Weather Holding Pattern

Long range forecasts for Wednesday of next week call for afternoon highs near 75.  The question is,  are temperatures that far out even to be taken seriously.  I am going to look at that even closer this evening and try to get a sense of where everything will be situated.   Wind direction,  cloud and Jet Stream along with thickness patterns.

It felt a bit nippy out here today in Central North Carolina.   This morning we experienced some light rain and drizzle.   As well the clouds have thinned out and went from 7/10s to about 2/10 this afternoon.    This trend will continue tonight and tomorrow.

https://i2.wp.com/forecast.weather.gov/wwamap/png/US.png

This evening is going to be more of a temperature forecast.  Generally the lowest temperature after a cold front is like 24-48hrs after passage.    And fronts depending on how strong and stacked will vary due to the density of that airmass.

http://www.spc.noaa.gov/obswx/maps/300_131023_12.gif

The Jetstreams are generally noted as any wind in excess of 50 knots.   Temperatures like frontal boundaries are pushed along by these Jets.   The flags are each equal to 50k,  so two would be 100,  three 150.    The single lines are 10 for a full barb and 5 for a 1/2.

Wind Speed & Direction

Wind speed. A combination of long/short barbs and pennants indicate the speed of the wind in station weather plots rounded to the nearest 5 knots. Calm wind is indicated by a large circle drawn around the skycover symbol.

One long barb is used to indicate each 10 knots with the short barb representing 5 knots. At 50 knots, the barbs changes to a pennant. For wind speeds higher than 50 knots, long and short barbs are used again in combination with the pennant(s). (See examples below.)

Observed
wind
speed
0-2 kts
(0-2 mph)
3-7 kts
(3-8 mph)
8-12 kts
(9-14 mph)
13-17 kts
(15-20 mph)
18-22 kts
(21-25 mph)
23-27 kts
(26-31 mph)
28-32 kts
(32-37 mph)
33-37 kts
(38-43 mph)
48-52 kts
(55-60 mph)
53-57 kts
(61-66 mph)
58-62 kts
(67-71 mph)
63-67 kts
(73-77 mph)
98-102 kts
(113-117 mph)
102-107 kts
(119-123 mph)
Rounded
to the
nearest 5
0 kts 5 kts 10 kts 15 kts 20 kts 25 kts 30 kts 35 kts 50 kts 55 kts 60 kts 65 kts 100 kts 105 kts
Plotted as 0 knot wind plot 5 knot wind plot 10 knot wind plot 15 knot wind plot 20 knot wind plot 25 knots wind plot 30 knots wind plot 35 knots wind plot 50 knots wind plot 55 knots wind plot 60 knots wind plot 65 knots wind plot 100 knots wind plot 105 knots wind plot

 

Wind FROM 340°
(NNW)
Wind FROM 040°
(NE)
Wind FROM 190°
(S)

The wind direction is indicated by the long shaft. The shaft will point to the direction FROM which the wind is blowing. The direction is based upon a 36-point compass.


These parameters are defined internationally and gives the user a simple way of interpreting the symbols (synoptics).      The National Weather Service (NWS) has it’s own weather school which break down what these weather codes infer.

http://www.srh.weather.gov/jetstream/synoptic/sfc_plot_symbols.htm

High and low pressure indicated by isobars The diagram to the left shows winds circulating around the Low southward and the High to the left does the same thing.    This kind of circulation will bring colder weather.

SPC Products Overview

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s