Astronomy, Photography and Weather
January 16, 2021, 09:17:26 am
Welcome, Guest. Please login or register.

Login with username, password and session length
News: IAA lecture programme continues alternate Wednesdays from September - an excellent programme of lectures- Queens University Belfast - Bell Lecture Theatre. Also keep an eye out for the Summer Events
 
  Home Help Search Gallery Staff List Login Register  

Ex-Hurricane Bill

Pages: [1]
  Print  
Author Topic: Ex-Hurricane Bill  (Read 166 times)
markt
Hero Member
*****
Posts: 1416

West Midlands, UK


View Profile
« on: August 25, 2009, 08:46:25 am »

Looks like we're in for a rough time, especially you guys in Ireland and Scotland over the next 36 hours or so as the remnants of Ex Hurricane Bill plough our way.  UK Met Office already has a 'weather advisory' out for Northern Ireland, though i'm sure that will get upgraded and extended as we go on.

I'm hoping to make the most of some solar observations this morning in the 'calm before the storm', but in the mean time batten down the hatches!
Report Spam   Logged

Share on Facebook Share on Twitter

brianb
Hero Member
*****
Posts: 1228



View Profile
« Reply #1 on: August 25, 2009, 09:23:51 am »

It may be the remnants of a hurricane but it looks like a very ordinary atlantic depression to me.

Judging from the awful smeared seeing last night the jet stream is strong & running right overhead my location.... "Bill" won't be the only one; the weather advisories relate to rain falling onto saturated ground giving a flooding risk rather than anything unusual in terms of wind or rainfall volumes.
Report Spam   Logged
martinastro
Martin Mc Kenna
Global Moderator
Hero Member
*****
Posts: 5182


Maghera, N. Ireland


View Profile WWW
« Reply #2 on: August 25, 2009, 02:06:13 pm »

Nothing too severe is expected other than heavy rain and gusty winds although ESTOFEX mentions the slight risk of a tornado and strong wind gusts...



Storm Forecast
Valid: Tue 25 Aug 2009 06:00 to Wed 26 Aug 2009 06:00 UTC
Issued: Tue 25 Aug 2009 01:58
Forecaster: VAN DER VELDE
A level 1 was issued for NE Spain mainly for large hail and flash floods.

A level 1 was issued for France and Germany mainly for flash floods and a small chance of large hail / tornado.

A level 1 was issued for Ireland for tornadoes and gusts, if storms do develop.

SYNOPSIS

Early on Tuesday, a surface level depression develops over the east coast of Spain, in advance of the upper trough, drifting to the Balearic islands and further northeastwards. The airmass around this low is unstably stratified. A weak Atlantic cold front enters eastern France and western Germany during the period and will stall there. There is little quasi-geostrophic lift over it in GFS. The model plots convergence inside the warm airmass on the north flank of the Alps where CAPE can reach over 1000 J/kg. However, remains of the overnight MCSses may degrade the conditions compared to Tuesdays model output and lay the front more to the east.

DISCUSSION

...Ireland...

During the night, an active front from a new Atlantic depression will affect the country. Some marginal instabilty is predicted at the warm front/occlusion point, in very strong shear conditions: 450 mē/sē SREH, 17 m/s LLS, and 20 m/s DLS. LCL is very low. One should be alert if indeed a convective cell forms, the primary risks would be tornado and severe gusts.


Report Spam   Logged



Pages: [1]
  Print  
 
Jump to:  

Bookmark this site! | Upgrade This Forum
SMF For Free - Create your own Forum

Powered by SMF | SMF © 2016, Simple Machines
Privacy Policy