN SEEMS TO
ADVANCE FOG POTENTIAL WESTWARD SO THIS WILL BE MONITORED CLOSELY
THROUGH THE EARLY AM HOURS. OTHERWISE...EXPECT SOME SCT-BKN200
CIRRUS THROUGH SUNDAY. WINDS WILL INCREASE FROM THE SOUTH TO
SOUTHWEST AT 12-24 KTS AT ALL 3 TERMINALS SUNDAY AFTERNOON. -KT
&&
.PREV DISCUSSION... /ISSUED 927 PM MDT SAT MAR 24 2012/
UPDATE...
UPDATED FORECAST TO PUT OUT A DENSE FOG ADVISORY FOR KIOWA
COUNTY...AND TO EXPAND AREAS OF FOG WESTWARD ACROSS CROWLEY AND
OTERO COUNTIES. LATEST SFC OBS ALREADY SHOWING DEW POINTS IN THE
UPPER 40S ADVECTING WESTWARD INTO SOUTHEAST CO. WITH FAIRLY STRONG
EAST TO SOUTHEAST WINDS...EXPECT SOME LOWER 50 DEW POINTS TO MAKE
IT INTO KIOWA AND PROWERS COUNTY TOWARDS MORNING. LATEST HRRR
LOOKS A BIT OVERLY AGGRESSIVE BRINGING LOW LEVEL MOISTURE BACK AS
FAR WESTWARD AS EL PASO AND PUEBLO COUNTIES...AND HAVE GONE WITH A
COMPROMISE BETWEEN THE HRRR AND DRIER NAM12 FOR THESE AREAS.
HOWEVER...APPEARS KIOWA COUNTY MAY HAVE THE BEST SHOT OF SEEING
SOME DENSE FOG FORMATION...THUS PER COORD WITH SURROUNDING
OFFICES...HAVE PUT OUT A DENSE FOG ADVISORY FOR THIS AREA. LATER
SHIFTS WILL NEED TO MONITOR PROWERS COUNTY AS WELL...BUT MODEL
SOUNDINGS ARE NOT AS IMPRESSIVE WITH LOW LEVEL MOISTURE ACROSS
THIS ZONE...WITH RUC13 KEEPING RICHER MOISTURE FARTHER EAST AND NORTH.
SO WILL LEAVE THIS ZONE OUT FOR NOW AND CONTINUE TO MONITOR. -KT
PREV DISCUSSION... /ISSUED 308 PM MDT SAT MAR 24 2012/
SHORT TERM...
(TONIGHT AND SUNDAY)
AN UPPER LEVEL RIDGE IS FORECAST TO SHIFT EAST INTO THE CENTRAL
PLAINS TONIGHT WITH INCREASING SOUTHWESTERLY FLOW EXPECTED ON
SUNDAY. CURRENTLY A WEAK SURFACE BOUNDARY HAS BEEN TRACKING SOUTH
ACROSS THE PLAINS. THE MAIN INFLUENCE OF THIS FRONT IS A NORTHERLY
WIND SHIFT AND A FEW BRIEF GUSTS OF WIND. TEMPERATURES HAVE
EXCEEDED OR TIED RECORDS AT COLORADO SPRINGS AND PUEBLO SO FAR THIS
AFTERNOON.
TONIGHT AND TOMORROW...GIVEN CLEAR SKIES AND DIMINISHING WINDS WILL
LEAD TO OVERNIGHT LOWS IN THE 40S ACROSS SOUTHERN COLORADO. MODELS
TRYING TO DEVELOP FOG OUT ALONG THE KANSAS BORDER WHERE WEAK
SOUTHEASTERLY UPSLOPE FLOW AND DEEPER MOISTURE RESIDE. THINK AREAS
UP THE ARKANSAS RIVER VALLEY NEAR THE KANSAS BORDER STAND THE BEST
CHANCE AT SEEING FOG FOR TONIGHT.
SOUTHWESTERLY FLOW INCREASES TOMORROW WITH THE MAIN CONCERN BEING THE
NEAR RED FLAG CONDITIONS FOR PORTIONS OF THE PLAINS. HUMIDITIES
WILL BE LOW GIVEN THE DOWNSLOPE SOUTHWESTERLIES AND DRY AIR MIXING
DOWN. WINDS LOOK MARGINAL...WITH A FEW AREAS SEEING GUSTS 20 TO 25
KTS DURING THE AFTERNOON. CAUTION IS ADVISED...ESPECIALLY SOUTH OF
HIGHWAY 50 AND ALONG THE KANSAS BORDER. OTHERWISE EXPECT WARM
TEMPERATURES WITH RECORD HIGHS ONCE AGAIN FOR SOUTHEAST COLORADO.
ALSO OF NOTE...MODELS HINTING AT AN ISOLATED THUNDERSTORM OVER THE
SOUTHERN SAN JUAN AND SANGRE DE CRISTO RANGES...BUT CURRENTLY THINK
THIS WILL ONLY AMOUNT TO CUMULUS BUILD UPS IN THE AFTERNOON GIVEN
LACK OF MOISTURE. 88
LONG TERM...
(SUNDAY THROUGH FRIDAY)
.CRITICAL FIRE WEATHER CONDITIONS EXPECTED ON MONDAY...
MAIN CONCERN THIS FCST PD IS FIRE WX CONCERNS ON MONDAY.
AS HAS BEEN FCSTD BY THE SIMULATIONS FOR DAYS...IT WILL LIKELY BE
VERY WINDY WITH LOW HUMIDITY VALUES OVER THE REGION ON MONDAY.
WIDESPREAD WINDS OF 30 TO 45 MPH WILL OCCUR BY AFTERNOON ACROSS THE
ENTIRE REGION AS A VIGOROUS SHORT WAVE MOVES TO OUR NORTH DURING
PRIME HEATING. LAPSE RATED OF 8.5 TO 9.5C/KM AND 50 KNOT 700 MB
WINDS WILL ALLOW FOR VERY GUST WINDS. WITH THE STRONG
WINDS...BLOWING DUST WILL BE AN ISSUE ONCE AGAIN DUE TO THE
SUSTAINED DROUGHT CONDITIONS. ALTHOUGH BACA COUNTY RECEIVED ALMOST AN
INCH OF RAIN THE OTHER DAY...I AM CONFIDENT THAT THIS AREA WILL DRY
OUT SIGNIFICANTLY (1 HOUR FUELS...I.E., GRASSES) BY THE TIME MONDAY
ROLLS AROUND.
THE DRYLINE WILL LIKELY MIX OUT INTO KS RELATIVELY EARLY IN THE
DAY...SO I DO NOT ANTICIPATE ANY CONVECTION ALONG THE BORDER ATTM.
IN THE MTNS...SHORT WAVE MAY BE CLOSE ENOUGH ALONG WITH STRONG LIFT
TO ALLOW FOR SOME SHOWERS ALONG THE CONTDVD...MAINLY OVER THE C
MTNS.
ONCE THIS TROUGH GOES BY...GENERAL WEAK WSW FLOW ALOFT WILL BE OVER
THE REGION THROUGH LATE WEEK. WX DURING THIS PD WILL BE SEASONAL
WITH ABOVE NORMAL TEMPS.
A WEAK TROUGH AT MID LVLS WILL MOVE ACROSS THE REGION ON FRIDAY. NO
SENSIBLE WX WILL LIKELY OCCUR WITH IT. TEMPS WILL COOL A COUPLE OF
DEGREES AS COMPARED TO THURSDAY.
WE WILL LIKELY NOT SEE ANY PRECIP AT KCOS...KPUB OR KALS THROUGH THE
END OF THE MONTH. TO DATE...AT KPUB WE HAVE RECEIVED 0.11
INCHES...OUR NORMAL IS 0.93. AT KCOS...WE HAVE RECEIVED 0.06...THE
NORMAL IS 1.00 INCHES. AT KALS WE RECEIVED 0.10...NORMAL IS 0.53.
WITHOUT SAYING...WE NEED PRECIP. /34
AVIATION...
VFR CONDITIONS AT ALL TERMINALS THROUGH THE NEXT 24 HOURS. 88
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING
FOR COZ221-222-226>237.
DENSE FOG ADVISORY FROM 2 AM TO 8 AM MDT SUNDAY FOR COZ095-096.
&&
$$
31/44
AREA FORECAST DISCUSSION
NWS NEW YORK NY
135 AM EDT SUN MAR 25 2012
.SYNOPSIS...
SLOW MOVING LOW PRESSURE OVER THE SOUTHERN MID ATLANTIC REGION WILL
PASS TO THE SOUTH SUNDAY NIGHT...THEN HEAD NORTHEAST OUT TO SEA AND
STRENGTHEN AFTER A COLD FRONT MOVES THROUGH MONDAY MORNING.
HIGH PRESSURE WILL THEN BUILD IN FROM THE NORTH MONDAY AFTERNOON
THROUGH TUESDAY...AND THEN SLIDE EAST TUESDAY NIGHT. LOW PRESSURE
AND AN ASSOCIATED FRONTAL SYSTEM WILL MOVE ACROSS FROM WEDNESDAY
INTO EARLY THURSDAY...FOLLOWED BY HIGH PRESSURE LATER THURSDAY INTO
FRIDAY. A WARM FRONT WILL APPROACH LATE FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
RAIN ASSOCIATED WITH THE LOW TO OUR SW IS FINALLY OVERCOMING LOW
LEVEL DRY AIR IN THE NYC METRO AREA...SO HAVE ADJUSTED OVERNIGHT
POP ACCORDINGLY...WITH ALL AREAS EVENTUALLY GETTING SOME SHOWERS
OVERNIGHT. BACK EDGE OF THESE SHOWERS MOVING SLOWLY N FROM
SOUTHERN NJ SHOULD REACH THE NYC METRO AREA IN THE PREDAWN HOURS.
THE INCOMING 00Z NAM APPEARS TO AGREE WITH THIS ENDING
TIME...THOUGH THE 00Z HRRR HINTS THAT ADDITIONAL SHOWERS COULD
FILL IN TO THE SW AND SPREAD INTO THE AREA INTO THE EARLY DAYLIGHT
HOURS.
SOME ELEVATED INSTABILITY PRESENT BUT AT LEVELS TOO LOW
TO PRODUCE THUNDER. EARLIER MAV/MET MOS BLEND LOOKED GOOD FOR
LOWS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
LOW PRESSURE CENTER EMERGES OFF THE MID ATLANTIC COAST AND CONTINUES
TO HEAD EAST DURING THE DAY ON SUNDAY. WITH THE ISENTROPIC LIFT
EXITING THE EASTERN ZONES IN THE MORNING...THE ONLY OTHER SOURCES OF
LIFT WILL BE A WEAK MID LEVEL SHORTWAVE ENTERING DURING THE
AFTERNOON HOURS...WITH PERHAPS A LITTLE BIT OF ADDITIONAL SYNOPTIC
LIFT SUPPLIED BY AN UPPER JET STREAK. POPS THEREFORE NO HIGHER THAN
THE CHANCE CATEGORY ONCE THE MAIN BATCH OF RAIN EXITS TO THE EAST IN
THE MORNING. THE AFTERNOON COULD VERY WELL END UP COMPLETELY DRY FOR
MOST SPOTS. LEANED A LITTLE MORE TOWARDS THE COOLER NAM MOS FOR
HIGHS...BUT THIS STILL YIELDS HIGHS WARMER THAN NORMAL.
THE LOW BEGINS TO HEAD NORTHEAST SUNDAY NIGHT...BUT ONLY A SLIGHT
CHANCE OF A SHOWER FOR US EARLY IN THE EVENING...ASSOCIATED WITH THE
SHORTWAVE. DRY THEN FOR THE REST OF SUNDAY NIGHT.
ON MONDAY...WITH THE STORM CENTER HEADING NE FARTHER OUT TO SEA...A
COLD FRONT DROPS DOWN FROM THE NORTH EARLY ON. WITH LIMITED MOISTURE
DURING ITS PASSAGE...WILL GO WITH A DRY FORECAST. A STRONG MID LEVEL
SHORTWAVE FOLLOWS LATE IN THE DAY INTO THE EVENING HOURS...BUT AGAIN
NO RAINFALL EXPECTED WITH IT...JUST SOME CU BUILDUP AT BEST.
THE PRESSURE GRADIENT WILL TIGHTEN THROUGH THE DAY AS HIGH PRESSURE
BUILDS IN FROM THE NORTH...THIS COMBINED WITH STRONG COLD AIR
ADVECTION WILL BRING US A BREEZY DAY WITH GUSTY WINDS.
HIGH TEMPERATURE FORECAST FOR MONDAY WILL BE A LITTLE TRICKY WITH
THE COLD AIR ADVECTION INCREASING AS THE DAY WEARS ON. BUT AT THE
SAME TIME...STRONG DOWNSLOPING COULD OFFSET THIS A LITTLE. IT MIGHT
NOT BE THE TYPICAL DIURNAL HEATING PATTERN...AND HIGHS COULD BE
ACHIEVED NEAR NOONTIME INSTEAD OF MID-LATE AFTERNOON. TOOK A BLEND
OF THE NAM/MAV MOS FOR HIGHS...WHICH ENDS UP A LITTLE ABOVE NORMAL
FOR THIS TIME OF THE YEAR.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
A DEEP UPPER TROUGH WILL MOVE TO THE EAST MON NIGHT INTO EARLY TUE
MORNING...WITH THE AREA CAUGHT BETWEEN INTENSIFYING LOW PRESSURE SE
OF NOVA SCOTIA...AND A STRONG HIGH BUILDING S FROM HUDSON BAY.
THE TIGHT PRESSURE GRADIENT BETWEEN THE TWO WILL PRODUCE COLD AND
BRISK CONDITIONS MON NIGHT INTO EARLY TUE AFTERNOON. SIDED WITH
WARMER MAV MOS GUIDANCE VS NAM FOR LOWS MON NIGHT...BUT EVEN SO MON
NIGHT WILL BE QUITE COLD...WITH LOWS ABOVE FREEZING ONLY IN
NYC...BELOW 30 OUTSIDE THE NYC METRO AREA...AND POSSIBLY CLOSING IN
ON 20 IN SOME OF THE INTERIOR VALLEYS...ESPECIALLY IF WINDS DROP OFF
VERY LATE AT NIGHT. WIND CHILLS ACROSS THE INTERIOR WILL ALSO DROP
INTO THE TEENS LATE MON NIGHT.
DESPITE THE COLD OF MON NIGHT...RISING HEIGHTS ALOFT SHOULD ACTUALLY
HELP KEEP HIGHS NEAR AVG ON TUE. FULL MIXING OF 875 MB TEMPS NEAR
-2C PLUS DOWNSLOPE FLOW WILL RESULT IN HIGHS IN THE LOWER 50S IN NYC
AND COASTAL SECTIONS...AND UPPER 40S INLAND. MORE ROBUST WAA SHOULD
TAKE PLACE TUE NIGHT-WED IN RETURN S-SW FLOW AS THE HIGH SLIDES TO
THE E-SE AND A WARM FRONT APPROACHES...WITH HIGHS REBOUNDING TO THE
UPPER 50S/LOWER 60S. EXPECT A CHANCE OF SHOWERS MAINLY WED
AFTERNOON/NIGHT AS THIS FRONT MOVES THROUGH AND A COLD FRONT
TRAILING FROM LOW PRESSURE PASSING TO THE NORTH APPROACHES...THEN
ONLY SLIGHTLY COOLER BUT STILL ABOVE AVG TEMPS ON THU/FRI AS ANOTHER
HIGH BUILDS IN...WITH 50S TO NEAR 60. AFTER THIS HIGH MOVES EAST...
ANOTHER WARM FRONT WILL APPROACH LATE FRI NIGHT INTO SAT WITH
ANOTHER CHANCE OF SHOWERS.
NOTE FOR AGRICULTURAL CONCERNS...TEMPS WILL FALL TO AT OR JUST BELOW
FREEZING JUST OUTSIDE OF NYC...AND INTO THE 20S OVER THE LOWER
HUDSON VALLEY...INTERIOR NE NJ...SOUTHERN CT...AND CENTRAL/EASTERN
LONG ISLAND. SUB-FREEZING TEMPS ARE ALSO POSSIBLE TUE NIGHT OUTSIDE
OF URBAN CENTERS IF RADIATIONAL COOLING CONDITIONS ARE RIGHT.
WINDS WILL BE LIGHT BUT SOME MID LEVEL CLOUDS PASSING THROUGH MAY
MITIGATE THIS SOMEWHAT.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
A WARM FRONT REMAINS TO THE SOUTH...WHILE LOW PRESSURE MOVES
SLOWLY ACROSS THE MID ATLANTIC REGION. A COLD FRONT GRADUALLY
MOVES ACROSS THE REGION THROUGH MONDAY MORNING.
SPOTTY LIGHT RAIN WITH MVFR CIGS ACROSS THE TERMINALS THROUGH THIS
MORNING. OCNL IFR CIGS ARE POSSIBLE FROM TIME TO TIME BETWEEN
10-14Z...BUT CONFIDENCE IS TOO LOW TO MENTION IN THE TAFS AT THIS
TIME.
LIGHT E-NE FLOW CONTINUES TODAY...KEEPING LOW LEVEL MOISTURE AND
MVFR CIGS ACROSS THE REGION THROUGH MOST OF TODAY. IMPROVEMENT TO
VFR...EXCEPT FOR KGON...IS LIKELY LATE IN THE AFTERNOON. MVFR CIGS
WILL REMAIN AT KGON...POSSIBLY LOWERING TO IFR AFTER 00Z MONDAY AS
ONSHORE FLOW CONTINUES THROUGH TONIGHT.
COLD FRONT BEGINS TO MOVE ACROSS THE REGION THIS EVENING...
RESULTING IN A SHIFT IN WINDS TO A NW FLOW...HELPING TO DRY THE
LOWER LEVELS OF THE ATMOSPHERE OUT.
OUTLOOK FOR 06Z MONDAY THROUGH THURSDAY...
.TONIGHT...LINGERING MOISTURE AND LIGHT WINDS COULD LEAD TO LOW
CLOUDS AND/OR FOG WITH SUB-VFR CONDITIONS LATE...MAINLY AT
KHPN/KISP/KBDR/KGON.
.MONDAY-TUESDAY...VFR. COLD FRONT MOVES THROUGH MONDAY MORNING...
FOLLOWED BY GUSTY NW-N FLOW. DIMINISHING WINDS TUESDAY AFTERNOON.
.WEDNESDAY...MVFR CONDITIONS ARE POSSIBLE IN THE AFTERNOON AND AT
NIGHT AS LOW PRESSURE AND A WARM FRONT APPROACH. GUSTY SW FLOW IN
THE AFTERNOON.
.THURSDAY...VFR. GUSTY NW FLOW.
&&
.MARINE...
E FLOW AROUND 15 KT WILL PERSIST TONIGHT...AND OCEAN SEAS MAY COME
VERY CLOSE TO REACHING 5 FT. ANY GUSTS TO 25 KT AT THE SAME TIME
WOULD BE OCCASIONAL. HAVE THEREFORE HELD OFF ON ISSUING SCA.
WAVEWATCH APPEARS TO BE TO HIGH GIVEN THE WIND FORECAST AND LACK OF
A SIGNIFICANT SWELL LATE TONIGHT INTO SUNDAY NIGHT...AND HAVE KEPT
SEAS BELOW 5 FT. WINDS WILL AT LEAST DIMINISH DURING SUNDAY AND
SUNDAY EVENING.
FOR MON/MON NIGHT...AT LEAST AN SCA WILL LIKELY BE NEEDED BY
AFTERNOON...AND POSSIBLY A GALE WARNING ESPECIALLY ON THE OCEAN.
WINDS WILL STRENGTHEN AFTER A COLD FRONTAL PASSAGE MON
MORNING...WITH A TIGHTENING PRESSURE GRADIENT AND STRONG COLD AIR
ADVECTION MOVING IN. WILL CONTINUE TO MENTION THE THREAT OF GALES IN
THE HWO.
CONDS SHOULD GRADUALLY FALL THROUGH SCA AND THEN BELOW ON TUE.
SCA CONDS POSSIBLE ONCE AGAIN ON THE OCEAN WATERS WED
AFTERNOON/NIGHT IN STRENGTHENING S-SW FLOW AHEAD OF A COLD FRONT...
AND AGAIN THE AFTERNOON/EVENING IN POST-FRONTAL NW FLOW.
&&
.HYDROLOGY...
RELATIVELY DRY CONDITIONS WILL CONTINUE...WITH NO SIGNIFICANT QPF OF
1/2 INCH OR MORE EXPECTED FOR THE NEXT 7 DAYS. IN FACT...THE U.S.
DROUGHT MONITOR CATEGORIZES SE CT AS BEING IN MODERATE DROUGHT...AND
THE REST OF THE REGION AS ABNORMALLY DRY.
&&
.TIDES/COASTAL FLOODING...
A PERSISTENT EAST TO NORTHEAST FLOW WILL EXIST TONIGHT INTO SUNDAY
MORNING AS MID ATLANTIC LOW PRESSURE TRACKS SOUTH AND THEN EAST
OF THE AREA. THERE IS ONLY A LOW POTENTIAL AT BEST FOR MINOR
COASTAL FLOODING...AS 1 1/2 TO 2 FT POSITIVE DEPARTURES ARE NEEDED
TO REACH THESE THRESHOLDS. BASED ON CURRENT DEPARTURES AND LATEST
MODEL GUIDANCE...FLOODING IS NOT EXPECTED TONIGHT OR SUNDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JC
NEAR TERM...JC/GOODMAN
SHORT TERM...JC
LONG TERM...GOODMAN
AVIATION...MPS
MARINE...JC/GOODMAN
HYDROLOGY...JC/GOODMAN
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MIAMI FL
402 AM EDT SUN MAR 25 2012
.DISCUSSION...
CUTOFF UPPER LEVEL LOW SPINNING OVER THE SOUTHEAST...WITH SURFACE
COLD FRONT MOVING THROUGH NORTH CENTRAL FLORIDA THIS MORNING.
SHOWERS AND ISOLATED THUNDERSTORMS WERE ACROSS THE EASTERN GULF
MOVING TOWARDS CENTRAL FLORIDA. THE UPPER LEVEL LOW WILL CONTINUE
TO SLIDE TO THE EAST TODAY...AND MOVE INTO THE ATLANTIC BY THIS
EVENING.
WEST TO SOUTHWEST FLOW WILL CONTINUE ACROSS THE REGION AHEAD OF
THE FRONT. MODELS CONTINUE TO SHOW DESTABILIZING CONDITIONS
THROUGH THE AFTERNOON. 500MB TEMPS ARE AROUND -12C...LOW LEVEL
LAPSE RATES ARE STEEP AND EVEN SLIGHT DAYTIME HEATING IS EXPECTED
TO BRING TEMPERATURES INTO THE LOW TO MID 80S. THIS SHOULD ALLOW
AT LEAST ISOLATED THUNDERSTORMS TO DEVELOP AHEAD OF AND ALONG THE
FRONT. SO EXPANDED THE THUNDERSTORM AREA TO MOST OF THE REGION
ALONG AND AHEAD OF THE FRONT. HRRR SHOWS SCATTERED SHOWERS AND
SOME THUNDERSTORMS DEVELOPING ACROSS THE EASTERN HALF OF THE
REGION BY 18Z. THIS FOLLOWS WITH OTHER MODEL SOLUTIONS...SO EXPECT
THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE EAST FROM
NORTHERN MIAMI-DADE COUNTY NORTHWARD THIS AFTERNOON. MID LEVEL
LAPSE RATES ARE NOT IMPRESSIVE...MOIST ADIABATIC ABOVE
700-800MB...SO LEFT MENTION OF HAIL OUT.
THE FRONT IS EXPECTED TO MAKE ITS WAY TOWARDS THE LAKE REGION
AROUND 18Z WITH PRECIPITATION ENDING THERE BY 21Z. THE FRONT
SHOULD MOVE OFF THE FLORIDA PENINSULA AROUND 00Z...WITH ANY
LEFTOVER SHOWERS ACROSS THE SOUTH ENDING BY EARLY EVENING. A DRY
NORTHWEST FLOW IS EXPECTED BEHIND THE FRONT...WHICH WILL BRING
COOLER CONDITIONS TONIGHT TO THE REGION. OVERNIGHT LOWS ARE
EXPECTED TO DROP INTO THE 50S NORTHWEST TO THE LOW TO MID 60S
ACROSS THE SOUTHEAST ATLANTIC COAST.
SURFACE HIGH PRESSURE IS EXPECTED TO MOVE OUT OF CANADA AND
TOWARDS THE MID ATLANTIC STATES ON MONDAY...AND WINDS WILL SHIFT
FROM THE NORTHWEST TO THE NORTHEAST BY TUESDAY MORNING. MODELS
CONTINUE TO SHOW A WEAK INVERTED TROUGH MOVING ACROSS SOUTH
FLORIDA ON TUESDAY...BRINGING A MOISTURE AND WIND SURGE TO THE
REGION. SO BREEZY CONDITIONS ARE EXPECTED ACROSS SOUTH FLORIDA ON
TUESDAY...WITH ISOLATED SHOWERS ACROSS THE EASTERN HALF OF THE
REGION. MODELS THEN SHOW DRIER AIR MOVING BACK INTO THE REGION
THROUGH THE END OF THE WEEK. HOWEVER...HIGH PRESSURE IS STILL
EXPECTED TO BE NORTHEAST OF THE REGION THROUGH WEDNESDAY...SO
THERE WILL STILL BE A CHANCE FOR A PASSING LIGHT SHOWER ACROSS THE
EAST COAST METRO AREAS. SO LEFT THE 10 POPS WITH MENTION OF
PRECIP THROUGH THE DAY ON WEDNESDAY.
HIGH PRESSURE WILL WEAKEN AND SHIFT EAST ON THURSDAY AS A
SHORTWAVE TROUGH PUSHES INTO THE MID ATLANTIC STATES. SO LIGHT
WINDS AND DRY CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK.
TEMPERATURES WILL REMAIN WARM...WITH HIGHS IN THE LOW TO MID 80S
AND LOWS AROUND 60 TO AROUND 70.
&&
.AVIATION...
FRONTAL BOUNDARY MOVING SLOWLY SOUTHWARD ACROSS THE
FLORIDA PENINSULA. SW FLOW EXPECTED AT ALL TERMINALS THROUGH THE
PERIOD AS THE BOUNDARY APPROACHES. CURRENT GUIDANCE DID NOT CHANGE
MUCH FROM PREVIOUS RUNS THEREFORE...KEPT VCSH AT ALL TERMINALS TO
BEGIN AT 25/16Z...ALONG WITH GUSTY WINDS. MOSTLY CLEAR SKIES AND
LIGHTER WINDS ARE EXPECTED BY 26/00Z.
&&
.MARINE...
SOUTHWEST WINDS ARE EXPECTED AHEAD OF A COLD FRONT TODAY...WITH
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ALONG THE BOUNDARY.
WINDS WILL SHIFT TO THE NORTHWEST ACROSS THE LOCAL WATERS THIS
AFTERNOON THROUGH THE EVENING AS THE COLD FRONT MOVES THROUGH. BY
LATE MONDAY...WINDS WILL BECOME EASTERLY AGAIN AS HIGH PRESSURE
BUILDS ACROSS THE ATLANTIC. CURRENT GUIDANCE STILL SHOWING A WEAK
INVERTED TROUGH MOVING INTO THE LOCAL ATLANTIC WATERS ON
TUESDAY. THIS WILL INCREASE THE WINDS ACROSS THE ATLANTIC WATERS
WITH SCEC AND POSSIBLY A SHORT PERIOD OF SCA CONDITIONS IN
WEDNESDAY MORNING.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS TODAY AS A COLD FRONT MOVES THROUGH THE
REGION. ISOLATED THUNDERSTORMS ARE POSSIBLE ALONG THE FRONT.
RELATIVE HUMIDITY VALUES MAY DROP TO AROUND 35 PERCENT ACROSS A
LARGE PORTION OF THE REGION MONDAY AFTERNOON AS DRIER AIR MOVES
DOWN THE PENINSULA BEHIND THE FRONT. WINDS SHIFT TO THE EAST
MONDAY NIGHT...WITH LOW LEVEL MOISTURE RETURNING TO THE AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 63 81 66 / 50 10 0 -
FORT LAUDERDALE 85 66 83 68 / 40 20 0 -
MIAMI 85 65 83 66 / 40 20 0 -
NAPLES 82 64 83 63 / 30 10 0 -
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...84/AK
AVIATION/RADAR...17/ERA
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
139 AM EDT SUN MAR 25 2012
.SYNOPSIS...
A STRONG UPPER LEVEL LOW WILL MOVE SOUTHEAST OVER THE NEXT 24
HOURS INTO THE CAROLINAS. THIS SYSTEM WILL CONTINUE TO GIVE THE
AREA SCATTERED SHOWERS AND THUNDERSTORMS THROUGH SUNDAY. THE RAIN
SHOULD END BY SUNDAY EVENING AS THE LOW PULLS EAST OF THE AREA.
MOSTLY DRY AND MILD WEATHER CAN BE EXPECTED THROUGH MUCH OF NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE COLD FRONT WILL CONTINUE MOVING EAST THROUGH THE AREA
OVERNIGHT. THIS WILL KEEP SHOWERS MAINLY TO THE EAST BUT A 20
PERCENT CHANCE IS EXPECTED MOST OF THE REGION FOR THE REST OF THE
NIGHT EXCEPT MAYBE 10 PERCENT IN THE CSRA. WV IMAGERY SHOWS A DRY
SLOT MOVING IN FROM THE WEST. BUT THE NAM AND RUC MODELS SHOW
MOISTURE WRAPPING AROUND THE STRONG UPPER LOW BRINGING MOISTURE
BACK IN ALTHOUGH MOISTURE IS NOT AS DEEP AS AHEAD OF COLD FRONT.
DECIDED GO INCLUDE A 40-60 PERCENT CHANCE OF MAINLY SHOWERS NORTH
PART IN THE EARLY MORNING HOURS AND 20 PERCENT ELSEWHERE. AS
MENTIONED...WILL HAVE ONLY 10 PERCENT POP CSRA. OTHERWISE...WINDS
AND TEMPERATURES LOOK OK THIS MORNING.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
ALTHOUGH THE FRONT WILL BE EAST OF THE AREA ON SUNDAY...THE MAIN
COLD POOL OF AIR ASSOCIATED WITH THE UPPER LOW STILL BE CROSSING
THROUGH THE REGION DURING THE DAY. SHOULD HAVE PLENTY OF CLOUD
COVER THROUGH THE DAY...WHICH WILL LIMIT TEMPS SLIGHTLY. EVEN
SO...DUE TO THE STRENGTH OF THE COLD CORE...CAN NOT RULE OUT SOME
SHOWERS AND ISOLATED STORMS THROUGH THE DAY. ONCE THE UPPER LOW
PUSHES EAST...RAIN CHANCES WILL DIMINISH. DRYING WILL OCCUR
OVERNIGHT SUNDAY INTO MONDAY...WITH DRY CONDITIONS RETURNING
THROUGH TUESDAY NIGHT. AS FOR TEMPS...NOT REALLY EXPECTING A
SIGNIFICANT COOL DOWN BEHIND THE LOW. TEMPS WILL STILL BE IN THE
70S DURING THE DAY THROUGH THE PERIOD. THE REAL DIFFERENCE WILL BE
IN THE DRIER DEWPOINTS THAT WILL SETTLE IN THROUGH TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS WE MOVE INTO WEDNESDAY...ANOTHER STORM SYSTEM WILL PASS CLOSE
TO OUR NORTH PUSHING A COLD FRONT INTO THE UPSTATE INTO WEDNESDAY
NIGHT. STILL DO NOT EXPECT MUCH IN THE WAY OF PRECIP WITH THIS
SYSTEM...SO ONLY LOW POPS WEDNESDAY NIGHT/THURSDAY WITH THAT
SYSTEM. OTHERWISE...MOSTLY DRY CONDITIONS INTO NEXT WEEKEND.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
CLOSED LOW OVER NORTHERN GEORGIA WILL MOVE ACROSS NORTHERN SOUTH
CAROLINA OVER THE NEXT 24 HOURS. THIS WILL KEEP VFR CEILINGS ACROSS
ALL TERMINALS FOR THE FORECAST PERIOD EXCEPT FOR AGS AND DNL WHERE
CLEARING IS EXPECTED SUNDAY EVENING AS THE LOW PULLS AWAY TO THE
NORTHEAST OF THE STATE. COLD AIR IN THE CENTER OF THE SYSTEM WILL
DESTABILIZE THE ATMOSPHERE THIS AFTERNOON GIVING A CHANCE OF SHOWERS
AND POSSIBLY THUNDERSTORMS WITH ATTENDANT MVFR/IFR CONDITIONS
POSSIBLE.
THE CHANCE OF THUNDER IS BEST OVER KCAE...KCUB AND KOGB IN THE
BETTER MOISTURE. THERE MAY BE SOME MVFR FOG AT KCAE...KCUB AND KOBG
THIS MORNING AS A MID LEVEL DRY AIR PATCH CROSSES THE AREA...
ALLOWING SOME RADIATIONAL COOLING PLUS MOISTURE FROM RECENT RAINS.
WEST TO NORTHWEST WIND WILL KEEP REDUCE THE CHANCE OF IFR CEILINGS
AND VISIBILITY.
EXTENDED AVIATION OUTLOOK...UNRESTRICTED FLYING CONDITIONS WILL
RETURN MONDAY INTO WEDNESDAY...WHEN THE NEXT STORM SYSTEM APPROACHES
THE AREA FROM THE NORTHWEST.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
SYNOPSIS...07
NEAR TERM...07
SHORT TERM...
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION...CORRECTED
NWS DODGE CITY KS
1252 AM CDT SUN MAR 25 2012
...UPDATED AVIATION SECTION AND NEAR TERM SECTION...
.UPDATE...
ISSUED AT 1255 AM CDT SAT MAR 24 2012
LATEST MODELS CONTINUE TO SUGGEST THAT 50 DEGREE DEWPOINTS WILL BE
FOUND ACROSS WESTERN KANSAS EARLY THIS MORNING AND WITH
TEMPERATURES FALLING TO NEAR 50 DEGREES FOG MAY FORM TOWARDS
SUNRISE. THE HRRR AND NAM DEPICT DENSE FOG DEVELOPING ACROSS THE TWO
WESTERN ROWS OF COUNTIES BY 08Z WITH A FEW POCKETS OF LOWER
VISIBILITIES TO THE EAST OF THIS AREA. A FEW HIGH CLOUDS ARE
FORMING ACROSS EASTERN COLORADO AND IF THEY MOVE INTO KANSAS IT MAY
HINDER FOG DEVELOPMENT. NEVERTHELESS, I HAVE KEPT THE DENSE FOG
ADVISORY AS IS FOR THE TIME BEING. THE REMAINDER OF THE FORECAST
IS ON TRACK FOR THE NEAR TERM PERIOD.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 345 PM CDT SAT MAR 24 2012
A GENERAL WARMING TREND IS ANTICIPATED IN THE VERY SHORT TERM
FORECAST. TEMPERATURES WARMED INTO THE LOW TO MID 70S THIS
AFTERNOON AND WERE HEADED TOWARD THE 80 DEGREE MARK IN THE LATE
AFTERNOON. THE AREA WILL REMAIN IN THE WARM SECTOR SOUTH TO SOUTHEAST
FLOW AS WEAK CYCLOGENESIS REMAINS FOCUSED DIURNALLY OVER SOUTHEAST
COLORADO. SURFACE MOISTURE WILL INCREASE ACROSS THE AREA INCREASING
DEW POINTS INTO THE 50S THE NEXT FEW DAYS. THE COMBINATION OF
SOUTHEAST UPSLOPE WINDS AND HIGHER LEVEL MOISTURE AIR, ACROSS THE
AREA WILL BE FAVORABLE FOR DENSE FOG DEVELOPMENT AS TEMPERATURES
FALL OVERNIGHT UNDER A VERY DRY MID AND UPPER LEVEL AIRMASS. THE
RUC AND NAM BOTH INDICATE DENSE FOG DEVELOPMENT, AND ARE NOT IN
AGREEMENT AT ALL ON THE PLACEMENT. HOWEVER THE MOST FAVORABLE
LOCATION FOR WIDESPREAD DENSE FOG DEVELOPMENT WILL BE WHERE THE
WINDS GO LIGHT IN THE ZONE OF SURFACE WIND CONVERGENCE PROBABLY
AFTER 8Z.
DEW POINTS WILL LIKELY MIX OUT TO LOWER VALUES IN THE FAR WESTERN
COUNTIES ON SUNDAY. THE NAM INDICATED THE REAL DRYLINE TO BE
POSITIONED WELL TO THE SOUTHWEST IN NE NEW MEXICO WHERE IT WANTS
TO DEVELOP CONVECTIVE PRECIPITATION IN THE LATE AFTERNOON AS IT IS
RETREATING. HAVING SAID THAT, THE SURFACE POSITIVE BUOYANT ENERGY IS
A RESPECTABLE 1000-2000 J/KG FROM A DIGHTON TO MEADE CORRIDOR AS
MODELED BY THE NAM. HOWEVER, THE ATMOSPHERE ALOFT REMAINS DRY ON
SUNDAY. THE WARM NOSE ON THE 21 UTC NAM SOUNDING SUGGESTS PARCELS
WOULD NEED TO BE LIFTED FROM ABOVE 800 MB WHICH DOESN`T APPEAR
PLAUSIBLE WITH SUCH WEAK SURFACE CONVERGENCE AND DRY AIR.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 256 PM CDT SAT MAR 24 2012
SUNDAY NIGHT WILL SEE AN UPPER LEVEL RIDGE WORK EASTWARD INTO
EASTERN KANSAS. AN UPPER LOW PRESSURE SYSTEM OVER SOUTHERN NEVADA
WILL ALLOW A SOUTHWEST UPPER FLOW TO DEVELOP ACROSS WESTERN KANSAS
MONDAY. A DRY LINE WILL START ADVANCING WEST EARLY IN THE DAY
MONDAY, AND SOUTH WINDS WILL BECOME STRONG, ESPECIALLY IN OUR WEST
ON THE MOIST SIDE OF THE DRY LINE. FOR NOW, GRIDS WILL HAVE
25-35KTS G40KTS IN MY WESTERN 1/2 OF THE CWA, AND 15-25KTS G30KTS IN
THE EASTERN CWA. A WIND ADVISORY WILL LIKELY BE NEEDED FOR MONDAY
AFTERNOON, BUT WILL HOLD OFF ONE OR TWO MORE SHIFTS BEFORE ISSUING
THE NPW PRODUCT. STORMS MAY FIRE IN THE LATE DAY IN OUR WEST NEAR
THE DRY LINE, BUT THE BETTER UPPER LEVEL DYNAMICS ARE TO OUR NORTH.
THE 20 POPS SEEM APPROPRIATE FOR THIS SITUATION, UNLESS LATER MODEL
RUNS SHOW SOMETHING DIFFERENT. FOR WHAT IT IS WORTH, THE GFS BACKED
OFF ON THUNDERSTORMS MONDAY AFTERNOON, KEEPING THE PRECIPITATION FAR
TO OUR NORTH.
MONDAY NIGHT WILL BE PARTLY TO MOSTLY CLOUDY WITH A WEAK UPPER
TROUGH CROSSING JUST TO OUR NORTH. A FAIRLY STRONG COLD FRONT WILL
SLIP INTO OUR NORTHWEST SECTIONS AFTER MIDNIGHT AND BE NEAR OUR
SOUTHERN BORDER BY TUESDAY MORNING. THEN, THE FRONT APPEARS TO
DISSIPATE NEAR THE OKLAHOMA TUESDAY MORNING, BEFORE STARTING TO
ADVANCE BACK NORTH AS A WARM FRONT WEDNESDAY. SINCE THAT FRONT IS
PLOWING THROUGH DECENT LOW LEVEL MOISTURE, 20 PERCENT POPS WILL
START IN THE WEST LATE MONDAY AND TRANSFER TO THE EAST MONDAY
NIGHT. SEEMS THERE WILL BE AT LEAST A SMALL CHANCE FOR SEVERE
STORMS WITH HAIL MONDAY NIGHT, BUT WITH 20 POPS DO NOT PLAN TO
MENTION SEVERE STORMS IN THE GRIDS. WILL UPDATE THE HWO TO AT LEAST
MENTION SEVERE STORMS ARE POSSIBLE. NO PLANS IN OUR 3 WESTERN
COUNTIES FOR POPS MONDAY NIGHT. MIN TEMPS MON NIGHT WILL DEPEND
STRONGLY ON THE COLD FRONT MOVEMENT AND POSITION, AND RANGE FROM THE
LOWER 40S IN OUR EXTREME NORTHWEST COUNTIES SUCH AS HAMILTON TO THE
LOWER 50S FROM HAYS TO DODGE CITY TO NEAR LIBERAL, AND THE MID 50S
IN THE PRATT AND BARBER COUNTY AREAS.
ANY PRECIP SHOULD BE EAST OF OUR CWA BY TUESDAY, WITH MAX TEMPS
BEHIND THE FRONT 10 TO 15 DEGREES COLDER THAN MONDAY, MAXING IN THE
70 DEGREE RANGE IN SCOTT CITY TO NEAR 77 DEGREES IN MEDICINE LODGE.
TUESDAY SHOULD PRODUCE SUNNY SKIES AS WELL. TUESDAY NIGHT WILL BE
MOSTLY CLEAR WITH NO PRECIPITATION, AND MINIMUMS IN THE LOWER 40S IN
OUR NORTHWEST RANGING TO THE MID 50S IN OUR SOUTHEAST. ON
WEDNESDAY, THAT FRONT WILL ADVANCE NORTH AS A WARM FRONT AND MOVE
INTO OUR SOUTHERN CWA. SOUTHERN PARTS OF OUR CWA WILL BECOME PARTLY
CLOUDY WHILE NORTHERN PARTS OF OUR FORECAST CONTINUING TO BE MOSTLY
SUNNY. LATE WEDNESDAY, THERE IS A SLIGHT CHANCE FOR A THUNDERSTORM
IN OUR EXTREME SOUTHEAST, DUE TO DAY TIME HEATING AND DEW POINTS
NEAR 60F DEGREES. EXPECT PARTLY CLOUDY SKIES WEDNESDAY NIGHT, LOW
TEMPS IN THE 50F TO 56F DEGREE RANGE, AND A SLIGHT CHANCE OF STORMS
IN OUR EASTERN 2 COUNTIES OF THE CWA.
ON THURSDAY, THE DRY LINE WILL COME BACK INTO PLAY, MARCHING EAST
ACROSS OUR AREA DURING THE DAY. BY THE TIME OF MAX HEATING, WITH
HIGHS EXPECTED IN THE UPPER 70S TO LOWER 80S, A THUNDERSTORM OR TWO
WILL BE POSSIBLE NEAR THE DRY LINE. THURSDAY NIGHT WILL CONTINUE TO
SEE SLIGHT CHANCES FOR STORMS, WITH THAT CHANCE SPREADING WEST
ACROSS ALL OUR CWA BY FRIDAY. AN UPPER WAVE WILL CROSS JUST NORTH
OF OUR CWA, AND MAY FIRE OFF A FEW STORMS FRIDAY AND FRIDAY NIGHT.
MAX TEMPS EXPECTED FRIDAY ARE IN THE MID 70S, WITH MIN TEMPS FROM
46F TO 54F DEGREES FRIDAY NIGHT, AND MAXIMUM TEMPERATURES ON
SATURDAY RANGING IN THE MID TO UPPER 70S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1255 AM CDT SUN MAR 25 2012
HIGH PRESSURE WILL BE FOUND ACROSS EASTERN KANSAS AND LEE
TROUGHING WILL BE FOUND ACROSS THE KS/CO BORDER THROUGHOUT THE TAF
PERIOD. THIS WILL BRING SOUTH SOUTHEAST WINDS AROUND 10 KNOTS TO
THE TAF SITES OVERNIGHT. WITH THIS UPSLOPE FLOW AND DEWPOINTS IN
THE 50S SOME LOWER VISIBILITIES MAY FORM ACROSS THE GARDEN CITY
AND DODGE CITY TERMINALS. AS FOR NOW I WENT WITH 5SM AT DDC AND
AROUND 1SM AT GCK. VISIBILITIES BELOW A MILE ARE POSSIBLE WEST OF
GARDEN CITY AND MAY HAVE TO UPDATE TAFS IF THIS MOVES FARTHER EAST
THAN ANTICIPATED. ANY FOG THAT DOES DEVELOP SHOULD ERODE BY 14Z.
THE PRESSURE GRADIENT WILL TIGHTEN LATE IN THE MORNING AS LEE
TROUGHING STRENGTHENS AND THE ATMOSPHERE MIXES. WINDS WILL SHIFT
MORE TO THE SOUTH AND INCREASE TO AROUND 20 KNOTS WITH SOME GUSTS
OVER 25 KNOTS. VFR CONDITIONS WILL PREVAIL THROUGHOUT THE LATE
MORNING AND AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 57 82 52 74 / 0 20 20 0
GCK 56 83 48 73 / 0 20 20 0
EHA 55 85 45 73 / 0 10 10 0
LBL 56 83 48 75 / 0 20 20 0
HYS 57 82 51 73 / 0 10 20 0
P28 57 82 56 76 / 0 10 20 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CDT /8 AM MDT/ THIS MORNING FOR
KSZ030-043>045-061>063-074-075-084-085.
&&
$$
UPDATE...HOVORKA 42
SHORT TERM...RUSSELL
LONG TERM....BURKE
AVIATION...HOVORKA 42
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1140 PM MDT SAT MAR 24 2012
.UPDATE...
ISSUED AT 1137 PM MDT SAT MAR 24 2012
MADE A FEW QUICK UPDATES TO ACCOUNT FOR INCREASING AREA OF HIGH
CLOUDS ACROSS NORTHERN CWA AND INCREASE CLOUD COVER IN AREAS WHERE
DENSE FOG IS EXPECTED LATER THIS MORNING. THESE PERSISTENT HIGH
CLOUDS BRING SOME CONCERN ABOUT FOG POTENTIAL IN THIS AREA...BUT
OTHERWISE LIGHT SOUTHEASTERLY FLOW WITH TDS AROUND 50 AND
CONFLUENT ZONE CONTINUE TO SUPPORT FOG POTENTIAL LATER.
UPDATE ISSUED AT 843 PM MDT SAT MAR 24 2012
JUST COMPLETED AN UPDATE. MAIN CHANGES WERE TO INCREASE COVERAGE
OF THE FOG OVER THE ENTIRE AREA AND ISSUED A DENSE FOG ADVISORY FOR
EAST CENTRAL COLORADO AND MUCH OF NORTHWEST KANSAS UNTIL 15Z SUNDAY
MORNING. 00Z DDC AND LBF SOUNDINGS SHOW LOW LEVEL MOISTURE HAS
INCREASED IN VALUE AND DEPTH FROM 24 HOURS AGO. MOST MODEL OUTPUT IS
UNDERDOING THE LOW LEVEL MOISTURE. HOWEVER...THE RUC AND HRRR HAVE
CAUGHT ONTO THIS HIGHER MOISTURE AND HAVE BEEN CONSISTENT IN
KEEPING AND/OR INCREASING NOT ONLY THE COVERAGE OF THE FOG BUT THE
EXTENT OF THE DENSE FOG. THE 00Z NAM HAS FINALLY CAUGHT ON AS
WELL. ALL THREE MODELS ARE VERY CLOSE IN THEIR DEPICTION OF THE
DENSE FOG AREA.
SO HAD FAIRLY HIGH CONFIDENCE IN ISSUING THE ADVISORY FOR THE
AREA IN QUESTION. OVERNIGHT SHIFT CAN TWEAK THIS FURTHER AS THE
NIGHT PROGRESSES. WITH HIGHER DEWPOINTS ALSO RAISED THE MINS
ACCORDINGLY...ESPECIALLY IN THE SOUTHERN HALF BASED ON
REALITY/LATEST RUC/HRRR. RUC/HRRR WERE DOING WELL ON
DEWPOINTS/WINDS AND USED THEM FOR THE UPDATE AS WELL.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 254 PM MDT SAT MAR 24 2012
500 MB RIDGE WILL REMAIN OVER THE FORECAST AREA THROUGH SUNDAY
BEFORE IT SHIFTS EAST SUNDAY NIGHT. SURFACE DEWPOINTS WILL BE IN
THE 40S MOST AREAS TONIGHT...AND DEW POINT DEPRESSIONS WILL BE LOW
AFTER 09Z. WITH LIGHT WINDS AND WEAK SUBSIDENCE...EXPECT PATCHY FOG
TO DEVELOP LATE TONIGHT. FOG MAY BE MORE WIDESPREAD/DENSE THAN LAST
NIGHT GIVEN THE INCREASE OF LOW LEVEL DEW POINTS...BUT WILL MONITOR
THE EVOLUTION OF FOG FORMATION BEFORE HOISTING ANY HIGHLIGHTS. WILL
UPDATE THE HAZARDOUS WEATHER OUTLOOK...HOWEVER...FOR FOG
POSSIBILITIES.
THERMAL RIDGE WILL MOVE ACROSS THE AREA SUNDAY WHICH WILL PRODUCE
HIGH TEMPERATURES IN THE LOWER 80S. A DRY LINE WILL DEVELOP OVER
EASTERN COLORADO DURING THE AFTERNOON...AND IT WILL PUSH EAST DURING
THE AFTERNOON REACHING THE KANSAS BORDER BY 21Z. CONSIDERED
INTRODUCING CONVECTION INTO THE FORECAST EAST OF THE DRY LINE AS
MIXED LAYER CAPES WILL BE DECENT IN THE MOIST AIR. HODOGRAPHS ALSO
SHOW GOOD SHEAR. HOWEVER...WITH THE AMOUNT OF INHIBITION AND LACK OF
DECENT LOW TO MID LEVEL SUPPORT...DECIDED AGAINST THUNDERSTORMS.
WEST OF THE DRY LINE...EXPECT RELATIVE HUMIDITIES TO DROP TO 15
PERCENT IN EASTERN COLORADO MAINLY ACROSS WESTERN KIT CARSON AND
WESTERN CHEYENNE COUNTIES. SURFACE WINDS WILL ONLY BE AROUND 15
MPH...SO WILL NOT MENTION ANY FIRE WEATHER HIGHLIGHTS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 254 PM MDT SAT MAR 24 2012
NUMEROUS CONCERNS FOR FORECAST AREA ON MONDAY INCLUDING POTENTIAL
FOR A FEW RECORD HIGHS (SEE CLIMATE SECTION BELOW), STRONG FIRE
WEATHER POTENTIAL (SEE FIRE WEATHER SECTION BELOW), AND POTENTIAL
FOR CONVECTION DURING THE LATE AFTERNOON AND EVENING HOURS. FAIRLY
POTENT SHORTWAVE TROUGH IS PROGGED TO MOVE OUT OF THE GREAT BASIN
AND INTO THE WESTERN DAKOTAS DURING THE DAY. A DRYLINE WILL SET UP
INITIALLY ALONG THE KS/CO BORDER AND IS PROGGED TO MIX EASTWARD
TOWARD THE HIGHWAY 25 CORRIDOR BY MID AFTERNOON. THERE IS SOME
DEGREE OF UNCERTAINTY WITH REGARD TO THE EXACT PLACEMENT OF THE
DRYLINE AND THIS WILL HAVE AN IMPACT ON THE POTENTIAL FOR
CONVECTION AT ANY ONE LOCATION. ADDITIONALLY, STRONGEST FORCING
FOR ASCENT WILL RESIDE NORTH OF THE FORECAST AREA SO FEEL
CONFIDENT IN KEEPING SLIGHT CHANCE POPS GOING. HAVING SAID
THAT...PARAMETERS WOULD FAVOR STRONG/SEVERE CONVECTION SHOULD
SOMETHING GET GOING. FEEL BEST SHOT FOR CONVECTION IS FURTHER EAST
THAN PREVIOUSLY ADVERTISED SO NUDGED POPS THAT DIRECTION. HAVE
ALSO INSERTED BLOWING DUST MENTION FOR LOCATIONS TO THE WEST OF
THE DRYLINE. DESPITE RECENT PRECIP...SOIL MOISTURE DEFICITS REMAIN
HIGH. ALSO VERY CONCERNED ABOUT BLOWING DUST/SAND ACROSS CENTRAL
PORTIONS OF YUMA COUNTY WHERE A VERY LARGE BURN SCAR FROM A FIRE
LAST SUNDAY WILL ENHANCED POTENTIAL FOR REDUCED VISIBILITIES.
SLIGHTLY COOLER...BUT STILL MUCH ABOVE NORMAL...AIR MOVES INTO
THE CENTRAL HIGH PLAINS ON TUESDAY. GIVEN LATEST PROGS...DID BUMP
MAX TEMPS UP A FEW DEGREES ACROSS THE AREA.
BROAD/FLAT RIDGE BUILDS BACK ACROSS THE CENTRAL HIGH PLAINS
WEDNESDAY WITH A WEAK SHORTWAVE TROUGH PROGGED TO PASS THURSDAY
INTO THURSDAY NIGHT. SLIGHT CHANCE POPS ACROSS THE EAST INITIALLY
IN MOIST SOUTHEAST FLOW BEFORE SPREADING OVER THE REMAINDER OF THE
FORECAST AREA.
MUCH ABOVE NORMAL TEMPS WILL CONTINUE INTO THE WEEKEND WITH TEMPS
REMAINING IN THE 70S TO NEAR 80.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1057 PM MDT SAT MAR 24 2012
FOG AND STRATUS ARE EXPECTED TO DEVELOP ROUGHLY IN THE 08Z TO 11Z
TIME FRAME. CONDITIONS AT KGLD ARE EXPECTED TO DROP INTO THE IFR
TO LIFR CATEGORY AND LAST UNTIL NEAR 15Z WHEN THE FOG IS GONE AND
THE CEILINGS RISE INTO THE MVFR CATEGORY. CONDITIONS SHOULD BE VFR
BY 18Z AS THE WINDS BECOME GUSTY AT 18Z. FOR KMCK THE MAIN PROBLEM
WILL BE FOG REDUCING VISIBILITIES INTO THE MVFR CATEGORY WITH NO
CEILINGS EXPECTED AT THIS TIME. CONDITIONS WILL IMPROVE EARLIER
THERE THAN AT KGLD AS WINDS ALSO BECOME STRONGER AND GUSTY FROM
THE SOUTH.
&&
.FIRE WEATHER...
ISSUED AT 254 PM MDT SAT MAR 24 2012
BORDERLINE FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS EASTERN
COLORADO ON SUNDAY. HOWEVER...WIND SPEEDS ARE EXPECTED TO REMAIN
BELOW CRITERIA NEEDED FOR ISSUANCE OF A RED FLAG WARNING.
A MORE SUBSTANTIAL CRITICAL FIRE WEATHER DAY APPEARS LIKELY ALONG
AND WEST OF HIGHWAY 25 ON MONDAY TO THE WEST OF A FAIRLY STOUT
DRYLINE. GIVEN HIGH CONFIDENCE...WILL GO AHEAD AND ISSUE A FIRE
WEATHER WATCH FOR THESE LOCATIONS. RECENT PRECIP AND THE RESULTANT
GREEN UP MAY HELP MITIGATE THE THREAT BUT SUBSTANTIAL DRY FUELS
REMAIN ACROSS THE TRI-STATE REGION.
RH VALUES WILL BE BELOW 20 PERCENT AGAIN ON TUESDAY...WEDNESDAY
...AND THURSDAY ACROSS WESTERN PORTIONS OF THE AREA BUT CURRENT
INDICATIONS WOULD SHOW THE WIND SPEEDS SHOULD REMAIN LIGHT AT
AROUND 10 MPH OR LESS.
&&
.CLIMATE...
ISSUED AT 254 PM MDT SAT MAR 24 2012
POTENTIAL CONTINUES TO EXIST FOR A FEW RECORD HIGHS TO FALL ON
MONDAY BUT THE BIGGER STORY BY THIS TIME NEXT WEEKEND WILL BE THE
FACT THAT A FEW LOCATIONS WILL HAVE SET AN ALL-TIME RECORD FOR THE
WARMEST AVERAGE TEMPERATURE. CURRENT RECORDS ARE AS FOLLOWS:
GOODLAND - 48.8 DEGREES SET IN 1907 - CURRENT AVERAGE TEMP 48.0
BURLINGTON - 47.7 DEGREES SET IN 1986 - CURRENT AVERAGE TEMP 46.7
MCCOOK - 48.3 DEGREES SET IN 2007 - CURRENT AVERAGE TEMP 49.5
HILL CITY - 54.3 DEGREES SET IN 1910 - CURRENT AVERAGE TEMP 50.8
WITH FORECASTED TEMPS...CONFIDENCE IS HIGH THAT AT LEAST
GOODLAND...BURLINGTON...AND MCCOOK WILL SEE THE WARMEST MARCH ON
RECORD. IT REMAINS TO BE SEEN IF HILL CITY WILL BREAK THE RECORD
AS WELL.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING
FOR COZ252>254.
DENSE FOG ADVISORY UNTIL 9 AM MDT SUNDAY FOR COZ090>092.
KS...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING
FOR KSZ001-002-013-014-027-028-041-042.
DENSE FOG ADVISORY UNTIL 9 AM MDT /10 AM CDT/ SUNDAY FOR
KSZ013>016-027>029-041-042.
NE...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING
FOR NEZ079-080.
&&
$$
UPDATE...JRM
SHORT TERM...MENTZER
LONG TERM....FOLTZ
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1102 PM MDT SAT MAR 24 2012
.UPDATE...
ISSUED AT 843 PM MDT SAT MAR 24 2012
JUST COMPLETED AN UPDATE. MAIN CHANGES WERE TO INCREASE COVERAGE
OF THE FOG OVER THE ENTIRE AREA AND ISSUED A DENSE FOG ADVISORY FOR
EAST CENTRAL COLORADO AND MUCH OF NORTHWEST KANSAS UNTIL 15Z SUNDAY
MORNING. 00Z DDC AND LBF SOUNDINGS SHOW LOW LEVEL MOISTURE HAS
INCREASED IN VALUE AND DEPTH FROM 24 HOURS AGO. MOST MODEL OUTPUT IS
UNDERDOING THE LOW LEVEL MOISTURE. HOWEVER...THE RUC AND HRRR HAVE
CAUGHT ONTO THIS HIGHER MOISTURE AND HAVE BEEN CONSISTENT IN
KEEPING AND/OR INCREASING NOT ONLY THE COVERAGE OF THE FOG BUT THE
EXTENT OF THE DENSE FOG. THE 00Z NAM HAS FINALLY CAUGHT ON AS
WELL. ALL THREE MODELS ARE VERY CLOSE IN THEIR DEPICTION OF THE
DENSE FOG AREA.
SO HAD FAIRLY HIGH CONFIDENCE IN ISSUING THE ADVISORY FOR THE
AREA IN QUESTION. OVERNIGHT SHIFT CAN TWEAK THIS FURTHER AS THE
NIGHT PROGRESSES. WITH HIGHER DEWPOINTS ALSO RAISED THE MINS
ACCORDINGLY...ESPECIALLY IN THE SOUTHERN HALF BASED ON
REALITY/LATEST RUC/HRRR. RUC/HRRR WERE DOING WELL ON
DEWPOINTS/WINDS AND USED THEM FOR THE UPDATE AS WELL.
UPDATE ISSUED AT 549 PM MDT SAT MAR 24 2012
DID AN EARLY UPDATE. CURRENT DEWPOINTS OVER THE FORECAST AREA AND
UPSTREAM ARE HIGHER THAN WHAT MOST MODEL OUTPUT INDICATES. THE HRRR
FOOLLOWED BY THE RUC ARE CATCHING THE DEWPOINTS THE BEST AND INCREASE
THE DEWPOINTS OVER THE ENTIRE AREA THROUGH THE NIGHT. USED THE HRRR
FOR THE UPDATE. LATEST RUC AND NAM OUTPUT IS NOT ONLY INCREASING
THE AREAL COVERAGE OF THE FOG BUT ALSO IS DECREASING THE VISIBILITY.
SO INCREASED THE COVERAGE AND ALSO ADDED DENSE WORDING TO THE
GRIDS. WILL CONTINUE TO WATCH THE TRENDS ON THE OBSERVATIONS PLUS
WAIT FOR THE 00Z SOUNDINGS TO SEE IF A DENSE FOG ADVISORY WILL BE
NEEDED BUT CHANCES OF THIS ARE ON THE INCREASE.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 254 PM MDT SAT MAR 24 2012
500 MB RIDGE WILL REMAIN OVER THE FORECAST AREA THROUGH SUNDAY
BEFORE IT SHIFTS EAST SUNDAY NIGHT. SURFACE DEWPOINTS WILL BE IN
THE 40S MOST AREAS TONIGHT...AND DEW POINT DEPRESSIONS WILL BE LOW
AFTER 09Z. WITH LIGHT WINDS AND WEAK SUBSIDENCE...EXPECT PATCHY FOG
TO DEVELOP LATE TONIGHT. FOG MAY BE MORE WIDESPREAD/DENSE THAN LAST
NIGHT GIVEN THE INCREASE OF LOW LEVEL DEW POINTS...BUT WILL MONITOR
THE EVOLUTION OF FOG FORMATION BEFORE HOISTING ANY HIGHLIGHTS. WILL
UPDATE THE HAZARDOUS WEATHER OUTLOOK...HOWEVER...FOR FOG
POSSIBILITIES.
THERMAL RIDGE WILL MOVE ACROSS THE AREA SUNDAY WHICH WILL PRODUCE
HIGH TEMPERATURES IN THE LOWER 80S. A DRY LINE WILL DEVELOP OVER
EASTERN COLORADO DURING THE AFTERNOON...AND IT WILL PUSH EAST DURING
THE AFTERNOON REACHING THE KANSAS BORDER BY 21Z. CONSIDERED
INTRODUCING CONVECTION INTO THE FORECAST EAST OF THE DRY LINE AS
MIXED LAYER CAPES WILL BE DECENT IN THE MOIST AIR. HODOGRAPHS ALSO
SHOW GOOD SHEAR. HOWEVER...WITH THE AMOUNT OF INHIBITION AND LACK OF
DECENT LOW TO MID LEVEL SUPPORT...DECIDED AGAINST THUNDERSTORMS.
WEST OF THE DRY LINE...EXPECT RELATIVE HUMIDITIES TO DROP TO 15
PERCENT IN EASTERN COLORADO MAINLY ACROSS WESTERN KIT CARSON AND
WESTERN CHEYENNE COUNTIES. SURFACE WINDS WILL ONLY BE AROUND 15
MPH...SO WILL NOT MENTION ANY FIRE WEATHER HIGHLIGHTS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 254 PM MDT SAT MAR 24 2012
NUMEROUS CONCERNS FOR FORECAST AREA ON MONDAY INCLUDING POTENTIAL
FOR A FEW RECORD HIGHS (SEE CLIMATE SECTION BELOW), STRONG FIRE
WEATHER POTENTIAL (SEE FIRE WEATHER SECTION BELOW), AND POTENTIAL
FOR CONVECTION DURING THE LATE AFTERNOON AND EVENING HOURS. FAIRLY
POTENT SHORTWAVE TROUGH IS PROGGED TO MOVE OUT OF THE GREAT BASIN
AND INTO THE WESTERN DAKOTAS DURING THE DAY. A DRYLINE WILL SET UP
INITIALLY ALONG THE KS/CO BORDER AND IS PROGGED TO MIX EASTWARD
TOWARD THE HIGHWAY 25 CORRIDOR BY MID AFTERNOON. THERE IS SOME
DEGREE OF UNCERTAINTY WITH REGARD TO THE EXACT PLACEMENT OF THE
DRYLINE AND THIS WILL HAVE AN IMPACT ON THE POTENTIAL FOR
CONVECTION AT ANY ONE LOCATION. ADDITIONALLY, STRONGEST FORCING
FOR ASCENT WILL RESIDE NORTH OF THE FORECAST AREA SO FEEL
CONFIDENT IN KEEPING SLIGHT CHANCE POPS GOING. HAVING SAID
THAT...PARAMETERS WOULD FAVOR STRONG/SEVERE CONVECTION SHOULD
SOMETHING GET GOING. FEEL BEST SHOT FOR CONVECTION IS FURTHER EAST
THAN PREVIOUSLY ADVERTISED SO NUDGED POPS THAT DIRECTION. HAVE
ALSO INSERTED BLOWING DUST MENTION FOR LOCATIONS TO THE WEST OF
THE DRYLINE. DESPITE RECENT PRECIP...SOIL MOISTURE DEFICITS REMAIN
HIGH. ALSO VERY CONCERNED ABOUT BLOWING DUST/SAND ACROSS CENTRAL
PORTIONS OF YUMA COUNTY WHERE A VERY LARGE BURN SCAR FROM A FIRE
LAST SUNDAY WILL ENHANCED POTENTIAL FOR REDUCED VISIBILITIES.
SLIGHTLY COOLER...BUT STILL MUCH ABOVE NORMAL...AIR MOVES INTO
THE CENTRAL HIGH PLAINS ON TUESDAY. GIVEN LATEST PROGS...DID BUMP
MAX TEMPS UP A FEW DEGREES ACROSS THE AREA.
BROAD/FLAT RIDGE BUILDS BACK ACROSS THE CENTRAL HIGH PLAINS
WEDNESDAY WITH A WEAK SHORTWAVE TROUGH PROGGED TO PASS THURSDAY
INTO THURSDAY NIGHT. SLIGHT CHANCE POPS ACROSS THE EAST INITIALLY
IN MOIST SOUTHEAST FLOW BEFORE SPREADING OVER THE REMAINDER OF THE
FORECAST AREA.
MUCH ABOVE NORMAL TEMPS WILL CONTINUE INTO THE WEEKEND WITH TEMPS
REMAINING IN THE 70S TO NEAR 80.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1057 PM MDT SAT MAR 24 2012
FOG AND STRATUS ARE EXPECTED TO DEVELOP ROUGHLY IN THE 08Z TO 11Z
TIME FRAME. CONDITIONS AT KGLD ARE EXPECTED TO DROP INTO THE IFR
TO LIFR CATEGORY AND LAST UNTIL NEAR 15Z WHEN THE FOG IS GONE AND
THE CEILINGS RISE INTO THE MVFR CATEGORY. CONDITIONS SHOULD BE VFR
BY 18Z AS THE WINDS BECOME GUSTY AT 18Z. FOR KMCK THE MAIN PROBLEM
WILL BE FOG REDUCING VISIBILITIES INTO THE MVFR CATEGORY WITH NO
CEILINGS EXPECTED AT THIS TIME. CONDITIONS WILL IMPROVE EARLIER
THERE THAN AT KGLD AS WINDS ALSO BECOME STRONGER AND GUSTY FROM
THE SOUTH.
&&
.FIRE WEATHER...
ISSUED AT 254 PM MDT SAT MAR 24 2012
BORDERLINE FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS EASTERN
COLORADO ON SUNDAY. HOWEVER...WIND SPEEDS ARE EXPECTED TO REMAIN
BELOW CRITERIA NEEDED FOR ISSUANCE OF A RED FLAG WARNING.
A MORE SUBSTANTIAL CRITICAL FIRE WEATHER DAY APPEARS LIKELY ALONG
AND WEST OF HIGHWAY 25 ON MONDAY TO THE WEST OF A FAIRLY STOUT
DRYLINE. GIVEN HIGH CONFIDENCE...WILL GO AHEAD AND ISSUE A FIRE
WEATHER WATCH FOR THESE LOCATIONS. RECENT PRECIP AND THE RESULTANT
GREEN UP MAY HELP MITIGATE THE THREAT BUT SUBSTANTIAL DRY FUELS
REMAIN ACROSS THE TRI-STATE REGION.
RH VALUES WILL BE BELOW 20 PERCENT AGAIN ON TUESDAY...WEDNESDAY
...AND THURSDAY ACROSS WESTERN PORTIONS OF THE AREA BUT CURRENT
INDICATIONS WOULD SHOW THE WIND SPEEDS SHOULD REMAIN LIGHT AT
AROUND 10 MPH OR LESS.
&&
.CLIMATE...
ISSUED AT 254 PM MDT SAT MAR 24 2012
POTENTIAL CONTINUES TO EXIST FOR A FEW RECORD HIGHS TO FALL ON
MONDAY BUT THE BIGGER STORY BY THIS TIME NEXT WEEKEND WILL BE THE
FACT THAT A FEW LOCATIONS WILL HAVE SET AN ALL-TIME RECORD FOR THE
WARMEST AVERAGE TEMPERATURE. CURRENT RECORDS ARE AS FOLLOWS:
GOODLAND - 48.8 DEGREES SET IN 1907 - CURRENT AVERAGE TEMP 48.0
BURLINGTON - 47.7 DEGREES SET IN 1986 - CURRENT AVERAGE TEMP 46.7
MCCOOK - 48.3 DEGREES SET IN 2007 - CURRENT AVERAGE TEMP 49.5
HILL CITY - 54.3 DEGREES SET IN 1910 - CURRENT AVERAGE TEMP 50.8
WITH FORECASTED TEMPS...CONFIDENCE IS HIGH THAT AT LEAST
GOODLAND...BURLINGTON...AND MCCOOK WILL SEE THE WARMEST MARCH ON
RECORD. IT REMAINS TO BE SEEN IF HILL CITY WILL BREAK THE RECORD
AS WELL.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING
FOR COZ252>254.
DENSE FOG ADVISORY UNTIL 9 AM MDT SUNDAY FOR COZ090>092.
KS...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING
FOR KSZ001-002-013-014-027-028-041-042.
DENSE FOG ADVISORY UNTIL 9 AM MDT /10 AM CDT/ SUNDAY FOR
KSZ013>016-027>029-041-042.
NE...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING
FOR NEZ079-080.
&&
$$
UPDATE...BULLER
SHORT TERM...MENTZER
LONG TERM....FOLTZ
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
110 AM EDT SUN MAR 25 2012
.Update...
Issued at 1213 AM EDT Mar 25 2012
A quick update this evening to slide precipitation chances to the
west just a bit, skirting our extreme western fringes of the CWA.
Latest HRRR models continue to handle light showers almost perfectly
so have relied heavily on this data for latest sky and POP trends.
Also of note, temperatures are dropping off nicely where sky cover
is not (mainly eastern CWA). Therefore have lowered low temperatures
in these locations. Updated products already out.
Update issued at 753 PM EDT Mar 24 2012
Main change with this update was to translate the scattered showers
currently in central Indiana down into western sections of the LMK
CWA after dark. Adjusted cloud cover accordingly as well.
.Short Term (Tonight through Sunday night)...
Issued at 305 PM EDT Sat Mar 24 2012
Upper low currently centered over west-central Kentucky continues to
slide southeast. The latest satellite imagery indicates the low is
starting to pick up the pace as a vort max currently rounds the
base. While this low is in the vicinity of our area, expect
scattered showers and thunderstorms. Latest radar data illustrates
convection is starting to develop across portions of central
Kentucky. The best areal coverage for the remainder of the afternoon
will be across our south and southeastern forecast area. The low
will move over the Lake Cumberland region by the early evening
hours, which will shift the greatest precip chances eastward. Any
storm that develops this afternoon will be capable of heavy rainfall
and small hail.
Will likely see a break in shower/storm activity tonight, before
deeper moisture wrapping around the broad upper low moves back into
the eastern CWA. This will provide isolated-scattered shower chances
mainly along the I-75 corridor during the day Sunday. The best
chances appear to be during the late morning and early afternoon
hours, aided by diurnal heating. Upper level ridging and associated
subsidence will then work into the eastern CWA, cutting off shower
activity by Sunday evening. This will be the start of a dry period
for the entire region.
Temperatures made it into the upper 50s and low 60s this afternoon,
before the cloud cover increased and slowed the warming trend. Still
expect some cloud cover overnight, with low temperatures ranging
from the mid 40s to low 50s. Could see some patchy fog in the
morning if clouds clear enough, particularly where rain will fall
this afternoon. High temperatures Sunday will get into the upper 60s
across the Bluegrass region, with lower 70s expected elsewhere.
Temperatures Sunday night will be similar to tonight, with perhaps
some locations running a few degrees cooler with less cloud cover
anticipated.
.Long Term (Monday through Saturday)...
Updated at 246 PM EDT Mar 24 2012
Monday-Tuesday...
Upper-level ridging will move into the region from the west to start
the work week off. Low pressure will develop over the northern
Rockies on Monday, moving eastward across the Upper Plains into
Tuesday. With ridging over us, however, we will remain dry with
still above normal temps Mon-Tues. Our far northeastern counties may
see some northwest flow cloudiness (perhaps the reason for the
cooler temps from the NAM), so will trend temps down over those
areas for Monday. Ridge will be centered overhead Tuesday so no
large temp gradient expected. Highs Monday should range from the
upper 60s northeast to the low-mid 70s southwest. With strong warm
air advection on Tuesday, went above guidance for highs in the low
70s northeast to the upper 70s southwest. Our coolest night of
recent should be Monday night under sfc high pressure. Temps should
drop to the upper 30s/around 40 northeast to the mid 40s south.
Tuesday night-Thursday night...
By Tuesday night, the cold front from the low pressure over the
Upper Midwest will drop across the mid-Mississippi Valley region and
approach our CWA towards dawn Wednesday. This should bring a quick
shot of showers and thunderstorms to the area mainly Wednesday and
Wednesday night as the front sweeps across the CWA to the
south-southeast. By Thursday morning, this boundary should be just
south of the CWA, so have opted to keep Thursday-Thursday night dry
for now, though it is possible a shower or two could squeak north of
the TN border during the day Thursday. Although it`s still far out,
progged soundings for Wednesday show the possibility of severe
storms along the front as it passes through. Looks like
unidirectional shear and possibly 1000 J/kg of CAPE may combine to
form a strong line of thunderstorms, not overly organized, at least
at this time. Best chance for this should be around the Ohio River
Wed morn, shifting toward central/south-central KY by Wednesday
evening. With the front laying out Wednesday night, threat would
likely transition to a heavy rain event, but brief, generally
speaking. May mention strong storms in HWO. Have precip ending Wed
night from north to south.
For highs Wednesday, we should be close to 80 in some spots given
the warm start to the day (near 60 degrees). However, behind the
front, temps will drop into the low 50s Wed night, and climb into
the upper 60s/low 70s for Thursday.
Friday on...
Differences in the long term do not really arise until Friday as the
Euro keeps a hold of the ridge overhead, whereas the GFS flattens it
out more and brings a series of shortwaves across the region. Looks
like the extended model guidance though as trended upwards as far as
POPs are concerned, so will at least keep a slight chance for POPs
in on Friday/Friday night as previous forecast did. Will increase
POPs to high chance/low likely for Saturday as timing of one upper
wave in particular is caught by the GFS and Euro. Trended temps down
as a result with upper 60s north to low 70s south for Saturday.
&&
.Aviation (06Z TAF Issuance)...
Updated at 111 AM EDT Mar 25 2012
Expecting VFR conditions to prevail at the TAF sites through the
forecast period, with the exception of a brief MVFR period of BR at
LEX early this morning. Center of the upper low that has plagued the
area for several days is now moving into the Carolinas with a few
light rain showers still rotating from north to south along west
central Kentucky. These showers are expected to slide just west of
the BWG terminal and would likely not cause any category drops
anyway. Further east, mid level ceilings will likely hold off at LEX
the longest and will provide the opportunity for a brief BR scenario
between 4 and 7 am EDT.
Expect scattered to broken cu/stratocu around 2500-3500 feet by mid
to late morning with northwest winds between 5 and 10 mph. Best
chance for a stray shower would be at LEX but will leave out of
forecast for now.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........13/BJS
Short Term.......MJP
Long Term........AL
Aviation.........BJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1211 AM EDT SUN MAR 25 2012
.Update...
Issued at 1213 AM EDT Mar 25 2012
A quick update this evening to slide precipitation chances to the
west just a bit, skirting our extreme western fringes of the CWA.
Latest HRRR models continue to handle light showers almost perfectly
so have relied heavily on this data for latest sky and POP trends.
Also of note, temperatures are dropping off nicely where sky cover
is not (mainly eastern CWA). Therefore have lowered low temperatures
in these locations. Updated products already out.
Update issued at 753 PM EDT Mar 24 2012
Main change with this update was to translate the scattered showers
currently in central Indiana down into western sections of the LMK
CWA after dark. Adjusted cloud cover accordingly as well.
.Short Term (Tonight through Sunday night)...
Issued at 305 PM EDT Sat Mar 24 2012
Upper low currently centered over west-central Kentucky continues to
slide southeast. The latest satellite imagery indicates the low is
starting to pick up the pace as a vort max currently rounds the
base. While this low is in the vicinity of our area, expect
scattered showers and thunderstorms. Latest radar data illustrates
convection is starting to develop across portions of central
Kentucky. The best areal coverage for the remainder of the afternoon
will be across our south and southeastern forecast area. The low
will move over the Lake Cumberland region by the early evening
hours, which will shift the greatest precip chances eastward. Any
storm that develops this afternoon will be capable of heavy rainfall
and small hail.
Will likely see a break in shower/storm activity tonight, before
deeper moisture wrapping around the broad upper low moves back into
the eastern CWA. This will provide isolated-scattered shower chances
mainly along the I-75 corridor during the day Sunday. The best
chances appear to be during the late morning and early afternoon
hours, aided by diurnal heating. Upper level ridging and associated
subsidence will then work into the eastern CWA, cutting off shower
activity by Sunday evening. This will be the start of a dry period
for the entire region.
Temperatures made it into the upper 50s and low 60s this afternoon,
before the cloud cover increased and slowed the warming trend. Still
expect some cloud cover overnight, with low temperatures ranging
from the mid 40s to low 50s. Could see some patchy fog in the
morning if clouds clear enough, particularly where rain will fall
this afternoon. High temperatures Sunday will get into the upper 60s
across the Bluegrass region, with lower 70s expected elsewhere.
Temperatures Sunday night will be similar to tonight, with perhaps
some locations running a few degrees cooler with less cloud cover
anticipated.
.Long Term (Monday through Saturday)...
Updated at 246 PM EDT Mar 24 2012
Monday-Tuesday...
Upper-level ridging will move into the region from the west to start
the work week off. Low pressure will develop over the northern
Rockies on Monday, moving eastward across the Upper Plains into
Tuesday. With ridging over us, however, we will remain dry with
still above normal temps Mon-Tues. Our far northeastern counties may
see some northwest flow cloudiness (perhaps the reason for the
cooler temps from the NAM), so will trend temps down over those
areas for Monday. Ridge will be centered overhead Tuesday so no
large temp gradient expected. Highs Monday should range from the
upper 60s northeast to the low-mid 70s southwest. With strong warm
air advection on Tuesday, went above guidance for highs in the low
70s northeast to the upper 70s southwest. Our coolest night of
recent should be Monday night under sfc high pressure. Temps should
drop to the upper 30s/around 40 northeast to the mid 40s south.
Tuesday night-Thursday night...
By Tuesday night, the cold front from the low pressure over the
Upper Midwest will drop across the mid-Mississippi Valley region and
approach our CWA towards dawn Wednesday. This should bring a quick
shot of showers and thunderstorms to the area mainly Wednesday and
Wednesday night as the front sweeps across the CWA to the
south-southeast. By Thursday morning, this boundary should be just
south of the CWA, so have opted to keep Thursday-Thursday night dry
for now, though it is possible a shower or two could squeak north of
the TN border during the day Thursday. Although it`s still far out,
progged soundings for Wednesday show the possibility of severe
storms along the front as it passes through. Looks like
unidirectional shear and possibly 1000 J/kg of CAPE may combine to
form a strong line of thunderstorms, not overly organized, at least
at this time. Best chance for this should be around the Ohio River
Wed morn, shifting toward central/south-central KY by Wednesday
evening. With the front laying out Wednesday night, threat would
likely transition to a heavy rain event, but brief, generally
speaking. May mention strong storms in HWO. Have precip ending Wed
night from north to south.
For highs Wednesday, we should be close to 80 in some spots given
the warm start to the day (near 60 degrees). However, behind the
front, temps will drop into the low 50s Wed night, and climb into
the upper 60s/low 70s for Thursday.
Friday on...
Differences in the long term do not really arise until Friday as the
Euro keeps a hold of the ridge overhead, whereas the GFS flattens it
out more and brings a series of shortwaves across the region. Looks
like the extended model guidance though as trended upwards as far as
POPs are concerned, so will at least keep a slight chance for POPs
in on Friday/Friday night as previous forecast did. Will increase
POPs to high chance/low likely for Saturday as timing of one upper
wave in particular is caught by the GFS and Euro. Trended temps down
as a result with upper 60s north to low 70s south for Saturday.
&&
.Aviation (00Z TAF Issuance)...
Updated at 653 PM EDT Mar 24 2012
A big upper low centered over Tennessee and Kentucky today will
continue to push to the east, moving off the North Carolina coast
Sunday afternoon.
Tonight winds will be nearly calm with scattered VFR clouds. The
HRRR has been advertising a patch of rain developing over central
Indiana this afternoon and sliding south tonight, affecting BWG
during the pre-dawn hours. The IND radar matches up pretty well
with the model projection, so will trust the model and include VCSH
at BWG between 05Z and 10Z. Also, some MVFR vsby will be possible
at BWG with light winds and dew point depressions dropping to about
zero.
SDF could see a stray shower from the Indiana activity tonight, but
even if they do it would be of minimal impact to aviation so will
not include it in the TAF. LEX should be precipitation free
overnight.
On Sunday some afternoon showers could percolate over the Blue Grass
INVOF LEX, but for the most part it should be an uneventful day with
low-end VFR stratocu cigs and northwest breezes of 5 to 10 knots.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
UpdateS..........13/BJS
Short Term.......MJP
Long Term........AL
Aviation.........13
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1219 AM CDT SUN MAR 25 2012
.UPDATE...
UPDATED FOR THE 06Z AVIATION DISCUSSION BELOW.
.DISCUSSION...
SEVERAL FEATURES OF INTEREST WILL IMPACT THE REGION OVER THE
COMING WEEK... ALTHOUGH AT THIS POINT NO PARTICULARLY SIGNIFICANT
WEATHER APPEARS LIKELY. IN THE BIG PICTURE... THE LARGE SCALE
UPPER FLOW WILL BECOME LESS AMPLIFIED AND HENCE MORE
PROGRESSIVE AND SLIGHTLY MORE SEASONABLE IN OUR NECK OF THE WOODS.
THIS MEANS THAT INSTEAD OF SEEING TEMPERATURES OF 20-30 DEGREES
ABOVE NORMAL... THEY MAY BE MORE ON THE ORDER OF 10-15 DEGREES
ABOVE NORMAL FOR A GOOD PART OF THE UPCOMING WEEK. ONE MAJOR
CONCERN COULD BE THE POTENTIAL FOR FREEZING TEMPERATURES IN THE
UPCOMING WEEK... SINCE SOME OF THE CALENDAR-DEFICIENT PLANTS HAVE
DECIDED IT/S ALREADY TIME TO START GROWING. IT DOESN/T APPEAR AS
THOUGH ANY WIDESPREAD FREEZING TEMPERATURES WILL OCCUR THROUGH THE
UPCOMING WEEK... BUT PORTIONS OF THE AREA COULD SEE READINGS DIP
NEAR OR BELOW FREEZING ON A COUPLE OF MORNINGS. THE GFS AND ECMWF
ARE IN DECENT AGREEMENT THROUGH MOST OF THE WEEK... SO GENERALLY
FOLLOWED A BLEND OF THEIR GUIDANCE... INCREASINGLY BLENDING IT
WITH THE PREVIOUS FORECAST IN THE LATER PERIODS.
VISIBLE IMAGERY SHOWS THIS MORNING/S LOW CLOUDS AND FOG HAVE
FINALLY BURNED OFF OVER MOST OF THE AREA. TEMPERATURES ARE
RESPONDING QUICKLY TO THE SUNSHINE... WITH READINGS CLIMBING
THROUGH THE 60S TO AROUND 70. SHOULD CONTINUE TO SEE READINGS WORK
UPWARD THE NEXT COUPLE OF HOURS... THEN THINGS WILL COOL OFF BOTH
IN RESPONSE TO DARKNESS AND THE COLD FRONT MARCHING SOUTHEAST
THROUGH THE AREA. THE FRONT CURRENTLY STRETCHES FROM NEAR
INTERNATIONAL FALLS SOUTHWEST INTO EASTERN SOUTH DAKOTA.
TEMPERATURES DROP OFF BEHIND THE FRONT... WITH A BIG DROP IN
DEWPOINTS NOTED AS WELL. A FEW SHRA COULD DEVELOP IN NORTHEAST
MINNESOTA AND NORTHWEST WISCONSIN AS THE FRONT MOVES THROUGH THIS
AFTERNOON AND EVENING... BUT AT THIS POINT IT LOOKS LIKE ANY OF
THAT ACTIVITY SHOULD STAY NORTH OF OUR AREA. THE HRRR AND LOCAL
4KM WRF-ARW DO MANAGE TO PRODUCE SOME LIGHT SHRA INTO THE
NORTHEAST PART OF OUR AREA... BUT AT THIS POINT WOULD RATHER SEE
MORE GOING ON IN THE REAL WORLD TO INCLUDE A MENTION. AS
MENTIONED... THE FRONT WILL SLIDE THROUGH TONIGHT... WITH RIDGING
AND COOLER/DRIER AIR ARRIVING FOR OVERNIGHT THROUGH THE DAY ON
SUNDAY. BUT... GIVEN THE MORE PROGRESSIVE FLOW... THIS CHANGE WILL
BE SHORT-LIVED... WITH RETURN FLOW SETTING UP QUICKLY SUNDAY
NIGHT. ISENTROPIC LIFT SUNDAY NIGHT INTO MONDAY IS IMPRESSIVE AS
THE ELEVATED WARM FRONT LIFTS BACK NORTHEAST ACROSS THE AREA. IN
ADDITION TO THE ISENTROPIC LIFT... FAIRLY SUBSTANTIAL LOW-MID
LEVEL FRONTOGENESIS IS PROGGED FROM LATE SUNDAY NIGHT THROUGH THE
DAY ON MONDAY AS THE BOUNDARY SLOWLY LIFTS NORTHEAST ACROSS THE
AREA. A LOOK AT ELEVATED INSTABILITY... PER 850-500MB DIFFERENTIAL
THETA-E VALUES... SHOWS SOME POTENTIAL FOR THUNDER CREEPING IN
FROM WEST TO EAST LATE SUNDAY NIGHT INTO MONDAY NIGHT... WITH A
CHANCE FOR SOME THUNDER ACROSS THE ENTIRE AREA BY LATER MONDAY
NIGHT AS THE WARM SECTOR FULLY ESTABLISHES ITSELF OVER SOUTHERN
MINNESOTA INTO WEST CENTRAL WISCONSIN. EXPECT AN INITIAL ARC OF
PCPN ASSOCIATED WITH ELEVATED WARM ADVECTION TO LIFT INTO THE AREA
LATE SUNDAY NIGHT INTO MONDAY MORNING... THEN A SECONDARY
DEVELOPMENT OF PCPN BEHIND THAT OWING TO INCREASING ISENTROPIC
LIFT ALONG WITH FRONTOGENESIS AND THE ARRIVAL OF ELEVATED
INSTABILITY. IN ADDITION... SOME POTENT STORMS MAY DEVELOP TO OUR
WEST MONDAY AFTERNOON INTO MONDAY EVENING... AND WHAT IS LEFT OF
THOSE COULD WORK INTO THE AREA MONDAY NIGHT.
LOW PRESSURE IS EXPECTED TO LIFT NORTHEAST INTO NORTHWEST
MINNESOTA BY TUESDAY AFTERNOON... WORKING TO DRAG A COLD FRONT
EAST THROUGH OUR AREA SOMEWHAT EARLY IN THE DAY. THE FRONT LOOKS
TO GET ACROSS MOST OF THE MINNESOTA CWFA BY 18Z... AND THROUGH THE
WISCONSIN PORTION OF THE AREA BY MID AFTERNOON. ALTHOUGH DEEP
LAYER SHEAR SHOULD STILL BE QUITE STRONG ON TUESDAY... LOW LEVEL
SHEAR DOES NOT LOOK TO BE AS IMPRESSIVE AS IT DID YESTERDAY...
MAINLY DUE TO THE EARLIER PROGGED ARRIVAL OF THE FRONT. THE
EARLIER FROPA WOULD ALSO LIMIT INSTABILITY INTO THE AREA... WHICH
IS A NEGATIVE TOWARD THE SEVERE WEATHER POSSIBILITIES. SO... AT
THIS POINT... THE OVERALL SEVERE WEATHER CHANCES FROM MONDAY NIGHT
THROUGH TUESDAY DO NOT APPEAR PARTICULARLY HIGH ACROSS THE AREA.
BUT... IT IS STILL A FEW DAYS AWAY... SO ANY CHANGES IN THE TIMING
AND POSITION OF FEATURES COULD STILL CHANGE THINGS A BIT... SO IT
IS WORTH KEEPING AN EYE ON THE SITUATION. STRONG WESTERLY WINDS
WILL USHER IN DRIER AIR BEHIND THE FRONT LATE TUESDAY AFTERNOON
INTO TUESDAY NIGHT... WITH 850MB TEMPERATURES OF BELOW ZERO
ACTUALLY MAKING IT INTO THE AREA FOR A TIME ON WEDNESDAY INTO
WEDNESDAY NIGHT. HOWEVER... THIS CHANGE WILL BE SHORTLIVED ONCE
AGAIN... WITH RETURN FLOW AND WARMER AIR WORKING BACK INTO THE
REGION BY LATER THURSDAY AND INTO FRIDAY. CHANCES FOR SHOWERS AND
A FEW THUNDERSTORMS WILL ACCOMPANY THE RETURN OF WARMER
TEMPERATURES THURSDAY INTO FRIDAY WITH PERHAPS SOME SHOWER CHANCES
LINGERING INTO SATURDAY AS A SHORTWAVE MOVES BY TO OUR NORTH.
&&
.AVIATION.../00Z TAF ISSUANCE/
WE`VE GONE BACK AND FORTH TONIGHT ON HOW FAR SOUTH TO TAKE THE
MVFR CEILINGS ASSOCIATED WITH THAT STRATUS DECK BEHIND THE
ADVANCING COLD FRONT. THE CLOUDS HAD SLOWED THIS EVENING...BUT NOW
THE PUSH OF COLD AIR SEEMS TO BE ADVANCING THE LEADING EDGE OF THE
CLOUD COVER TO THE SOUTH AT 10-15KTS. THE CLOUDS SHOULD MIX OUT
LATE IN THE MORNING. IN TERMS OF WINDS...AFTER SOME INITIAL GUSTS
TONIGHT IN THE 10-20KT RANGE...WIND WILL REMAIN N-NE TODAY AT
5-10KTS. MID TO HIGH CLOUDS INCREASE NEAR THE END OF THE 06Z TAF
PERIOD.
KMSP...BASED ON THE LATEST CLOUD TREND...THE MVFR CEILINGS WOULD
ARRIVE RIGHT AROUND OR JUST BEFORE 12Z IF THE CURRENT RATE HOLDS.
REINTRODUCED A TEMPO GROUP FOR THE STRATUS CLOUDS BACK INTO THE
TAF. SHOULDN`T LAST ALL DAY EVEN IF IT MAKES TO THE AIRPORT THIS
MORNING. NOT OUT OF THE QUESTION THAT A FEW SHOWERS SNEAK IN HERE
EARLY MONDAY MORNING...BUT LEFT THE TAF DRY FOR NOW.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
TRH/CLF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
305 AM EDT SUN MAR 25 2012
.SYNOPSIS...
UNSETTLED WEATHER WILL PERSIST TODAY AS A POTENT UPPER LEVEL LOW
PROGRESSES EAST OVER THE CAROLINAS. MUCH DRIER CONDITIONS WILL
RETURN FOR MONDAY AND TUESDAY AS UPPER LEVEL HIGH PRESSURE BUILDS IN
FROM THE WEST.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
AS OF 1045 PM SATURDAY...
RECENT SFC ANALYSIS SHOWS A LOW PRESSURE SYSTEM CENTERED OVER THE
FOOTHILLS NEAR HICKORY. CONVECTION EARLIER THIS EVENING HAS LARGELY
WEAKENED AND SHIFTED NORTHEAST INTO VA. STABLE OUTFLOW FROM THE
LARGE LINEAR CONVECTIVE COMPLEX HAS OVERSPREAD NEARLY ALL OF THE
PIEDMONT AND INTO THE NORTHERN COASTAL PLAIN. LATEST MESOANALYSIS
AND RUC PROXIMITY SOUNDINGS INDICATE THE BOUNDARY LAYER HAS
STABILIZED BUT ELEVATED INSTABILITY WITH MUCAPE VALUES OF ~500 J/KG
REMAIN. WITH 0-6KM BULK SHEAR VALUES OF 30-40KTS...ELEVATED
ORGANIZED CONVECTION IS POSSIBLE OVERNIGHT. EXPECT THE CONVECTIVE
COVERAGE TO BE SOMEWHAT LIMITED BUT WILL MAINTAIN SLIGHT CHANCE AND
CHANCE POPS FOR THE OVERNIGHT. WITH THIS IN MIND...WILL CLEAR THE
TORNADO WATCH FOR ALL LOCATIONS WHILE ACKNOWLEDGING THAT A STRONGER
STORM WHILE NOT ROOTED IN THE BOUNDARY LAYER COULD STILL PRODUCE
SOME HAIL...WITH THE WIND THREAT AND ESPECIALLY THE TORNADO THREAT
MINIMAL.
THE SURFACE LOW IS EXPECTED TO SHIFT SLOWLY EAST OVERNIGHT AND BE
CENTERED NEAR KFAY BY DAYBREAK SUNDAY. HAVE ADJUSTED WIND FORECAST
OVERNIGHT ACCORDINGLY. LOWS OVERNIGHT WILL RANGE FROM THE LOWER 50S
IN THE WEST/NW PIEDMONT TO THE UPPER 50S IN THE COASTAL PLAIN. -BLAES
FOR SUNDAY AND SUNDAY NIGHT...IF THERE IS A LULL IN SHOWER ACTIVITY
SUNDAY MORNING...INSTABILITY SHOWERS AND THUNDERSTORMS ARE EXPECTED
TO RE-DEVELOP SUNDAY AFTERNOON UNDERNEATH THE -20 TO 21C H5 COLD
CORE...ESPECIALLY IN THE WARM SECTOR EAST OF THE SFC COLD FRONT
WHERE STRONGER HEATING WITHIN THE LINGERING LOW-LEVEL MOISTURE
TONGUE SHOULD SUPPORT MARGINAL INSTABILITY BETWEEN 500 TO 1000 J/KG
OF MUCAPE. HOWEVER...VERY WEAK FLOW BENEATH THE UPPER-LEVEL LOW WILL
FAVOR PULSE AS THE MAIN CONVECTIVE MODE WITH THE WIND DAMAGE AND
HAIL THREATS LIKELY REMAINING MARGINAL.
WILL CONTINUE TO MENTION THE THREAT OF SMALL TO MARGINALLY
SEVERE HAIL FOR SUNDAY IN THE HWO.
HIGHS SUNDAY AFTERNOON RANGING FROM LOWER 70S NW TO MID/UPPER 70S IN
THE EAST. LOWS SUNDAY NIGHT WILL DEPEND ON THE TIMING OF THE SYSTEM
EXITING...WITH DRIER AIR/CLEARING FILTERING INTO THE WESTERN
PIEDMONT AOA DAYBREAK. LOWS RANGING FROM LOWER TO MID 50S NORTHWEST
TO MID/UPPER 50S SOUTHEAST.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 255 AM SUNDAY...
THE LATEST GFS/EUROPEAN MODELS ARE FAVORED WITH THE TIMING/STRENGTH
OF THE UPPER LOW THAT WILL BE MOVING AWAY FROM OUR REGION ON MONDAY.
STRONG SUBSIDENCE IN THE REAR OF THE UPPER LOW WILL COMBINE WITH A
DOWNSLOPE FLOW FROM THE NNW OF 10-15 MPH OFF THE BLUE RIDGE INTO THE
PIEDMONT TO BRING MOSTLY SUNNY SKIES TO CENTRAL NC MONDAY. MODELS
ARE IN GOOD AGREEMENT IN THE TIMING OF A SURFACE COLD FRONT THAT IS
FORECAST TO PUSH SOUTH THROUGH NC MONDAY AFTERNOON. WITH STRONG
DRYING EXPECTED ALONG AND BEHIND THE FRONT... DEW POINTS ARE
FORECAST TO DROP OFF INTO THE 30S BY MID TO LATE AFTERNOON. HIGHS
ARE EXPECTED TO REACH 75 TO 80 WITH THE WARMEST READINGS EXPECTED
ACROSS THE SANDHILLS.
WITH HIGH CONFIDENCE... THE FORECAST FOR MONDAY NIGHT AND TUESDAY IS
FOR BREEZY AND MUCH COOLER CONDITIONS WITH MOSTLY CLEAR SKIES MONDAY
EVENING... WITH WINDS EXPECTED TO DIE OFF BY LATE EVENING. A STRONG
HIGH PRESSURE WILL BUILD SOUTH FROM THE EASTERN GREAT LAKES DEEP
INTO GA BY TUESDAY. ANOTHER ISSUE MAY BE A POTENTIAL FROST ADVISORY
ACROSS THE NORTH MONDAY NIGHT AS TEMPERATURES CRASH AFTER THE WINDS
DIE OFF. LOWS OF 35-40 EXPECTED NORTH... WITH AROUND 40 IN THE SE.
THE MAIN THREAT WILL BE SCATTERED FROST IN LOW LYING AND NON-URBAN
AREAS OF THE PIEDMONT BETWEEN 400 AM AND SUNRISE. HIGHS TUESDAY WILL
BE MOSTLY IN THE 60S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 300 AM SUNDAY...
A SPRING TEMPERATURE SEE-SAW IS EXPECTED WEDNESDAY THROUGH LATE
WEEK.
A RAPID WARM-UP WEDNESDAY WILL BRING HIGHS BACK INTO THE MID 70S TO
AROUND 80. THIS WARMTH WILL PEAK THURSDAY WHEN THERE MAY BE A CHANCE
OF A SHOWER OR THUNDERSTORM DEPENDING ON THE TIMING OF THE NEXT COLD
FRONT. THIS WARMTH WILL BE FOLLOWED BY ANOTHER QUICK SHOT OF COOLER
AIR WITH HIGHS BACK INTO THE 65-72 RANGE EXPECTED BY FRIDAY. MOST
GUIDANCE SUGGESTS LOWS SHOULD STAY ABOVE THE FROST THRESHOLD DURING
THE NEXT COOL SNAP FRIDAY MORNING (MOSTLY 38+ DEGREES).
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 215 AM SUNDAY...
24-HR TAF PERIOD:
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL PERSIST THROUGH
THE TAF PERIOD AS A POTENT UPPER LEVEL LOW PROGRESSES EAST/SE
THROUGH THE CAROLINAS. TRANSIENT SUB-VFR CONDITIONS CAN BE EXPECTED
IN ASSOC/W ANY CONVECTION THROUGHOUT THE TAF PERIOD. ADDITIONALLY...
MVFR/IFR CEILINGS AND/OR MVFR VISBYS WILL BE POSSIBLE AT ANY TAF
SITE THROUGH 12Z THIS MORNING IN ASSOC/W A RESIDUAL MOIST BOUNDARY
LAYER AND NOCTURNAL COOLING. WINDS WILL BE LIGHT/VARIABLE THROUGH
18-21Z THIS AFTERNOON...EVENTUALLY BECOMING NORTHWEST AT 5-10 KT BY
THE END OF THE TAF PERIOD AS THE UPPER LEVEL LOW AND IT`S SURFACE
REFLECTION PROGRESS OFFSHORE THE CAROLINA COAST AND HIGH PRESSURE
BEGINS BUILDING INTO THE AREA FROM THE NORTHWEST.
LOOKING AHEAD:
CLEAR SKIES/VFR CONDITIONS ASSOCIATED WITH AN UPPER LEVEL RIDGE AND
SURFACE HIGH PRESSURE WILL PREVAIL OVER CENTRAL NC MONDAY/TUESDAY.
MVFR/IFR CEILINGS WILL BE POSSIBLE WEDNESDAY MORNING AS HIGH
PRESSURE SHIFTS OFFSHORE AND A MOIST SOUTHERLY RETURN FLOW DEVELOPS.
SUB-VFR CONDITIONS WILL ALSO BE POSSIBLE WEDNESDAY NIGHT AND
THURSDAY IN ASSOC/W A BACKDOOR COLD FRONT EXPECTED TO PROGRESS
SLOWLY SOUTHWARD THROUGH CENTRAL NC. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...BLAES/CBL
SHORT TERM...BADGETT
LONG TERM...BADGETT
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
222 AM EDT SUN MAR 25 2012
.SYNOPSIS...
UNSETTLED WEATHER WILL PERSIST TODAY AS A POTENT UPPER LEVEL LOW
PROGRESSES EAST THROUGH THE CAROLINAS. DRY AND SUNNY CONDITIONS WILL
RETURN FOR MONDAY AND TUESDAY AS AN UPPER LEVEL RIDGE BUILDS OVER
THE CAROLINAS FROM THE WEST.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
AS OF 1045 PM SATURDAY...
RECENT SFC ANALYSIS SHOWS A LOW PRESSURE SYSTEM CENTERED OVER THE
FOOTHILLS NEAR HICKORY. CONVECTION EARLIER THIS EVENING HAS LARGELY
WEAKENED AND SHIFTED NORTHEAST INTO VA. STABLE OUTFLOW FROM THE
LARGE LINEAR CONVECTIVE COMPLEX HAS OVERSPREAD NEARLY ALL OF THE
PIEDMONT AND INTO THE NORTHERN COASTAL PLAIN. LATEST MESOANALYSIS
AND RUC PROXIMITY SOUNDINGS INDICATE THE BOUNDARY LAYER HAS
STABILIZED BUT ELEVATED INSTABILITY WITH MUCAPE VALUES OF ~500 J/KG
REMAIN. WITH 0-6KM BULK SHEAR VALUES OF 30-40KTS...ELEVATED
ORGANIZED CONVECTION IS POSSIBLE OVERNIGHT. EXPECT THE CONVECTIVE
COVERAGE TO BE SOMEWHAT LIMITED BUT WILL MAINTAIN SLIGHT CHANCE AND
CHANCE POPS FOR THE OVERNIGHT. WITH THIS IN MIND...WILL CLEAR THE
TORNADO WATCH FOR ALL LOCATIONS WHILE ACKNOWLEDGING THAT A STRONGER
STORM WHILE NOT ROOTED IN THE BOUNDARY LAYER COULD STILL PRODUCE
SOME HAIL...WITH THE WIND THREAT AND ESPECIALLY THE TORNADO THREAT
MINIMAL.
THE SURFACE LOW IS EXPECTED TO SHIFT SLOWLY EAST OVERNIGHT AND BE
CENTERED NEAR KFAY BY DAYBREAK SUNDAY. HAVE ADJUSTED WIND FORECAST
OVERNIGHT ACCORDINGLY. LOWS OVERNIGHT WILL RANGE FROM THE LOWER 50S
IN THE WEST/NW PIEDMONT TO THE UPPER 50S IN THE COASTAL PLAIN. -BLAES
FOR SUNDAY AND SUNDAY NIGHT...IF THERE IS A LULL IN SHOWER ACTIVITY
SUNDAY MORNING...INSTABILITY SHOWERS AND THUNDERSTORMS ARE EXPECTED
TO RE-DEVELOP SUNDAY AFTERNOON UNDERNEATH THE -20 TO 21C H5 COLD
CORE...ESPECIALLY IN THE WARM SECTOR EAST OF THE SFC COLD FRONT
WHERE STRONGER HEATING WITHIN THE LINGERING LOW-LEVEL MOISTURE
TONGUE SHOULD SUPPORT MARGINAL INSTABILITY BETWEEN 500 TO 1000 J/KG
OF MUCAPE. HOWEVER...VERY WEAK FLOW BENEATH THE UPPER-LEVEL LOW WILL
FAVOR PULSE AS THE MAIN CONVECTIVE MODE WITH THE WIND DAMAGE AND
HAIL THREATS LIKELY REMAINING MARGINAL.
WILL CONTINUE TO MENTION THE THREAT OF SMALL TO MARGINALLY
SEVERE HAIL FOR SUNDAY IN THE HWO.
HIGHS SUNDAY AFTERNOON RANGING FROM LOWER 70S NW TO MID/UPPER 70S IN
THE EAST. LOWS SUNDAY NIGHT WILL DEPEND ON THE TIMING OF THE SYSTEM
EXITING...WITH DRIER AIR/CLEARING FILTERING INTO THE WESTERN
PIEDMONT AOA DAYBREAK. LOWS RANGING FROM LOWER TO MID 50S NORTHWEST
TO MID/UPPER 50S SOUTHEAST.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SATURDAY...
ON MONDAY THE UPPER LEVEL LOW WILL EXIT OFF THE ATLANTIC COAST AND
AN H500 RIDGE WILL MOVE EAST TO TAKE ITS PLACE. AT THE SURFACE THE
PARENT HIGH WILL MOVE INTO WESTERN ONTARIO. LOW LEVEL FLOW WILL BE
OUT OF THE NORTH ON MONDAY AND CONDITIONS MAY BECOME GUSTY BY
AFTERNOON IN A WELL MIXED LAYER...15-20 KNOTS. THE ONSET OF COLD AIR
ADVECTION WILL BE GENERALLY WEAK DURING THE AFTERNOON BUT WILL
INCREASE OVERNIGHT. THIS WILL LEAVE ONE MORE DAY OF HIGH
TEMPERATURES CLOSE TO 80 DEGREES. WITH DEWPOINTS RUNNING IN THE
40S...DRY AND PLEASANT CONDITIONS WILL PREVAIL THROUGHOUT THE DAY.
HIGHS NEAR 80 WITH LOWS TUESDAY MORNING IN THE MID 40S.
STRONGER COLD AIR ADVECTION WILL BEGIN OVERNIGHT MONDAY AND EARLY
TUESDAY MORNING AS THE UPPER LEVEL FLOW TURNS NORTHWESTERLY. THE DAY
WILL ONCE AGAIN BE DRY AS HIGH PRESSURE MOVES OVER THE REGION WITH
LIGHT EASTERLY WINDS AT THE SURFACE. HIGHS WILL BE ON THE ORDER OF
15 DEGREES COOLER THAN MONDAY AS THICKNESSES DROP 40-50 METERS.
HIGHS IN THE MID 60S...LOWS IN THE UPPER 40S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 300 PM SATURDAY...
ON WEDNESDAY THE SURFACE HIGH MOVES OFF THE CAROLINA COAST. A
SURFACE LOW WILL TRACK OVER THE GREAT LAKES WITH ITS ASSOCIATED
SHORTWAVE TROUGH. EXPECT SOUTHWESTERLY FLOW ON WEDNESDAY AS CENTRAL
NC WILL BE STUCK BETWEEN THE DEPARTING HIGH AND THE APPROACHING LOW.
ANY PRECIPITATION WITH THE FRONT SHOULD STAY WELL NORTH OF THE AREA
ON WEDNESDAY...KEEPING CONDITIONS WARM AND DRY. HIGH TEMPERATURES
WILL RECOVER ABOUT 10 DEGREES FROM TUESDAY AND MOISTURE ADVECTION
WILL BEGIN FROM THE SOUTH AS DEWPOINTS WILL RISE INTO THE 50S BY THE
END OF THE DAY. HIGHS MID TO UPPER 70S WITH LOWS THURSDAY MORNING IN
THE LOWER 50S.
THURSDAY IS THE MOST UNCERTAIN DAY IN THE LONG TERM WITH REGARDS TO
WHETHER OR NOT THE FRONT DROPPING DOWN FROM THE NORTH WILL FOR ONE
MAKE IT COMPLETELY THROUGH THE CWA...AND TWO IF IT WILL BRING
PRECIPITATION OR NOT. AT CURRENT TIME THE ECMWF BRINGS IT THROUGH AS
A DRY FRONT BY 12Z THURSDAY...WHILE THE GFS IS A LITTLE BIT MORE
ROBUST BRINGING SOME SHOWERS THROUGH AT LEAST THE NORTHERN PORTION
OF THE CWA AND THEN DRIES OUT WHILE LINGERING ACROSS THE SOUTH
THROUGH 18Z OR SO. FOR THIS FORECAST PACKAGE...WILL INTRODUCE SLIGHT
CHANCE OF POPS IN THE NORTH AND KEEP THE SOUTHERN PORTION OF THE CWA
DRY...SOUTH OF HIGHWAY 64. WITH THE FRONT LINGERING...TEMPERATURES
WILL STILL MAKE IT UP INTO THE UPPER 70S TO LOWER 80S WITH A LITTLE
BIT COOLER ACROSS THE NORTH. WINDS WILL BE LIGHT AND GRADUALLY VEER
TO NORTHWESTERLY AS THE FRONT MOVES SOUTH. LOWS THURSDAY NIGHT UPPER
40S TO LOW 50S.
FRIDAY AND SATURDAY WILL BE GENERALLY DRY BEHIND THE FRONT ALTHOUGH
THERE IS SOME UNCERTAINTY ON SATURDAY AS A WEAK FRONTAL SYSTEM
APPROACHES FROM THE WEST. THE ECMWF KEEPS THE AREA DRY...HOLDING OFF
PRECIPITATION UNTIL SUNDAY WHEREAS THE GFS BRINGS IN SCATTERED
SHOWERS BY SATURDAY AFTERNOON. SINCE THIS SYSTEM APPEARS WEAK
AT THIS TIME...TIMING OF THE ONSET OF PRECIPITATION MAY BE LARGELY
DETERMINED BY HOW FAR OFF OF THE COAST THE SURFACE HIGH SETTLES ON
SATURDAY. WITH LIGHT UPPER LEVEL FLOW...WILL GO WITH THE ECMWF AT
THIS TIME WHICH KEEPS THE HIGH CLOSER TO SHORE AND THUS DRY
CONDITIONS FOR SATURDAY. HIGHS DURING THIS PERIOD WILL BE IN THE
UPPER 60S TO LOW 70S WITH LOWS IN THE UPPER 40S TO LOWER 50S.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 215 AM SUNDAY...
24-HR TAF PERIOD:
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL PERSIST THROUGH
THE TAF PERIOD AS A POTENT UPPER LEVEL LOW PROGRESSES EAST/SE
THROUGH THE CAROLINAS. TRANSIENT SUB-VFR CONDITIONS CAN BE EXPECTED
IN ASSOC/W ANY CONVECTION THROUGHOUT THE TAF PERIOD. ADDITIONALLY...
MVFR/IFR CEILINGS AND/OR MVFR VISBYS WILL BE POSSIBLE AT ANY TAF
SITE THROUGH 12Z THIS MORNING IN ASSOC/W A RESIDUAL MOIST BOUNDARY
LAYER AND NOCTURNAL COOLING. WINDS WILL BE LIGHT/VARIABLE THROUGH
18-21Z THIS AFTERNOON...EVENTUALLY BECOMING NORTHWEST AT 5-10 KT BY
THE END OF THE TAF PERIOD AS THE UPPER LEVEL LOW AND IT`S SURFACE
REFLECTION PROGRESS OFFSHORE THE CAROLINA COAST AND HIGH PRESSURE
BEGINS BUILDING INTO THE AREA FROM THE NORTHWEST.
LOOKING AHEAD:
CLEAR SKIES/VFR CONDITIONS ASSOCIATED WITH AN UPPER LEVEL RIDGE AND
SURFACE HIGH PRESSURE WILL PREVAIL OVER CENTRAL NC MONDAY/TUESDAY.
MVFR/IFR CEILINGS WILL BE POSSIBLE WEDNESDAY MORNING AS HIGH
PRESSURE SHIFTS OFFSHORE AND A MOIST SOUTHERLY RETURN FLOW DEVELOPS.
SUB-VFR CONDITIONS WILL ALSO BE POSSIBLE WEDNESDAY NIGHT AND
THURSDAY IN ASSOC/W A BACKDOOR COLD FRONT EXPECTED TO PROGRESS
SLOWLY SOUTHWARD THROUGH CENTRAL NC. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...BLAES/CBL
SHORT TERM...RTE
LONG TERM...RTE
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1151 PM CDT SAT MAR 24 2012
.AVIATION...
FOR THE 06Z TAFS...VFR CONDITIONS ARE EXPECTED TO PREVAIL FOR ALL
SITES WITH THE EXCEPTION OF WACO THROUGH THE VALID FORECAST
PERIOD. AREAS OF GROUND FOG MAY CAUSE VISIBILITY RESTRICTIONS AT
WACO AROUND SUNRISE.
THERE HAS BEEN NO SIGNIFICANT CHANGE IN THE THINKING FROM THE 00Z
TAFS. SURFACE RIDGING IS EXPECTED TO BE IN PLACE OVER NORTHEAST
TEXAS BY SUNRISE ON SUNDAY. THIS WILL ALLOW SHALLOW MOISTURE TO
MOVE NORTHWEST INTO THE SOUTHWESTERN HALF OF NORTH TX. AT THIS
TIME SHALLOW MOISTURE LOOKS AS THOUGH IT WILL BE MOST ROBUST AT
KACT AND SHOULD REMAIN SOUTHWEST OF METROPLEX TAF SITES THROUGH
SUNRISE. ASSUMING SHALLOW FOG PANS OUT...A FEW HOURS OF LOW MVFR
OR IFR VSBYS CAN BE EXPECTED AT WACO UNTIL DAYTIME HEATING QUICKLY
MIXES OUT THE SHALLOW MORNING INVERSION. ONCE THE INVERSION MIXES
EXPECT A RAPID DISPERSION OF GROUND FOG AROUND WACO. VFR
CONDITIONS AND SOUTHERLY FLOW IS EXPECT FOR THE REMAINDER OF THE
FORECAST PERIOD.
CAVANAUGH
.../PREVIOUS AVIATION DISCUSSION/...
FOR THE 00Z TAFS...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH
THE VALID FORECAST PERIOD EXCEPT FOR THE POSSIBILITY OF SOME EARLY
MORNING FOG AROUND WACO.
A SURFACE RIDGE OF HIGH PRESSURE IN PLACE OVER NORTH TX WILL SLIDE
SLOWLY OFF TO THE NORTHEAST THROUGH THE OVERNIGHT HRS. THIS WILL
ALLOW FOR A RETURN OF SHALLOW MOISTURE TO THE AREA SOUTHWEST OF
THE RIDGE AXIS BY SUNRISE. LATEST GUIDANCE INDICATES THAT THIS
RETURN OF SHALLOW MOISTURE WILL REMAIN SOUTHWEST OF METROPLEX AREA
TAF SITES...BUT WILL END UP AFFECTING THE WACO AREA JUST BEFORE
SUNRISE. BASED ON LATEST RUC FORECAST SOUNDINGS DECIDED TO INCLUDE
A FEW HRS OF IFR VSBYS AT KACT IN THE 11 TO 15Z TIMEFRAME AS A
SHALLOW INVERSION OF TEMPERATURE AND MOISTURE IS INDICATED. WITH
CLEAR SKIES AND LIGHT WIND IN PLACE THIS SET-UP SHOULD RESULT IN
AREAS OF GROUND FOG WITHIN THIS TIMEFRAME. AFTER A COUPLE OF HOURS
OF HEATING...EXPECT THIS SHALLOW INVERSION TO MIX OUT RESULTING IN
A QUICK DISPERSION OF ANY GROUND FOG NEAR KACT. VFR CONDITIONS ARE
EXPECTED FOR THE REMAINDER OF THE FORECAST PERIOD.
CAVANAUGH
&&
.UPDATE...
TEMPERATURES WERE RUNNING A BIT WARMER THAN PREVIOUSLY FORECAST
OVER AREAS NORTHEAST OF THE DALLAS FORT WORTH METROPLEX. WILL
INCREASE OVERNIGHT LOWS BY A FEW DEGREES IN THESE AREAS BASED ON
TRENDS AND NEW GUIDANCE. OTHERWISE PATCHY FOG STILL LOOKS LIKE A
POSSIBILITY PRIMARILY SOUTH OF I 20 BY SUNRISE.
30
&&
.PREV DISCUSSION... /ISSUED 336 PM CDT SAT MAR 24 2012/
SURFACE RIDGE AXIS REMAINS OVER THE EASTERN CWA WITH WEAK
SOUTHERLY FLOW OVER THE WESTERN ZONES BEGINNING TO BRING HIGHER
GULF MOISTURE NORTHWARD. DENSE FOG DEVELOPED OVER THE HILL CENTRAL
AND SOUTHEAST TEXAS LAST NIGHT. EXPECT FOG TO DEVELOP AGAIN
TONIGHT...THIS TIME A LITTLE FARTHER NORTH...PRIMARILY ALONG AND
WEST OF THE BRAZOS RIVER VALLEY WHERE TONGUE OF HIGHER SURFACE
MOISTURE WILL SET UP. ASIDE FROM ANY FOG...A GENERALLY
CLEAR...CALM...AND COMFORTABLE NIGHT IS IN STORE. ANOTHER MILD AND
PLEASANT DAY IS EXPECTED SUNDAY WITH HIGHS IN THE LOWER 80S.
SURFACE RIDGE WILL SHIFT TO THE EAST BY SUNDAY NIGHT AND SOUTHERLY
WINDS WILL GRADUALLY INCREASE TO 10-15 MPH BY MONDAY. AS A RESULT
GULF MOISTURE AND OVERNIGHT LOW TEMPS SLOWLY INCREASE EARLY NEXT
WEEK...BUT HIGH TEMPS REMAIN MILD.
CLOUD COVER IS EXPECTED TO ARRIVE MONDAY NIGHT AND TUESDAY AS A
SHORTWAVE TRACKS ACROSS COLORADO AND INTO THE NORTHERN PLAINS. A
FEW STORMS MAY FIRE ALONG THE DRY LINE IN THE TX PANHANDLE MONDAY
EVENING BUT THE FORCING REMAINS WELL NORTHWEST OF OUR AREA FOR ANY
RAIN CHANCES HERE. MID-HIGH CLOUD COVER WILL BE MOST ABUNDANT ON
TUESDAY WHICH MAY HOLD AFTERNOON HIGHS DOWN A DEGREE OR TWO FROM
MONDAY/S READINGS. OTHERWISE WITH SOUTHERLY FLOW CONTINUING...
EXPECT MORNING STRATUS AND AFTERNOON SUN WITH HIGHS NEAR 80 AND
LOWS NEAR 60 FOR THE MIDWEEK PERIOD.
MODELS ARE IN DECENT AGREEMENT IN THE SYNOPTIC PATTERN BY THE END
OF THE WEEK. THE WESTERLIES ARE EXPECTED TO WEAKEN ACROSS THE
REGION AS THE POLAR JET SETS UP OVER THE CANADIAN BORDER AND THE
SUBTROPICAL JET BECOMES SITUATED ACROSS CENTRAL MEXICO. IN THE VOID
BETWEEN THE TWO...IT APPEARS THE SYNOPTIC ENVIRONMENT WILL BE
FAVORABLE FOR A SHORTWAVE TO INTENSIFY INTO A SLOW MOVING UPPER
LOW OVER TEXAS BY FRIDAY. THE INTENSIFICATION OF THE SHORTWAVE
INTO AN UPPER LOW RESULTS PRIMARILY FROM AN ATMOSPHERIC CONVECTIVE
FEEDBACK...WHERE THE RELEASE OF LATENT HEAT FROM CONVECTION /NOT
THERMAL GRADIENTS/ STRENGTHEN THE VORTEX. GFS/ECMWF/GEM ALL SHOW
THIS UPPER LOW BECOMING A VERTICALLY STACKED AND WARM-CORE
SYSTEM...WITH THE CYCLONIC CIRCULATION EXTENDING DOWN TO THE
SURFACE. CYCLONES OF THIS NATURE ARE NOT UNCOMMON IN THE SUMMER
MONTHS AND ARE NOTORIOUS FOR HEAVY RAIN. HOWEVER...SINCE THIS IS
OCCURRING SO EARLY IN THE YEAR...MOISTURE/INSTABILITY CONTENT IS
PROBABLY NOT HIGH ENOUGH TO RESULT IN SIGNIFICANT CONVECTION OR
HEAVY RAINS. THE BEST CHANCES OF RAIN WILL PROBABLY OCCUR ON
FRIDAY WHEN THE LOW IS OVERHEAD...BUT WILL BE CONSERVATIVE WITH
POPS FOR NOW. HIGH TEMPS SHOULD COOL INTO THE 70S DUE TO CLOUD
COVER AND SCATTERED RAIN SHOWERS...WITH LOWS IN THE LOW-MID 60S.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 57 83 59 83 61 / 0 0 0 0 10
WACO, TX 55 82 56 83 58 / 0 0 0 0 5
PARIS, TX 52 80 53 82 57 / 0 0 0 0 5
DENTON, TX 51 83 56 83 59 / 0 0 0 0 10
MCKINNEY, TX 50 81 53 81 57 / 0 0 0 0 10
DALLAS, TX 58 83 60 83 61 / 0 0 0 0 10
TERRELL, TX 51 82 55 82 58 / 0 0 0 0 5
CORSICANA, TX 57 83 56 82 58 / 0 0 0 0 5
TEMPLE, TX 56 83 56 83 57 / 0 0 0 0 5
MINERAL WELLS, TX 57 84 55 83 57 / 0 0 0 0 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1121 PM CDT SAT MAR 24 2012
.DISCUSSION...UPDATED FOR 06Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...TERMINALS WILL TRANSITION FROM VFR TO IFR BY LATE
TONIGHT WITH A SLOW RETURN BACK TO VFR BY SUN AFTN. AS OF WRITING
STRATUS WAS DVLPING ALONG MID TX COAST WITH KCRP FLIRTING WITH IFR
CRITERIA. XPCTING STRATUS DECK TO BUILD INLAND THRU THE NIGHT WITH
CIGS LOWERING TO IFR LEVELS AND AFFECTING ALL TERMINALS BY
SUNRISE. AREAS OF FOG ALSO POSSIBLE IF STRATUS IS SLOWER TO DVLP
INLAND. KALI AND KVCT MAY XPERIENCE IFR VSBYS IF FOG AFFECTS
TERMINALS. BY LATE SUN MRNG AND THRU THE AFTN STRATUS SHOULD MIX
OUT WITH CIGS RISING AND CONDITIONS BECOMING VFR ALL TERMINALS.
LIGHT WINDS TONIGHT WILL CONTINUE THRU SUN MRNG AND INCREASE TO
MODERATE LEVELS SUN AFTN.
&&
.PREV DISCUSSION... /ISSUED 1000 PM CDT SAT MAR 24 2012/
DISCUSSION...CURRENT OBS AND MSAS DATA INDICATE HIGHER SWATH OF
MOISTURE LOCATED ALONG AND OFFSHORE OF THE SOUTHERN COASTAL BEND
AND LOWER TEXAS COAST. THIS MOISTURE...ALBEIT SHALLOW...WILL
CONTINUE TO ADVECT INLAND OVERNIGHT WITH STRATUS LIKELY TO DEVELOP
ALONG WITH SOME FOG. NAM AND RUC PROG GREATEST FOG POTENTIAL TO BE
LOCATED INLAND ALONG AND IN BETWEEN THE HWY 281 AND 77 CORRIDORS.
CHANGES TO THE FORECAST WERE TO ALTER DIURNAL DROP OF HOURLY
TEMPS ACROSS THE REGION TO SHOW MORE TEMPERATE COOLING THIS
EVENING AND TO CHANGE DEWPOINTS TO REFLECT HIGHER MOISTURE VALUES
MOVING ONSHORE. ALSO ENHANCED FOG WORKING SLIGHTLY FOR AREAS
MENTIONED ABOVE. UPDATED PRODUCTS WILL BE OUT SHORTLY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 65 84 64 83 66 / 0 0 10 0 10
VICTORIA 61 83 60 84 62 / 0 0 10 0 10
LAREDO 68 91 68 90 69 / 0 10 10 10 10
ALICE 65 86 65 86 64 / 0 0 10 10 10
ROCKPORT 67 80 67 80 68 / 0 0 10 0 10
COTULLA 62 86 63 86 64 / 0 10 10 10 10
KINGSVILLE 65 83 65 85 65 / 0 0 10 0 10
NAVY CORPUS 68 79 66 79 69 / 0 0 10 0 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AVIATION...HART/79
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1059 AM EDT SUN MAR 25 2012
.SYNOPSIS...
SLOW MOVING LOW PRESSURE OVER THE MID ATLANTIC REGION WILL PASS
TO THE SOUTH INTO TONIGHT...THEN HEAD NORTHEAST OUT TO SEA AND
STRENGTHEN THROUGH MONDAY. A STRONG COLD FRONT WILL MOVES THROUGH
MONDAY MORNING IN ITS WAKE. HIGH PRESSURE WILL THEN BUILD IN FROM
THE NORTH MONDAY AFTERNOON THROUGH TUESDAY...AND THEN SLIDE EAST
TUESDAY NIGHT. LOW PRESSURE AND AN ASSOCIATED FRONTAL SYSTEM WILL
MOVE ACROSS FROM WEDNESDAY INTO EARLY THURSDAY...FOLLOWED BY HIGH
PRESSURE LATER THURSDAY INTO FRIDAY. A WARM FRONT WILL APPROACH
LATE FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
850 WARM FRONT HAS LIFTED TO OUR NORTH...SO STEADY PRECIPITATION
HAS COME TO AN END...LATEST GUIDANCE AND RADAR TRENDS SUGGEST ONLY
NEEDING POPS FOR ISOLD-SCT -SHRA FOR REMAINDER OF DAY...AND
FORECAST HAS BEEN ADJUSTED ACCORDINGLY.
EVEN WITH 850 WARM FRONT TO OUR N...MODEL AND 12Z KOKX AND KALY
SUGGEST MIXING TO AT MOST 950 HPA...WITH RELATIVELY STRONG ENE
FLOW KEEPING A MARITIME AIRMASS IN PLACE. HAVE ADJUSTED HIGHS
DOWNWARD BASED ON BLEND OF MIXING DOWN FROM 950 HPA AWAY FROM THE
COAST...WITH LAV AND MET GUIDANCE AS WELL AS NAM AND HRRR 2-METER
TEMPERATURES. THIS LOWERED HIGHS ABOUT 1 CATEGORY AWAY FROM THE
COAST. STILL HAVE SOME CONCERN THIS MIGHT END UP BEING TO
WARM...AND ULTIMATELY WE WILL END UP TOPPING OUT FROM THE UPPER
40S ACROSS NORTHERN INTERIOR ZONES TO LOWER 50S COASTAL/NYC METRO
ZONES...BUT NOT QUITE CONFIDENT ENOUGH TO MAKE THAT CHANGE YET. IF
CURRENT TRENDS HOLD THOUGH...WILL MAKE THAT CHANGE IN THE NEXT
UPDATE WHICH WILL GO OUT BY ABOUT 1230 THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
THE UPPER LOW SHEARS NORTH INTO A STRONG NORTHERN STREAM SHORTWAVE
DIGGING THROUGH THE NORTHEAST ON TONIGHT INTO MONDAY. AT THE
SURFACE...LOW PRESSURE TRACKS NE FROM EAST OF CAPE COD TONIGHT TO
THE EAST OF THE CANADIAN MARITIMES ON MONDAY. MEANWHILE ANOTHER
LOW...ASSOCIATED WITH THE NORTHERN STREAM SHORTWAVE...TRACKS EAST
THROUGH QUEBEC INTO SE CANADA TONIGHT INTO MON MORNING...PUSHING A
STRONG COLD FRONT ACROSS THE AREA MONDAY MORNING. THE NORTHERN
STREAM AND COASTAL LOW WILL EVENTUALLY MERGE INTO A STRONG COASTAL
LOW OVER THE CANADIAN MARITIMES BY MON AFTERNOON...AND THEN
GRADUALLY TRACK UP THE COAST.
DRYING CONDITIONS EXPECTED TONIGHT IN THE WAKE OF THE WEAK
SHORTWAVE AND DEPARTING LOW...BUT STILL UNSEASONABLY MILD AHEAD OF
COLD FRONT.
THEN CHILLY CONDITIONS EXPECTED ON MONDAY IN THE WAKE OF THE COLD
FRONTAL PASSAGE...WITH MODERATELY STRONG NW WINDS (20 TO 30 MPH
WITH GUSTS UP TO 40 MPH) PROVIDING STRONG CAA. WIND ADVISORY
CONDITIONS LOOK TO BE ISOLATED. SCT-BKN AFTERNOON CLOUD COVER
LIKELY AS AS THE STRONG NORTHERN STREAM SHORTWAVE PIVOTS THROUGH
THE REGION AS WELL. TEMPS WILL LIKELY PEAK IN THE MORNING...AND
THEN SLOWLY FALL DURING THE DAY WITH CLOUD COVER AND CAA. HIGH
TEMPS FORECAST IS TRICKY DUE TO THE EXACT TIMING OF THE
FRONT...BUT TEMPS LIKELY SLOWLY FALL THROUGH THE 50S INTO THE 40S
DURING THE AFTERNOON.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
DEEP TROUGH GRADUALLY PIVOTS OFFSHORE MON NIGHT INTO TUESDAY...WITH
CANADIAN HIGH PRESSURE BUILDING DOWN FROM HUDSON BAY. THE RESULT
WILL BE DRY BUT CONTINUED WINDY CONDITIONS MONDAY NIGHT INTO
TUESDAY AFTERNOON BETWEEN THE STRONG CANADIAN MARITIMES LOW AND
HIGH PRESSURE BUILDING DOWN FROM HUDSON BAY. RIDGING
SURFACE/ALOFT BUILDS OVERHEAD TUESDAY NIGHT.
NOTE FOR AGRICULTURAL AND HORTICULTURAL CONCERNS...TEMPS ARE
EXPECTED TO FALL INTO THE LOWER TO MID 20S ACROSS NORTHERN
ZONES...MID TO UPPER 20S COAST...AND AROUND FREEZING IN THE NYC/NJ
METRO MON NIGHT. SUB- FREEZING TEMPS ARE ALSO POSSIBLE TUE NIGHT
OUTSIDE OF URBAN CENTERS IF RADIATIONAL COOLING CONDITIONS ARE
RIGHT. WINDS WILL BE LIGHT BUT SOME INCREASING HIGH/MID LEVEL
CLOUDS MAY MITIGATE THIS SOMEWHAT.
MORE ROBUST WAA SHOULD TAKE PLACE TUE NIGHT-WED IN RETURN S-SW
FLOW AS THE HIGH SLIDES TO THE E-SE AND A WARM FRONT
APPROACHES...WITH HIGHS REBOUNDING TO THE UPPER 50S/LOWER 60S.
EXPECT A CHANCE OF SHOWERS MAINLY WED AFTERNOON/NIGHT AS THIS
FRONT MOVES THROUGH AND A COLD FRONT TRAILING FROM LOW PRESSURE
PASSING TO THE NORTH APPROACHES...THEN ONLY SLIGHTLY COOLER BUT
STILL ABOVE AVG TEMPS ON THU/FRI AS ANOTHER HIGH BUILDS IN...WITH
50S TO NEAR 60. AFTER THIS HIGH MOVES EAST... ANOTHER WARM FRONT
WILL APPROACH LATE FRI NIGHT INTO SAT WITH ANOTHER CHANCE OF
SHOWERS.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
A WARM FRONT REMAINS TO THE SOUTH...WHILE LOW PRESSURE MOVES
SLOWLY ACROSS THE MID ATLANTIC REGION. A COLD FRONT GRADUALLY
MOVES ACROSS THE REGION MONDAY MORNING.
SCATTERED SHOWERS WILL DIMINISH IN COVERAGE LATER THIS AFTERNOON.
CIGS HAVE BEEN MVFR WITH VSBYS STAYING VFR. OCCASIONAL MVFR VSBYS
WILL BE POSSIBLE WITH SOME SHOWERS AS WELL AS SOME WIND GUSTS
BETWEEN 15 AND 20 KTS BUT DO NOT THINK THESE WILL OCCUR OFTEN
ENOUGH TO INCLUDE IN TAF FOR MOST SITES. CIGS WILL BE SLOW TO
IMPROVE WITH THE STEADY EASTERLY FLOW AROUND 10 KTS.
WINDS BACK TO MORE NE DIRECTION LATER THIS AFTERNOON AT LESS THAN
10 KTS. LINGERING MOISTURE WILL KEEP MVFR CIGS ACROSS MOST
TERMINALS WITH IFR CIGS POSSIBLE AT OUTLYING TERMINALS FOR AT
LEAST A PART OF THE EVENING. COLD FRONT APPROACHES LATER TONIGHT
AND A MORE NORTHERLY FLOW WILL LEAD TO DRIER AIR WITH VFR
RETURNING. NW WINDS INCREASE 10-15 KT BY DAYBREAK MONDAY.
OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY...
.MONDAY-TUESDAY...VFR. COLD FRONT MOVES THROUGH MONDAY MORNING...
FOLLOWED BY GUSTY NW-N FLOW. DIMINISHING WINDS TUESDAY AFTERNOON.
.WEDNESDAY...MVFR CONDITIONS ARE POSSIBLE IN THE AFTERNOON AND AT
NIGHT AS LOW PRESSURE AND A WARM FRONT APPROACH. GUSTY SW FLOW IN
THE AFTERNOON.
.THURSDAY...VFR. GUSTY NW FLOW.
&&
.MARINE...
MINOR CHANGES MADE TO REFLECT LATEST TRENDS IN THE OBSERVATIONS
AND GUIDANCE...FORECAST APPEARS ON TRACK.
MARGINAL SCA ENE WIND GUSTS ON THE OCEAN WILL CONTINUE INTO THIS
AFTERNOON AND THEN WEAKEN THIS EVENING AS A WEAK SURFACE TROUGH
WORKS ACROSS THE AREA. 5 TO 6 FT OCEAN SEAS MAY BRIEFLY FALL BELOW
SCA TONIGHT.
THEN STRONG SCA CONDITIONS EXPECTED ON ALL WATERS...WITH MARGINAL GALE
CONDITIONS ON THE OCEAN EXPECTED MON MORNING THROUGH MON NIGHT IN THE
WAKE OF A STRONG COLD FRONTAL PASSAGE. HAVE ISSUED GALE WATCH FOR
THE OCEAN WATERS TO ADDRESS THIS POTENTIAL...AND SCA ELSEWHERE
DURING THIS TIME.
CONDITIONS SHOULD GRADUALLY FALL THROUGH SCA AND THEN BELOW ON TUE AS
HIGH PRESSURE BUILDS INTO THE REGION. SCA CONDITIONS POSSIBLE ONCE AGAIN
ON THE OCEAN WATERS WED AFTERNOON/NIGHT IN STRENGTHENING S-SW FLOW
AHEAD OF A COLD FRONT...AND AGAIN THE AFTERNOON/EVENING IN
POST-FRONTAL NW FLOW.
&&
.FIRE WEATHER...
LACK OF RAINFALL...AND COMBINATION OF STRONG WINDS(20 TO 30 MPH
WITH GUSTS UP TO 40 MPH) AND LOW RH VALUES (LOWER 20S PERCENT) ON
MONDAY WILL RESULT IN A SIGNIFICANTLY ENHANCED THREAT FOR THE
SPREAD OF BRUSH FIRES. WILL ADDRESS POTENTIAL IN HWO.
&&
.HYDROLOGY...
RELATIVELY DRY CONDITIONS WILL CONTINUE...WITH NO SIGNIFICANT QPF OF
1/2 INCH OR MORE EXPECTED FOR THE NEXT 7 DAYS. IN FACT...THE U.S.
DROUGHT MONITOR CATEGORIZES SE CT AS BEING IN MODERATE DROUGHT...AND
THE REST OF THE REGION AS ABNORMALLY DRY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM MONDAY TO 6 AM EDT TUESDAY FOR
ANZ330-335-338-340-345.
GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
ANZ350-353-355.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ350-
353-355.
&&
$$
SYNOPSIS...MALOIT/NV
NEAR TERM...MALOIT
SHORT TERM...NV
LONG TERM...NV/GOODMAN
AVIATION...MPS/JM
MARINE...MALOIT/NV/GOODMAN
FIRE WEATHER...NV
HYDROLOGY...NV
AREA FORECAST DISCUSSION
NWS MIAMI FL
902 AM EDT SUN MAR 25 2012
.UPDATE...
AREA OF SHOWERS/ISOLATED TSTMS AFFECTING WESTERN HALF OF SOUTH
FLORIDA PENINSULA THIS MORNING AHEAD OF A COLD FRONT OVER CENTRAL
FLORIDA DEPICTED FAIRLY WELL IN CURRENT FORECAST. 12Z MIAMI
SOUNDINGS SHOWS DECENT INSTABILITY WITH RATHER STEEP LAPSE RATES
BETWEEN 750 AND 600 MB AND ONLY WEAK CAPPING. THIS SHOULD SUPPORT
ISOLATED TSTMS THROUGHOUT THE DAY, BUT MOST LIKELY DURING PEAK
HEATING THIS AFTERNOON OVER EASTERN SECTIONS. SHORT RANGE MODELS
SHOW AREA OF PRECIP OVER WESTERN AREAS GRADUALLY DISSIPATING AND
TRANSITIONING TO SCATTERED CONVECTION OVER THE EASTERN COUNTIES,
WHICH APPEARS REASONABLE AND IS CONSISTENT WITH CURRENT TRENDS.
FOR FORECAST UPDATE THIS MORNING, INCREASED POPS TO 50 PERCENT
OVER COLLIER AND HENDRY COUNTIES TO ACC0UNT FOR CURRENT AREA OF
PRECIP WHICH SHOULD DECREASE THIS AFTERNOON. INCREASED CLOUD
COVER WESTERN AREAS TODAY SHOULD KEEP TEMPS FROM REACHING MID 80S,
THEREFORE LOWERED MAX TEMPS A FEW DEGREES THESE AREAS. ELSEWHERE,
LITTLE CHANGE AS ENOUGH HEATING SHOULD ENABLE TEMPS TO REACH
FORECAST VALUE OF MID 80S METRO AREAS BROWARD AND MIAMI-DADE,
SLIGHTLY COOLER PALM BEACHES WHERE CLOUDS SHOULD ARRIVE SOONER.
POPS FOR EASTERN AREAS LOOK GOOD.
OVER THE LOCAL WATERS, CURRENT WINDS AND SEAS LOOK GOOD AND NO
CHANGES ANTICIPATED. /MOLLEDA
&&
.PREV DISCUSSION... /ISSUED 721 AM EDT SUN MAR 25 2012/
AVIATION...
FRONTAL BOUNDARY MOVING SLOWLY SOUTHWARD ACROSS THE FLORIDA
PENINSULA. SW FLOW EXPECTED AT ALL TERMINALS THROUGH THE PERIOD AS
THE BOUNDARY APPROACHES. CURRENT GUIDANCE DID NOT CHANGE MUCH FROM
PREVIOUS RUNS THEREFORE...KEPT VCSH AT ALL TERMINALS TO BEGIN AT
25/13-14Z...ALONG WITH GUSTY WINDS. MOSTLY CLEAR SKIES AND LIGHTER
WINDS ARE EXPECTED BY 26/00Z.
PREV DISCUSSION... /ISSUED 402 AM EDT SUN MAR 25 2012/
DISCUSSION...
CUTOFF UPPER LEVEL LOW SPINNING OVER THE SOUTHEAST...WITH SURFACE
COLD FRONT MOVING THROUGH NORTH CENTRAL FLORIDA THIS MORNING.
SHOWERS AND ISOLATED THUNDERSTORMS WERE ACROSS THE EASTERN GULF
MOVING TOWARDS CENTRAL FLORIDA. THE UPPER LEVEL LOW WILL CONTINUE
TO SLIDE TO THE EAST TODAY...AND MOVE INTO THE ATLANTIC BY THIS
EVENING.
WEST TO SOUTHWEST FLOW WILL CONTINUE ACROSS THE REGION AHEAD OF
THE FRONT. MODELS CONTINUE TO SHOW DESTABILIZING CONDITIONS
THROUGH THE AFTERNOON. 500MB TEMPS ARE AROUND -12C...LOW LEVEL
LAPSE RATES ARE STEEP AND EVEN SLIGHT DAYTIME HEATING IS EXPECTED
TO BRING TEMPERATURES INTO THE LOW TO MID 80S. THIS SHOULD ALLOW
AT LEAST ISOLATED THUNDERSTORMS TO DEVELOP AHEAD OF AND ALONG THE
FRONT. SO EXPANDED THE THUNDERSTORM AREA TO MOST OF THE REGION
ALONG AND AHEAD OF THE FRONT. HRRR SHOWS SCATTERED SHOWERS AND
SOME THUNDERSTORMS DEVELOPING ACROSS THE EASTERN HALF OF THE
REGION BY 18Z. THIS FOLLOWS WITH OTHER MODEL SOLUTIONS...SO EXPECT
THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE EAST FROM
NORTHERN MIAMI-DADE COUNTY NORTHWARD THIS AFTERNOON. MID LEVEL
LAPSE RATES ARE NOT IMPRESSIVE...MOIST ADIABATIC ABOVE
700-800MB...SO LEFT MENTION OF HAIL OUT.
THE FRONT IS EXPECTED TO MAKE ITS WAY TOWARDS THE LAKE REGION
AROUND 18Z WITH PRECIPITATION ENDING THERE BY 21Z. THE FRONT
SHOULD MOVE OFF THE FLORIDA PENINSULA AROUND 00Z...WITH ANY
LEFTOVER SHOWERS ACROSS THE SOUTH ENDING BY EARLY EVENING. A DRY
NORTHWEST FLOW IS EXPECTED BEHIND THE FRONT...WHICH WILL BRING
COOLER CONDITIONS TONIGHT TO THE REGION. OVERNIGHT LOWS ARE
EXPECTED TO DROP INTO THE 50S NORTHWEST TO THE LOW TO MID 60S
ACROSS THE SOUTHEAST ATLANTIC COAST.
SURFACE HIGH PRESSURE IS EXPECTED TO MOVE OUT OF CANADA AND
TOWARDS THE MID ATLANTIC STATES ON MONDAY...AND WINDS WILL SHIFT
FROM THE NORTHWEST TO THE NORTHEAST BY TUESDAY MORNING. MODELS
CONTINUE TO SHOW A WEAK INVERTED TROUGH MOVING ACROSS SOUTH
FLORIDA ON TUESDAY...BRINGING A MOISTURE AND WIND SURGE TO THE
REGION. SO BREEZY CONDITIONS ARE EXPECTED ACROSS SOUTH FLORIDA ON
TUESDAY...WITH ISOLATED SHOWERS ACROSS THE EASTERN HALF OF THE
REGION. MODELS THEN SHOW DRIER AIR MOVING BACK INTO THE REGION
THROUGH THE END OF THE WEEK. HOWEVER...HIGH PRESSURE IS STILL
EXPECTED TO BE NORTHEAST OF THE REGION THROUGH WEDNESDAY...SO
THERE WILL STILL BE A CHANCE FOR A PASSING LIGHT SHOWER ACROSS THE
EAST COAST METRO AREAS. SO LEFT THE 10 POPS WITH MENTION OF
PRECIP THROUGH THE DAY ON WEDNESDAY.
HIGH PRESSURE WILL WEAKEN AND SHIFT EAST ON THURSDAY AS A
SHORTWAVE TROUGH PUSHES INTO THE MID ATLANTIC STATES. SO LIGHT
WINDS AND DRY CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK.
TEMPERATURES WILL REMAIN WARM...WITH HIGHS IN THE LOW TO MID 80S
AND LOWS AROUND 60 TO AROUND 70.
AVIATION...
FRONTAL BOUNDARY MOVING SLOWLY SOUTHWARD ACROSS THE
FLORIDA PENINSULA. SW FLOW EXPECTED AT ALL TERMINALS THROUGH THE
PERIOD AS THE BOUNDARY APPROACHES. CURRENT GUIDANCE DID NOT CHANGE
MUCH FROM PREVIOUS RUNS THEREFORE...KEPT VCSH AT ALL TERMINALS TO
BEGIN AT 25/16Z...ALONG WITH GUSTY WINDS. MOSTLY CLEAR SKIES AND
LIGHTER WINDS ARE EXPECTED BY 26/00Z.
MARINE...
SOUTHWEST WINDS ARE EXPECTED AHEAD OF A COLD FRONT TODAY...WITH
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ALONG THE BOUNDARY.
WINDS WILL SHIFT TO THE NORTHWEST ACROSS THE LOCAL WATERS THIS
AFTERNOON THROUGH THE EVENING AS THE COLD FRONT MOVES THROUGH. BY
LATE MONDAY...WINDS WILL BECOME EASTERLY AGAIN AS HIGH PRESSURE
BUILDS ACROSS THE ATLANTIC. CURRENT GUIDANCE STILL SHOWING A WEAK
INVERTED TROUGH MOVING INTO THE LOCAL ATLANTIC WATERS ON
TUESDAY. THIS WILL INCREASE THE WINDS ACROSS THE ATLANTIC WATERS
WITH SCEC AND POSSIBLY A SHORT PERIOD OF SCA CONDITIONS IN
WEDNESDAY MORNING.
FIRE WEATHER...
NO FIRE WEATHER CONCERNS TODAY AS A COLD FRONT MOVES THROUGH THE
REGION. ISOLATED THUNDERSTORMS ARE POSSIBLE ALONG THE FRONT.
RELATIVE HUMIDITY VALUES MAY DROP TO AROUND 35 PERCENT ACROSS A
LARGE PORTION OF THE REGION MONDAY AFTERNOON AS DRIER AIR MOVES
DOWN THE PENINSULA BEHIND THE FRONT. WINDS SHIFT TO THE EAST
MONDAY NIGHT...WITH LOW LEVEL MOISTURE RETURNING TO THE AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 83 63 81 66 / 50 10 0 -
FORT LAUDERDALE 86 66 83 68 / 40 20 0 -
MIAMI 87 65 83 66 / 40 20 0 -
NAPLES 79 64 83 63 / 50 10 0 -
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE...59/MOLLEDA
AVIATION/FIRE/RADAR...71/JE
AREA FORECAST DISCUSSION
NWS MIAMI FL
721 AM EDT SUN MAR 25 2012
.AVIATION...
FRONTAL BOUNDARY MOVING SLOWLY SOUTHWARD ACROSS THE FLORIDA
PENINSULA. SW FLOW EXPECTED AT ALL TERMINALS THROUGH THE PERIOD AS
THE BOUNDARY APPROACHES. CURRENT GUIDANCE DID NOT CHANGE MUCH FROM
PREVIOUS RUNS THEREFORE...KEPT VCSH AT ALL TERMINALS TO BEGIN AT
25/13-14Z...ALONG WITH GUSTY WINDS. MOSTLY CLEAR SKIES AND LIGHTER
WINDS ARE EXPECTED BY 26/00Z.
&&
.PREV DISCUSSION... /ISSUED 402 AM EDT SUN MAR 25 2012/
DISCUSSION...
CUTOFF UPPER LEVEL LOW SPINNING OVER THE SOUTHEAST...WITH SURFACE
COLD FRONT MOVING THROUGH NORTH CENTRAL FLORIDA THIS MORNING.
SHOWERS AND ISOLATED THUNDERSTORMS WERE ACROSS THE EASTERN GULF
MOVING TOWARDS CENTRAL FLORIDA. THE UPPER LEVEL LOW WILL CONTINUE
TO SLIDE TO THE EAST TODAY...AND MOVE INTO THE ATLANTIC BY THIS
EVENING.
WEST TO SOUTHWEST FLOW WILL CONTINUE ACROSS THE REGION AHEAD OF
THE FRONT. MODELS CONTINUE TO SHOW DESTABILIZING CONDITIONS
THROUGH THE AFTERNOON. 500MB TEMPS ARE AROUND -12C...LOW LEVEL
LAPSE RATES ARE STEEP AND EVEN SLIGHT DAYTIME HEATING IS EXPECTED
TO BRING TEMPERATURES INTO THE LOW TO MID 80S. THIS SHOULD ALLOW
AT LEAST ISOLATED THUNDERSTORMS TO DEVELOP AHEAD OF AND ALONG THE
FRONT. SO EXPANDED THE THUNDERSTORM AREA TO MOST OF THE REGION
ALONG AND AHEAD OF THE FRONT. HRRR SHOWS SCATTERED SHOWERS AND
SOME THUNDERSTORMS DEVELOPING ACROSS THE EASTERN HALF OF THE
REGION BY 18Z. THIS FOLLOWS WITH OTHER MODEL SOLUTIONS...SO EXPECT
THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE EAST FROM
NORTHERN MIAMI-DADE COUNTY NORTHWARD THIS AFTERNOON. MID LEVEL
LAPSE RATES ARE NOT IMPRESSIVE...MOIST ADIABATIC ABOVE
700-800MB...SO LEFT MENTION OF HAIL OUT.
THE FRONT IS EXPECTED TO MAKE ITS WAY TOWARDS THE LAKE REGION
AROUND 18Z WITH PRECIPITATION ENDING THERE BY 21Z. THE FRONT
SHOULD MOVE OFF THE FLORIDA PENINSULA AROUND 00Z...WITH ANY
LEFTOVER SHOWERS ACROSS THE SOUTH ENDING BY EARLY EVENING. A DRY
NORTHWEST FLOW IS EXPECTED BEHIND THE FRONT...WHICH WILL BRING
COOLER CONDITIONS TONIGHT TO THE REGION. OVERNIGHT LOWS ARE
EXPECTED TO DROP INTO THE 50S NORTHWEST TO THE LOW TO MID 60S
ACROSS THE SOUTHEAST ATLANTIC COAST.
SURFACE HIGH PRESSURE IS EXPECTED TO MOVE OUT OF CANADA AND
TOWARDS THE MID ATLANTIC STATES ON MONDAY...AND WINDS WILL SHIFT
FROM THE NORTHWEST TO THE NORTHEAST BY TUESDAY MORNING. MODELS
CONTINUE TO SHOW A WEAK INVERTED TROUGH MOVING ACROSS SOUTH
FLORIDA ON TUESDAY...BRINGING A MOISTURE AND WIND SURGE TO THE
REGION. SO BREEZY CONDITIONS ARE EXPECTED ACROSS SOUTH FLORIDA ON
TUESDAY...WITH ISOLATED SHOWERS ACROSS THE EASTERN HALF OF THE
REGION. MODELS THEN SHOW DRIER AIR MOVING BACK INTO THE REGION
THROUGH THE END OF THE WEEK. HOWEVER...HIGH PRESSURE IS STILL
EXPECTED TO BE NORTHEAST OF THE REGION THROUGH WEDNESDAY...SO
THERE WILL STILL BE A CHANCE FOR A PASSING LIGHT SHOWER ACROSS THE
EAST COAST METRO AREAS. SO LEFT THE 10 POPS WITH MENTION OF
PRECIP THROUGH THE DAY ON WEDNESDAY.
HIGH PRESSURE WILL WEAKEN AND SHIFT EAST ON THURSDAY AS A
SHORTWAVE TROUGH PUSHES INTO THE MID ATLANTIC STATES. SO LIGHT
WINDS AND DRY CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK.
TEMPERATURES WILL REMAIN WARM...WITH HIGHS IN THE LOW TO MID 80S
AND LOWS AROUND 60 TO AROUND 70.
AVIATION...
FRONTAL BOUNDARY MOVING SLOWLY SOUTHWARD ACROSS THE
FLORIDA PENINSULA. SW FLOW EXPECTED AT ALL TERMINALS THROUGH THE
PERIOD AS THE BOUNDARY APPROACHES. CURRENT GUIDANCE DID NOT CHANGE
MUCH FROM PREVIOUS RUNS THEREFORE...KEPT VCSH AT ALL TERMINALS TO
BEGIN AT 25/16Z...ALONG WITH GUSTY WINDS. MOSTLY CLEAR SKIES AND
LIGHTER WINDS ARE EXPECTED BY 26/00Z.
MARINE...
SOUTHWEST WINDS ARE EXPECTED AHEAD OF A COLD FRONT TODAY...WITH
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ALONG THE BOUNDARY.
WINDS WILL SHIFT TO THE NORTHWEST ACROSS THE LOCAL WATERS THIS
AFTERNOON THROUGH THE EVENING AS THE COLD FRONT MOVES THROUGH. BY
LATE MONDAY...WINDS WILL BECOME EASTERLY AGAIN AS HIGH PRESSURE
BUILDS ACROSS THE ATLANTIC. CURRENT GUIDANCE STILL SHOWING A WEAK
INVERTED TROUGH MOVING INTO THE LOCAL ATLANTIC WATERS ON
TUESDAY. THIS WILL INCREASE THE WINDS ACROSS THE ATLANTIC WATERS
WITH SCEC AND POSSIBLY A SHORT PERIOD OF SCA CONDITIONS IN
WEDNESDAY MORNING.
FIRE WEATHER...
NO FIRE WEATHER CONCERNS TODAY AS A COLD FRONT MOVES THROUGH THE
REGION. ISOLATED THUNDERSTORMS ARE POSSIBLE ALONG THE FRONT.
RELATIVE HUMIDITY VALUES MAY DROP TO AROUND 35 PERCENT ACROSS A
LARGE PORTION OF THE REGION MONDAY AFTERNOON AS DRIER AIR MOVES
DOWN THE PENINSULA BEHIND THE FRONT. WINDS SHIFT TO THE EAST
MONDAY NIGHT...WITH LOW LEVEL MOISTURE RETURNING TO THE AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 63 81 66 / 50 10 0 -
FORT LAUDERDALE 85 66 83 68 / 40 20 0 -
MIAMI 85 65 83 66 / 40 20 0 -
NAPLES 82 64 83 63 / 30 10 0 -
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...59/RM
AVIATION/RADAR...71/JE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
724 AM CDT SUN MAR 25 2012
.UPDATE...
UPDATED TO INCLUDE 12Z AVIATION DISCUSSION BELOW.
&&
.DISCUSSION...
MANY DIFFERENT CONCERNS WITH THE FORECAST OVER THE NEXT FEW DAYS.
INITIALLY RATHER QUIET WITH SURFACE HIGH DROPPING ACROSS THE
WESTERN GREAT LAKES REGION TODAY AND TODAY. COLD AIR IS CURRENTLY
INVADING THE AREA WITH SOME COLD ADVECTION STRATUS WORKING ITS WAS
SOUTH OVER THE AREA. STILL A QUESTION HOW FAR SOUTH IT WILL MAKE
IT BEFORE SUNRISE. SOME BREAKS NOTED OVER NORTHWEST MINNESOTA
ALREADY SO DO EXPECT CLEARING TO TAKE HOLD LATE MORNING/AFTERNOON.
SOME HIGH OR MID LEVEL CLOUDS EXPECTED TO MOVE INTO THE WESTERN
AREAS DURING THE AFTERNOON AS WELL. MUCH COOLER TODAY WITH
READINGS REMAIN IN THE 50S FOR MUCH OF THE FORECAST AREA.
NEXT WEATHER MAKER JUST COMING ASHORE TO THE SOUTHWEST. SOME
ENERGY FROM THE TROUGH RIDING UP ACROSS THE CENTRAL ROCKIES TO THE
WESTERN DAKOTAS. APPEARS TROUGH IS PROGRESSIVE WITH THE NEXT
KICKER WAVE DROPPING SOUTHEAST SOUTH OF THE THE GULF OF ALASKA
REGION. EXPECT CLOUDS TO THICKEN OVERNIGHT...AS MID LEVEL
FRONTOGENESIS/WAA PATTERN DEVELOPS ON THE BACKSIDE OF THE HIGH.
WILL START OUT VERY DRY...ESPECIALLY OVER EASTERN AREAS. LIMITED
ANY SHOWER THREAT TO MAINLY MN OVERNIGHT...AND THAT IS ALSO
DOUBTFUL. WILL START OUT AS VIRGA...AND POSSIBLY SATURATING LATER
TONIGHT. MODELS HAVE BEEN ALL OVER THE PLACE WHERE PLACEMENT OF
THIS LIGHT QPF WILL BE. 00Z ECMWF DROPPED IT FARTHER SOUTH AND NOW
THE 06Z NAM DROPS IT ALONG THE MINNESOTA RIVER VALLEY. WILL ADJUST
POP A BIT BUT WILL MAINTAIN SMALL CHANCE. THUNDER THREAT LOOKS
MARGINAL AT BEST INTO MONDAY. MAIN INSTABILITY AND BEST FORCING
REMAINS OVER THE DAKOTAS INTO THE AFTERNOON. SOME WEAK INSTABILITY
WITH BEST LI`S GENERALLY AROUND ZERO...SLIGHTLY BELOW BY 12Z
MONDAY OVER THE SOUTHWEST. LATEST NAM GENERATES EVEN WEAKER MID
LEVEL/ELEVATED CAPE AS THIS FGEN SURGE MOVES THROUGH MONDAY. WILL
KEEP THE THUNDER THREAT ISOLATED OVER THE WESTERN PORTION OF THE
FORECAST AREA THROUGH MONDAY. HIGH TEMPERATURES WILL STRUGGLE TO
WARM THROUGH THE 50S ON MONDAY WITH CLOUD...EAST WIND.
MAIN ENERGY LIFTS NORTHEAST ACROSS THE DAKOTAS AND NORTHWEST
MINNESOTA MONDAY NIGHT INTO TUESDAY. PV ANOMALY MOVES MAINLY OVER
THE EASTERN DAKOTAS INTO WESTERN CENTRAL MN TUESDAY MORNING. WILL
HAVE TO MONITOR THIS REGION FOR VERY STRONG WINDS POSSIBLY 50KT
GUSTS WITH FRONT AS IT MOVES THROUGH. IT APPEARS COLD FRONT WILL
HAVE SWEPT INTO CENTRAL MN BY 12Z TUE AND WILL EXIT INTO WISCONSIN
IN THE AFTERNOON. WARM SECTOR IS EVIDENT WITH SOME INSTABILITY...BUT
TIMING NOT GOOD AND SYSTEM IS MOVING FAST. WILL CONTINUE LIKELY
POPS TO THE NORTHEAST WITH JUST CHANCE POPS ELSEWHERE...TRAILING
OFF OVER THE EAST ON TUESDAY. DRY SURGE MOVES IN BEHIND THE
FRONT...AND SURFACE DEWPOINTS WILL DROP OFF AGAIN. WIND ADVISORY
WILL BE LIKELY OVER THE WESTERN AND SOUTH TUESDAY...AND HUMIDITY`S
WILL DROP OFF TO PERHAPS 25 PERCENT BY LATE AFTERNOON...RAISING
FIRE WEATHER CONCERNS.
THIS SYSTEM EXITS THE AREA TUESDAY NIGHT PROVIDING A DRY AND COOL
TREND INTO WEDNESDAY NIGHT. NEXT FRONT TO AFFECT THE AREA LATER
THURSDAY INTO FRIDAY WITH SOME CHANCE POPS. SEVERE POTENTIAL
APPEARS LIMITED WITH THIS AS WELL. UPPER AIR PATTERN DOES APPEAR
TO TREND TO ANOTHER LONG WAVE TROUGH DEVELOPING OVER THE WESTERN
CONUS BY NEXT WEEKEND. THIS SHOULD PROVIDE WARMER TEMPERATURES AND
AN INCREASING RISK OF THUNDER INTO THE WEEKEND.
&&
.AVIATION.../12Z TAF ISSUANCE/
SWATH OF LOW STRATUS HAS SMOTHERED MUCH OF MN AND WRN WI THIS MRNG
BEHIND THE CDFNT...WHICH IS NOW FROM KMKX TO THE IA/MO BORDER. THE
FNT WILL STALL OUT THEREABOUTS THRU MON. THE ISSUE FOR TDA IS HOW
LONG UNTIL THE LOW CLOUDS BREAK UP TO ALLOW PARTIAL SUNSHINE.
MODELS HAVE HAD A DIFFICULT TIME WITH THE STRATUS THIS MRNG...BUT
THE HRRR SEEMS TO HAVE HAD THE BEST HANDLE SO USING ITS
DEPICTIONS...THE LOW STRATUS WILL LINGER UNTIL THE 16Z-18Z RANGE.
ALSO DIFFICULT TO TELL IF SITES THAT ARE OVC010-012 WILL DROP TO
IFR. HAVE KEPT THOSE SITES THAT HAVE DROPPED TO LOWER MVFR IN
MVFR...WHILE KEEPING THOSE REPORTING IFR IN IFR...OPTING NOT TO
HAVE BOUNCING OF CATEGORIES WITH LOW LEVEL MOISTURE DIFFICULT TO
RECOVER IN A LOW-LEVEL MIXED ENVIRONMENT. AROUND NOON...ADDITIONAL
DRY AIR PLUS DEEPER MIXING SHOULD ERODE THE LOWER CLOUDS SUCH THAT
SCATTERED LOW CLOUDS WILL REMAIN THROUGH LATE AFTN. ATTENTION THEN
TURNS TO THE INCOMING SYSTEM FOR MONDAY. CLOUDS WILL STREAM IN
AHEAD OF IT...FIRST AT HIGH LEVELS THEN GRADUALLY LOWERING WITH
TIME. THERE IS A LOW CHANCE OF SOME RAIN SHOWERS REACHING THE
WESTERN SITES BY 12Z...BUT WITH WEAK MODEL CONFIDENCE DUE TO
MEAGER LOW-LEVEL MOISTURE PLAYING A KEY FACTOR...AM HESITANT TO
INCLUDE ANY PRECIP AT THIS POINT. NORTHERLY WINDS TODAY WILL
BECOME MORE EASTERLY TONIGHT AS HIGH PRESSURE TO THE NORTH SLIDES
EAST.
MSP...INITIALIZED WITH BKN011 AS A WIDE SWATH OF LOW CLOUDS HAS
SHIFTED SOUTH ENOUGH TO MOVE ACRS KMSP. DEBATED HOW LOW TO GO WITH
CLOUDS CONSIDERING ALL SITES W OF KFCM AND KANE ARE AT IFR...BUT
AFTER COLLAB WITH CWSU ZMP HAVE KEPT THINGS AT LOW MVFR LEVELS.
CONFIDENCE HIGH THAT CIGS WILL LINGER BELOW 1700FT THRU MIDDAY BUT
CANNOT RULE OUT THAT CIGS MAY BRIEFLY DROP BELOW 1000FT BEFORE
BREAKING UP. LOW-LEVEL SCATTERED CLOUDS WILL THEN PREVAIL THRU
MUCH OF THE AFTN BEFORE ALLOWING HIGHER CLOUDS TO BECOME DOMINANT.
HIGH CLOUDS WILL THEN INCREASE IN COVERAGE AND LOWER TNGT THRU
TMRW AS A POTENT STORM SYSTEM DEVELOPING OVER THE NRN ROCKIES
SHIFTS INTO THE DAKOTAS. LOW PRECIP CHCS AND MODEL UNCERTAINTY
OVERCOMING THE LOW-LEVEL DRY AIR TO PRODUCE PRECIP MAKES FOR NOT
INCLUDING PRECIP IN THIS TAF...EVEN IN THE 12Z-18Z PERIOD TMRW.
THOUGHT ABOUT INCLUDING CB MENTION SINCE THERE ARE SOME
INDICATIONS OF CONVECTION ALOFT...BUT WOULD RATHER WAIT FOR LATER
MODEL RUNS TO HELP CLEAR UP THE PICTURE.
OUTLOOK...
/MON-TUE/...STRONG ORGANIZED STORM SYSTEM WILL BRING SHWRS/TSTMS
MAINLY MON NIGHT THRU TUE. PERIODS OF MVFR-IFR CONDITIONS...ALONG
WITH BREEZY CONDITIONS.
/WED/...VFR WITH CONTINUED BREEZY CONDITIONS.
/THU/...WEAK SYSTEM TO BRING SCATTERED SHWRS/TSTMS...POSSIBLE MVFR
CONDITIONS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPC
AREA FORECAST DISCUSSION
NWS GLASGOW MT
904 AM MDT SUN MAR 25 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH TUESDAY...
MORNING UPDATE...
MOST THINGS FOR TODAY LOOK GOOD. DID SOME MANIPULATION OF THE WIND
FIELDS TO INCLUDE MOST RECENT HRRR DATA. THIS SEEMS TO BRING DOWN
OVER ALL WIND SPEEDS EXCEPT FOR HILL TOPS AND MICROSCALE DOWNSLOPE
EFFECTS. CLOUD COVER WAS ALSO TWEAKED TO ADD THE LIMITED LOW
STRATUS THIS MORNING ACROSS THE EASTERN SIDE OF THE YELLOWSTONE
VALLEY... MOST OF WHICH WILL BURN OFF BY THE AFTERNOON HOURS. ALSO
TWEAKED SKY COVER GRIDS TO GIVE A BETTER INTERPRETATION OF THE
THIN STRATO-CIRRUS DECK THAT WILL ENCOMPASS MOST OF THE CWA OTHER
THAN THE NORTH. GAH
PREVIOUS SHORT TERM DISCUSSION...
TWO MAIN IMPACTS TO THINK ABOUT IN THE SHORT TERM FOR MONDAY ARE
FIRE WEATHER CONCERNS ACROSS FIRE WEATHER ZONE 122 MONDAY AFTERNOON
AND EVENING AND THE STRONG WINDS BEHIND A COLD FRONT THAT WILL
MOVE THROUGH LATE MONDAY EVENING.
AN UPPER LEVEL RIDGE THAT SITS OVER EASTERN MONTANA WILL CONTROL
THE WEATHER OVER THE NEXT 24 HOURS. A UPPER LOW/TROUGH COMBO OFF
THE OREGON AND CALIFORNIA COAST IS POISED TO BE EJECTED OVER THE
SIERRA NEVADA MOUNTAIN AND ACROSS THE GREAT BASIN BY ANOTHER UPPER
LOW MOVING OUT OF THE GULF OF ALASKA. THE UPPER LOW WILL MOVE
ACROSS WYOMING AS A NEGATIVELY TILTED TROUGH AND DRAG A
DEVELOPING COLD FRONT ACROSS EASTERN MONTANA.
SUNDAY THROUGH SUNDAY NIGHT... THE SOUTHWEST FLOW ALOFT OVER THE
INTER MOUNTAIN WEST WILL HELP WARM THINGS UP THIS AFTERNOON. THE
WINDS WILL BE OUT OF THE EAST AROUND 15 TO 25 MPH. IT WILL BE
CLOSE TO LAKE WIND ADVISORY CONDITIONS BUT WILL LET THE MORNING
SHIFT TAKE ANOTHER LOOK. THE MET AND MAV GUIDANCE SEEMS A LITTLE
TO STRONG FOR THIS AFTERNOON.
MONDAY AFTERNOON CONDITIONS WILL BECOME DRY ACROSS ZONE 122 SO WE
HAVE ISSUED A FIRE WEATHER WATCH FOR THE ABOVE NORMAL
TEMPERATURES...BREEZY WINDS AND DRY FUELS. AS THE NEGATIVELY
TITLED TROUGH APPROACHES EASTERN MONTANA WITH ITS COLD FRONT
LEADING THE WAY IT WILL ENCOUNTER CAPE BETWEEN 450 AND 1000 J/KG
AND LI`S DOWN TO -4*C. THE STRONGEST CAPE SIGNATURE WILL BE OVER
THE YELLOWSTONE VALLEY SO THIS IS THE AREA THAT WILL HAVE THE BEST
CHANCE FOR STRONG THUNDERSTORMS. SMALL HAIL ALONG WITH LIGHTNING
WILL BE THE BIGGEST THREAT. OTHER AREAS COULD SEE A FEW SCATTERED
WEAKER THUNDERSTORMS AS WELL. THE SYSTEM WILL MOVE OVER NORTH
DAKOTA AND IT WILL BECOME VERTICALLY STACKED. AS IT WRAPS UP IT
WILL PULL MUCH COLDER AIR ACROSS EASTERN MONTANA FROM ALBERTA.
WINDS WILL INCREASE BEHIND THE FRONT MONDAY NIGHT INTO TUESDAY
MORNING IN THE 30 TO 40 MPH RANGE WITH GUSTS OVER 50 MPH LIKELY
OVER THE YELLOWSTONE VALLEY. GOOD OMEGA VALUES PULLING THE STRONG
50 TO 65 KNOT WINDS TO THE SURFACE AFTER MIDNIGHT FROM THE 850 TO
700 MB LEVEL ON A NAM TIME SERIES IN WESTERN PRAIRIE COUNTY.
DECIDED TO HOLD OFF ON A HIGH WIND WATCH FOR NOW SINCE WE ALREADY
HAVE ANOTHER HIGHLIGHT FOR THE SAME GENERAL AREA WITH THE FIRE
WEATHER WATCH.
TUESDAY THE SYSTEM SHIFTS EAST AND THERE COULD BE A BRIEF CHANGE
OVER TO A RAIN SNOW MIX ACROSS THE FAR NORTHEAST ZONES OF DANIELS
AND SHERIDAN COUNTIES. ONE GROUP THAT WILL BE SEVERALLY IMPACTED
WITH THIS SYSTEM ACROSS ALL OF EASTERN MONTANA IS THE YOUNG
LIVESTOCK. WE HAVE STRONG WINDS...COLD AND RAINY WEATHER WHICH IS
NOT A GOOD COMBINATION FOR NEWLY BORN LIVESTOCK. RSMITH
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
THE EXTENDED BEINGS WITH A SHORT WAVE RIDGE IN PLACE OVER MONTANA.
THE GFS AND EC ARE IN GOOD AGREEMENT ON THIS FEATURE. THE RIDGE
MIGRATES TO THE EAST PUTTING MONTANA IN SOUTHWEST FLOW ALOFT. FROM
DAY 5 AND BEYOND THE EC AND GFS HAVE DIFFERENT TIMING AND
POSITIONING OF FEATURES MOVING THROUGH THE UPPER FLOW PATTERN.
CONFIDENCE IS LOW IN PINNING DOWN THE EVENTS THIS WEEK WITH THE
MODEL DIFFERENCES ON TIMING... HOWEVER THE OVERALL PATTERN IS
WESTERLY TO SOUTHWESTERLY WITH CHANCES OF WEAK CONVECTION WITH
STRONGER SHORTWAVES AND FRONTS. OVERALL NOT ANY BIG TEMPERATURE
SWINGS ARE EXPECTED THROUGH THE PERIOD.
FOR THE SOLUTION IN THE EXTENDED LEANED ON A HEAVY EC CONSALL
BLEND FOR FORECAST ELEMENTS WHICH KEPT WITH THE CURRENT FORECAST
TREND. PROTON
&&
.AVIATION...
VFR. THE MAIN ISSUE WILL BE EAST WINDS KICKING EARLY THIS MORNING
AND LASTING THROUGH THE NEXT 24 HOURS. THE STRONGEST WINDS WILL BE
ALONG THE MILK RIVER VALLEY AND HIGHER ELEVATIONS. RIVER BOTTOM
AIRPORTS COULD HAVE MINOR LLWS ISSUES IN THE AFTERNOON. PROTON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 3 PM MDT MONDAY FOR FORT PECK LAKE.
FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING
FOR MTZ122.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
626 AM CDT SUN MAR 25 2012
.DISCUSSION...
ARCTIC AIR CONTINUES TO BACK IN ACROSS NCNTL NEB THIS MORNING
PRODUCING A SHALLOW DECK OF STRATUS. WINDS STAY EAST MOST OF THE
DAY BENEATH THE DECK. WORSE THE RUC SHOWS PWAT POOLING BEHIND THE
FRONT ALONG THE SD BORDER WHICH CANT BE A GOOD WAY TO ERODE
STRATUS. SO 1ST PERIOD HIGH TEMPS HAVE BEEN MARKED DOWN USING THE
RUC13 AS A GUIDE.
&&
.AVIATION...
THE RUC SUGGESTED THE STRATUS WILL DISSIPATE BETWEEN 18Z AND 21Z.
SO LIFR/IFR SHOULD GRADUALLY ERODE THIS MORNING BECOMING IFR/MVFR
EARLY THIS AFTN AND THEN VFR BY 21Z. VFR IS EXPECTED THEREAFTER.
ISOLATED THUNDERSTORMS MAY DEVELOP LATE THIS AFTN AND OVERNIGHT
ALONG AND NORTH OF HIGHWAY 20.
ELSEWHERE VFR TODAY AND TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 351 AM CDT SUN MAR 25 2012/
SYNOPSIS...
HAND ANALYSIS OF THE H5 CHART REVEALS THAT SHORTWAVE
RIDGING HAS BECOME FULLY ESTABLISHED ACROSS THE CENTRAL
STATES...WITH A TROUGH OF LOW PRESSURE DIGGING SOUTH OFF CENTRAL
CALIFORNIA. A SECOND AREA OF LOW PRESSURE RESIDES EAST OF THE
CENTRAL MISSISSIPPI RIVER VALLEY AND CONTINUES TO PUSH SOUTHEAST
TOWARD THE COAST OF SOUTH CAROLINA. THIS PATTERN PRESENTS GENERAL
SOUTHWEST FLOW ALOFT ACROSS WESTERN NEBRASKA WITH THE RIDGE AXIS
BISECTING THE FORECAST AREA. AT THE SURFACE...WIND SPEEDS ARE
GENERALLY LIGHT AND FROM THE NORTHEAST ACROSS WEST CENTRAL NEBRASKA
WITH AN AREA OF HIGH PRESSURE CENTERED NORTH OF THE US/CANADIAN
BORDER. FURTHER WEST OVER THE HIGHER TERRAIN OF EASTERN
WYOMING/COLORADO...THE WIND IS BEGINNING TO VEER SLIGHTLY TO THE
SOUTHEAST...AS A BROAD AREA OF LOW PRESSURE BEGINS TO DEEPEN.
DISCUSSION...
THROUGH 12Z MONDAY. SURFACE HIGH PRESSURE OVER CANADA
WILL BUILD EAST THROUGH THE DAY TODAY AS WEST COAST UPPER TROUGH
ROTATES INLAND AND TAKES ON A STRONG NEGATIVE TILT. SURFACE LOW
PRESSURE OVER THE ROCKIES WILL CONTINUE TO DEEPEN AND THUS
STRENGTHEN SOUTHERLY RETURN FLOW BACK ACROSS ALL OF WESTERN AND
NORTH CENTRAL NEBRASKA. MODEL GUIDANCE INDICATES INCREASING
ATMOSPHERIC MOISTURE WITH THE SOUTHERLY FLOW AS SURFACE TD/S RETURN
ABOVE 45F FOR MOST IF NOT ALL LOCATIONS ACROSS THE CWA. THIS SHOULD
HELP DECREASE THE FIRE POTENTIAL THIS AFTERNOON AS SURFACE T/S
REMAIN IN THE 70/S TO LOW 80/S ALLOWING FOR EXPECTED RH VALUES WELL
ABOVE RED FLAG MINIMUM CRITERIA.
WITH THE INCREASING MOISTURE...STORM CHANCES ARE A POSSIBILITY LATE
THIS AFTERNOON AND TONIGHT /FOR LOCATIONS MAINLY NORTH OF HIGHWAY
TWO ACROSS NORTHWEST NEBRASKA/. A WARM FRONT WILL CONTINUE TO LIFT
NORTHWARD THROUGH THE AFTERNOON...STALLING ALONG OR NEAR THE SOUTH
DAKOTA BORDER BY 00Z MONDAY. SYNOPTIC LIFT WILL BE ON THE INCREASE
AS THETA-E ADVECTION OCCURS AND IS MAXIMIZED ACROSS NORTHWEST
NEBRASKA. MIDLEVEL LAPSE RATES WILL BE STEEP...HOWEVER THERE IS
QUESTION AS TO IF STORMS ARE ABLE TO BREACH THE CAPPING INVERSION
AS STRONG RIDGING REMAINS ENTRENCHED OVER THE CENTRAL AND NORTHERN
PLAINS. IF SO...THE STORMS WOULD BE ABLE TO WORK ON MODEST
INSTABILITY OF 500-1000 J/KG OF CAPE AND 0-6KM BULK SHEAR OF 45KTS.
STORMS WOULD HAVE THE POTENTIAL TO PRODUCE SEVERE HAIL AND CERTAINLY
SEVERE WIND GUSTS AS A SOMEWHAT INVERTED V PROFILE IS SHOWN IN BUFR
SOUNDINGS. GOING INTO THE EVENING...A LOW LEVEL JET WILL STRENGTHEN
AND PROVIDE A FURTHER FOCUS OF STORM DEVELOPMENT ACROSS NORTHERN AND
NORTH CENTRAL NEBRASKA OVERNIGHT...WILL CONTINUE THE MENTION OF
ELEVATED SHOWERS/THUNDERSTORMS.
SEVERAL CONCERNS IN THE FORECAST FOR MONDAY AS A PLETHORA OF WEATHER
IS EXPECTED. FIRST...WILL ISSUE A FIRE WEATHER WATCH FOR FIRE ZONES
204 AND 210 WITH THIS MORNING FORECAST PACKAGE. A DRY LINE IS
EXPECTED BECOME ESTABLISHED AND PUSH EAST ACROSS THE PANHANDLE INTO
WEST CENTRAL NEBRASKA MONDAY AFTERNOON. MODEL GUIDANCE INDICATES
TD/S FALLING BELOW 25F WITH THE PASSAGE. GIVEN ABNORMALLY HIGH
EXPECTED TEMPERATURES...RH VALUES ACROSS THE EASTERN PANHANDLE WILL
FALL BELOW 15 PERCENT /RED FLAG CRITERIA/ BY MIDAFTERNOON ON
MONDAY. MEANWHILE A TIGHT SURFACE GRADIENT WILL EXIST ACROSS THE
HIGH PLAINS AS SURFACE PRESSURE RAPIDLY FALLS IN ADVANCE OF THE WEST
COAST TROUGH. EXPECT SURFACE WIND SPEEDS TO GUST ABOVE 30 MPH FOR
MUCH OF THE AFTERNOON MONDAY. SURFACE LOW PRESSURE WILL QUICKLY
DEEPEN AND PUSH NORTHEAST INTO EASTERN NORTH DAKOTA ON LATE MONDAY
NIGHT...WHICH WILL DRAG A COLD FRONT THROUGH WESTERN NEBRASKA.
AGAIN WIND SPEEDS LOOK PROBLEMATIC....AS HEIGHT RISES ON THE ORDER
OF 14MB/3HR ARE SUGGESTED BY SHORT TERM SOLUTIONS. A WIND ADVISORY
IS EXPECTED...IF NOT HIGH WIND HIGHLIGHTS MONDAY AFTERNOON AND
NIGHT. THE COLD FRONT IS EXPECTED TO QUICKLY CROSS THE CWA MONDAY
EVENING...EVENTUALLY OVERTAKING THE DRYLINE. INITIALLY A STRONG
CAPPING INVERSION WILL LIMIT STORM DEVELOPMENT ACROSS MUCH OF THE
CWA...HOWEVER AS LOW-LEVEL CONVERGENCE ALONG THE COLD FRONT
INCREASES...STORM DEVELOPMENT SHOULD BEGIN. LOOKING AT MODEST
CAPE OF 500-1000 J/KG WITH 6KM SHEAR OF GREATER THAN 40KTS WOULD
PROVIDE THE OPPORTUNITY FOR SEVERE STORMS WITH HAIL AND AND POSSIBLY
DAMAGING WINDS.
TUESDAY MAY BE ACTIVE IN TERMS OF FIRE WEATHER AGAIN AS ABNORMALLY DRY
AIR WILL REMAIN IN PLACE BEHIND THE DEPARTING SYSTEM. POOR RH
RECOVERY WILL AID IN PRIMING AVAILABLE FUELS...AND WITH A GOOD
PORTION OF THE FA WELL BELOW 20 PERCENT RH TUESDAY AFTERNOON...FIRE
CONCERNS MAY BE REALIZED. A COUPLE FACTORS GOING AGAINST THE FIRE
POTENTIAL FOR NOW...ONE IS THAT WIND SPEEDS SHOULD EASE WITH THE
RELAXING PRESSURE GRADIENT. AND TWO...EARLY GREEN UP IS
OCCURRING...WILL NEED TO CONTACT AREA FMO/S TO DETERMINE FUEL
AVAILABILITY. AS FOR TEMPERATURES...WILL TREND THE FORECAST DOWN
SLIGHTLY ON TUESDAY WITH THE FRONTAL PASSAGE...YET HIGHS WILL STILL
BE ABOVE AVERAGE RANGING FROM THE MID 60S ACROSS NORTHWEST
NEBRASKA...TO THE LOW TO MID 70S SOUTH OF I80.
BEYOND TUESDAY...A WEAK DISTURBANCE CROSSES THE REGION LATE THURSDAY
BRINGING A SLIGHT CHANCE OF POPS BACK ACROSS WESTERN AND NORTH
CENTRAL NEBRASKA. OTHERWISE SHORTWAVE RIDGING RETURNS JUST IN
TIME FOR THE WEEKEND...WITH ANOTHER TROUGH DIGGING DOWN THE WEST
COAST OF NA. WILL KEEP T/S ABOVE AVERAGE THROUGH THE EXTENDED AND
GO DRY BEYOND FRIDAY MORNING.
AVIATION...
VFR IS EXPECTED ALL AREAS AFTER 18Z THROUGH 06Z TONIGHT.
A WEAK ARCTIC FRONT DRAPED THROUGH KLBF SHOULD LIFT NORTH TO NEAR
THE SD BORDER THIS AFTERNOON. THE FRONT AND AREAS NORTH WILL BE THE
FOCUS FOR IFR CIGS AND PATCHY FOG THROUGH AT LEAST 15Z. THE RUC
SUGGESTS THERE IS POTENTIAL OF IFR TO LINGER ACROSS NRN NEB THROUGH
18Z DEPENDING ON THE NORTHWARD PROGRESS OF THE FRONT WHICH IS SHOWN
BY THE MODEL TO BE NEAR HIGHWAY 20 AT 18Z.
THUS IFR VS VFR CONDITIONS NEAR KVTN ARE CONTINGENT ON THE FORMATION
OF IFR CIGS. THE LATEST SATELLITE INDICATES A BROAD AREA OF STRATUS
FORMING WHICH SHOULD CONTINUE EXPANDING UNTIL 14Z-15Z FOLLOWED BY A
GRADUAL NORTHWARD EROSION AND CONTRACTION ASSOCIATED WITH THE FRONT
LIFTING NORTH.
FIRE WEATHER...
STRONG DOUBLE BARREL LOW PRESSURE WILL DEEPEN TO AROUND 990MB ACROSS
THE NRN HIGH PLAINS MONDAY AFTERNOON. ALL MODELS ARE DRAWING VERY
DRY AIR NORTH INTO THE LOW AND PRODUCING SOUTH WINDS IN EXCESS OF 30
MPH THROUGHOUT WRN NEB AS THE LOW DEEPENS. A POWERFUL PACIFIC COLD
FRONT WILL THEN RACE EAST THROUGH WRN NEBRASKA MONDAY EVENING
PRODUCING VERY STRONG WEST WIND GUSTS. ISOLATED THUNDERSTORMS AND
DRY LIGHTNING MAY DEVELOP ALONG THE DRYLINE AHEAD OF THE COLD FRONT.
THE DRYLINE SHOULD BE LOCATED NEAR HIGHWAY 61 MONDAY AFTERNOON.
A FIRE WEATHER WATCH WILL BE ISSUED THROUGH 9 PM MDT MONDAY EVENING
COVERING WRN NEBRASKA AND THE FRENCHMAN BASIN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING
FOR NEZ204-210.
&&
$$
SHORT TERM/EXTENDED...CDC
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
922 AM CDT SUN MAR 25 2012
.UPDATE...
MADE SEVERAL CHANGES THIS MORNING TO INCREASE CLOUD COVER AND LOWER MAX
TEMPS SIGNIFICANTLY FOR TODAY. STRONG CAA BELOW ABOUT H9 CONTINUES
THIS MORNING AND WITH 12Z RUC INDICATING THAT WE WILL BE HARD
PRESSED TO MAKE MUCH PROGRESS MIXING MUCH DURING THE REMAINDER OF
THE DAY... ANTICIPATING THAT ALL AREAS WILL REMAIN IN THE UPPER
40S TO MID 50S...IF NOT COOLER. BEST CHANCES FOR PARTLY TO MOSTLY
SUNNY SKIES WILL BE OVER THE FAR NORTHEAST WHERE SOME OF THE LLV
STRATUS CONTINUES TO ERODE SWWD.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH TUESDAY
THE POSSIBILITY OF SEVERE STORMS TONIGHT AND AGAIN MONDAY NIGHT
WILL BE THE MAIN FORECAST CHALLENGE.
AS OF 8Z...AN AREA OF HIGH PRESSURE IS IN CONTROL OF THE NORTHERN
PLAINS. THIS HIGH PRESSURE WILL PRODUCE NORTHEASTERLY WINDS IN THE
LOWER LEVELS TODAY...WHICH SHOULD RESULT IN CHILLY...BUT ABOVE
NORMAL TEMPERATURES. BY LATE THIS AFTERNOON...MODELS DEVELOP A
WEAK LLJ WHICH WILL BRING MOISTURE/WAA INTO THE DAKOTAS. SOME HI-RES
MODELS ARE INDICATING SHOWER ACTIVITY COULD BE POSSIBLE AFTER 0Z
MONDAY IN THE NE CWA...OR WHERE THE BETTER LIFT AND LLM MOISTURE
WILL BE HAD. WITH VERY LITTLE CAPE...BELIEVE MOST OF THE ACTIVITY
TONIGHT WILL CONSIST OF SHOWERS.
MOST OF MONDAY APPEARS TO BE CAPPED WITH BUFFER SOUNDINGS SHOWING
A STRATUS LAYER BELOW THE MID LEVEL WAA. HOWEVER THERE SHOULD BE
ENOUGH CLEARING DURING THE LATE AFTERNOON HOURS IN THE WESTERN CWA
TO ALLOW FOR SURFACE DESTABILIZATION. ATTM...MODELS SHOW AN AREA
OF LOW PRESSURE SYSTEM MOVING ACROSS ND...WITH A SURFACE COLD
FRONT TRAILING ACROSS WESTERN SD. CONVECTIVE INITIATION SEEMS
LIKELY ALONG THE COLD FRONT WITH CONVECTION POSSIBILITY REACHING
THE WESTERN CWA AROUND 0Z TUESDAY. BEYOND 0Z TUESDAY...IT BECOMES
UNCLEAR WHETHER SURFACE CONVECTION WILL BE ABLE TO MAINTAIN ITSELF
OR FRIZZLES WITH A MORE STABLE ENVIRONMENT IN THE EAST. THE
CURRENT THINKING IS THAT CONVECTION MAY BECOME ELEVATED DUE TO
COOLING OF THE BL.
MOST OF TUESDAY IS BEGINNING TO LOOK DRY BUT WINDY WITH CAA MOVING
INTO THE REGION BEHIND THE EXITING AREA OF LOW PRESSURE. WITH
DECENT MOMENTUM TRANSFER...WINDS WILL LIKELY REACH WIND ADVISORY
CRITERIA OF SUSTAINED WINDS OF 30 MPH WITH GUSTS OF 45 MPH. OF
NOTE...IF DECENT RAINFALL IN NOT ACHIEVED BY TUESDAY...THEN VERY
HIGH TO EXTREME FIRE DANGER WILL BE POSSIBLE.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
AN UPPER RIDGE BUILDS IN FOR MID WEEK WITH A RETURN OF WARMER AIR
ON THURSDAY. SOME OF THIS WARM AIR MAY BE TEMPERED BY INCREASED
CLOUD COVER AS A SURFACE LOW AND SHORTWAVE TRACK ACROSS SOUTH
DAKOTA...BRINGING THE CHANCE FOR SHOWERS AND TSTORMS THURSDAY AND
THURSDAY NIGHT. UPPER RIDGING FRIDAY AND SATURDAY WILL BRING DRIER
AND WARMER CONDITIONS. MODELS ARE HINTING AT A MORE ENHANCED AREA
OF LOW PRESSURE MOVING ACROSS THE ROCKIES AND INTO THE PLAINS OVER
THE WEEKEND. GFS AND ECMWF DIFFER GREATLY WITH SYSTEM EVOLUTION
AND TIMING...WITH THE LATEST ECMWF BEING QUITE A BIT QUICKER AND
BRINGING A SYSTEM THROUGH ON FRI NIGHT/SAT WHILE THE GFS HAS
NOTHING UNTIL SUNDAY. WENT CLOSER TO GFS SOLUTION...KEEPING POPS
OUT OF THE FORECAST UNTIL SUNDAY.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
A LARGE SWATH OF STRATUS ADVECTING INTO THE REGION WILL LEAVE
IFR CONDITIONS IN PLACE AT ALL TAF SITES THROUGH 15Z. THERE IS AN
AREA OF CLEARING CURRENTLY MOVING INTO SOUTHEAST ND THAT SHOULD
PUNCH INTO EASTERN SD...PERHAPS CLEARING OUT KABR/KATY FOR A WHILE
AROUND 16Z. THIS SAME AREA WILL LIKELY CONTINUE ITS SOUTHWESTWARD
MOVEMENT PUSHING INTO KPIR LATER IN THE MORNING. THERE IS SOME
DIFFICULTY IN DETERMINING WHETHER THIS CLEARING WILL SPREAD OR
FILL BACK IN...BUT DECIDED TO LIFT ALL TAF SITES TO VFR THIS
AFTERNOON AS WINDS INCREASE TO 15 TO 25 KTS.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...CHURCH
SHORT TERM...SD
LONG TERM...WISE
AVIATION...WISE
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
342 PM MDT SUN MAR 25 2012
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 308 PM MDT SUN MAR 25 2012
MOIST AIR MASS CONTINUES TO RESIDE OVER THE TRI-STATE REGION THIS
AFTERNOON AHEAD OF A TROUGH WHICH IS CURRENTLY SITUATED OVER THE
PACIFIC COAST. PRIMARY QUESTION FOR TONIGHT IS WHETHER FOG WILL
REFORM ACROSS THE AREA. GUIDANCE IS DEPICTING ANYTHING BUT A
CONSENSUS WITH RUC MORE WIDESPREAD THAN MOST OTHER GUIDANCE. WILL
CONTINUE WITH PATCHY FOG MENTION OVER THE NORTHEAST BUT EVENING
SHIFT WILL NEED TO MONITOR SITUATION CLOSELY.
FOCUS THEN SHIFTS TO AN ACTIVE WEATHER DAY ON MONDAY WITH A
MULTITUDE OF HAZARDS POSSIBLE ACROSS THE AREA. CONFIDENCE IN
CRITICAL FIRE WEATHER CONDITIONS IS HIGHEST ACROSS EASTERN
COLORADO. SEE FIRE WEATHER SECTION BELOW FOR FURTHER DISCUSSION ON
THAT POTENTIAL. WESTERN CONUS TROUGH WILL BEGIN TO TRANSLATE
EASTWARD WITH A SHORTWAVE TROUGH LIFTING NORTHEASTWARD INTO THE
WESTERN DAKOTAS BY MONDAY EVENING. A DRYLINE WILL BECOME
ESTABLISHED OVER EASTERN COLORADO DURING THE LATE MORNING HOURS
BUT DOES NOT REALLY MIX EAST OF THE CO/KS BORDER UNTIL LATE MONDAY
EVENING. PRESSURE GRADIENT WILL TIGHTEN RAPIDLY AS THE LOW BEGINS
TO DEEPEN RESULTING IN ADVISORY CRITERIA WINDS ACROSS THE ENTIRE
FORECAST AREA DURING THE AFTERNOON AND EARLY EVENING. HAVE GONE
AHEAD AND EXPANDED THE GOING WIND ADVISORY FOR THIS LIKELIHOOD.
IN ADDITION TO FIRE WEATHER AND WIND CONCERNS...ALSO HAVE A SMALL
CHANCE FOR THUNDERSTORMS TO DEVELOP PRIMARILY ACROSS NORTHWEST
KANSAS AND SOUTHWEST NEBRASKA. STRONGEST DYNAMIC REMAIN NORTH OF
THE FORECAST AREA BUT ENOUGH FORCING FOR ASCENT SHOULD BE OBSERVED
FOR A FEW HOUR WINDOW. NOT COMPLETELY CONFIDENT THAT CONVECTION
WILL DEVELOP BUT THE ENVIRONMENT WOULD BE SUPPORTIVE OF STRONG
THUNDERSTORMS IF AN UPDRAFT CAN DEVELOP AND BE SUSTAINED. A COLD
FRONT SWEEPS THROUGH THE AREA BETWEEN 00Z AND 06Z. MAY HAVE A
BRIEF PERIOD OF GUSTY NORTHWESTERLY WINDS BEHIND THE FRONT GIVEN
ANTICIPATED 6 HOUR PRESSURE RISES AS PROGGED BY BOTH THE NAM AND GFS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 308 PM MDT SUN MAR 25 2012
DRY CONDITIONS AND A CONTINUATION OF MUCH ABOVE NORMAL
TEMPERATURES WILL CONTINUE FROM TUESDAY THROUGH EARLY THURSDAY AS
A BROAD MID/UPPER RIDGE BUILDS BACK ACROSS THE CENTRAL HIGH PLAINS.
BY THURSDAY AFTERNOON...FORCING FOR ASCENT ASSOCIATED WITH A
SHORTWAVE TROUGH TRANSLATING ACROSS THE DAKOTAS COULD PROVIDE
ENOUGH LIFT TO GENERATE CONVECTION ACROSS PRIMARILY NORTHEASTERN
PORTIONS OF THE TRI-STATE REGION. ADDITIONAL WEAK SHORTWAVE
TROUGHS PASS THROUGH THE AREA THURSDAY NIGHT AND FRIDAY WITH A
CONTINUED FOCUS ON EASTERN PORTIONS OF THE AREA.
DRY CONDITIONS WILL RETURN FOR THE WEEKEND WITH AFTERNOON TEMPS IN
THE MID TO UPPER 70S CONTINUING. SIGNIFICANT FORECAST UNCERTAINTY
DEVELOPS BY SUNDAY WITH THE OPERATIONAL GFS/GEFS MEAN AND EC
DEPICTING STARKLY DIFFERENT SCENARIOS. THE GFS ATTEMPTS TO DEVELOP
A DEEP TROUGH ACROSS THE GREAT BASIN/INTERMOUNTAIN WEST WHILE THE
EC SUPPORTS A RIDGE OVER THE SAME GENERAL AREA AND HOLDS THE
TROUGH OVER THE PACIFIC NORTHWEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1152 AM MDT SUN MAR 25 2012
KGLD...FOG AND BR ARE QUICKLY DISSIPATING WITH VISIBILITIES
IMPROVING. BY 19Z...VFR CONDITIONS WILL RETURN AND ARE EXPECTED TO
CONTINUE THROUGH THE REMAINDER OF THE PERIOD.
KMCK...WINDS HAVE BEEN SLOW TO INCREASE THIS MORNING. CURRENT
OBS SHOW INCREASING SURFACE WINDS ACROSS CENTRAL KANSAS AND
EXPECT KMCK TO INCREASE IN THE NEXT HOUR. BUFKIT SOUNDING SHOWS A
CHANCE FOR FOG DEVELOPING ONCE AGAIN OVERNIGHT THROUGH ABOUT 15Z.
OTHERWISE...WINDS WILL INCREASE THIS AFTERNOON AS COVER COVER
DECREASES...BECOMING LIGHT FOR A FEW HOURS THIS EVENING. WINDS
WILL BEGIN TO INCREASE EARLY TOMORROW MORNING INTO THE AFTERNOON
AS LEE TROUGH DEEPENS IN RESPONSE TO APPROACHING UPPER LEVEL
TROUGH.
&&
.FIRE WEATHER...
ISSUED AT 308 PM MDT SUN MAR 25 2012
HAVE GONE AHEAD AND UPGRADED THE THREE EASTERN COLORADO COUNTIES
TO A RED FLAG WARNING FOR MONDAY. LEFT THE FIRE WEATHER WATCH
INTACT FOR THE FIRST TIER OF KANSAS AND NEBRASKA COUNTIES AS THERE
IS SIGNIFICANT UNCERTAINTY WITH REGARD TO JUST HOW FAR EAST THE
DRYLINE WILL MIX DURING THE AFTERNOON. OPTED TO CANCEL THE FIRE
WEATHER WATCH FOR THE NEXT TIER OF COUNTIES TO THE EAST AS
CONFIDENCE WAS TOO LOW THAT CRITERIA WOULD BE MET IN THESE
LOCATIONS.
&&
.CLIMATE...
ISSUED AT 308 PM MDT SUN MAR 25 2012
STILL LOOKING AT THE POTENTIAL FOR A FEW RECORDS ACROSS THE TRI-
STATE REGION ON MONDAY. ALSO STILL WELL ON TRACK FOR THE WARMEST
MARCH ON RECORD AT GOODLAND...BURLINGTON...AND MCCOOK. HERE ARE
THE LATEST FIGURES THROUGH MARCH 24.
GOODLAND - 48.8 DEGREES SET IN 1907 - CURRENT AVERAGE TEMP 48.6
BURLINGTON - 47.7 DEGREES SET IN 1986 - CURRENT AVERAGE TEMP 47.1
MCCOOK - 48.3 DEGREES SET IN 2007 - CURRENT AVERAGE TEMP 49.9
HILL CITY - 54.3 DEGREES SET IN 1910 - CURRENT AVERAGE TEMP 51.1
WITH MUCH ABOVE NORMAL TEMPERATURES PROJECTED TO CONTINUE THROUGH
THE END OF THE MONTH...CONFIDENCE IS VERY HIGH THAT
GOODLAND...BURLINGTON...AND MCCOOK WILL SEE THE WARMEST MARCH ON
RECORD. IT REMAINS TO BE SEE IF HILL CITY WILL BREAK THE RECORD AS
WELL.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...WIND ADVISORY FROM NOON TO 9 PM MDT MONDAY FOR COZ090>092.
RED FLAG WARNING FROM NOON TO 9 PM MDT MONDAY FOR COZ252>254.
KS...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING
FOR KSZ001-013-027-041.
WIND ADVISORY FROM NOON MDT /1 PM CDT/ TO 9 PM MDT /10 PM CDT/
MONDAY FOR KSZ001>004-013>016-027>029-041-042.
NE...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING
FOR NEZ079.
WIND ADVISORY FROM NOON MDT /1 PM CDT/ TO 9 PM MDT /10 PM CDT/
MONDAY FOR NEZ079>081.
&&
$$
UPDATE...PMM
SHORT TERM...PMM/FOLTZ
LONG TERM....FOLTZ
AVIATION...PMM
FIRE WEATHER...PMM/FOLTZ
CLIMATE...FOLTZ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
456 PM EDT SUN MAR 25 2012
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 454 PM EDT SUN MAR 25 2012
LOW CLOUDS HAVE BEEN VERY PERSISTENT TODAY...AS THE H875 INVERSION
HAS BEEN DIFFICULT TO ERRODE. AWAY FROM THE COOLING OFF LK
SUPERIOR...THE CLOUDS HAVE MIXED OUT...BUT STILL HAVE A DECENT
SWATH OF CLOUDS OVER SRN ONTARIO NEAR THUNDER BAY.
MEANWHILE...1033MB SFC HIGH JUST NE OF LK WINNIPEG AND AN
ASSOCIATED SFC RIDGE HAS BEEN WORKING INTO WRN LK SUPERIOR. FARTHER
SW...DEVELOPING LOW OVER WYOMING AS LED TO SOME MID LVL WAA AND
CLOUDS OVER SD AND SRN MN. THESE CLOUDS SHOULD STAY S OF THE AREA
TONIGHT AS THE UPPER TROUGH DIGS OVER THE NEW ENGLAND STATES AND
BRINGS DRIER MID LVL AIR INTO THE UPPER GREAT LKS.
ISSUE FOR TONIGHT WILL BE THE CLOUDS NEAR/OVER LK SUPERIOR. WITH THE
WAY THEY HAVE HUNG IN TODAY OVER THE KEWEENAW AND ERN LK...FEELING
IS THAT THERE IS A GOOD CHANCE OF THEM HANGING AROUND FOR MUCH OF
THE NIGHT. THERE SHOULD BE PLENTY OF LK INSTABILITY...AS H950-925
TEMPS ARE AROUND -9C AND LK TEMPS AROUND 3-4C. QUESTION WILL BE IF
THE MOISTURE WILL REMAIN. THE MODELS HAVE BEEN HAVING A DIFFICULT
TIME WITH THIS MOISTURE AND MOST HAVE THE MOISTURE DIMINISHING THIS
EVENING WITH THE CONTINUED SUBSIDENCE AND DRY AIR WITH THE SFC
RIDGE. BUT THE PERSISTENCE OF THE CLOUDS OVER SRN ONTARIO AND
CNTRL/ERN LK SUPERIOR CREATES CONCERN ON IT COMPLETELY DIMINISHING.
HAVE BUMPED UP CLOUDS TO PARTLY CLOUDY NEAR LK SUPERIOR FOR THE
OVERNIGHT HOURS...AS TO SUBSIDENCE...ANTICYCLONIC FLOW...AND
DECREASING MOISTURE UNDER THE HIGH PRESSURE RIDGE MAY BE ENOUGH TO
DIMINISH THEM. THAT BEING SAID...COULD EASILY SEE THE MOISTURE
BECOMING TRAPPED WITH LOSS OF HEATING AND REMAINING WITH THE LK
INSTABILITY. DID TRY TO SHOW SOME MOVEMENT TO THE PARTLY CLOUDY SKY
AS H925 WINDS VEER THROUGH THE NIGHT...WHICH WOULD FOCUS THE CLOUDS
OVER THE N THEN NE FAVORED LOCATIONS. IN ADDITION...13-16Z RUC RUNS
TRY TO DEVELOP LK ENHANCED PCPN OVER CNTRL/ERN LK SUPERIOR THIS
EVENING AND THEN DROP IT INTO UPPER MI. THE ONLY OTHER HIRES MODEL
TO MENTION IT WAS THE REGIONAL GEM. WITH A FEW SHOWERS DEVELOPING
TODAY DEVELOPMENT WOULDN/T BE SURPRISING...BUT WITH CONCERNS ON AMNT
OF MOISTURE PRESENT DECIDED TO LEAVE OUT.
LOWS TONIGHT HAVE HIGH BUST POTENTIAL DUE TO SEVERAL INFLUENCES.
NEAR LK SUPERIOR...THE CLOUDS/WIND WILL BE THE MAIN FACTOR. THE
COMBINATION OF THE TWO CREATES UNCERTAINTY AND HAVE STUCK WITH A
MIDDLE GROUND IN THE UPPER 20S. FARTHER INLAND...TEMPS COULD REALLY
TANK ONCE THE WINDS DIMINISH THIS EVENING AND IF SKIES REMAIN
MOSTLY CLEAR. PWATS AROUND 0.25IN OR ABOUT 40 PERCENT OF NORMAL AND
LIGHT WINDS CREATES A GOOD RADIATIONAL COOLING NIGHT AND EXPECT
TEMPS TO FALL NEAR 20. IF THE CLOUDS REMAIN AWAY...COULD SEE VALUES
EVEN COLDER INTO THE TEENS OVER THE INTERIOR WEST COLD SPOTS.
MONDAY...HIGH PRESSURE CENTERED JUST SW OF JAMES BAY WILL KEEP THE
SFC RIDGE OVER THE AREA...WHILE AN UPPER RIDGE WILL START TO BUILD
OVER THE NRN PLAINS. RIDGE WILL GRADUALLY SHIFT E THROUGH THE
DAY...AS SFC LOW DEVELOPS OVER ERN MONTANA/WYOMING. OTHER THAN THE
PREVIOUSLY MENTIONED POTENTIAL FOR LINGERING LK CLOUDS IN THE
MORNING...DRY AIR AND SUBSIDENCE FROM THE HIGH SHOULD LEAD TO A
MOSTLY SUNNY DAY. MID CLOUDS DEVELOPING UNDER H700 WAA MON AFTN OVER
MN AND NW WI...AND WILL APPROACH THE FAR WRN CWA LATE IN THE AFTN.
COOL NRLY FLOW OFF LK SUPERIOR WILL KEEP MIXING DOWN NEAR THE LK
SHORE AND KEEP HIGHS IN THE 30S. FARTHER INLAND AWAY FROM THE LK
INFLUENCE...MIXING TOWARDS H850 TEMPS OF -4C WEST AND -9C EAST WILL
PRODUCE HIGHS IN THE LOW-MID 40S...ESPECIALLY ALONG THE WI BORDER.
AS FOR DEWPOINTS...MODEL MIXED LAYER DEWPOINT VALUES ARE IN THE LOW
SINGLE DIGITS ABOVE ZERO OVER THE E HALF OF THE LAND CWA. THIS HAS
BEEN CONSISTENT OVER THE LAST SEVERAL RUNS...SO HAVE ADJUSTED GOING
VALUES DOWN A TOUCH AWAY FROM THE MOISTENING AFFECTS OF LK
SUPERIOR. THIS LEADS TO RH VALUES FALLING INTO THE UPPER 20S...WITH
A FEW MID-LOWER 20S OVER THE ERN CWA. WITH WINDS MAINLY 10KTS OR
LESS AND ALONG WITH THE COOLER TEMPS...EXPECT FIRE WX CONCERNS
TO BE LIMITED.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 454 PM EDT SUN MAR 25 2012
MONDAY NIGHT AND TUE...THE GFS...ECMWF AND NAM HAVE BEEN CONSISTENT
AND WERE IN REASONABLY GOOD AGREEMENT WITH THE SHORTWAVE LIFTING FROM
THE PLAINS TO THE NRN GREAT LAKES. STRONG WAA AND 295K- 305K
ISENTROPIC LIFT (NOSE OF 850-800MB WINDS 50-55KT) WILL SUPPORT A BAND
OF PCPN THROUGH THE CWA LATE MONDAY NIGHT INTO TUESDAY MORNING. THE
VERY STRONG WAA IN THE 850-700 MB LAYER PUSHING WARM NOSE TEMPS TO
AROUND 5C SHOULD LEAD TO MOSTLY LIQUID PCPN. WITH INCREASING CLOUDS
AND WAA OVER THE FAR WEST EXPECT THAT SFC TEMPS SHOULD REBOUND ENOUGH
BY THE ONSET OF PCPN TO KEEP PCPN AS RAIN. HOWEVER...OVER INTERIOR
WEST AND CENTRAL UPPER MICHIGAN TEMPS INTO THE UPPER 20S TO AROUND 30
MAY LINGER AS THE PCPN MOVES IN. EVAPORATIVE COOLING AT THE ONSET OF
PCPN WILL ALSO DELAY LOW LEVEL WARMING. WITH RELATIVELY WARM GROUND
TEMPERATURES AFTER THE LONG WARM SPELL...THERE IS ADDITIONAL
UNCERTAINTY ON HOW MUCH ICE IF ANY WOULD ACCUMULATE. SO...MENTIONED
BOTH RA/FZRA FOR MOST OF THE THE CWA AND HIGHLIGHTED THE HAZARD IN A
PORTION OF THE SPS. INSTABILITY FOR TSRA LOOKS MARGINAL...BUT SOME
ELEVATED CAPE INTO EDING INTO THE CWA SUPPORTS AT LEAST CONTINUED
MENTION OF SLIGHT CHANCE FOR TSRA.
TUE NIGHT INTO WED...AS THE DRY SLOT SPREADS ACROSS THE ARA LATE TUE
INTO TUE EVENING...PCPN SHOULD DIMINISH TO AREAS OF DRIZZLE OR
ISOLATED SHOWERS DURING THE AFTERNOON AND EVENING. AS THE MID LEVEL
LOW MOVES OFF TO THE NORTHEAST OF LAKE SUPERIOR AND A TRAILING
SHORTWAVE MOVES THROUGH UPPER MI SOME ADDITIONAL WRAP-AROUND LIGHT
SHOWERS MAY BE POSSIBLE WED MORNNG. BY THE TIME THE COLDER AIR ARRIVES
WED AFTERNOON...DRIER AIR WILL ALSO SPREAD INTO THE REGION.
SO...ONLY LOW END POPS FOR SOME LIGHT LAKE ENHANCED PCPN.
THU-SUN...HIGH PRES SHOULD BUILD INTO THE AREA THU WITH COOL DRY AND
MOSTLY SUNNY CONDITIONS. MODELS CONTINUE TO SUGGEST POTENTIAL FOR
ANOTHER SHRTWV AND PCPN CHANCES MOVING INTO THE AREA THU NIGHT INTO
FRIDAY EVEN THOUGH CONFIDECNE IN DETAILS IS LOW. A BLOCKING RIDGE TO
THE NORTH WITH A SFC HUDSON BAY HIGH EXTENDEDING INTO THE AREA WILL
LIMIT PCPN CHANCES TO LOWER END POPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 132 PM EDT SUN MAR 25 2012
TRICKY AVIATION FORECAST THIS AFTERNOON...AS PERSISTENT LOW CLOUDS
HAVE BEEN AFFECTING ALL THREE TAF SITES LONGER THAN EXPECTED.
KIWD/KSAW ARE BOTH ON THE EDGE OF CLEARING OUT AND HAVE TRENDED THEM
THAT DIRECTION. KCMX WILL LIKELY BE IN THE LOWER CLOUDS THROUGH MUCH
OF THE AFTN AND INTO THE EARLY EVENING.
QUESTIONS IN THE FORECAST COMES INTO WHAT HAPPENS TONIGHT WITH THE
LOW CLOUDS. MODELS SEEM TO BE UNDER DOING THE LINGERING LOW CLOUDS
HERE AND IN SRN CANADA AND HAVE TRENDED A TOWARDS SCATTERED
CLOUDS...WHICH MAY BE UNDER DONE. THINK LOW CLOUDS WILL DEPEND ON
HOW MUCH THEY DIMINISH BY THIS EVENING BEFORE THE BETTER MIXING IS
LOST AND AT THIS POINT HAVE LOW CONFIDENCE THAT THEY WILL DIMINISH.
WITH WINDS VEERING THROUGH THE NIGHT...THE REMAINING CLOUDS WILL
PUSH BACK INTO ALL OF THE SITES IF THEY ARE PRESENT. FUTURE SHIFTS
WILL NEED TO MONITOR THE LATEST TRENDS THIS EVENING.
HIGH PRESSURE RIDGE AND ASSOCIATED SUBSIDENCE/DRIER AIR WILL ARRIVE
TOMORROW AND LEAD TO CLEARING SKIES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 454 PM EDT SUN MAR 25 2012
HIGH PRESSURE RIDGE MOVING INTO LAKE SUPERIOR TONIGHT WILL
GRADUALLY DIMINISH THE PRESSURE GRADIENT OVER LAKE SUPERIOR AND
LEAD TO A GRADUAL DIMINISHING TREND IN THE VEERING WINDS TONIGHT
INTO MONDAY MORNING. AS THE LOW SHIFTS E ON MONDAY...A LOW PRESSURE
SYSTEM DEVELOPING IN THE NRN PLAINS WILL SHIFT EAST AND ACROSS THE
UPPER GREAT LAKES TUESDAY NIGHT AND WEDNESDAY. THIS COULD PRODUCE A
SOUTHERLY GALE FORCE GUSTS TO 35KTS ON TUESDAY OVER EASTERN
LAKE SUPERIOR. HIGH PRESSURE RIDGE WILL THEN BUILD OVER THE UPPER
GREAT LAKES WED NIGHT AND THURSDAY...KEEPING WINDS BELOW 25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM TUESDAY MORNING THROUGH TUESDAY AFTERNOON FOR
LSZ266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...JLB
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
105 PM CDT SUN MAR 25 2012
.AVIATION...TWO AREAS OF STRATUS CONTINUE TO PERSIST ACROSS THE
AREA. ONE AREA HAS SHOWN SOME SIGNS OF DECREASING ACROSS NORTH
CENTRAL NEBRASKA...HOWEVER IT APPEARS THAT IT MAY THIN THIS
AFTERNOON BUT EXPAND AGAIN TONIGHT. ONLY MODERATE CONFIDENCE IN
THIS FORECAST...BUT IT APPEARS THAT MVFR AND LOCALLY IFR CEILINGS
WILL PERSIST THIS AFTERNOON AND INTO TONIGHT. THE OTHER AREA OF
STRATUS HAS BEEN EXPANDING ACROSS SOUTHWEST NEBRASKA...AND NOW
INTO THE KLBF TERMINAL. MODERATE CONFIDENCE HERE TOO...AS STRATUS
MAY PERSIST THROUGH MUCH OF THE AFTERNOON AND POSSIBLE INTO THE
EVENING. WILL CONTINUE TO UPDATE AND MONITOR. ISOLATED
THUNDERSTORMS MAY DEVELOP LATE THIS AFTERNOON AND OVERNIGHT ALONG
AND NORTH OF A KBUB TO KIEN LINE.
&&
.PREV DISCUSSION... /ISSUED 626 AM CDT SUN MAR 25 2012/
ARCTIC AIR CONTINUES TO BACK IN ACROSS NCNTL NEB THIS MORNING
PRODUCING A SHALLOW DECK OF STRATUS. WINDS STAY EAST MOST OF THE
DAY BENEATH THE DECK. WORSE THE RUC SHOWS PWAT POOLING BEHIND THE
FRONT ALONG THE SD BORDER WHICH CANT BE A GOOD WAY TO ERODE
STRATUS. SO 1ST PERIOD HIGH TEMPS HAVE BEEN MARKED DOWN USING THE
RUC13 AS A GUIDE.
PREV DISCUSSION... /ISSUED 351 AM CDT SUN MAR 25 2012/
HAND ANALYSIS OF THE H5 CHART REVEALS THAT SHORTWAVE RIDGING HAS
BECOME FULLY ESTABLISHED ACROSS THE CENTRAL STATES...WITH A TROUGH
OF LOW PRESSURE DIGGING SOUTH OFF CENTRAL CALIFORNIA. A SECOND
AREA OF LOW PRESSURE RESIDES EAST OF THE CENTRAL MISSISSIPPI RIVER
VALLEY AND CONTINUES TO PUSH SOUTHEAST TOWARD THE COAST OF SOUTH
CAROLINA. THIS PATTERN PRESENTS GENERAL SOUTHWEST FLOW ALOFT
ACROSS WESTERN NEBRASKA WITH THE RIDGE AXIS BISECTING THE FORECAST
AREA. AT THE SURFACE...WIND SPEEDS ARE GENERALLY LIGHT AND FROM
THE NORTHEAST ACROSS WEST CENTRAL NEBRASKA WITH AN AREA OF HIGH
PRESSURE CENTERED NORTH OF THE US/CANADIAN BORDER. FURTHER WEST
OVER THE HIGHER TERRAIN OF EASTERN WYOMING/COLORADO...THE WIND IS
BEGINNING TO VEER SLIGHTLY TO THE SOUTHEAST...AS A BROAD AREA OF
LOW PRESSURE BEGINS TO DEEPEN.
THROUGH 12Z MONDAY. SURFACE HIGH PRESSURE OVER CANADA WILL BUILD
EAST THROUGH THE DAY TODAY AS WEST COAST UPPER TROUGH ROTATES
INLAND AND TAKES ON A STRONG NEGATIVE TILT. SURFACE LOW PRESSURE
OVER THE ROCKIES WILL CONTINUE TO DEEPEN AND THUS STRENGTHEN
SOUTHERLY RETURN FLOW BACK ACROSS ALL OF WESTERN AND NORTH CENTRAL
NEBRASKA. MODEL GUIDANCE INDICATES INCREASING ATMOSPHERIC MOISTURE
WITH THE SOUTHERLY FLOW AS SURFACE TD/S RETURN ABOVE 45F FOR MOST
IF NOT ALL LOCATIONS ACROSS THE CWA. THIS SHOULD HELP DECREASE THE
FIRE POTENTIAL THIS AFTERNOON AS SURFACE T/S REMAIN IN THE 70/S TO
LOW 80/S ALLOWING FOR EXPECTED RH VALUES WELL ABOVE RED FLAG
MINIMUM CRITERIA.
WITH THE INCREASING MOISTURE...STORM CHANCES ARE A POSSIBILITY LATE
THIS AFTERNOON AND TONIGHT /FOR LOCATIONS MAINLY NORTH OF HIGHWAY
TWO ACROSS NORTHWEST NEBRASKA/. A WARM FRONT WILL CONTINUE TO LIFT
NORTHWARD THROUGH THE AFTERNOON...STALLING ALONG OR NEAR THE SOUTH
DAKOTA BORDER BY 00Z MONDAY. SYNOPTIC LIFT WILL BE ON THE INCREASE
AS THETA-E ADVECTION OCCURS AND IS MAXIMIZED ACROSS NORTHWEST
NEBRASKA. MIDLEVEL LAPSE RATES WILL BE STEEP...HOWEVER THERE IS
QUESTION AS TO IF STORMS ARE ABLE TO BREACH THE CAPPING INVERSION
AS STRONG RIDGING REMAINS ENTRENCHED OVER THE CENTRAL AND NORTHERN
PLAINS. IF SO...THE STORMS WOULD BE ABLE TO WORK ON MODEST
INSTABILITY OF 500-1000 J/KG OF CAPE AND 0-6KM BULK SHEAR OF 45KTS.
STORMS WOULD HAVE THE POTENTIAL TO PRODUCE SEVERE HAIL AND CERTAINLY
SEVERE WIND GUSTS AS A SOMEWHAT INVERTED V PROFILE IS SHOWN IN BUFR
SOUNDINGS. GOING INTO THE EVENING...A LOW LEVEL JET WILL STRENGTHEN
AND PROVIDE A FURTHER FOCUS OF STORM DEVELOPMENT ACROSS NORTHERN AND
NORTH CENTRAL NEBRASKA OVERNIGHT...WILL CONTINUE THE MENTION OF
ELEVATED SHOWERS/THUNDERSTORMS.
SEVERAL CONCERNS IN THE FORECAST FOR MONDAY AS A PLETHORA OF WEATHER
IS EXPECTED. FIRST...WILL ISSUE A FIRE WEATHER WATCH FOR FIRE ZONES
204 AND 210 WITH THIS MORNING FORECAST PACKAGE. A DRY LINE IS
EXPECTED BECOME ESTABLISHED AND PUSH EAST ACROSS THE PANHANDLE INTO
WEST CENTRAL NEBRASKA MONDAY AFTERNOON. MODEL GUIDANCE INDICATES
TD/S FALLING BELOW 25F WITH THE PASSAGE. GIVEN ABNORMALLY HIGH
EXPECTED TEMPERATURES...RH VALUES ACROSS THE EASTERN PANHANDLE WILL
FALL BELOW 15 PERCENT /RED FLAG CRITERIA/ BY MIDAFTERNOON ON
MONDAY. MEANWHILE A TIGHT SURFACE GRADIENT WILL EXIST ACROSS THE
HIGH PLAINS AS SURFACE PRESSURE RAPIDLY FALLS IN ADVANCE OF THE WEST
COAST TROUGH. EXPECT SURFACE WIND SPEEDS TO GUST ABOVE 30 MPH FOR
MUCH OF THE AFTERNOON MONDAY. SURFACE LOW PRESSURE WILL QUICKLY
DEEPEN AND PUSH NORTHEAST INTO EASTERN NORTH DAKOTA ON LATE MONDAY
NIGHT...WHICH WILL DRAG A COLD FRONT THROUGH WESTERN NEBRASKA.
AGAIN WIND SPEEDS LOOK PROBLEMATIC....AS HEIGHT RISES ON THE ORDER
OF 14MB/3HR ARE SUGGESTED BY SHORT TERM SOLUTIONS. A WIND ADVISORY
IS EXPECTED...IF NOT HIGH WIND HIGHLIGHTS MONDAY AFTERNOON AND
NIGHT. THE COLD FRONT IS EXPECTED TO QUICKLY CROSS THE CWA MONDAY
EVENING...EVENTUALLY OVERTAKING THE DRYLINE. INITIALLY A STRONG
CAPPING INVERSION WILL LIMIT STORM DEVELOPMENT ACROSS MUCH OF THE
CWA...HOWEVER AS LOW-LEVEL CONVERGENCE ALONG THE COLD FRONT
INCREASES...STORM DEVELOPMENT SHOULD BEGIN. LOOKING AT MODEST
CAPE OF 500-1000 J/KG WITH 6KM SHEAR OF GREATER THAN 40KTS WOULD
PROVIDE THE OPPORTUNITY FOR SEVERE STORMS WITH HAIL AND AND POSSIBLY
DAMAGING WINDS.
TUESDAY MAY BE ACTIVE IN TERMS OF FIRE WEATHER AGAIN AS ABNORMALLY DRY
AIR WILL REMAIN IN PLACE BEHIND THE DEPARTING SYSTEM. POOR RH
RECOVERY WILL AID IN PRIMING AVAILABLE FUELS...AND WITH A GOOD
PORTION OF THE FA WELL BELOW 20 PERCENT RH TUESDAY AFTERNOON...FIRE
CONCERNS MAY BE REALIZED. A COUPLE FACTORS GOING AGAINST THE FIRE
POTENTIAL FOR NOW...ONE IS THAT WIND SPEEDS SHOULD EASE WITH THE
RELAXING PRESSURE GRADIENT. AND TWO...EARLY GREEN UP IS
OCCURRING...WILL NEED TO CONTACT AREA FMO/S TO DETERMINE FUEL
AVAILABILITY. AS FOR TEMPERATURES...WILL TREND THE FORECAST DOWN
SLIGHTLY ON TUESDAY WITH THE FRONTAL PASSAGE...YET HIGHS WILL STILL
BE ABOVE AVERAGE RANGING FROM THE MID 60S ACROSS NORTHWEST
NEBRASKA...TO THE LOW TO MID 70S SOUTH OF I80.
BEYOND TUESDAY...A WEAK DISTURBANCE CROSSES THE REGION LATE THURSDAY
BRINGING A SLIGHT CHANCE OF POPS BACK ACROSS WESTERN AND NORTH
CENTRAL NEBRASKA. OTHERWISE SHORTWAVE RIDGING RETURNS JUST IN
TIME FOR THE WEEKEND...WITH ANOTHER TROUGH DIGGING DOWN THE WEST
COAST OF NA. WILL KEEP T/S ABOVE AVERAGE THROUGH THE EXTENDED AND
GO DRY BEYOND FRIDAY MORNING.
FIRE WEATHER... STRONG DOUBLE BARREL LOW PRESSURE WILL DEEPEN TO
AROUND 990MB ACROSS THE NRN HIGH PLAINS MONDAY AFTERNOON. ALL
MODELS ARE DRAWING VERY DRY AIR NORTH INTO THE LOW AND PRODUCING
SOUTH WINDS IN EXCESS OF 30 MPH THROUGHOUT WRN NEB AS THE LOW
DEEPENS. A POWERFUL PACIFIC COLD FRONT WILL THEN RACE EAST THROUGH
WRN NEBRASKA MONDAY EVENING PRODUCING VERY STRONG WEST WIND GUSTS.
ISOLATED THUNDERSTORMS AND DRY LIGHTNING MAY DEVELOP ALONG THE
DRYLINE AHEAD OF THE COLD FRONT. THE DRYLINE SHOULD BE LOCATED
NEAR HIGHWAY 61 MONDAY AFTERNOON.
A FIRE WEATHER WATCH WILL BE ISSUED THROUGH 9 PM MDT MONDAY EVENING
COVERING WRN NEBRASKA AND THE FRENCHMAN BASIN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...FIRE WEATHER WATCH FROM MONDAY
MORNING THROUGH MONDAY EVENING FOR NEZ204-210.
&&
$$
AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
1226 PM CDT SUN MAR 25 2012
.UPDATE...
UPDATED FORECAST TO INCREASE CLOUD COVER AND LOWER MAX TEMPS
SIGNIFICANTLY FOR TODAY. STRONG CAA BELOW ABOUT H9 CONTINUES THIS
MORNING AND WITH 12Z RUC INDICATING THAT WE WILL BE HARD PRESSED
TO MAKE MUCH PROGRESS MIXING MUCH DURING THE REMAINDER OF THE DAY...
ANTICIPATING THAT ALL AREAS WILL REMAIN IN THE UPPER 40S TO MID
50S...IF NOT COOLER. BEST CHANCES FOR PARTLY TO MOSTLY SUNNY SKIES
WILL BE OVER THE FAR NORTHEAST WHERE SOME OF THE LLV STRATUS
CONTINUES TO ERODE SWWD.
UPDATED AVIATION SECTION LISTED BELOW...
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH TUESDAY
THE POSSIBILITY OF SEVERE STORMS TONIGHT AND AGAIN MONDAY NIGHT
WILL BE THE MAIN FORECAST CHALLENGE.
AS OF 8Z...AN AREA OF HIGH PRESSURE IS IN CONTROL OF THE NORTHERN
PLAINS. THIS HIGH PRESSURE WILL PRODUCE NORTHEASTERLY WINDS IN THE
LOWER LEVELS TODAY...WHICH SHOULD RESULT IN CHILLY...BUT ABOVE
NORMAL TEMPERATURES. BY LATE THIS AFTERNOON...MODELS DEVELOP A
WEAK LLJ WHICH WILL BRING MOISTURE/WAA INTO THE DAKOTAS. SOME HI-RES
MODELS ARE INDICATING SHOWER ACTIVITY COULD BE POSSIBLE AFTER 0Z
MONDAY IN THE NE CWA...OR WHERE THE BETTER LIFT AND LLM MOISTURE
WILL BE HAD. WITH VERY LITTLE CAPE...BELIEVE MOST OF THE ACTIVITY
TONIGHT WILL CONSIST OF SHOWERS.
MOST OF MONDAY APPEARS TO BE CAPPED WITH BUFFER SOUNDINGS SHOWING
A STRATUS LAYER BELOW THE MID LEVEL WAA. HOWEVER THERE SHOULD BE
ENOUGH CLEARING DURING THE LATE AFTERNOON HOURS IN THE WESTERN CWA
TO ALLOW FOR SURFACE DESTABILIZATION. ATTM...MODELS SHOW AN AREA
OF LOW PRESSURE SYSTEM MOVING ACROSS ND...WITH A SURFACE COLD
FRONT TRAILING ACROSS WESTERN SD. CONVECTIVE INITIATION SEEMS
LIKELY ALONG THE COLD FRONT WITH CONVECTION POSSIBILITY REACHING
THE WESTERN CWA AROUND 0Z TUESDAY. BEYOND 0Z TUESDAY...IT BECOMES
UNCLEAR WHETHER SURFACE CONVECTION WILL BE ABLE TO MAINTAIN ITSELF
OR FRIZZLES WITH A MORE STABLE ENVIRONMENT IN THE EAST. THE
CURRENT THINKING IS THAT CONVECTION MAY BECOME ELEVATED DUE TO
COOLING OF THE BL.
MOST OF TUESDAY IS BEGINNING TO LOOK DRY BUT WINDY WITH CAA MOVING
INTO THE REGION BEHIND THE EXITING AREA OF LOW PRESSURE. WITH
DECENT MOMENTUM TRANSFER...WINDS WILL LIKELY REACH WIND ADVISORY
CRITERIA OF SUSTAINED WINDS OF 30 MPH WITH GUSTS OF 45 MPH. OF
NOTE...IF DECENT RAINFALL IN NOT ACHIEVED BY TUESDAY...THEN VERY
HIGH TO EXTREME FIRE DANGER WILL BE POSSIBLE.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
AN UPPER RIDGE BUILDS IN FOR MID WEEK WITH A RETURN OF WARMER AIR
ON THURSDAY. SOME OF THIS WARM AIR MAY BE TEMPERED BY INCREASED
CLOUD COVER AS A SURFACE LOW AND SHORTWAVE TRACK ACROSS SOUTH
DAKOTA...BRINGING THE CHANCE FOR SHOWERS AND TSTORMS THURSDAY AND
THURSDAY NIGHT. UPPER RIDGING FRIDAY AND SATURDAY WILL BRING DRIER
AND WARMER CONDITIONS. MODELS ARE HINTING AT A MORE ENHANCED AREA
OF LOW PRESSURE MOVING ACROSS THE ROCKIES AND INTO THE PLAINS OVER
THE WEEKEND. GFS AND ECMWF DIFFER GREATLY WITH SYSTEM EVOLUTION
AND TIMING...WITH THE LATEST ECMWF BEING QUITE A BIT QUICKER AND
BRINGING A SYSTEM THROUGH ON FRI NIGHT/SAT WHILE THE GFS HAS
NOTHING UNTIL SUNDAY. WENT CLOSER TO GFS SOLUTION...KEEPING POPS
OUT OF THE FORECAST UNTIL SUNDAY.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
IFR STRATUS LAYER HAS BROKEN SOMEWHAT AND MOVED
SOUTHWEST...ALLOWING FOR VFR CONDITIONS AT KATY/KABR AND SHORTLY
KMBG. THIS CLOUD DECK WILL STALL OVER KPIR...AND MAY LIFT SOMEWHAT
THROUGH THE REMAINDER OF THE DAY. AS LOW PRESSURE DEVELOPS TO THE
SOUTH...THE REMNANTS OF THE STRATUS AND A SECOND DEVELOPING
VFR/MVFR DECK WILL MOVE OVERHEAD. WINDS WILL CONTINUE OUT OF THE
EAST AND STRENGTHEN TOWARDS MORNING. VFR VISBY EXPECTED THROUGH
THE PERIOD...DO NOT ANTICIPATE ENOUGH WIDESPREAD SHOWER ACTIVITY
DURING THIS TAF PERIOD TO INCLUDE IN FORECAST.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...CHURCH
SHORT TERM...SD
LONG TERM...WISE
AVIATION...CONNELLY
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
251 PM CDT SUN MAR 25 2012
.SHORT TERM...TONIGHT AND MONDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE COLD
FRONT DROPPING INTO NORTHERN ILLINOIS EARLY THIS AFTERNOON WHILE
CANADIAN HIGH PRESSURE IS BUILDING SOUTH INTO THE NORTHERN
MISSISSIPPI VALLEY. LOW STRATO-CU DISSIPATED RATHER QUICKLY EARLIER
TODAY AS MIXING INTO DRIER AIR OVERWHELMED THE SHALLOW COOL AND
MOIST AIRMASS. STILL SOME LINGERING CU OVER EAST-CENTRAL
WISCONSIN...THOUGH TRENDS SUPPORT IT DISSIPATING AS WELL OVER THE
NEXT COUPLE HOURS. UPSTREAM IS PRETTY QUIET...WITH ONLY MID AND
HIGH CLOUDS PUSHING ACROSS THE DAKOTAS. AS HIGH PRESSURE CONTINUES
TO BUILD INTO THE REGION TONIGHT...LOW TEMPS AND HEADLINES ARE THE
MAIN FORECAST CONCERNS.
TONIGHT...LAST NIGHTS COLD FRONT WILL CONTINUE TO SAG SOUTH TOWARDS
THE OHIO VALLEY WHILE CANADIAN HIGH PRESSURE WILL BUILD INTO
SOUTHERN ONTARIO AND THE WESTERN GREAT LAKES. THIS INCOMING AIRMASS
FROM CANADA IS QUITE DRY AND WILL DROP PWATS TO UNDER A QUARTER OF
AN INCH. THOUGH AIRMASS IS VERY DRY...NOT IDEAL RADIATIONAL COOLING
CONDITIONS WILL BE IN PLACE FOR TONIGHT. WILL HAVE SCT-BKN MID AND
HIGH CLOUDS ARRIVE FROM THE NORTHERN PLAINS INTO MUCH OF CENTRAL AND
EAST-CENTRAL WISCONSIN BY LATE THIS EVENING. THE PRESSURE GRADIENT
WILL ALSO REMAIN FAIRLY TIGHT OVER NE WISCONSIN WHERE NE WINDS
FUNNELED DOWN THE BAY...AND ALSO OFF LAKE MICHIGAN WILL KEEP THE BL
RATHER BREEZY. NORTH-CENTRAL WISCONSIN WILL SEE 1000-850MB WINDS
AROUND 15 KTS...WHICH IS RIGHT ON THE EDGE FOR DECOUPLING. AM GOING
TO LEAN TOWARDS DECOUPLING OCCURRING...DUE TO SANDY SOIL EFFECTS AND
CLOUDS SHIFTING SOUTH THROUGH THE NIGHT. AS A RESULT...MID TWENTY
LOWS SEEM PERFECTLY REASONABLE UP NORTH...AND SEE LITTLE REASON TO
ADJUST HEADLINES. DID RAISE LOWS A DEGREE OR TWO OVER CENTRAL AND
EAST-CENTRAL WISCONSIN BECAUSE OF CLOUDS AND WIND. LOWS IN THE
LOWER TO MIDDLE 30S HERE.
MONDAY...MID-LEVEL CLOUDS WILL STALL OVER SW WISCONSIN TOMORROW
MORNING AND WILL RETURN NE IN THE AFTERNOON WHEN THE COLD FRONT
STARTS RETURNING NORTH. NE WISCONSIN WILL SEE A MOSTLY SUNNY
DAY...BUT CENTRAL AND NORTH-CENTRAL WISCONSIN WILL SEE A GRADUAL
INCREASE IN CLOUDS. HIGHS RANGING FROM THE LOWER TO MIDDLE 40S
EVERYWHERE.
.LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY. THE WEATHER WILL BE
MORE SEASONABLE THAN THE LAST TWO WEEKS WITH FLATTER ALMOST ZONAL
FLOW OVER MUCH OF THE REGION THROUGH FRIDAY. SIGNIFICANT MODEL
DIFFERENCES FOR NEXT SATURDAY AND SUNDAY WITH HIGH AMPLITUDE FLOW
EXPECTED NEXT WEEK.
UPPER TROUGH LIFTING NORTHEAST THROUGH THE NORTHERN PLAINS MONDAY
NIGHT WILL BRING SHOWERS AND ELEVATED THUNDERSTORMS MONDAY NIGHT
AND EARLY TUESDAY. THERE MIGHT BE ENOUGH COLD AIR FOR SLEET TO BE
MIXED IN ACROSS THE NORTHERN PART OF THE FORECAST AREA. A COLD
FRONT MOVES THROUGH TUESDAY AFTERNOON OR EVENING ACCOMPANIED BY
STRONG WINDS IN THE LOW LEVELS...LOTS OF SHEAR AND DECENT UPPER
SUPPORT. MOISTURE SHOULD BE LACKING THOUGH WHICH WILL LIMIT
INSTABILITY. THERE IS SOME CHANCE OF SEVERE THUNDERSTORMS IF
MOISTURE IS MORE PLENTIFUL THAN CURRENTLY EXPECTED.
COOLER WEATHER IS EXPECTED FOR WEDNESDAY NIGHT THROUGH FRIDAY AS
CANADIAN HIGH SINKS SOUTH INTO THE GREAT LAKES. WILL LIKELY HAVE
SOME SUB FREEZING NIGHTS...WHICH IS COMPLETELY NORMAL FOR THIS
TIME OF THE YEAR...BUT MORE OF A CONCERN THIS YEAR DUE TO UNUSUAL
WARMTH THAT HAS STARTED AN EARLY GROWING SEASON. BIG DIFFERENCES
FOR NEXT SATURDAY AND SUNDAY WITH THE GFS AND ECMWF ALMOST 180
DEGREES OUT OF PHASE OVER OUR AREA.
&&
.AVIATION...DRY AIR ARRIVING BEHIND A COLD FRONT WILL DISSIPATE ANY
LINGERING MVFR STRATUS EARLY THIS AFTERNOON WHICH WILL LEAVE VFR
CONDITIONS THROUGH TOMORROW. WINDS WILL SHIFT AROUND TO THE
NORTHEAST TONIGHT...AND WILL BECOME GUSTY AT TIMES OVER NORTHEAST WISCONSIN.
MID-LEVEL CLOUDS ALSO ARRIVE TONIGHT...BUT DRY AIR IN THE LOW LEVELS
WILL PREVENT ANY PRECIP. MID CLOUDS WILL SHIFT SW TOMORROW MORNING
BEFORE RETURNING NE TOMORROW AFTERNOON.
MPC
&&
.MARINE...
A WARM FRONT WILL PUSH NORTHWARD ACROSS THE AREA TUESDAY. GUSTS
TO NEAR GALE FORCE FROM THE SOUTHEAST/SOUTH ARE POSSIBLE ON
TUESDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING FROM 2 AM TO 8 AM CDT MONDAY FOR WIZ005-010>013-
018-019-021.
&&
$$
MPC/RDM
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
120 PM CDT SUN MAR 25 2012
.UPDATE...
STRATUS ON THE LEADING EDGE OF THE COLD FRONT IS WORKING ITS WAY
DOWN THE STATE INTO SOUTHERN WISCONSIN EARLY THIS AFTERNOON. WINDS
IN THE WESTERN HALF OF THE STATE HAVE BECOME MORE NW TO NNW BEHIND
THE FRONT. CLOUDS ASSOCIATED WITH THE FRONT IN THE WEST HALF WERE
LOW...BELOW 1000 FEET. MEANWHILE...THE COLD FRONT RACED DOWN THE
LONG AXIS OF LAKE MICHIGAN AND WINDS SHIFTED TO THE NORTHEAST IN
INCREASED. THE NORTHEAST WINDS HIT KENOSHA BEFORE 10 AM. THE
MOISTURE THAT PUSHED INLAND FROM THE LAKE HIT THE KETTLE MORRAINE
AND BROKEN CUMULUS CLOUDS POPPED UP. SKIES ARE ACTUALLY CLEAR ALONG
THE LAKE AT THIS TIME SOUTH OF MILWAUKEE...BUT EXPECTING THIS AREA
TO FILL IN SOON. BROKEN CU JUST FILLED IN ACROSS ALL OF SOUTHERN WI
IN THE PAST HALF HOUR AS WELL. CLOUDS ASSOCIATED WITH THE NORTHEAST
FLOW ARE A LITTLE HIGHER...AROUND 2000 FEET.
WINDS ARE NORTHEAST IN FOND DU LAC LATE THIS MORNING...WITH PRESSURE
RISES BEHIND THE NORTHEAST WIND SHIFT OFF THE LAKE FAIRLY STRONG.
THIS MEANS WE SHOULD EXPECT THE NORTHEASTERLY WIND DIRECTION TO WIN
OUT OVER THE NORTHWESTERLY WINDS THIS AFTERNOON...WITH THE NORTHEAST
WINDS PUSHING FURTHER AND FURTHER INLAND WITH TIME. RUC SHOWS THE
NNE WINDS SPREADING ACROSS THE WHOLE FORECAST AREA BY THIS
AFTERNOON. HOWEVER...CURRENT CONDITIONS WOULD SHOW THE NE/NW WIND
BOUNDARY TO STALL AROUND THE MADISON/JANESVILLE AREA.
WITH THE STRATUS SPREADING INTO SOUTHERN WI WITH THE FRONT COMING IN
EARLIER THAN ANTICIPATED...TEMPERATURES IN THE NORTHERN FORECAST
AREA WILL NOT MAKE IT INTO THE UPPER 60S...SO CUT BACK ON HIGH TEMPS
THERE AND ALONG THE LAKE AS WELL.
&&
.AVIATION/18Z TAFS/...
IFR STRATUS ASSOCIATED WITH A COLD FRONT MOVING DOWN FROM NORTHWEST
WI IS OVER WISCONSIN DELLS EARLY THIS AFTERNOON. THESE CLOUDS ARE
NOT EXPECTED TO MAKE IT TOO MUCH FURTHER SOUTHEAST DUE TO THE
NORTHEASTERLY WINDS OFF THE LAKE COLD FRONT BEATING THEM BACK.
A COLD FRONT RACED DOWN THE LAKE THIS MORNING...CAUSING WINDS TO
BECOME NORTHEAST AND INCREASE. THE COOL AIR ALONG THE FRONT BROUGHT
STRATUS CLOUDS DOWN THE LAKE...WHICH HAVE JUST RECENTLY SPREAD
INLAND TO MKE WITH IFR CIGS. CIGS ARE GENERALLY MVFR AROUND THE
AREA.
MEANWHILE...BROKEN MVFR TO VFR CUMULUS DEVELOPED ALL ACROSS SOUTHERN
WI WITH THE DAYTIME HEATING.
FOR TONIGHT...EXPECTING SOUTHEAST WI TO BE MUCH SLOWER TO CLEAR
AFTER DARK THAN SOUTH CENTRAL WI NEAR MSN. HOWEVER...EXPECT CLEARING
OVERNIGHT. THEN A SECOND SURGE OF COLDER AIR IS EXPECTED TO COME
DOWN THE LAKE MON MORNING WITH A CHANCE FOR STRATUS. MEDIUM TO LOW
CONFIDENCE ON THE STRATUS SCENARIO. OTHERWISE...MID CLOUDS SHOULD
SPREAD INTO WESTERN AND CENTRAL WI THROUGH THE DAY...WITH A CHANCE
FOR SHOWERS AND ISOLATED THUNDER MONDAY NIGHT.
&&
.MARINE...DRY AIR ON A LAKE COLD FRONT FUNNELED DOWN LAKE MICHIGAN
THIS MORNING...ERODING AWAY THE AREAS OF FOG THAT WERE JUST OFF
SHORE OF SOUTHEAST WI AND NORTHEAST IL. LOW CLOUDS ARE SPREADING
INTO THE SOUTH HALF OF LAKE MICHIGAN THIS AFTERNOON.
A REINFORCING PUSH OF LOW LEVEL COLD AIR OVER THE WARMER LAKE WATERS
TONIGHT WL RESULT IN STEEP LOW LEVEL LAPSE RATES. THESE LOW LEVEL
UNSTABLE CONDITIONS OVER THE LAKE WILL ALLOW GUSTY WINDS IN EXCESS
OF 22KTS TO REACH THE LAKE SURFACE OVERNIGHT. HENCE A SMALL CRAFT
ADVY IS IN EFFECT FROM THIS EVENING THROUGH MONDAY MORNING.
A TIGHTENING PRESSURE GRADIENT AHEAD OF STRONG LOW PRESSURE IN THE
NORTHERN PLAINS WILL RESULT IN GUSTY WINDS REDEVELOPING OVER THE
NEARSHORE WATERS OF LAKE MI LATE MONDAY NIGHT...CONTINUING ON
TUESDAY.
&&
.PREV DISCUSSION... /ISSUED 328 AM CDT SUN MAR 25 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM.
WL POST DENSE FOG ADVY FOR MOST OF MY WEST FOR EARLY THIS MORNING.
DRIER AIR IN THE MID LEVELS CAUSING CLEARING OF 4-5K FT CLOUDS
ACROSS WEST AND NORTH...AND APPEARS CLEARING TREND WL CONTINUE INTO
THE SOUTHEAST EARLY THIS MORNING. DENSE FOG FORMING RELATIVELY
QUICKLY BEHIND THE CLEARING LINE...AND THINKING DENSE FOG MAY LAST
FOR SEVERAL HOURS BEFORE DRIER AIR AT LOW LEVELS SAGS INTO THE SOUTH
FROM CENTRAL WI. MAY NEED TO EXPAND DENSE FOG ADVY EAST INTO PARTS
OF SOUTHEAST WI AS CLOUDS CLEAR EARLY THIS MRNG. SHORT TERM
GUIDANCE NOT HANDLING UPSTREAM WIDESPREAD STRATUS IN BETTER COLD AIR
ADVECTION OVER FAR NORTHERN WI INTO NRN MN EARLY THIS MRNG.
POTENTIAL FOR SOME OF THESE CLOUDS TO MAKE IT INTO SRN WI LATER
TODAY...BUT WL BE LESS OPTIMISTIC WITH CLOUD COVER TODAY INTO TNGT.
SHOULD BE ENOUGH SUNSHINE TO WARM BACK INTO THE 60S MOST AREAS AWAY
FROM LAKE MICHIGAN.
DOWNSTREAM AMPLIFYING LONG WAVE TROFFING OVER ERN CONUS WILL RESULT
IN SHORT WAVE RIDGING UPSTREAM OVER CENTRAL CONUS. LOW LEVEL JET WL
INCREASE TO THE WEST OF WI TONIGHT...FOCUSED OVER THE ERN DAKOTAS
INTO MN...NORTH AND WEST OF MAIN RIDGE. WHILE LOW LEVEL RIDGING AND
LIGHT WINDS WILL EXTEND INTO SRN WI...PUSH OF MID LEVEL MOISTURE
WITH WEAK MID-LEVEL WARM AIR ADVECTION WL BE LOCATED UPSTREAM OVER
SRN MN. MID LEVEL CLOUDS WL LIKELY PUSH INTO SRN WI...BUT NOT
ENOUGH MOISTURE AND FORCING EXPCD TO TRIGGER PRECIP IN THIS
AREA...SO REMOVED LOW POPS FROM WEST. EXPC TEMPS TO DROP INTO THE
30S...BUT BOUNDARY LAYER MIXING SHOULD PREVENT WIDESPREAD FROST
FORMATION.
MONDAY - CONFIDENCE...MEDIUM
EAST FLOW AROUND DEPARTING HIGH WILL MAKE FOR TEMPS CLOSER TO A
NORMAL MARCH DAY. SURFACE HIGH WILL DOMINATE WITH MODELS KEEPING
PRECIP FURTHER BACK TO THE WEST. ISENTROPIC ANALYSIS DOES SHOW MID
LEVEL MOISTENING WITH LOWER CONDENSATION PRESSURE DEFICITS AND SOME
WEAK ADIABATIC OMEGA...HOWEVER SOUNDINGS AND LOWER LEVEL ANALYSIS
REVEALS QUITE A BIT OF DRY AIR TO OVERCOME. WAS GOING TO GO THE
SPRINKLE ROUTE IN THE WESTERN CWA BUT PREFER TO GO DRY AT THIS
POINT.
MONDAY NIGHT - CONFIDENCE...MEDIUM
MID LEVEL RIDGE AXIS SHIFTS TO OUR EAST. STRONG VORT MAX RIDES INTO
THE DAKOTAS. 850 MILLIBAR SOUTHWEST JET INCREASES THOUGH CORE OF
STRONGEST WINDS TO OUR NORTHWEST CLOSER TO THE BETTER GRADIENT
AROUND THE STRONG DAKOTAS LOW. DECENT 850 MOISTURE/THERMAL ADVECTION
WITH THIS PATTERN. MARKED INCREASE IN ISENTROPIC ADIABATIC OMEGA AND
MIXING RATIOS. NAM ELEVATED CAPE FROM 825 MILLIBARS SEVERAL HUNDRED
J/KG. PLENTY OF LOW LEVEL MOISTURE BUT AIRMASS UPSTAIRS FAIRLY DRY.
GFS DRIER AND EVEN MORE STABLE. GEM/GFS AND SREF SKEWING QPF MAX
FURTHER NORTH AND JUST GRAZING CWA. ECMWF STILL GIVES THE ENTIRE
CWA A DECENT SHOT AT PRECIP. GUID POPS HAVE DROPPED AND LEANED
MORE IN THIS FAVOR GIVEN TRENDS NORTHWARD WITH QPF. STILL HAVE
SOME LIKELY POPS IN THE NORTHERN CWA IN THIS CASE.
TUESDAY AND TUESDAY NIGHT - CONFIDENCE...LOW TO MEDIUM
STRONG SHORT WAVE ROTATES FROM THE DAKOTAS TO NORTHEAST OF LAKE
SUPERIOR BY LATE TUESDAY NIGHT. BULK OF POSITIVE VORTICITY ADVECTION
WILL BE TO OUR NORTH. FAIR AMOUNT OF MOISTURE RETURN WITH MODEL
SURFACE DEWS PROGGD INTO THE MID 50S ACROSS SRN WI BY LATE
AFTERNOON/EARLY EVENING. MOS MORE CONSERVATIVE IN THE 40S. AFTER A
COOL START TEMPS WILL LIKELY REBOUND WITH 925 TEMPS REACHING 13-16C.
LOCALLY DERIVED SEVERE WX PARAMETER...THE CWASP...STILL KEEPS THE
MAX JUST SOUTH OF WI...BUT CLOSE CALL. IN FACT SWODY3 MATCHES CLOSE
TO AXIS OF MAX CWASP. IF A NARROW RIBBON OF WARMTH AND MOISTURE CAN
SNEAK INTO WI AHEAD OF THE COLD FRONT...THIS WOULD LEAD TO A
CORRIDOR OF ENOUGH CAPE AHEAD OF THE FRONT. CONFIDENCE NOT GREAT AT
THIS POINT ESPECIALLY WITH BRUNT OF VORT INFLUENCE TO THE NORTH AND
POTENTIAL FOR BETTER INSTABILITY TO REMAIN TO OUR SOUTH. TRACK OF THE
LOW AND STRENGTH OF WIND FIELDS RAISES SOME CONCERN. HOWEVER A LOOK
AT BOTH THE GFS AND NAM SOUNDINGS ARE QUITE UNIMPRESSIVE.
NEVERTHELESS...WILL KEEP THE CHANCE OF STORMS IN PLACE FOR TUESDAY
AND TUESDAY EVENING.
WEDNESDAY AND THURSDAY - CONFIDENCE...MEDIUM
SHOT OF 850 COLD AIR ADVECTION WRAPS INTO THE AREA WEDNESDAY AND
LINGERS INTO THURSDAY. SURFACE HIGH AND UPPER RIDGING GRADUALLY
BUILD IN ACROSS THE UPPER MIDWEST THURSDAY. SHORTWAVE TROUGH SWINGS
THROUGH FROM THE NORTHWEST ON WEDNESDAY THOUGH AIRMASS LOOKS TOO DRY
TO SUPPORT PRECIP BASED ON BUFFY SOUNDINGS.
FRIDAY AND SATURDAY - CONFIDENCE...LOW
UPPER FLOW FLATTENS A BIT WITH SHORTWAVE ENERGY PROGGD INTO THE AREA
ON FRIDAY. DECENT CONSISTENCY AMONGST THE MODELS ON THIS. ECMWF
DEVELOPS PRECIP WITH SURFACE LOW ON SATURDAY THOUGH GFS HAS HIGH
DOMINATING WITH PRECIP TO OUR SOUTH. EVEN THE ECMWF DEVELOPMENT HAS
PRECIP LARGELY TO OUR WEST. GIVEN THIS POPS MAY BE TOO HIGH...BUT
LOTS OF TIME YET TO FINE TUNE WITH CERTAIN CHANGES ON
TIMING/STRENGTH YET TO COME.
AVIATION/12Z TAFS/...VFR CLOUDS CONTINUE TO THIN AND DISSIPATE FROM
THE NORTH EARLY THIS MORNING WITH AREAS OF DENSE FOG RAPIDLY
DEVELOPING UPSTREAM IN THE CLEARING. KMSN MOST SUSCEPTIBLE TO A
PERIOD OF DENSE FOG EARLY THIS MORNING...BUT LATEST 11-3.9 MICRON
IMAGERY SHOWING SOME BINOVC OVER SOUTHEAST WI AS WELL LAST HOUR OR
TWO. HENCE FOG LIKELY AT ERN TAF SITES AS WELL EARLY. HOWEVER
BOUNDARY LAYER MIXING AND LINGERING HIGH LOW LEVEL RH MAY RESULT IN
MORE STRATUS REDEVELOPMENT EARLY THIS MRNG VS THICKER FOG.
UPSTREAM STRATUS OVER FAR NORTHERN WI INTO NRN MN BEHIND APPROACHING
CDFNT NOT BEING HANDLED WELL BE SHORT TERM GUIDANCE. CONFIDENCE LOW
BUT SOME OF THESE LOWER MVFR CLOUDS MAY AFFECT PORTIONS OF THE EAST
LATER TODAY INTO TNGT...ESPECIALLY WITH COLD AIR SURGE OFF OF LAKE
MICHIGAN.
MARINE...DRY AIR CONTINUES TO FUNNEL SOUTH ACROSS LAKE MI KEEPING
DENSE FOG AT BAY. LIGHT NORTH WINDS WILL TURN ONSHORE TODAY AS A
WEAK COOL FRONT SLIPS SOUTH ACROSS LAKE MI AND SOUTHERN WI. A
REINFORCING PUSH OF LOW LEVEL COLD AIR OVER THE WARMER LAKE WATERS
TONIGHT WL RESULT IN STEEP LOW LEVEL LAPSE RATES. THESE LOW LEVEL
UNSTABLE CONDITIONS OVER THE LAKE WILL ALLOW GUSTY WINDS IN EXCESS
OF 22KTS TO REACH THE LAKE SURFACE OVERNIGHT. HENCE A SMALL CRAFT
ADVY WL BE POSTED.
A TIGHTENING PRESSURE GRADIENT AHEAD OF STRONG LOW PRESSURE IN THE
NORTHERN PLAINS WILL RESULT IN GUSTY WINDS REDEVELOPING OVER THE
NEARSHORE WATERS OF LAKE MI LATE MONDAY NIGHT...CONTINUING ON
TUESDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 10 AM CDT MONDAY
FOR LMZ643>646.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...MBK
MONDAY THROUGH SATURDAY...COLLAR