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Wind Observations

Pacific Northwest Pressure Gradients

TTAA00 KSEW 080715
** SEW GRADIENT TABLE 11/08/09 07Z **                              080715Z

       UIL-  OTH-  PDX-  OLM-  UIL-  HQM-  AST-  BLI-  UKI-  AST-  BLI-  BLI-
DD/HH  BLI   SEA   BLI   BLI   NUW   SEA   UIL   YZT   UIL   SEA   YQQ   YWL 
08/07  -1.0  +5.2  +4.2  +1.7  -1.1  -1.0  +2.5  +5.8  +8.1  -0.4  +3.1  +6.5
08/05  -0.4  +6.1  +4.4  +1.8  -0.6  -0.6  +2.2  +5.4  +9.1  -0.2  +2.7  +6.0
08/03   0.0  +6.5  +5.1  +1.8  -0.3  -0.9  +1.9  +5.0  +8.4   0.0  +3.1  +6.4
08/01  -0.4  +7.1  +5.4  +1.8  -0.6  +0.1  +2.7  +4.2  +8.6  +0.8  +2.8  +6.4
07/23  -0.4  +6.4  +4.8  +1.6  -0.4  -0.8  +2.4  +3.8  +9.5  +0.2  +2.7  +7.5
07/21  +0.1  +7.5  +6.2  +2.1  -0.2  -0.8  +2.2  +4.0 +10.4  -0.1  +2.2  +7.0
07/19  -0.4  +7.9  +6.0  +2.6  -0.7  -1.5  +3.5  +4.3 +12.3  -0.2  +2.3  +6.3
07/17  -0.5  +8.6  +6.7  +3.1  -1.3  -1.9  +2.9  +4.8 +13.1  -0.7  +2.3  +6.5
07/15  -1.4  +7.8  +6.1  +2.3  -1.2  -1.7  +4.0  +6.0 +12.6  +0.2  +4.0  +7.5
07/13  -1.6  +7.5  +5.3  +2.1  -1.9  -0.9  +4.1  +6.9 +11.8  +0.3  +4.8  +8.4
07/11  -0.4  +7.7  +5.9  +2.3  -0.7  -0.8  +3.4  +6.5 +10.7  +0.4  +4.0  +8.2
07/09  -0.5  +7.7  +6.3  +2.8  -0.4  -0.8  +3.8  +5.9 +11.5  +0.4  +4.5  +7.5
07/07  -1.6  +7.3  +4.9  +2.1  -1.5  -1.4  +3.4  +6.7 +12.0  -0.9  +4.1  +7.1

       PDX-  UIL-  CLM-  SEA-  SEA-  OLM-  SEA-  YKM-  SHN-  SHN-  SEA-  SMP-
DD/HH  DLS   CLM   NUW   EAT   YKM   YKM   GEG   GEG   SEA   NUW   SMP   EAT 
08/07  -0.5  -0.3  -0.8  +3.0  +0.8  +0.6  +3.2  +2.4  -1.3  +0.5  +2.1  +0.9
08/05  -1.0  -0.9  +0.3  +2.5  +0.5  +0.3  +2.7  +2.2  -1.2  +0.6  +1.9  +0.6
08/03  +0.5  +0.5  -0.8  +2.5  +0.9  +0.8  +2.9  +2.0  -1.2  +0.4  +2.1  +0.4
08/01  +0.1  +0.1  -0.7  +1.6  +0.4  +0.7  +0.2  -0.2  -0.2  +1.1  +1.4  +0.2
07/23  +1.0  -0.2  -0.2  +1.3  +1.6  +1.4  +0.2  -1.4  -1.4  +0.4  +1.3   0.0
07/21  +2.6  +0.9  -1.1  +2.2  +0.9  +0.6  -0.2  -1.1  -1.5  +0.6  +0.8  +1.4
07/19  +0.4  -0.1  -0.6  +2.1  +0.7   0.0  -0.6  -1.3  -2.0  +1.0  +1.2  +0.9
07/17  -0.3  -1.0  -0.3  +0.4  -1.1  -1.1  -0.7  +0.4  -2.0  +0.3     M     M
07/15  +0.2  -0.3  -0.9  +0.7  -0.7  -0.8   0.0  +0.7  -1.8  +0.8  +0.6  +0.1
07/13  +0.3  -0.5  -1.4  +2.3  +0.3  +0.2  +0.6  +0.3  -0.9  +1.0  +1.4  +0.9
07/11  +0.6  -0.2  -0.5  +2.0  +1.1  +0.8  -0.3  -1.4  -1.9  +0.4  +1.5  +0.5
07/09  +0.7  +0.3  -0.7  +1.3   0.0  -0.1  -1.6  -1.6  -1.4  +1.6  +1.7  -0.4
07/07  -0.7  -0.6  -0.9  +1.1  +0.1  -0.5  -0.6  -0.7  -1.1  +1.7  +1.2  -0.1

 
 Rules of thumb for estimating wind speed and direction based on local pressure gradients:
  (UIL-BLI) x 10 = Use if gradient is positive. Results in west wind thru the Strait of Juan De Fuca.
  (UIL-BLI) x 5 = Use if gradient is negative. Results in east wind thru the Strait.

  (OTH-SEA)

= South wind at SEA if gradient is positive. North wind if gradient is negative.
  (PDX-BLI) x 5 =

South wind at SEA if gradient positive. North wind if gradient negative.

  (OLM-BLI) x 10

= South wind at SEA if gradient positive. North wind if gradient negative.
  (SEA-EAT) = Westerly component at SEA if gradient positive. Easterly if gradient negative.
  (SEA-GEG) = Westerly component at SEA if gradient positive. Easterly if gradient negative.
  (SEA-SMP) = Westerly component at SEA if gradient positive. Easterly if gradient negative.
 Show Decoded Data Show METAR/TAF 
KSEA   07 Nov 11:53 pm
Temperature43°F
Dew Point39°F
Ceiling (×100ft)035
Visibility9sm
Weather-RA
Altimeter29.97"Hg
Wind180° / 10kt
KSEA  METAR
KSEA 080753Z 18010KT 9SM -RA SCT030 BKN035 OVC045 06/04 A2997 AO2 SLP157 P0002 T00610039 400830044
KSEA  TAF
KSEA 080520Z 0806/0912 16010KT P6SM VCSH SCT025 BKN050 BKN100
    TEMPO 0810/0814 18012G22KT -SHRA BKN025 OVC050
  FM082100 14008KT P6SM SCT050 OVC100
  FM090500 12014KT P6SM SCT040 OVC080

SEA TRACON WEATHER IMPACTS
ISSUED: 11/7/2009 7:58:49 PM  
PSCZ CONF TIME WIND SHIFT INFO
BFI      
SEA      
WIND (>40KT AOB 050) DIR/SPD/LEVEL
SEA      
TS (WITHIN 10 MILES)
BFI    
SEA    
FOG (VIS < 1 MILE)
BFI    
SEA    
  

ZSE ARTCC PIREP REQUIREMENTS

Issued: 11/7/2009 7:45:18 PM

AREAS

HAZARDS    A       B       C       D   
ICING X X X X
LO-TURB X X X X
LLWS        
HI-TURB X X    
TSTM X X    
CIG <050 X X X X
IFR     X  

Click here for ZSE Area Map


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