September 21, 2016

Fall Equinox

Well the first dusting of snow has appeared in the high country.  I hope all had a fabulous summer and are gearing up for a great winter.

Below is the official ENSO (El Nino/ La Nino) Fall/Winter Forecast:

Summary: ENSO-neutral conditions are present.  La Niña is slightly favored to develop during August-October 2016, with about a 55-60% chance of La Niña during the fall and winter 2016-17.   In other words a neutral ESNO trending toward a weak La Nina winter.

What does this mean for us?  Historically,  an average winter.   What is average – 480” of snow starting in mid to late November.     




ENSO Alert System Status: Not Active

Synopsis:  ENSO-Neutral conditions are slightly favored (between 55-60%) during the upcoming Northern Hemisphere fall and winter 2016-17.
ENSO-Neutral conditions were observed over the past month, although sea surface temperatures (SSTs) were below-average over the east-central equatorial Pacific Ocean (Fig. 1). While the Niño-3.4 and Niño-3 regions remained around -0.5°C for most of the month, Niño-4 and Niño 1+2 were -0.1°C and +0.3°C, respectively, by the end of the month (Fig. 2). Subsurface temperatures across the eastern and central Pacific remained below average(Fig. 3), and negative temperature anomalies remained weak across the western Pacific (Fig. 4). Atmospheric anomalies over the tropical Pacific Ocean largely indicated ENSO-Neutral conditions. The traditional Southern Oscillation index and the equatorial Southern Oscillation index were weakly positive during August. The lower-level winds were near average, while the upper-level winds were anomalously westerly in a small region to the east of the International Date Line. Convection was suppressed over the western and central tropical Pacific, although less suppressed compared to last month (Fig. 5). Overall, the combined ocean and atmosphere system continues to reflect ENSO-Neutral.
The multi-model averages favor borderline Neutral-La Niña conditions (3-month average Niño-3.4 index less than or equal to -0.5°C) during the Northern Hemisphere fall, continuing into winter (Fig. 6). However, the more recently updated model runs from the North American Multi-Model Ensemble (NMME) more strongly favor ENSO-Neutral (Fig. 7). The forecaster consensus prefers this outcome, which is supported by the lack of significant anomalies in several indicators over the past month (winds, convection, subsurface temperatures). Overall, ENSO-Neutral conditions are slightly favored (between 55-60%) during the upcoming Northern Hemisphere fall and winter 2016-17 (click CPC/IRI consensus forecast for the chance of each outcome for each 3-month period).
This discussion is a consolidated effort of the National Oceanic and Atmospheric Administration (NOAA), NOAA's National Weather Service, and their funded institutions. Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center web site (El Niño/La Niña Current Conditions and Expert Discussions). Forecasts are also updated monthly in theForecast Forum of CPC's Climate Diagnostics Bulletin. Additional perspectives and analysis are also available in an ENSO blog. The next ENSO Diagnostics Discussion is scheduled for 13 October 2016 . To receive an e-mail notification when the monthly ENSO Diagnostic Discussions are released, please send an e-mail message to: ncep.list.enso-update@noaa.gov.

Climate Prediction Center
National Centers for Environmental Prediction
NOAA/National Weather Service
College Park, MD 20740

NOAA/ National Weather Service
National Centers for Environmental Prediction
Climate Prediction Center
5830 University Research Court
College Park, Maryland 20740
Page Author: Climate Prediction Center Internet Team
Page last modified: 8 September 2016


April 23, 2016

MOUNTAIN WEATHER FORECAST

Time and Day: 0700 Saturday

The Snapshot:   Breezy, cooler temperatures with light passing rain showers and sun break today; mixed rain and snow tonight with a drying trend beginning tomorrow. 

The Science: Satellite imagery shows spotty showers with patchy clouds over the Cascades this morning.  Some upper-level ridging will provide some clear periods between the showers for most of today.   This ridging will also play a part in keeping the bulk of the moisture west of the crest tomorrow.   Therefore, expect the weekend to have a mixed bag of sun, rain, and snow.  Fitting for the final weekend of the season. 

The Long Range:  Next week will be mostly dry with cooler temperatures.  

P.S. This will be the last official Mountain Weather Forecast for the season.  Have a great summer everyone.

Precipitation Ending at 4am:

Today 24hr water = .25-.5  Snow = 0-2

Tomorrow’s 24hr water = .25 snow = trace

Trend and Timing:
Rain showers today with mixed rain and snow tonight, partial clearing and drying tomorrow.


24hr temperature ending at 4 am tomorrow: 
                                     
Low:  30   High: 40
Freezing level: 6000’  4500’

Trend and Timing:   
Temperatures will climb to near 40 today with freezing temperatures likely early tomorrow morning.   

 
24hr Winds (mph) ending at 4 am tomorrow:
Base:  5-10 W
Ridge Top: 5-15 W

Trend and Timing:
Gusty westerly winds will continue through the next 24 hrs.




jM

April 22, 2016

MOUNTAIN WEATHER FORECAST

Time and Day: 1000 Friday

The Snapshot:   Cooler with periodic rain showers today and tomorrow; mixed rain and snow for Sunday.

The Science:  A low-pressure system off the coast of Oregon will spin bands of showers north today and tomorrow.  Cooler air aloft will also begin to invade, gradually lowering freezing levels through the weekend.  A cold front will bring more steady mixed precipitation and cooler temperatures on Sunday. 

The Long Range:  Next week will start out partly cloudy, dry and cold with some light rain showers expected towards the end of the week.

Precipitation Ending at 4am:

Today 24hr water =  .25 Snow = 0

Tomorrow’s 24hr water = .25-.5  snow =

Trend and Timing:
Light rain showers today and tomorrow. 


24hr temperature ending at 4 am tomorrow: 
                                     
Low:  34   High: 52
Freezing level: 9000’ – 5500.'

Trend and Timing:   
Freezing levels will fall to around 5000’ by early tomorrow morning and then continue to fall to 4000’ on Sunday.
b
 
24hr Winds (mph) ending at 4 am tomorrow:
Base: 0-10 WNW
Ridge Top: 5-10 WNW

Trend and Timing:
Winds begin to strengthen tomorrow with gusty ridge top winds expected tomorrow night into Sunday morning.




jM