FOBX51 EBWM 061830
SYNOPTIC BULLETIN VALID FROM :
07/01/09 00.00Z TILL 11/01/09 00.00Z
AREA : BELGIUM
ON DUTY : DJ
1. MODEL OUTPUT ASSESSMENT
==========================
MODELS AT HAND: DWD 06/12Z, GFS 06/12Z, HIRLAM 06/12Z AND
ECMWF 06/00Z. ALL MODELS ARE IN LINE TILL SUNDAY.
AFTERWARDS, ECMWF STANDS ALONE WITH FRONTAL INVASIONS
ANOUNCING THE ARRIVAL OF A MILDER, ZONAL FLOW. THE OTHERS
RETARD THAT EVENT TILL AT LEAST TUESDAY. EPS SHOWS THE SAME
INCERTAINTY, WITH LARGER SPREADING FROM SUNDAY ON. QUITE
NORMAL AS MODELS TRADITIONALLY ENDURE PROBLEMS CHANGING A
BLOCKING PATTERN IN A ZONAL.
NEVERTHELESS: LARGE RELIABILITY CAN BE RECOGNISED IN THE
MODELS.
2. SYNOPTIC SITUATION EVOLUTION UP TO D+4
=========================================
2.1 SHORT SUMMARY
-----------------
TODAY WILL BE ABOUT THE PASSAGE OF A WEAK AND FRONTOLYSING,
OCCLUDING FRONTAL SYSTEM. SLIGHTLY WARMER POLAR AND
MARITIME AIR WILL BE ADVECTED AFTERWARDS. HOWEVER, FROM
TOMORROW ON, A RIDGE OF HIGH PRESSURE TO THE N OF US WILL
GIVE WAY TO WEAK TO MOD E TO SE'LIES ADVECTING DRY AND COLD
CONTINENTAL AIR UNDER SUBSIDENCE INVERSION. DURING THE
WEEKEND, THE FLOW WILL GRADU VEER TO THE S, AND ONLY
SLIGHTLY MILDER AIR WILL BE ADVECTED. FIRST FRONTAL
INVASION IN A GRADU ZONAL FLOW IS NOT TO BE EXPECTED BEFORE
TUESDAY. TILL THEN, WINTER IS IN CHARGE.
2.2 DAILY EVOLUTION
-------------------
TODAY:
* AN UPPER RIDGE OVER THE ATLANTIC IS EXTENDING FURTHER N
WHILE SLOWLY TILTING NE. ON ITS SE'ERN FLANK, ANTICYCLONIC
DISRUPTION IS TAKING PLACE OVERHEAD AND ASSO CUT OFF LOW
WILL REMAIN OVER S'ERN FRANCE/IBERIA.
HIGH PRESSURE IS VERY MUCH IN CONTROL AND SUBSIDENCE IS AN
IMPORTANT FEATURE.
* A JET IS DIVING SE IN THE DOWNGOING BRANCH OVER
SCANDINAVIA AND ASSO COLD AIR/FRONTAL SYSTEM IS BOUND TO
MOVE OUR WAY. BELGIUM REMAINING ON THE WARM SIDE OF THE
JET, UNDER SUBSIDENCE INVERSION (FL060 TEMPO FL080-100 ON
FRONT) AND FRONT ENTERING INTO DIFFLUENCE: THE FRONT
(OCCLUDING COLD) WILL FURTHER LOOSE IDENTITY WHILST HEADING
S.
* PCIP ACCUMULATIONS INDICATE ONLY LOC 0.5-1.0L.
* T850HPA M09 TEMPO M05°C. RT18 ADJUSTED FOR PRESSURE: CA
1270GM TEMPO 1290GM ON FRONTAL PASSAGE. RT15 522-523DAM
TEMPO 525. SNOWFALL-LEVEL 0N SFC TEMPO 2-300M OVER WEST ON
FRONTAL PASSAGE. PCIP WILL BE WINTRY (SNOW), ONLY OVER
(EXTREME) WEST TEMPO SLEET OR FREEZING RAIN/DRIZZLE... NO
LARGE AMOUNTS, BUT DANGEROUS SITUATION JUST THE SAME.
* CLOUDS ENTERING N IN MORNING AND FIRST PCIP EXPECTED
ALONG DUTCH BORDER IN MORNING/EARLY FORENOON, REACHING S
AROUND NOON/ EARLY PM (INTERMITTENT! AND VERY VERY WEAK).
THURSDAY:
* SFC-HIGH AND UPPER HIGH TAKING POSITION OVER UK WITH
RIDGE-AXIS OVER HOLLAND INTO GERMANY. FLOW REMAINS E'LY
ADVECTING DRY, CONTINENTAL AIR UNDER SUBSIDENCE INVERSION.
CLOUDS WILL DISPERSE.
* NO FRONTAL INFLUENCES.
* T850HPA M09°C BECMG M03°C MAINLY CAUSED BY INCREASED
SUBSIDENCE.
FRIDAY:
* UPPER HIGH MOVING TOWARDS GERMAN BIGHT LEAVING BELGIUM ON
ITS S'ERN FLANK. SFC HIGH TAKING POSITION OVER CENTRAL
EUROPE WITH AXIS STILL OVER THE NETHERLANDS. NO CHANGE IN
WX-PATTERN.
* T850HPA GRADU M01°C.
SATURDAY:
* NO CHANGE. HIGH PRESSURE LOOSING GRIP IN COURSE OF THE
DAY. RIDGE CROSSING OVERNIGHT AND WEAK FLOW TURNING SSW
OVER WEST.
* T850HPA M01°C.
3. WEATHER
==========
3.1 FOR TODAY
--------------
OVER S AND CENTRE STARTING PARTLY CLOUDY AND MISTY. FROM N
BECMG CLOUDY TO MOSTLY CLOUDY AND VIS HARDLY IMPROVING/EVEN
DROPPING. TEMPO AND LOC LGT SNOW FROM MORNING/EARLY
FORENOON FROM THE N. OVER (EXTREME) WEST TEMPO LGT FREEZING
RAIN/DRIZZLE. NO LARGE AMOUNTS AT ALL.
IN AFTERNOON FROM N/NW SOME SMALL BREAKS AND BECMG DRY.
TMAX BTN M04°C OVER HG AND P02°C OVER WEST. WEAK TO MOD
SW'LIES GRADU VEERING NNE IN PM: 04-08KT INLAND AND 05-10KT
COT.
OVERNIGHT: PARTLY CLOUDY TO CLOUDY, MISTY AND LOC FREEZING
FOG. TMIN BTN M09 AND M03°C. MAINLY WEAK NE GRADU ENE'LIES:
03-06KT INLAND 04-08KT COT.
3.2 FOR TOMORROW
-----------------
MIST AND ISOL FREEZING FOGBANCS SOON VANISHING BECMG PARTLY
CLOUDY AND SUNNY. DRY AND COLD. TMAX BTN M05 AND 00°C. WEAK
TO MOD E'LIES 04-08KT.
OVERNIGHT: PARTLY CLOUDY AND DRY. CLEAR AND VERY COLD
NIGHT. SLIGHTLY MISTY IN MORNING. TMIN BTN M13°C OVER HG
AND M08°C COT, M10-11°C OVER CENTRE. WEAK TO MOD E TO
ESE'LIES 05-10KT.
3.3 FOR FRIDAY 09/01/09
------------------------------
PARTLY CLOUDY BY HIGH LOC MEDIUM CLOUDS AND SUNNY. DRY BUT
COLD. TMAX BTN M05°C HG AND M01°C COT. WEAK AND MOD SE'LIES
04-08KT.
OVERNIGHT: PARTLY CLOUDY AND DRY. CLEAR AND VERY COLD
NIGHT. SLIGHTLY MISTY IN MORNING. TMIN BTN M15°C OVER HG
AND M08°C COT, M10-11°C OVER CENTRE. WEAK TO MOD ESE TO
SE'LIES 04-08KT.
3.4 FOR SATURDAY 10/01/09
------------------------------
PARTLY CLOUDY BY HIGH AND LOC MEDIUM CLOUDS AND SUNNY. DRY
BUT RATHER COLD. TMAX BTN M03°C OVER CENTRE AND P01°C COT.
WEAK TO MOD E TO SE'LIES 04-07KT.
OVERNIGHT: PARTLY CLOUDY AND DRY. CLEAR AND COLD NIGHT.
GRADU MIST AND LOC FREEZING FOG-FORMATION. TMIN BTN M10°C
OVER HG AND M04°C COT. MAINLY WEAK SE'LIES 03-06KT, OVER
WEST GRADU MOD SSW.
4. OUTLOOK :
==========
4.1 FOR SUNDAY 11/01/09
------------------------------
UPPER HIGH MOVING TOWARDS POLAND WHILE UPPER RIDGE
EXTENDING FROM HIGH OF ACORES IS LINKING UP WITH IT. UPPR
RIDGE FAVOURABLY INFLUENCING OUR WX. MOBILITY REMAINS OVER
ATLANTIC TOWARDS SCANDINAVIA.
WX: MIST AND FREEZING FOG SLOWLY DISPERSING BECMG PARTLY
CLOUDY AND DRY. SUNNY. TMAX BTN M03°C HG AND P02°C COT.
WEAK TEMPO MOD S TO SSW'LIES, COT MOD SW.
OVERNIGHT: NO MAJOR CHANGE. PARTLY CLOUDY AND DRY. MIST AND
LOC FREEZING FOGBANCS. TMIN BTN M08°C HG AND M02°C COT. MOD
S'LIES, COT GRADU MOD TO RATHER STRONG.
4.2 FOR MONDAY 12/01/09
------------------------------
UPPER RIDGE SLOWLY MOVING SE OVER THE AREA. UPPER TROUGH
APPROACHING FROM WEST. ASSO WAVING FRONT ONLY IMPORTANT
FROM NEXT NIGHT OR TUESDAY ON.
WX: MIST AND LOC FREEZING FOG SLOWLY DISPERSING BECMG
PARTLY CLOUDY AND DRY. SUNNY. CLOUDINESS INCREASING FROM
WEST IN AFTERNOON/EVENING. TMAX BTN M01°C HG AND P04°C COT.
MOD TO RATHER STRONG S'LIES, COT RATHER STRONG TO STRONG
TEMPO GUSTS IN EVENING CA 25-30KT.
OVERNIGHT: FRONTAL RAIN SPREADING INLAND, WITH A GOOD RISK
OF FREEZING RAIN. OVER ARDENNES RAIN WILL TURN IN SNOW.
TMIN BTN M05°C OVER HG AND 00°C COT IN FIRST PART OF THE
NIGHT.
SYNOPTIC BULLETIN VALID FROM :
07/01/09 00.00Z TILL 11/01/09 00.00Z
AREA : BELGIUM
ON DUTY : DJ
1. MODEL OUTPUT ASSESSMENT
==========================
MODELS AT HAND: DWD 06/12Z, GFS 06/12Z, HIRLAM 06/12Z AND
ECMWF 06/00Z. ALL MODELS ARE IN LINE TILL SUNDAY.
AFTERWARDS, ECMWF STANDS ALONE WITH FRONTAL INVASIONS
ANOUNCING THE ARRIVAL OF A MILDER, ZONAL FLOW. THE OTHERS
RETARD THAT EVENT TILL AT LEAST TUESDAY. EPS SHOWS THE SAME
INCERTAINTY, WITH LARGER SPREADING FROM SUNDAY ON. QUITE
NORMAL AS MODELS TRADITIONALLY ENDURE PROBLEMS CHANGING A
BLOCKING PATTERN IN A ZONAL.
NEVERTHELESS: LARGE RELIABILITY CAN BE RECOGNISED IN THE
MODELS.
2. SYNOPTIC SITUATION EVOLUTION UP TO D+4
=========================================
2.1 SHORT SUMMARY
-----------------
TODAY WILL BE ABOUT THE PASSAGE OF A WEAK AND FRONTOLYSING,
OCCLUDING FRONTAL SYSTEM. SLIGHTLY WARMER POLAR AND
MARITIME AIR WILL BE ADVECTED AFTERWARDS. HOWEVER, FROM
TOMORROW ON, A RIDGE OF HIGH PRESSURE TO THE N OF US WILL
GIVE WAY TO WEAK TO MOD E TO SE'LIES ADVECTING DRY AND COLD
CONTINENTAL AIR UNDER SUBSIDENCE INVERSION. DURING THE
WEEKEND, THE FLOW WILL GRADU VEER TO THE S, AND ONLY
SLIGHTLY MILDER AIR WILL BE ADVECTED. FIRST FRONTAL
INVASION IN A GRADU ZONAL FLOW IS NOT TO BE EXPECTED BEFORE
TUESDAY. TILL THEN, WINTER IS IN CHARGE.
2.2 DAILY EVOLUTION
-------------------
TODAY:
* AN UPPER RIDGE OVER THE ATLANTIC IS EXTENDING FURTHER N
WHILE SLOWLY TILTING NE. ON ITS SE'ERN FLANK, ANTICYCLONIC
DISRUPTION IS TAKING PLACE OVERHEAD AND ASSO CUT OFF LOW
WILL REMAIN OVER S'ERN FRANCE/IBERIA.
HIGH PRESSURE IS VERY MUCH IN CONTROL AND SUBSIDENCE IS AN
IMPORTANT FEATURE.
* A JET IS DIVING SE IN THE DOWNGOING BRANCH OVER
SCANDINAVIA AND ASSO COLD AIR/FRONTAL SYSTEM IS BOUND TO
MOVE OUR WAY. BELGIUM REMAINING ON THE WARM SIDE OF THE
JET, UNDER SUBSIDENCE INVERSION (FL060 TEMPO FL080-100 ON
FRONT) AND FRONT ENTERING INTO DIFFLUENCE: THE FRONT
(OCCLUDING COLD) WILL FURTHER LOOSE IDENTITY WHILST HEADING
S.
* PCIP ACCUMULATIONS INDICATE ONLY LOC 0.5-1.0L.
* T850HPA M09 TEMPO M05°C. RT18 ADJUSTED FOR PRESSURE: CA
1270GM TEMPO 1290GM ON FRONTAL PASSAGE. RT15 522-523DAM
TEMPO 525. SNOWFALL-LEVEL 0N SFC TEMPO 2-300M OVER WEST ON
FRONTAL PASSAGE. PCIP WILL BE WINTRY (SNOW), ONLY OVER
(EXTREME) WEST TEMPO SLEET OR FREEZING RAIN/DRIZZLE... NO
LARGE AMOUNTS, BUT DANGEROUS SITUATION JUST THE SAME.
* CLOUDS ENTERING N IN MORNING AND FIRST PCIP EXPECTED
ALONG DUTCH BORDER IN MORNING/EARLY FORENOON, REACHING S
AROUND NOON/ EARLY PM (INTERMITTENT! AND VERY VERY WEAK).
THURSDAY:
* SFC-HIGH AND UPPER HIGH TAKING POSITION OVER UK WITH
RIDGE-AXIS OVER HOLLAND INTO GERMANY. FLOW REMAINS E'LY
ADVECTING DRY, CONTINENTAL AIR UNDER SUBSIDENCE INVERSION.
CLOUDS WILL DISPERSE.
* NO FRONTAL INFLUENCES.
* T850HPA M09°C BECMG M03°C MAINLY CAUSED BY INCREASED
SUBSIDENCE.
FRIDAY:
* UPPER HIGH MOVING TOWARDS GERMAN BIGHT LEAVING BELGIUM ON
ITS S'ERN FLANK. SFC HIGH TAKING POSITION OVER CENTRAL
EUROPE WITH AXIS STILL OVER THE NETHERLANDS. NO CHANGE IN
WX-PATTERN.
* T850HPA GRADU M01°C.
SATURDAY:
* NO CHANGE. HIGH PRESSURE LOOSING GRIP IN COURSE OF THE
DAY. RIDGE CROSSING OVERNIGHT AND WEAK FLOW TURNING SSW
OVER WEST.
* T850HPA M01°C.
3. WEATHER
==========
3.1 FOR TODAY
--------------
OVER S AND CENTRE STARTING PARTLY CLOUDY AND MISTY. FROM N
BECMG CLOUDY TO MOSTLY CLOUDY AND VIS HARDLY IMPROVING/EVEN
DROPPING. TEMPO AND LOC LGT SNOW FROM MORNING/EARLY
FORENOON FROM THE N. OVER (EXTREME) WEST TEMPO LGT FREEZING
RAIN/DRIZZLE. NO LARGE AMOUNTS AT ALL.
IN AFTERNOON FROM N/NW SOME SMALL BREAKS AND BECMG DRY.
TMAX BTN M04°C OVER HG AND P02°C OVER WEST. WEAK TO MOD
SW'LIES GRADU VEERING NNE IN PM: 04-08KT INLAND AND 05-10KT
COT.
OVERNIGHT: PARTLY CLOUDY TO CLOUDY, MISTY AND LOC FREEZING
FOG. TMIN BTN M09 AND M03°C. MAINLY WEAK NE GRADU ENE'LIES:
03-06KT INLAND 04-08KT COT.
3.2 FOR TOMORROW
-----------------
MIST AND ISOL FREEZING FOGBANCS SOON VANISHING BECMG PARTLY
CLOUDY AND SUNNY. DRY AND COLD. TMAX BTN M05 AND 00°C. WEAK
TO MOD E'LIES 04-08KT.
OVERNIGHT: PARTLY CLOUDY AND DRY. CLEAR AND VERY COLD
NIGHT. SLIGHTLY MISTY IN MORNING. TMIN BTN M13°C OVER HG
AND M08°C COT, M10-11°C OVER CENTRE. WEAK TO MOD E TO
ESE'LIES 05-10KT.
3.3 FOR FRIDAY 09/01/09
------------------------------
PARTLY CLOUDY BY HIGH LOC MEDIUM CLOUDS AND SUNNY. DRY BUT
COLD. TMAX BTN M05°C HG AND M01°C COT. WEAK AND MOD SE'LIES
04-08KT.
OVERNIGHT: PARTLY CLOUDY AND DRY. CLEAR AND VERY COLD
NIGHT. SLIGHTLY MISTY IN MORNING. TMIN BTN M15°C OVER HG
AND M08°C COT, M10-11°C OVER CENTRE. WEAK TO MOD ESE TO
SE'LIES 04-08KT.
3.4 FOR SATURDAY 10/01/09
------------------------------
PARTLY CLOUDY BY HIGH AND LOC MEDIUM CLOUDS AND SUNNY. DRY
BUT RATHER COLD. TMAX BTN M03°C OVER CENTRE AND P01°C COT.
WEAK TO MOD E TO SE'LIES 04-07KT.
OVERNIGHT: PARTLY CLOUDY AND DRY. CLEAR AND COLD NIGHT.
GRADU MIST AND LOC FREEZING FOG-FORMATION. TMIN BTN M10°C
OVER HG AND M04°C COT. MAINLY WEAK SE'LIES 03-06KT, OVER
WEST GRADU MOD SSW.
4. OUTLOOK :
==========
4.1 FOR SUNDAY 11/01/09
------------------------------
UPPER HIGH MOVING TOWARDS POLAND WHILE UPPER RIDGE
EXTENDING FROM HIGH OF ACORES IS LINKING UP WITH IT. UPPR
RIDGE FAVOURABLY INFLUENCING OUR WX. MOBILITY REMAINS OVER
ATLANTIC TOWARDS SCANDINAVIA.
WX: MIST AND FREEZING FOG SLOWLY DISPERSING BECMG PARTLY
CLOUDY AND DRY. SUNNY. TMAX BTN M03°C HG AND P02°C COT.
WEAK TEMPO MOD S TO SSW'LIES, COT MOD SW.
OVERNIGHT: NO MAJOR CHANGE. PARTLY CLOUDY AND DRY. MIST AND
LOC FREEZING FOGBANCS. TMIN BTN M08°C HG AND M02°C COT. MOD
S'LIES, COT GRADU MOD TO RATHER STRONG.
4.2 FOR MONDAY 12/01/09
------------------------------
UPPER RIDGE SLOWLY MOVING SE OVER THE AREA. UPPER TROUGH
APPROACHING FROM WEST. ASSO WAVING FRONT ONLY IMPORTANT
FROM NEXT NIGHT OR TUESDAY ON.
WX: MIST AND LOC FREEZING FOG SLOWLY DISPERSING BECMG
PARTLY CLOUDY AND DRY. SUNNY. CLOUDINESS INCREASING FROM
WEST IN AFTERNOON/EVENING. TMAX BTN M01°C HG AND P04°C COT.
MOD TO RATHER STRONG S'LIES, COT RATHER STRONG TO STRONG
TEMPO GUSTS IN EVENING CA 25-30KT.
OVERNIGHT: FRONTAL RAIN SPREADING INLAND, WITH A GOOD RISK
OF FREEZING RAIN. OVER ARDENNES RAIN WILL TURN IN SNOW.
TMIN BTN M05°C OVER HG AND 00°C COT IN FIRST PART OF THE
NIGHT.
Bericht laatst bijgewerkt: 06-01-2009 20:31