DAY 2 CONVECTIVE OUTLOOK
VALID 06Z THU 27/03 - 06Z FRI 28/03 2003
ISSUED: 26/03 18:45Z
FORECASTER: GATZEN

GENERAL THUNDERSTORMS ARE FORECAST ACROSS IBERIAN PENINSULA

GENERAL THUNDERSTORMS ARE FORECAST ACROSS CENTRAL EUROPE

SYNOPSIS

HIGH GEOPOTENTIAL IS STILL PRESENT OVER CENTRAL EUROPE. LONG-WAVE TROUGHS ARE PLACED WEST OF THE IBERIAN PENINSULA AND OVER EASTERN EUROPE. A WEAK CUT-OFF LOW IS SITUATED OVER NORTHWESTERN GERMANY/ BENELUX/ NORTHEASTERN FRANCE. COLD AND DRY AIR IS STILL PRESENT OVER EASTERN AND SOUTHERN EUROPE. HIGHER THETA-E CAN BE FOUND OVER WESTERN AND CENTRAL EUROPE, WHERE AT PRESENT WEAK THUNDERSTORMS HAVE DEVELOPED. SOUTHWESTERN EUROPE ... WILL BE EFFECTED BY A STRONG JET STREAK ON LATE THURSDAY/ EARLY FRIDAY.

DISCUSSION

...IBERIAN PENINSULA...
EAST OF ATLANTIC LONG-WAVE TROUGH ... WARM AIRMASS HAS REACHED SOUTHWESTERN EUROPE. ABOVE 850 HPA ... 12 UTC-SOUNDINGS SHOW DRY AIR/ STEEP LAPSE RATES AND TSTMS HAVE FORMED OVER PARTS OF SPAIN. ON THURSDAY ... OCCLUSION OF ATLANTIC SURFACE-LOW IS FORECAST TO CROSS THE IBERIAN PENINSULA. ALONG THIS FRONTAL BOUNDARY, SYNOPTIC-SCALE LIFT WILL SUPPORT CONVECTION, AND THUNDERSTORMS ARE LIKELY. ON LATE THURSDAY, STRONG JET STREAK WILL REACH SOUTHERN SPAIN, AND 300 HPA- WINDS SHOULD REACH MORE THAN 100 KNOTS. ORGANISED TSTMS SHOULD BE POSSIBLE DUE TO MODERATE VERTICAL SHEAR. STRONG WIND GUSTS AND SMALL HAIL ARE LIKELY. HOWEVER ... IT IS STILL POSSIBLE, THAT STRATIFORM RAIN WILL STABILIZE THE BOUNDARY LAYER. AN UPDATE TO SLIGHT RISK OF SEVERE THUNDERSTORMS COULD BE NEEDED TOMORROW.

...CENTRAL EUROPE...
IN THE RANGE OF CUT-OFF LOW, WARM AIRMASS WILL DESTABILIZE DUE TO DIURNAL HEATING. WEAK SHEAR WILL NOT SUPPORT STRONG THUNDERSTORM DEVELOPMENT.

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