Alert archive / Arkansas / Flash Flood Warnings in 1999

Flash Flood Warning 83, NWS Tulsa, OK

July 1, 1999Benton County, Arkansas

NWS Tulsa, OK issued this flash flood warning at Jul 1, 1999, 10:34 AM CDT for Benton County, Arkansas. It was in force for 116 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued
Jul 1, 1999, 10:34 AM CDT (15:34 UTC)
Expired
Jul 1, 1999, 12:30 PM CDT
In force
116 min
Issued by
NWS Tulsa, OK
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Benton County, AR

The radar

The Springfield radar (KSGF), 89 km from the middle of the area, began a volume at 15:48 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.

The nearest sounding before it

Springfield, MO (KSGF), launched 12:00Z, 3.6 hours before the alert went out and 39 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Springfield, MO at 12:00Z on 1999-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1227 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Springfield, MO at 12:00Z on 1999-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 332 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1227 J/kg
Mixed-layer CIN
-62 J/kg
Mixed-layer LCL
839 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
332 m²/s²
0-3 km storm-relative helicity
339 m²/s²
Significant tornado parameter
1.6
Supercell composite
9.7

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KTUL 011535
FFWTUL
ARC007-011730-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TULSA OK
1034 AM CDT THU JUL 1 1999

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A

* FLASH FLOOD WARNING FOR
  BENTON COUNTY IN NORTHWEST ARKANSAS

* UNTIL 1230 PM CDT

* AT 1034 AM CDT RADAR INDICATED THUNDERSTORMS WITH VERY HEAVY       
  RAIN WILL CONTINUE TO MOVE EAST OVER BENTON COUNTY.  AN ESTIMATED  
  1 TO 2 INCHES OF RAIN HAS ALREADY FALLEN AND ANOTHER 1 TO 2 INCHES 
  IS POSSIBLE.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT. MOST FLASH FLOOD DEATHS OCCUR IN AUTOMOBILES. DO NOT
ATTEMPT TO CROSS BRIDGES...DIPS...OR OTHER LOW SPOTS IF WATER COVERS
THE ROADWAY. NEVER TRY TO CROSS A FLOWING STREAM...EVEN A SMALL
ONE...ON FOOT. TO ESCAPE RISING WATER MOVE UP TO HIGHER GROUND.

LAT...LON 3637 9437 3624 9421 3684 9330 3709 9362

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Tulsa, OK wrote its last area forecast discussion before this flash flood warning went out at Jul 1, 4:40 AM CDT, 5 hours 54 minutes earlier.

Area forecast discussion, Jul 1, 4:40 AM CDT, 5 hours 54 minutes before
EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
440 AM CDT THU JUL 1 1999

PROBLEMS OF THE DAY:
WILL THERE BE SEVERE CONVECTION?
HOW MUCH RAIN WILL FALL?
TEMPERATURES

SUMMER IS FINALLY COMING BUT NOT BEFORE ONE LAST HURRAH FROM MOTHER
NATURE THIS MORNING. MESOSCALE CONVECTIVE SYSTEM STARTING TO BECOME
ORGANIZED ACROSS SOUTHERN KANSAS AND IS LIKELY TO SOON EVOLVE INTO A
FAST MOVING SQUALL LINE WHICH WILL RACE EAST SOUTHEAST ACROSS THE
FORECAST AREA THIS MORNING. LOW LEVEL JET OF 30-40 KNOTS AND LAMONT
PROFILER SHOWS MID LEVEL FLOW HAS INCREASED TO 55 KNOTS DURING THE
PAST COUPLE HOURS WITH IMPRESSIVE VEERING SO PLETY OF REASONS TO
SUPPORT THE SQUALL LINE BLASTING THROUGH MUCH OF THE AREA. THINK IT
WILL FINALLY RUN OUT OF GAS ONCE IT PASSES MCALESTER AND FORT SMITH
AS IT ENCOUNTERS WEAKER MID LEVEL FLOW AND A STRONGER CAP. GIVEN THE
EXCESSIVE RAINS WHICH FELL WEDNESDAY MORNING AND THE POTENTIAL FOR A
QUICK 1-2 INCHES THIS MORNING...WILL ISSUE A FLASH FLOOD WATCH FOR
ALL AREAS EXCEPT FAR SOUTHEAST OKLAHOMA FOR THIS MORNING.

WEAKENING MID LEVEL FLOW...RISING HEIGHTS ALOFT AND WARMING MID LEVEL
TEMPERATURES SHOULD FINALLY LEAD TO AN EXTENDED DRY PERIOD AFTER
TODAY. WILL KEEP SMALL POPS IN NORTHEAST OKLAHOMA AND NORTHWEST
ARKANSAS TONIGHT ALTHOUGH THE MAIN ACTION SHOULD BE TO THE NORTH.
WILL THEN HEAT THINGS UP OVER THE WEEKEND ALTHOUGH TEMPERATURES WILL
BE HELD IN CHECK SOME DUE TO ALL THE RECENT RAIN AND RESULTANT LUSH
VEGETATION. SLIM CHANCE FOR ISOLATED STORMS IN FAR SOUTHEAST OKLAHOMA
BY THE END OF THE WEEKEND DUE TO A WEAKNESS IN THE UPPER RIDGE OVER
THAT AREA BUT THE CHANCES LOOK TOO SLIM TO MENTION AT THIS POINT IN
TIME.

GUIDANCE TEMPERATURES LOOK REASONABLE AS THE RETURN OF SUNSHINE THIS
AFTERNOON SHOULD RESULT IN A GOOD WARMUP AFTER THE MORNING RAINS.
GUIDANCE POPS CONTINUE TO BE TOO LOW TODAY.

FCSTID = 5
TUL   88  76  92  78 / 100  20  10  10
FSM   88  74  92  75 /  70  10   5   5
MLC   88  76  92  78 /  60  10   5   5
BVO   88  75  92  77 / 100  20  10  10
FYV   84  72  89  74 /  90  20  10  10
IDB   90  74  92  74 /  20  10   5   5
BYV   84  72  89  74 /  90  20  10  10
MIO   86  74  90  76 /  90  20  10  10
MKO   88  75  92  78 /  80  10   5   5
F10   88  76  92  78 /  80  10   5   5
HHW   90  76  92  77 /  20  10   5   5

.TUL...
AR...FLASH FLOOD WATCH FOR THIS MORNING FOR ZONES ARZ001>002...
ARZ010>011...ARZ019>020...ARZ029.

OK...FLASH FLOOD WATCH FOR THIS MORNING FOR ZONES OKZ054>076.

PLATE

--------------------
EXPERIMENTAL OUTPUT:

HAZARDOUS WEATHER EXPECTED NEXT 24 HOURS: GOOD CHANCE SEVERE
THUNDERSTORMS
NGM CONFIDENCE:  4 ON A SCALE OF 0 TO 10
ETA CONFIDENCE:  7 ON A SCALE OF 0 TO 10
AVN CONFIDENCE:  7 ON A SCALE OF 0 TO 10
FCST CONFIDENCE: 7 ON A SCALE OF 0 TO 10

In the hours before

Special weather statement, Jul 1, 6:10 AM CDT, 4 hours 24 minutes before
ARZ001-002-010-011-019-020-029-OKZ049-053>076-021100-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
610 AM CDT THU JUL 1 1999

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 10 AM FOR OSAGE...
   PAWNEE AND CREEK COUNTIES IN NORTHEAST OKLAHOMA...
...A FLASH FLOOD WATCH IS IN EFFECT FOR THIS MORNING FOR MUCH OF
   EASTERN OKLAHOMA AND NORTHWEST ARKANSAS...
...A FEW SEVERE THUNDERSTORMS ARE EXPECTED OVER NORTHEAST OKLAHOMA THIS
   MORNING...

.SYNOPSIS...
EARLY THIS MORNING LOW PRESSURE WAS LOCATED OVER THE TEXAS AND OKLAHOMA
PANHANDLES.  A STRONG LOW LEVEL JET HAS DEVELOPED OVERNIGHT OVER THE
SOUTHERN PLAINS AHEAD OF THIS FEATURE.  THIS JET COMBINED WITH
APPROACHING RELATIVELY STRONG WINDS IN THE MID LEVELS OF THE ATMOSPHERE
WILL PROVIDE AN ENVIRONMENT FAVORABLE FOR SEVERE THUNDERSTORMS OVER
NORTHEAST OKLAHOMA THIS MORNING.  WIND FIELDS WILL WEAKEN SOMEWHAT THIS
AFTERNOON AND TONIGHT AND WARMING MID LEVELS OF THE ATMOSPHERE WILL ACT
TO SUPPRESS THE REDEVELOPMENT OF THUNDERSTORMS LATER IN THE DAY AND
OVERNIGHT TONIGHT.

.DISCUSSION...
A COMPLEX OF STRONG TO SEVERE THUNDERSTORMS FORMED OVER SOUTHWEST KANSAS
OVERNIGHT.  THE LEADING EDGE OF THIS COMPLEX OF STORMS IS EXPECTED TO
DEVELOP INTO A SQUALL LINE AND MOVE SOUTHEAST ACROSS EASTERN OKLAHOMA
AND NORTHWEST ARKANSAS THIS MORNING.  THE THUNDERSTORMS WILL LIKELY
WEAKEN AS THEY CROSS THE AREA.  HOWEVER...THEY WILL LIKELY REMAIN STRONG
ENOUGH TO PRODUCE SOME DAMAGING WINDS AND MARGINALLY SEVERE HAIL ACROSS
NORTHEAST OKLAHOMA . THE STORMS WILL ALSO BRING A PERIOD OF VERY HEAVY
RAINFALL WHICH COMBINED WITH SOILS THAT ARE SATURATED FROM LAST MORNINGS
RAIN COULD RESULT IN FLASH FLOODING.

.EMERGENCY MANAGEMENT AGENCY AND SPOTTER ACTIVATION...
CIVIL DEFENSE AGENCIES AND SPOTTER GROUPS OVER NORTHEAST OKLAHOMA SHOULD
BE PREPARED FOR POSSIBLE ACTIVATION THIS MORNING.  INFORMATION
CONCERNING THE DEVELOPMENT OF FLASH FLOODING MAY BE NEEDED OVER THE
WHOLE AREA.
Special weather statement, Jul 1, 6:10 AM CDT, 4 hours 24 minutes before
ARZ001-002-010-011-019-020-029-OKZ049-053>076-021100-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
610 AM CDT THU JUL 1 1999

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 10 AM FOR OSAGE...
   PAWNEE AND CREEK COUNTIES IN NORTHEAST OKLAHOMA...
...A FLASH FLOOD WATCH IS IN EFFECT FOR THIS MORNING FOR MUCH OF
   EASTERN OKLAHOMA AND NORTHWEST ARKANSAS...
...A FEW SEVERE THUNDERSTORMS ARE EXPECTED OVER NORTHEAST OKLAHOMA THIS
   MORNING...

.SYNOPSIS...
EARLY THIS MORNING LOW PRESSURE WAS LOCATED OVER THE TEXAS AND OKLAHOMA
PANHANDLES.  A STRONG LOW LEVEL JET HAS DEVELOPED OVERNIGHT OVER THE
SOUTHERN PLAINS AHEAD OF THIS FEATURE.  THIS JET COMBINED WITH
APPROACHING RELATIVELY STRONG WINDS IN THE MID LEVELS OF THE ATMOSPHERE
WILL PROVIDE AN ENVIRONMENT FAVORABLE FOR SEVERE THUNDERSTORMS OVER
NORTHEAST OKLAHOMA THIS MORNING.  WIND FIELDS WILL WEAKEN SOMEWHAT THIS
AFTERNOON AND TONIGHT AND WARMING MID LEVELS OF THE ATMOSPHERE WILL ACT
TO SUPPRESS THE REDEVELOPMENT OF THUNDERSTORMS LATER IN THE DAY AND
OVERNIGHT TONIGHT.

.DISCUSSION...
A COMPLEX OF STRONG TO SEVERE THUNDERSTORMS FORMED OVER SOUTHWEST KANSAS
OVERNIGHT.  THE LEADING EDGE OF THIS COMPLEX OF STORMS IS EXPECTED TO
DEVELOP INTO A SQUALL LINE AND MOVE SOUTHEAST ACROSS EASTERN OKLAHOMA
AND NORTHWEST ARKANSAS THIS MORNING.  THE THUNDERSTORMS WILL LIKELY
WEAKEN AS THEY CROSS THE AREA.  HOWEVER...THEY WILL LIKELY REMAIN STRONG
ENOUGH TO PRODUCE SOME DAMAGING WINDS AND MARGINALLY SEVERE HAIL ACROSS
NORTHEAST OKLAHOMA . THE STORMS WILL ALSO BRING A PERIOD OF VERY HEAVY
RAINFALL WHICH COMBINED WITH SOILS THAT ARE SATURATED FROM LAST MORNINGS
RAIN COULD RESULT IN FLASH FLOODING.

.EMERGENCY MANAGEMENT AGENCY AND SPOTTER ACTIVATION...
CIVIL DEFENSE AGENCIES AND SPOTTER GROUPS OVER NORTHEAST OKLAHOMA SHOULD
BE PREPARED FOR POSSIBLE ACTIVATION THIS MORNING.  INFORMATION
CONCERNING THE DEVELOPMENT OF FLASH FLOODING MAY BE NEEDED OVER THE
WHOLE AREA.

The office that day

Everything else NWS Tulsa, OK issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 1, 10:05 AM CDTSevere Thunderstorm WarningTSABenton55 min
Jul 1, 11:15 AM CDTFlash Flood WarningTSACarroll2 hr

Nearby

Flash Flood Warnings in Arkansas, 1999Every flash flood warning in 1999

Sources

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.