FXUS63 KOAX 252046
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
346 PM CDT MON OCT 25 2010
.SHORT TERM...TONIGHT THROUGH THURSDAY
12Z UPPR AIR ANLYS INDCD IMPRESSIVE UPPR LVL JET /ARND 150 KT AT
H3/ DIVING INTO THE WRN US. THIS WAS DRIVING A SIG UPPR LVL SYSTEM
THRU THE GREAT BASIN WITH 160 M H5 HEIGHT FALLS. AT H85 THE MAIN
MOISTURE AXIS EXTNDD FM THE GULF NWD THRU THE MS RVR VALLEY...BUT
SOME MOISTURE EXTNDD BACK W THRU THE CNTRL PLAINS WITH DEW POINTS
GREATER THAN 0 C. 20Z SFC ANLYS INDCD DEEPENING LO PRES OF 982 MB
OVR CNTRL KS WITH AN INVERTED TROF NWD THRU CNTRL NEB AND A STG
CDFNT SWWD INTO SE CO. PRECIP SO FAR THIS AFTN HAS BEEN ON BOTH
SIDES OF THE FNT FM SW NEB INTO SE SD.
IMPRESSIVE LATE OCT SYSTEM WILL BE MOVING THRU THE FA OVER THE
NEXT 48 HRS WITH THE MAIN STORY BEING WIND...BUT ALSO SOME
CONVECTIVE CHC THIS EVNG. LO PRES SHLD CONT TO DEEPEN AND LIFT
NEWD THIS EVNG CROSSING ERN NEB INTO NW IA THRU THE EVNG HOURS AS
THE SYSTEM STARTS TO BOMB OUT. SFC CDFNT WL SLOWLY MAKE EWD
PROGRESS THIS EVNG WITH THE FNT MOVG THRU THE ENTIRE FA BY 08Z.
MODELS PROG SOME INCREASE IN H85 MOISTURE JUST AHEAD OF THE FNT IN
OUR ERN FA...BUT POINT FORECAST SOUNDINGS CONT TO SHOW A
CONSIDERABLE AMOUNT OF SBCIN NEAR THE FNT. HI-RES GUIDANCE FM
VARIOUS SOURCES CONT TO INDC BEST NEAR SFC-BASED CONVECTIVE
DVLPMENT WL BE E OF THE FA LATE THIS EVNG AND INTO THE OVERNIGHT
HOURS. NEVERTHELESS...GIVEN SUCH IMPRESSIVE FORCING...CLD NOT RULE
OUT SOME DEVELOPMENT VERY NEAR OR SLIGHTLY BEHIND THE CDFNT THIS
EVNG INTO THE CNTRL/ERN FA AND WL ADD THUNDER TO THE EVNG
FORECAST. OTHERWISE...HAVE NEAR 100 POPS FOR MOST OF THE CNTRL AND
NRN FA IN ASSOCIATED WITH THE STG FRONTOGENESIS AND Q-G FORCING IN
A WEAKLY STABLE ATMOSPHERE. AS THE UPPR LVL SYSTEM CLOSES OFF IN
ERN SD AND MOVS SLOWLY INTO SW MN OVERNIGHT...SHLD SEE A
DEFORMATION BAND DVLP IN NE NEB INTO THE DAKOTAS AND HAVE EXTENDED
POPS THRU THE NIGHT IN THE NRN CWA. NEXT ISSUE FOR TONIGHT WL BE
WIND. STG PRES GRADIENT IMMEDIATELY BEHIND THE FNT WL LEAD TO 6-8
MB 6-HR SFC PRES RISES THIS EVNG /ESPECIALLY CNTRL AND S FA/. THIS
ALNG WITH THE STG LO LVL CAA MAY BE ENOUGH TO OVERCOME NEAR SFC
INVERSION AND ALLOW FOR A COUPLE HOURS OF NEAR WIND ADVISORY TYPE
WINDS TO OCCUR. SINCE THE MAIN WIND STORY WL BE ON TUES/WED...WILL
TRY AND KEEP THINGS SIMPLE AND NOT ISSUE AN ADVRY FOR THIS
EVNG..BUT WL HAVE SOME PRETTY STG WINDS IN THE FORECAST FOR A
COUPLE OF HOURS BEFORE TAPERING OFF AFTER MIDNIGHT.
STG MID LVL DRYING TAKES PLACE ON TUES AS LARGE-SCALE SUBSIDENCE
WORKS THRU THE FA. AS SYSTEM OVR MN BOTTOMS OUT AT NEAR 960
MB...INTENSE PRES GRADIENT WL BECOME ESTABLISHED ACRS THE FA. STG
UNIDIRECTIONAL FLOW...STEEP LO LVL LAPSE RATES AND CONTD CAA WL
LEAD TO A VERY WINDY DAY. WE SHLD SEE EASY WIND ADVISORY CRITERIA
OVR MOST OF THE FA AND NEAR HIGH WIND CRITERIA OVR THE N. WINDS AT
THE TOP OF THE MIXED LAYER ARE NEAR 58 KT OVR THE N LEADING TO
GUST POTENTIAL NEAR 50 KT AT THE SFC. WLD LIKE TO SEE WINDS A
LITTLE STRONGER AT 925 AND 850 MB BEFORE GOING WITH A HIGH WIND
WARNING THOUGH...AND THUS JUST HAVE AN ADVISORY IN EFFECT FOR
TOMORROW. THIS WL HAVE TO BE WATCHED OVR THE NEXT TWO SHIFTS
THOUGH FOR AN UPGRADE.
WINDS SHLD DIMINISH ON TUESDAY NIGHT WITH LOSS OF STEEP LO-LVL
LAPSE RATES...BUT WL QUICKLY INCREASE AGAIN ON WED...AND MAY EVEN
BE STRONGER THAN ON TUES. SFC LO OVR NRN MN WL START TO SHIFT SEWD
THRU THE GREAT LAKES AND ALLOW FOR A SECOND SURGE OF PRES
ADVECTION DURING THE DAY ON WED. THIS ALNG WITH AGAIN STEEP LO-LVL
LAPSE RATES AND UNIDIRECTIONAL FLOW SHLD ALLOW FOR A VERY WINDY
DAY. CONSIDERED HIGH WIND WATCH FOR THE N...BUT WITH WINDS TONIGHT
AND TUES WL HOLD OFF FOR NOW...BUT EVENTUALLY SOME SORT OF WIND
HIGHLIGHT WL ONCE AGAIN BE NEEDED FOR WED. THINGS START TO CALM
DOWN ON WED NIGHT THOUGH AS SFC RIDGE AXIS STARTS TO ADVANCE EWD
INTO THE FA AND WL CONT IN THE AREA THRU THURS WITH LIGHT WINDS
AND CLEAR SKIES.
AS FOR TEMPERATURES...GENERALLY KEPT GOING FORECAST HIGHS/LOWS
THRU THE PERIOD WITH A FEW TWEAKS HERE AND THERE. INCREASED GOING
HIGHS ON TUES AND WED IN THE S...BUT CONDS STILL EXPECTED TO BE
COOL FOR THE MIDDLE OF THE WEEK.
BOUSTEAD
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
TEMPERATURES ARE STILL THE PRIMARY FORECAST CONCERN. AT THE START OF
THIS PERIOD...A MID TROPOSPHERIC RIDGE WILL BE BUILDING OVER THE
WESTERN HIGH PLAINS AND HIGH PRESSURE AT THE SURFACE WILL EXTEND
FROM THE DAKOTAS AND MINNESOTA DOWN INTO TEXAS. THE 12Z GFS AND THE
00Z ECMWF START TO SHOW TIMING DIFFERENCES WITH MOVEMENT OF 500 MB
RIDGE OVER THE CENTRAL U.S. AND A SHORTWAVE TROUGH THAT WILL BE
MOVING INTO THE CENTRAL AND SOUTHERN ROCKIES. 00Z ECMWF WAS FASTER
WITH SYSTEM AND PCPN PUSHING OUT INTO THE PLAINS NEXT WEEKEND. FOR
NOW GENERALLY FAVORED A BLEND OF THOSE SOLUTIONS WITH MORE WEIGHT
GIVEN TO GFS. DID INCLUDE A SLIGHT CHANCE OF SHOWERS FOR MUCH OF OUR
AREA SATURDAY NIGHT. RAIN ALSO POSSIBLE MONDAY...BUT THERE ARE SOME
FAIRLY BIG MODEL DIFFERENCES AT THIS TIME. ONLY WENT WITH A SLIGHT
CHANCE FOR MONDAY AT THIS TIME...BUT 00Z ECMWF SOLUTION WAS VERY
WET.
GENERALLY STAYED FAIRLY CLOSE TO GUIDANCE TEMPERATURES BUT BOOSTED
HIGHS AHEAD OF THE FRONT SATURDAY. LOWS THURSDAY NIGHT SHOULD BE
MOSTLY IN THE 30S...THEN UPPER 30S TO MID 40S FRIDAY NIGHT THROUGH
SUNDAY NIGHT. SO A HARD FREEZE DOES NOT APPEAR LIKELY THROUGH EARLY
NEXT WEEK. EXPECT HIGHS GENERALLY IN THE 60S...WITH SOME LOWER 70S
POSSIBLE SATURDAY IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA.
MILLER
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
THE PRIMARY CONCERNS FOR THE 18Z TAFS WERE THE WINDS AND
PRECIPITATION. A LARGER SYSTEM AFFECTING MUCH OF THE ROCKIES AND
PLAINS WILL BRING A COLD FRONT THRU THIS AFTERNOON AND EARLY
EVENING...ALONG WITH PRECIPITATION AND STRONG WINDS.
AT 19Z THE WINDS WERE BEGINNING TO SHIFT AT KONL...WITH GUSTY
SOUTHEAST WINDS AT 10 TO 20KT AHEAD OF THE FRONT. SFC WINDS AT KOFK
SHOULD BEGIN TO SHIFT TO THE WEST AND NW 21-23Z AND AT KOMA AND KLNK
23Z-01Z. NW WINDS AT 15 TO 20KTS WITH GUSTS 20-30KTS. SHOWERS WILL
BE THE PREDOMINANT PRECIP TYPE...BUT WILL ALSO NEED TO BE ALERT FOR
ISOLATED -TSRA. PERIODS OF SHOWERS AT KOFK NOW THRU 06Z AND AFT 00Z
AT KOMA AND KLNK. VFR CIGS WILL CONTINUE...HOWEVER THERE WILL BE
MVFR CIGS AND VSBYS AT TIMES WITH THE PRECIPITATION. AFT 15Z
TUESDAY...LOOK FOR STRONG WESTERLY WINDS TO MIX DOWN...25 TO 30 KTS
SUSTAINED WITH GUSTS 35 TO 40KTS.
ZAPOTOCNY
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY FROM 8 AM TO 8 PM CDT TUESDAY FOR NEZ011-012-
015>018-030>034-042>045-050>053-065>068-078-088>093.
IA...WIND ADVISORY FROM 8 AM TO 8 PM CDT TUESDAY FOR IAZ043-055-056-
069-079-080-090-091.
&&
$$