Severe Thunderstorm Warning 301, NWS Des Moines, IA

000 
WWUS53 KDMX 122116
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
316 PM CST SAT NOV 12 2005

IAC047-122130-
/O.CON.KDMX.SV.W.0301.000000T0000Z-051112T2130Z/
CRAWFORD IA-
316 PM CST SAT NOV 12 2005

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR EASTERN
CRAWFORD COUNTY UNTIL 330 PM CST...

AT 315 PM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
DESTRUCTIVE WINDS IN EXCESS OF 70 MPH.  THIS STORM WAS LOCATED 6
MILES NORTHEAST OF DENISON...OR 62 MILES SOUTHWEST OF FORT DODGE...
AND MOVING NORTH AT 50 MPH.

THE SEVERE THUNDERSTORM WILL BE...
  6 MILES EAST OF KIRON BY 325 PM CST.

THE LOCATIONS OF VAIL AND DELOIT ARE ALSO IN THE PATH OF THIS SEVERE
THUNDERSTORM.

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. SEVERE
THUNDERSTORMS CAN PRODUCE TORNADOES WITH LITTLE OR NO WARNING.
ALTHOUGH NOT IMMEDIATELY LIKELY...IF A TORNADO IS SPOTTED ACT QUICKLY
AND MOVE TO A PLACE OF SAFETY INSIDE A STURDY STRUCTURE...SUCH AS A
BASEMENT OR SMALL INTERIOR ROOM.

IF SEVERE WEATHER WAS OBSERVED...CONTACT THE NATIONAL WEATHER SERVICE
OFFICE IN DES MOINES AT 1-800-759-9276.

LAT...LON 4187 9554 4187 9510 4220 9508 4221 9542

$$

MYERS

000 
WWUS53 KDMX 122128
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
328 PM CST SAT NOV 12 2005

IAC047-122138-
/O.EXP.KDMX.SV.W.0301.000000T0000Z-051112T2130Z/
CRAWFORD IA-
328 PM CST SAT NOV 12 2005

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN CRAWFORD COUNTY HAS
BEEN ALLOWED TO EXPIRE...

AT 324 PM CST...WEATHER SERVICE DOPPLER RADAR INDICATED THAT THE
THUNDERSTORMS WHICH PROMPTED THE WARNING HAVE WEAKENED...AND NO
LONGER POSE AN IMMEDIATE THREAT TO LIFE OR PROPERTY.

IF SEVERE WEATHER WAS OBSERVED...CONTACT THE NATIONAL WEATHER SERVICE
OFFICE IN DES MOINES AT 1-800-759-9276.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 900 PM CST SATURDAY EVENING
FOR IOWA.

LAT...LON 4187 9554 4187 9510 4220 9508 4221 9542

$$

MYERS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
400 AM CST SAT NOV 12 2005

.SHORT TERM...TDA THRU SUN NGT
THE SEASON IS OBVIOUSLY STARTING TO CHG WHEN YOU HAVE TO CONSIDER
SVR WX...WND ADVYS AND SNW OVR THE COURSE OF A FEW DAYS.  FOR
STARTERS...SHRT WV NOW ADVANCING FM CO INTO WRN NE WITH STG DPVA IN
BASED OF TROF.  MID LVL QG FORCING AND STEEP LAPSE RATES HAVE
ALREADY DVLPD ELEVATED CONVECTION AND ISOLD TSTMS OVR KS...AND THIS
IS BHND LOW LVL THETA-E RDG.  09Z SFC ANLYS SHOWS AOA 55 DWPNTS FM
OK JUST INTO SRN NE INVOF KHJH.  NOSE OF 500 J/KG MUCAPES NR THIS
AXIS AND SYS DEEPING RPDLY WITH PRES FALL CNTR AOA 4MB NOTED BHND
994MB LOW OVR WRN NE.

MDLS APPR TO HAVE LOCKED ONTO SOLUTION FOR APCHG SYS...BUT STILL
FAVOR GFS BASED ON PAST HISTORY AND BETTER DEPICTION OF SFC LOW.
NAM 12Z PSN S OF CURRENT SFC ANLYS.  LOW SHOULD ADVANCE FM NE INTO
MN THIS AFTN WITH MLCAPES 500-1000 J/KG DRNG PEAK HEATING AND DWPNTS
WELL INTO THE 50S.  QG FORCING MAX AND SFC CNVGNC SHOULD BE NRLY
COINCIDENT THIS AFTN...AND ALTHOUGH THERE IS AN INITIAL WRM LYR ARND
5KFT TO OVERCOME...STG LRG SCALE FORCING AND STEEP LAPSE RATES
PUSHING EWD QUICKLY MODIFY VERTICAL PROFILE TO RELEASE INSTABILITY
ARND 21Z.  HAVE MENTIONED SVR WORDING FA WIDE DUE TO DAMAGING WND
THREAT.  MEAN STORM MOTION SW-NE AT 45-55KTS WITH SOME DRIER AIR
ALF.  STG SHEAR AVBL AT ALL LVS SO COULD SEE A FEW FAST MOVING
SUPERCELLS.  WOULD NOT BE SURPRISED TO HAVE A TORNADO RPT OR
TWO...BUT CONFIDENCE NOT HIGH ENOUGH TO MENTION.  0-3KM CAPE AXIS
DOES NOT QUITE WRAP FAR ENOUGH AHD OF SFC LOW TO REALIZE FAVORABLE
LOW LVL SHEAR.

SYS SHOULD EXIT QUICKY WITH ONLY BRIEF WINDOW OF PCPN AS ATTN TURNS
TWRD WNDS.  GFS SOUNDINGS KEEP LOW LVLS MIXED TNGT ACRS NRN IA WITH
MIXING POTENTIAL HAVING GUSTS AOA 40KTS AND EVEN TO 55KTS AT TOP OF
MIXED LYR AT MCW AT 09Z.  LATER SHIFTS WL HAVE TO WATCH FOR HIGH WND
WRNG CRITIERA...SPCLLY DRNG THE DAY.  SIMILAR CONDS CONT THRU 21Z SO
WL ISSUE WND ADVY OVNGT TNGT AND SUN.

STAYED NR PERSISTENCE TDA FOR TEMPS WITH INCR SLY WNDS NR NAM MOS.
ST IS DVLPG UPSTREAM BUT THAT MAY NOT MAKE MUCH DIFFERENCE WITH
UPSTREAM TEMPS ALREADY IN THE LWR 60S ACRS KS.  HAVE LOWERED TEMPS
SUN AND SUN NGT.  FCST SOUNDINGS SHOW LTL HOPE OF MUCH
REBOUND...LIKELY SOMEWHERE INVOF FWC/GFS MOS BLEND.  WITH DRY AMS IN
PLACE AND TRANSIENT SFC RDG DROPPED SUN NGT MINS TO ARND 20 DEGREE
DROP TWRD COOL END OF GUIDANCE.  WRM ADVCTN AND INCR CLDS LATE MAY
KEEP THINGS FM REALLY DROPPING OFF THE TABLE.  LATER SHIFTS MAY HAVE
TO LOWER MORE...BUT THIS APPRS TO BE STEP IN THE RIGHT DIRECTION.

.LONG TERM...MON THRU FRI
MDLS HAVE SLOWED MON/TUE SYS A BIT SINCE YDA...SPCLLY GFS.  ALTHOUGH
ALL ARE GENERALLY IN THE SAME BALLPARK WITH UPR SYS...GFS/NAM SHOW
MORE SEPARATION BTWN UPR LOW AND SFC REFLECTION WITH TRAILING TROF
INVOF PARENT LOW.  EURO MDLS AND GEM WEAKER AND CLOSER TO VERTICALLY
STACKED MUCH LIKE 11/00Z GFS SOLUTION ALBEIT SLOWER.  THIS DOES NOT
HAVE TOO MUCH IMPACT ON IA WX HWVR AS ALL MDLS KEEP MAJORITY OF PCPN
OVR NRN SXNS AND STATES TO THE N.  HAVE NOT CHGD PCPN WORDING TOO
MUCH IN THIS PD BESIDES DELAYING PCPN TIL MON AFT 12Z.  FCST
SOUNDINGS CERTAINLY SUPPORT ICE INTRODUCTION BUT WITH LOW LVL WRM
LYR ABV INVERSION. EVAPORATIVE COOLING AND MELTING WOULD LIKELY
ERODE THIS HWVR SO HAVE KEPT MENTION OF SNW DRNG FAVORABLE NIGHTTIME
AND MRNG HRS.  DID NOT GO TOO EXTREME...BUT DID RAISE WNDS ON TUE AS
ALL MDLS SUPPORT AT LEAST ANOTHER ADVY LVL WND EVENT.  ECMWF SHOWS
20MB SLP GRADIENT FM MO TO MS RVRS 00Z WED SO COULD BE WRNG IF THAT
PANS OUT.  WL BE HIGHLIGHTED IN HWO.

SGFNT DIFFERENCE IN NAM/GFS GUIDANCE MON.  WL LIKELY BE EVAPORATIVE
COOLING FOLLOWED BY PCPN BASED ON GFS SO WRMR NAM MOS APPRS TO BE IN
WRONG DIRECTION.  QUESTION IS HOW FAR TO BITE ON COOLER GFS MOS
NUMBERS.  AT THIS POINT WL GO WITH COMPROMISE WHICH IS 5-10F COOLER
THAN CURRENT FCST.  DO NOT WANT TO GET TOO DRASTIC IN 5TH PD.  AS
NOTED EARLIER...DAY SHIFT MAY HAVE TO LOWER MORE BUT THIS SEEMS LIKE
A REASONABLE TREND.  NO OTHER SGFNT CHGS IN LATER PDS.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...WND ADVY ALG AND N OF HIGHWAY 20
OVGNT AND SUN (13/03Z-14/00Z).

&&

SMALL/JOHNSON

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
145 PM CST SAT NOV 12 2005

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-
081>086-092>097-131200-
EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO-
POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-BUTLER-BREMER-SAC-CALHOUN-
WEBSTER-HAMILTON-HARDIN-GRUNDY-BLACK HAWK-CRAWFORD-CARROLL-GREENE-
BOONE-STORY-MARSHALL-TAMA-AUDUBON-GUTHRIE-DALLAS-POLK-JASPER-
POWESHIEK-CASS-ADAIR-MADISON-WARREN-MARION-MAHASKA-ADAMS-UNION-
CLARKE-LUCAS-MONROE-WAPELLO-TAYLOR-RINGGOLD-DECATUR-WAYNE-
APPANOOSE-DAVIS-
145 PM CST SAT NOV 12 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR MUCH OF CENTRAL IOWA.

.DAY ONE...TODAY AND TONIGHT

SCATTERED THUNDERSTORMS ARE FORECAST TO DEVELOP ALONG THE NEBRASKA
BORDER LATER THIS AFTERNOON...THEN MOVE RAPIDLY NORTHEAST AROUND 50
MPH. THE PRIME THREAT TIME WILL BE FROM 3 PM TO 7 PM. A FEW STORMS
MAY PRODUCE WIND GUSTS EXCEEDING 60 MPH WITH AN ISOLATED TORNADO A
SMALLER RISK. ON THE OVERNIGHT...WINDS OF 20 TO 35 MPH ARE LIKELY
WITH GUSTS TO 50 MPH POSSIBLE NORTH OF HIGHWAY 20.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

LITTLE CHANGE IN THE WEATHER IS EXPECTED THROUGH SUNDAY AFTERNOON
WITH CONTINUED WEST TO NORTHWEST WINDS OF 20 TO 35 MPH...GUSTING TO
50 MPH. THE STRONGEST WINDS WILL AGAIN BE ALONG AND NORTH OF HIGHWAY
20 BEFORE DIMINISHING.

ANOTHER PERIOD OF WINDY WEATHER IS ANTICIPATED TUESDAY WITH
NORTHWEST WINDS OF 25 TO 35 MPH...AND GUSTS TO AROUND 45 MPH.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED FOR A BRIEF PERIOD LATER TODAY.

MYERS