Severe Thunderstorm Warning 177, NWS Des Moines, IA

Issued

Jul 7, 2003, 1:25 AM CDT (06:25 UTC)

Expired

Jul 7, 2003, 1:45 AM CDT

In force

20 min

Issued by

NWS Des Moines, IA

Area

Counties, with a storm outline in the text

County Franklin County, IA

The Des Moines radar (KDMX), 122 km from the middle of the area, began a volume at 06:25 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

572 
WUUS53 KDMX 070625
SVRDMX
IAC069-070645-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
125 AM CDT MON JUL 7 2003

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  FRANKLIN COUNTY IN NORTH CENTRAL IOWA

* UNTIL 145 AM CDT

* AT 119 AM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A LINE
  OF SEVERE THUNDERSTORMS FROM 6 MILES WEST OF SHEFFIELD TO 11 MILES
  WEST OF ACKLEY...OR FROM 20 MILES SOUTH OF MASON CITY TO 43 MILES
  SOUTH OF MASON CITY...MOVING EAST AT 35 MPH.

* SEVERE THUNDERSTORMS WILL BE...

  NEAR SHEFFIELD AROUND 130 AM...
  NEAR HANSELL AROUND 135 AM AND
  NEAR ACKLEY MUNICIPAL AIRPORT AROUND 140 AM.

HAIL UP TO THE SIZE OF NICKELS IS LIKELY IN THE WARNED AREA.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 300 AM MONDAY MORNING FOR
WESTERN IOWA.

LAT...LON 4292 9340 4255 9332 4255 9303 4291 9303


$$

NWS Des Moines, IA wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 6, 4:00 PM CDT, 9 hours 25 minutes earlier.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
400 PM CDT SUN JUL 6 2003

SAME OLD SAME OLD. PATTERN REMAINS STUCK FOR THE NEXT COUPLE DAYS.
THOUGH THERE IS SOUTHWARD MOVEMENT OF THE MAIN FRONTAL SYSTEM BY
LATE TONIGHT...CWA WILL REMAIN IN LOW LEVEL CONVERGENCE ZONE/S DUE
TO FRONTAL AND OR OUTFLOW BOUNDARIES. MAIN DIFFICULTIES CONTINUE TO
BE EXACTLY WHERE CONVECTION WILL FIRE AS EACH CONVECTIVE SYSTEM
MODIFIES ENVIRONMENT AND CHANGES PLACEMENT OF NEXT CONVECTIVE
DEVELOPMENT. OVERALL ONCE AGAIN MADE ONLY MINOR CHANGES TO UPCOMING
FORECAST AND BEYOND 24 HOURS BROADBRUSHED PCPN CHANCES DUE TO
UNCERTAINTIES OF BOUNDARY PLACEMENT.

IN THE SHORT TERM...CWA IS ONCE AGAIN HOME TO A FAIRLY SIGNIFICANT
OUTFLOW BOUNDARY WHICH SHOWS NICELY ON SAT PICS...SFC OBS...AND
RADAR. ADDITIONAL SECONDARY BOUNDARY JUST SW OF KMCW. MAIN QUESTION
IS WHETHER OR NOT THESE BOUNDARIES WILL LIGHT UP EARLY THIS EVENING.
LAPS AND SPC MESO DATA INDICATE AREA ALONG AND JUST TO THE SOUTH OF
THE MAIN BOUNDARY ARE NOT CAPPED WITH NEAR 3K OF CAPE. AREA JUST
NORTH OF BOUNDARY STILL WEAKLY CAPPED. NARROW ZONE OF SLIGHTLY
ENHANCES CU RIGHT ALONG BOUNDARY HAS WEAKEN OVER THE LAST COUPLE
HOURS THOUGH LOW LEVEL CONVERGENCE REMAINS FAIRLY STRONG. HAVE
INCLUDED EVENING POPS ALONG AND NORTH OF BOUNDARY. CONVECTION SHOULD
THEN DEVELOP OVER AREAS TO OUR NORTH AND MOVE SE ALONG THESE LOW
LEVEL BOUNDARIES WHICH WILL ALSO BE WERE H850 THETA-E CONVERGENCE
WILL BE LOCATED AND EDGE OF BEST H7 BAROCLINIC ZONE. BEST CHANCE FOR
PCPN OVER MCW AND ALO ZONES WITH DECREASING CHANCES FURTHER SW.

IN LATER PERIODS HAVE BECOME LESS SPECIFIC WITH DEFINITION OF POPS
AS FRONTAL POSITION WILL BE DIFFICULT. HAVE GENERALLY SHIFTED BEST
POPS AND HIGHER QPF FURTHER SOUTH INTO TUES. SHORT WAVES MOVING OVER
THE AREA WEDS WILL ALLOW THE FRONT TO LINGER CLOSE TO THE AREA
BEFORE BEING DISPLACED FURTHER S THURS AND FRIDAY.

.DSM...NONE

JAW

Severe Thunderstorm Warnings in Iowa, 2003Every severe thunderstorm warning in 2003

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.