Alert archive / Arizona / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 23, NWS Phoenix, AZ
NWS Phoenix, AZ issued this severe thunderstorm warning at Jul 18, 1999, 4:26 PM MST for Yuma County, Arizona. It was in force for 64 min. 1 report came from inside the area while it was in force.
The area
The counties it named, with what was reported inside it.
The facts
- Issued
- Jul 18, 1999, 4:26 PM MST (23:26 UTC)
- Expired
- Jul 18, 1999, 5:30 PM MST
- In force
- 64 min
- Issued by
- NWS Phoenix, AZ
- Area
- Whole counties
County Yuma County, AZ
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 18, 4:38 PM MST | Hail 0.75 | Tacna, AZ | Dime size hail reported by spotter. |
NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.
The text
The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.
What forecasters said that day
The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Phoenix, AZ wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 18, 2:59 PM MST, 1 hour 27 minutes earlier.
Area forecast discussion, Jul 18, 2:59 PM MST, 1 hour 27 minutes before
SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PHOENIX AZ 945 AM MST SUN JUL 18 1999 .SYNOPSIS... MOISTURE HAS RETURNED TO MOST OF THE REGION IN ONE FORM OR ANOTHER... WITH SHOWERS AND THUNDERSTORMS BECOMING POSSIBLE MOST ANYWHERE. THE MOISTURE RETURN CAME ABOUT AS A RESULT OF A WEAK LOW PRESSURE SYSTEM IN SOUTHEASTERN ARIZONA...MOIST OUTFLOWS FROM THUNDERSTORMS EAST OF THE REGION LAST EVENING AND THE FLOW ALOFT TURNING MORE SOUTHERLY IN RESPONSE TO A DISTURBANCE THAT MOVED THROUGH THE LOW PRESSURE TROUGH ALONG THE WEST COAST. IN ADDITION...A DISTURBANCE MOVING NORTHWARD OFF THE WEST COAST OF BAJA HAS HELPED BRING MOISTURE NORTHWARD INTO SOUTHEASTERN CALIFORNIA. .DISCUSSION... DEFINITE UPSWING IN CONVECTIVE ACTIVITY AS MOISTURE SURGED BACK NWWD INTO THE REGION. ISOLATED SHOWERS AND THUNDERSTORMS APPEAR POSSIBLE IN MOST OF THE CWA NOW...WITH JUST THE RIVER ZONES AND YUMA LEFT OUT FOR NOW. STORMS ON THE BAJA SPINE SHOULD NOT MOVE FAR ENOUGH NEWD TO REACH THE YUMA AREA....WHILE THE SERN CA ZONES WILL SEE SOME ACTIVITY OVER THE HIGHER TERRAIN AREAS. MODELS ARE AT ODDS ABOUT KEEPING THE MOISTURE OR DRYING THE REGION OUT. OPTING FOR THE WETTER CHOICE...AS IT SEEMS IT WILL NOT DEVELOP A STRONG ENOUGH SWLY FLOW OVER THE AREA TO SCOUR THINGS OUT. IN ADDITION...LOOKING OUT FOR VORT MAXIMA MOVING NEWD IN THE FLOW TO CAUSE SOME PROBLEMS. JUST TOO HARD TO TIME THEM TO REFINE THE FORECAST. SO...ZWILL USE A FAIRLY BROAD-BRUSHED FORECAST APPROACH...STAYING A LITTLE MORE CONSERVATIVE THAN THE ETA BUT NOT AS MUCH AS THE OTHER MODELS. WILT
In the hours before
Special weather statement, Jul 18, 11:52 AM MST, 4 hours 34 minutes before
AZZ022>024-028-190640- HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE PHOENIX AZ 1152 AM MST SUN JUL 18 1999 ...THERE WILL BE A CHANCE OF SHOWERS AND THUNDERSTORMS...WITH HEAVY RAIN POSSIBLE...IN NORTHERN MARICOPA...NORTHWEST PINAL AND SOUTHERN GILA COUNTIES THIS AFTERNOON AND THIS EVENING... A LOW PRESSURE SYSTEM OVER SOUTHEASTERN ARIZONA WILL MOVE NORTHEAST TODAY AND TONIGHT...ENHANCING THE POSSIBILITY OF THUNDERSTORMS WITH HEAVY RAIN IN THE AFOREMENTIONED AREAS...INCLUDING THE METROPOLITAN PHOENIX AREA. MOTORISTS AND OTHERS WITH OUTDOOR INTERESTS SHOULD BE ALERT TO THE POSSIBILITY OF LOCAL FLOODING OF WASHES...HIGHWAY DIPS AND OTHER NORMALLY DRY AREAS IF THUNDERSTORMS DEVELOP AS FORECAST. THIS OUTLOOK WILL BE ISSUED ONLY ON DAYS WHEN SOME FORM OF HAZARDOUS WEATHER IS EXPECTED SOMEWHERE OVER THE PHOENIX AREA OF WARNING RESPONSIBILITY...WHICH INCLUDES SOUTH-CENTRAL AND SOUTHWEST ARIZONA AS WELL AS FAR SOUTHEAST CALIFORNIA. FOR PURPOSES OF THIS OUTLOOK HAZARDOUS WEATHER REFERS TO ANY OF THE FOLLOWING...LOCALLY HEAVY RAINFALL WHICH RESULTS IN FLOODING AND RUNNING WASHES...SAND OR DUST STORM WHICH REDUCES VISIBILITY TO ONE QUARTER MILE OR LESS...DAMAGING WINDS IN EXCESS OF 57 MPH...AND HAIL AT LEAST THREE QUARTERS OF AN INCH IN DIAMETER. WHEN HAZARDOUS WEATHER IS IMMINENT OR OCCURRING...THE PHOENIX NATIONAL WEATHER SERVICE FORECAST OFFICE WILL PROVIDE IMPORTANT LIFE- SAVING INFORMATION IN THE FORM OF WARNINGS...FOLLOW-UP STATEMENTS... AND SHORT TERM FORECASTS. STORM SPOTTER ACTIVATION MAY BE NECESSARY LATER TODAY. WILT
Special weather statement, Jul 18, 11:52 AM MST, 4 hours 34 minutes before
AZZ022>024-028-190640- HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE PHOENIX AZ 1152 AM MST SUN JUL 18 1999 ...THERE WILL BE A CHANCE OF SHOWERS AND THUNDERSTORMS...WITH HEAVY RAIN POSSIBLE...IN NORTHERN MARICOPA...NORTHWEST PINAL AND SOUTHERN GILA COUNTIES THIS AFTERNOON AND THIS EVENING... A LOW PRESSURE SYSTEM OVER SOUTHEASTERN ARIZONA WILL MOVE NORTHEAST TODAY AND TONIGHT...ENHANCING THE POSSIBILITY OF THUNDERSTORMS WITH HEAVY RAIN IN THE AFOREMENTIONED AREAS...INCLUDING THE METROPOLITAN PHOENIX AREA. MOTORISTS AND OTHERS WITH OUTDOOR INTERESTS SHOULD BE ALERT TO THE POSSIBILITY OF LOCAL FLOODING OF WASHES...HIGHWAY DIPS AND OTHER NORMALLY DRY AREAS IF THUNDERSTORMS DEVELOP AS FORECAST. THIS OUTLOOK WILL BE ISSUED ONLY ON DAYS WHEN SOME FORM OF HAZARDOUS WEATHER IS EXPECTED SOMEWHERE OVER THE PHOENIX AREA OF WARNING RESPONSIBILITY...WHICH INCLUDES SOUTH-CENTRAL AND SOUTHWEST ARIZONA AS WELL AS FAR SOUTHEAST CALIFORNIA. FOR PURPOSES OF THIS OUTLOOK HAZARDOUS WEATHER REFERS TO ANY OF THE FOLLOWING...LOCALLY HEAVY RAINFALL WHICH RESULTS IN FLOODING AND RUNNING WASHES...SAND OR DUST STORM WHICH REDUCES VISIBILITY TO ONE QUARTER MILE OR LESS...DAMAGING WINDS IN EXCESS OF 57 MPH...AND HAIL AT LEAST THREE QUARTERS OF AN INCH IN DIAMETER. WHEN HAZARDOUS WEATHER IS IMMINENT OR OCCURRING...THE PHOENIX NATIONAL WEATHER SERVICE FORECAST OFFICE WILL PROVIDE IMPORTANT LIFE- SAVING INFORMATION IN THE FORM OF WARNINGS...FOLLOW-UP STATEMENTS... AND SHORT TERM FORECASTS. STORM SPOTTER ACTIVATION MAY BE NECESSARY LATER TODAY. WILT
The office that day
Everything else NWS Phoenix, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 18, 4:16 PM MST | Flash Flood Warning | PSR | Gila | 119 min |
Nearby
Severe Thunderstorm Warnings in Arizona, 1999Every severe thunderstorm 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; verification from NCEI's Storm Data.