Final Spring Series Racing - post Ark-like weather

 SYNOPTIC SITUATION
The UK has been affected by some fairly stormy conditions this week and this morning starts off as no exception
A low pressure sits n the English channel and unusually so will track WNW maintaining severe gale force NE that will back and moderate by 1100 to near gale force airflow.
The airmass is currently extremely stable and there form despite the strong airflow the surface wind conditions are lower than you might expect- but the maximum gust is still high

Air temperature 13-15 Celsius

Weather: Overcast with moderate rain and drizzle until 1300-1400 then scattered cloud

Portsmouth:   HW 0450    LW 1029




KEY POINTS
- big mean to gust ratio- so will be squally- www.bramblemet.co.uk
- rain and drizzle easing  0900-0930- cloud lifting but not breaking indicating veer to east
- cloud breaking and clearing 1330-1400 further veer to the SE
-Gusty to begin with- with long period shifts
- shift period decreasing with clearing skies and further increasing wind

Time	Wind direction	Wind speed (KT)	MAX	Comments
0900-1100	030-060 veering 070-090	25-30 decreasing 16-21	35-40	Warm front clears through 0930-1000 wind veers and decreases
1100-1300	070-090	16-21, occasionally 12	30	Still overcast with isolated rain and drizzle
1300-1500	070-090 becoming 130-150	16-21 increasing 20-25	30	Cloud clearing increasing instability- wind building
1500-1700	130-150	20-25	30	Little change

Spring Championships part 2: no chance to dodge the rain

SYNOPTIC SITUATION
 Low pressure sits to the SSW of the UK and through the course of the day is expected to deepen and track NE.
The associated occluded front will remain slow moving over the southern half of the UK providing wet conditions
The result is a strong NE airflow will dominate the Solent building mid afternoon.

Air temperature: 12-13 Celsius

Weather: Overcast cloud with outbreaks of slight to moderate rain and drizzle through out

Portsmouth    
LW 0928      HW 1642




KEY POINTS
- A small directional trend LEFT in the surface wind conditions with the increasing breeze
- Offshore with cold sea and land- relatively stable
- Shift range increasing towards the shore 10 deg increasing to 20 deg
- marked increase in surface wind from 1400

Time	Wind direction	Wind Speed (KNOTS)	Comments
0900-1100	040-060	12-14 building 14-18	Increasing in surface as temperature increase and mixing establishes
1100-1300	040-060	14-18	Little change
1300-1500	040-060 backing 020-050	14-18 building 20-24	Gradient increasing and potentially slight backing – could see gusts to 28 KT
1500-1700	020-050	20-24 building 30-35	Max speed 40 KT

Day two of the Spring Championships and another blustery day!

Yesterday saw some fairly heavy showers and hail for some and with that some large changes in wind speed and direction- words such as squally, blustery often spring to mind.
Clouds are always a very interesting feature and often a race winning one.

SYNOPTIC SITUATION

Low pressure dominates the area with a strong WNW airflow throughout the day
Initially showers are at the periphery of the country but the airmass is deeply unstable and again expect large clouds and showers to readily develop

Air temperature: 09-11 Celsius

Portsmouth LW 0606   HW 1255

KEY POINTS
- Clouds will become the key feature from 1100 as clouds build over land
- While the wind will initially track left expect these large clouds/showers to provide up to 30 deg wind shifts and increase the wind markedly up to 25-30 KT with a small probability of 35-40 KT where there is hail associated

Time	Wind direction	Wind Speed (KNOTS)	Comments
0900-1100	260-290	10-14 occasional 17	Building breeze with increasing temperatures and cumulus developing overland
1100-1300	260-290 backing 230-260	10-14 building 16-20 occasional 22	Cumulus clouds readily turning to showers and providing squally conditions- wind speeds up to 25-30 KT and directions 300-310
1300-1500	230-260	16-20 occasional 22
1500-1700	230-260 becoming 250-270	16-20 decreasing 12-16	Gradient easing but still risk of squally showers

Its a double whammy weekend- 21st-22nd April- Warsash Spring Championships

The first of the Warsash Spring Championships this weekend with things kicking off tomorrow in a gentle to moderate WNW airflow. Last week proved to be stronger winds than forecast in association with some fairly large cumulus clouds and this week we could see the same.

SYNOPTIC SITUATION
The heavy showers and rumbles of thunder experienced overnight and early this morning are slowly disappearing as a moderate WNW builds, but as temperature scrabble towards double figures again expect further showers and possible rumbles of thunder.
A gentle to moderate WNW backing WSW airflow is expect to cover the area

Air temperature: 09-11 Celsius

Weather: partly cloudy with showers clearing SE. Large cumulus developing turning to moderate showers late afternoon

KEY POINTS
- gradient driven with cloud features being key
- could see wind up to 28-30 KT after 1400-1500
- max right likely 300-310 with showers in the afternoon

Portsmouth: LW 0536 HW 1223

Time	Wind direction	Wind speed	Comments
0900-1100	270-300	08-12 becoming 06-08 at times	Initial showers/clouds clearing to leave sunny spells but clouds beginning to build
1100-1300	270-300 backing 250-290	08-12 building 15-19	Wind speed quick to build and wind range increasing as clouds develop
1300-1500	250-290	17-19 occasional 22	Large cloud dominated features
1500-1700	250-290	17-19 building 22-25	Building gradient could touch 28 at times

What a difference 2 weeks make...Warsash Spring Series - 15th April

SYNOPTIC SITUATION
An unusual Arctic airflow covers the UK as a col has formed to the west. The result is a NNE airflow with no imminent change expected. Unstable to day time temperatures further cloud development and possible showers are expected though the risk of thunderstorms is expected to remain LOW

Air Temperature: 08-10 Celsius, wind chill 05-06 Celsius

Weather: Small amounts of cloud and early mist/haze. As temperatures increase expect increasing cloud and and possible showers from 1300

Portsmouth HW 0720 LW 1308

KEY POINTS
- Feels cold with wind
- unstable offshore conditions: short period shifts 2-4 mins up to 20 deg, gusty conditions
- slight trend left but shifts will dominate and land effects funnelling the wind out of Southampton Water
- strongest breeze likely on white group course
- decreasing breeze, slow trend left with lighter wind- quick shift right with stronger breeze

Time	Wind Direction	Wind Speed (KNOTS)	Comments
0900-1100	360-030	14-18	Wind speed increasing through thee range as mist clears- could be as light as 08 KT to begin with
1100-1300	360-020 backing 340-010	16-18 decreasing 12-16	Wind decreasing and then backing. Cumulus developing inland
1300-1500	340-010	12-16	Broken cloud spreading in
1500-1700	340-010	10-14	Little change slight decrease in surface wind with extensive cloud cover

Warsash Spring Series- Another sunny day but not as warm

SYNOPTIC SITUATION

High pressure dominates the area maintaining a gentle ENE airflow over the Solent
As temperatures increase expect this breeze to fade as a sea breeze attempts to develop

Air temperature: 15-16 Celsius

Weather:: Initially clear skies with cumulus developing

KEY POINTS
- Cumulus clouds will make the wind patchy
- decaying NE will hold longer along the shore
- developing sea breeze will be stronger along the shore

Time	Wind direction	Wind speed	Comments
0900-1100	050-080	06-09 occasional 11	Shifty and puffy conditions 15-25 deg
1100-1300	050-080 becoming variable	06-09 becoming 01-04	Wind decreasing as temperatures increase expect NE to hold for longer along the shore
1300-1500	Variable becoming 150-180	01-04	Initial light SE sea breeze attempting to establish
1500-1700	150-180 becoming 220-250	01-04 becoming 06-08	SW sea breeze finally dominating from 1530-1600