City #10: Grand Forks, ND (KGFK) & The Final City of the Year!

Congratulations on making it to the end of the WxChallenge 2013-14 year! The final standard forecast city of the challenge is the one that we all had the chance to vote on and the winner is Grand Forks, ND (KGFK)! I'm biased and think that's a random location and would much prefer to forecast for an adorable city on the coast of Maine or something like that but Grand Forks will have to do. If you advance into the tournament (are in the top 64 of all forecasters at all levels who are full-year participants) then you have one last city after KGFK, otherwise everyone can forecast for the tournament city as a low-pressure bonus city just for fun. We will be forecasting for Grand Forks, ND from 24 March - 3 April for the 24-h period from 06-06 UTC (1 AM - 1 AM CDT). Forecasts are still due by 00 UTC (8 PM EDT).

Grand Forks, ND (KGFK) is in northeastern North Dakota right near the border of Minnesota. The city is found along the Red River (where it forks from the Red Lake River, and it forks grandly at that) and is forever remembered for the 1997 Red River Flood that thankfully wasn't responsible for any fatalities but was responsible for about $3.5 billion in damage. There's no topography to speak of so that saves some typing. Let's just jump straight to stalking the airport.



The airport is Grand Forks International Airport and is located to the west of the city center and the Red River seemingly surrounded by farm fields. The WMO ID is 72757. The average high temperature for March - April can vary from 30's - 50's F and the average low temperature is in the 30's - 40's F but just looking at the 850-hPa temperature standardized anomaly forecast from the GFS shows that Grand Forks will be dealing with an air mass that is -2 sigma colder than normal. After familiarizing oneself with observations (satellite, surface obs, etc.) it would be a good idea to head over to see what the experts are saying at the Grand Forks NWS WFO.

Large-Scale Pattern:

The pattern looks to be amplified early in the period but then flattening out to become more zonal during our first week of forecasting for GFK according to the GFS 500-hPa geopotential height forecast. The main story early on will be how cold it will get with much lower than average temperatures expected. A few short waves passing either to the north or south of GFK may provide some scattered snow showers but there are no strong, organized systems on the horizon for our first week.


Tips/Comments for Forecasting in General:

• Check out the current weather first via satellite, radar (pretty good radar coverage in ND!), surface observations, METAR, etc. You have to understand the present before you can look to the future. 
• Get a feel for general pattern from NAM, GFS, etc. (available from here and here, for example). Identify the general pattern of low and high surface pressure systems and their progression, temperature advection at 850 mb, moisture at 700 mb, vorticity at 500 mb and the general jet structure at 300 mb. Make sure you are focusing your attention on Grand Forks.
• Look at forecast model soundings for the period for KGFK.
• How are the models evolving in time? Check out d(model)/dt plots like this one that focuses on the GFS.
• Ensembles are your friend. Here's a cool page for some spaghetti from the GEFS. Here's a winter-specific SREF page just for fun.  
• Compare your idea for values with MOS (model output statistics).  Keep in mind these are instantaneous output values and you can always have values above/below that between output times. 
• Read the Grand Forks, ND WFO forecast discussion for info on KGFK. These are the experts for that location, after all! 
• Other universities have great WxChallenge-specific pages:
• http://www.atmos.washington.edu/~wxchallenge/
• http://www.meteor.iastate.edu/ams/wxchallenge/
• http://schumacher.atmos.colostate.edu/weather/model_compare_wxc.php  

• The SBU-WRF run by Professor Colle's research group has Grand Forks in their 36-km domain and can be found here:
• http://dendrite.somas.stonybrook.edu/LI_WRF/

Tips/Comments for Forecasting for High/Low temperature (Fahrenheit):

• Recall such basics as nighttime radiative cooling and daytime solar radiative heating, both of which are affected by cloud cover, snow cover, and fog. Is there snow cover? Check out here!
• Frontal passages can affect your temperature forecast. Pay attention to the forecast timing of such frontal passages.
• Given quiet synoptic players, the evening dew point can act as a rough guess for the nighttime low (some forecasters use this as a first guess when they think the model output statistics (MOS) is bonkers). Therefore the wind direction may be a good indicator of humidity which may affect the nighttime temperatures.

Tips/Comments for Forecasting Wind Speed (knots):

• NWS outputs wind speed in mph so if you are comparing your forecast value to theirs keep that in mind. Otherwise the models output wind speed (WSP) in knots.
• Look through METAR or surface obs for wind direction and temperature changes. 

Tips/Comments for Forecasting Precipitation (inches):

• Take a look at some higher-resolution models (e.g. WRF, hi-res NAM) or compare a whole bunch at once using a meteogram (ISU)
• What does the WPC show? 
• Take a look at some GFS model-derived standardized anomalies of precipitable water (PWAT) to get a handle on any significant movement of the forecast of dry air or very moist air.
• Take a look at some ensemble data (e.g. SREF or for a zoomed-in national look try here. And for a winter-weather specific SREF page then check this out.)
• Most products you will be looking at will output the QPF in inches already so no conversion is necessary. Recall that we are forecasting for the liquid precipitation so if the forecast calls for snow, make sure you aren't forecasting 4 inches-- use the liquid equivalent.

Be sure to check out a previous post found here for a long list of great resources that you should check out! Most of them are also found on Dr. Colle's Coastal Meteorology and Atmospheric Prediction (COMAP) group's website. Please feel free to comment below with any cool sites or tools that you've discovered from your experience!

Forget the spoons. Forget the knives. Grab your grandest forks for this point-forecast! Best of luck with forecasting for KGFK and let's go Team SBU!

City #9: Redding, CA (KRDD)

Say good-bye to the East Coast since we are now going to be moving on to City #9 of the year which is Redding, California (KRDD). Does anyone know where Redding, CA is? I sure don't because I have only been in California for half of a day at Death Valley National Park (#sheltered Long Islander). All the more reason to get aquainted with KRDD with this blog post! Anyway, we will be forecasting for Redding from 10-20 March for the 24-h period from 06-06 UTC which is 11-11 PM PDT and the forecasts are still due by 00 UTC which is now 8 PM EDT!!! Hopefully you noticed that the clocks changed (Spring ahead) otherwise you may have been having a rough week with showing up late to classes.

Source

Redding, CA is located in north-central California (NORCAL)  on the northern periphery of the Sacramento Valley essentially surrounded by mountains except to its south. The Klamath Mountains are to its northwest and the Cascades are to its east and northeast. With all that terrain and with the Pacific Ocean so close by, I'd start out every forecast by checking out the latest loop of water vapor imagery to pick out potential moisture plumes and systems off the coast. (Check out this loop for a 500 mb analysis overlaid on satellite. Or this one with NCEP-analyzed surface fronts!) For a focused look at the forecast moisture transport, check out this link for integrated water vapor transport from the GEFS (global ensemble forecast system) for out to 384 forecast hours. Time to stalk the airport!

KRDD is Redding Municipal Airport and is located to the southeast of the city center. It has a WMO ID of 72592 and an elevation of 153 m which is actually pretty low considering all of the surrounding terrain and that parts of the outskirts of Redding rise to about 800 m. The representative NWS WFO is Sacramento, CA and after looking at some satellite imagery I'd totally read up on what these expert forecasting for NORCAL have to say in their area forecast discussion (AFD).   



Given that we are forecasting for a site entrenched in terrain on the West Coast of the United States, I think it would be a good idea to review the concept of orographic precipitation. We all know that if air is sufficiently moist and is lifted that it reaches a point in which the air becomes saturated and the water vapor condenses into cloud. If that parcel keeps rising then some of that water can precipitate out. That's the simple idea about stable orographic flow over terrain that can cause precipitation on its windward slopes. The situation can be a bit more complex when you have preexisting synoptic features translating across areas of terrain; then you can have orographically-enhanced precipitation. And don't be fooled if the moisture is coming directly from the west and Redding lies within the shadow of the Coastal Mountains-- it may not be safe from precipitation for many reasons including that the Cascades are higher (can wring out more moisture) and perturbed flow can develop over the Coastal Mountains that can actually form a wave-like appearance and cause air to lift downstream and produce precipitation. It's a little bit long and you'll have to zoom-in, but a great guide to forecasting out west for these types of situations was put out by the Warning Decision Training Branch of NOAA and a pdf going through a whole bunch of orographic precip. goodies is found here.

Summarizing Thoughts & Large-Scale Pattern:

The pattern looks to be drying out just as we start to forecast for RDD. According to the 500 hPa heights of the GFS, a trough (that we are all very much paying attention to for its potential role in weather for us on the East Coast!) is moving out of the area and a ridge builds in its wake that remains and builds throughout our first full week of forecasting for Redding. Therefore, the forecast challenges for our first week of forecasting will be catching the temperature trends and getting those winds right. There may be some moisture to play with next week, but we'll have to wait and see.

In general-- I'd focus my particular attention to the large-scale synoptic pattern, with land falling mature cyclones and their associated moisture plumes being the most important thing to watch out for. I'd use the available hi-resolution models to get a better feel for wind patterns and diurnal temperature variations (see sections below for links).

Tips/Comments for Forecasting in General:

• Check out the current weather first via satellite, radar (beware of beam blockage out west!), surface observations, METAR, etc. You have to understand the present before you can look to the future. 
• Get a feel for general pattern from NAM, GFS, etc. (available from here and here, for example). Identify the general pattern of low and high surface pressure systems and their progression, temperature advection at 850 mb, moisture at 700 mb, vorticity at 500 mb and the general jet structure at 300 mb. Make sure you are focusing your attention on Redding.
• For forecasting for Redding, I'd look hemispherically or look at the Pacific specifically which can be done at the following links (Note: can only be done with global models for obvious reasons, i.e. domain boundaries):
•  GFS: http://www.atmos.albany.edu/student/kgriffin/maps/npac.html
•  GFS: http://www.atmos.washington.edu/~ovens/wxloop.cgi?h500+/-168//
• Look at forecast model soundings for the period for KRDD.
• How are the models evolving in time? Check out d(model)/dt plots like this one that focuses on the GFS.
• Ensembles are your friend. Here's a cool page for some spaghetti from the GEFS. Here's a winter-specific SREF page just for fun.  
• Compare your idea for values with MOS (model output statistics).  Keep in mind these are instantaneous output values and you can always have values above/below that between output times. 
• Read the Sacramento, CA WFO forecast discussion for info on KRDD. These are the experts for that location, after all! 
• Other universities have great WxChallenge-specific pages:
• http://www.atmos.washington.edu/~wxchallenge/
• http://www.meteor.iastate.edu/ams/wxchallenge/
• http://schumacher.atmos.colostate.edu/weather/model_compare_wxc.php  

• The GFS-WRF run by the University of Washington has Redding in their 36-km domain and a list of all of the types of qpf products can be found here:
• http://www.atmos.washington.edu/mm5rt/gfsinit.html

Tips/Comments for Forecasting for High/Low temperature (Fahrenheit):

• Recall such basics as nighttime radiative cooling and daytime solar radiative heating, both of which are affected by cloud cover, snow cover, and fog.
• Frontal passages can affect your temperature forecast. Pay attention to the forecast timing of such frontal passages especially right at the start of our first week of forecasting for KRDD!
• Given quiet synoptic players, the evening dew point can act as a rough guess for the nighttime low (some forecasters use this as a first guess when they think the model output statistics (MOS) is bonkers). Therefore the wind direction may be a good indicator of humidity which may affect the nighttime temperatures.
• The terrain around KRDD makes it a little complex to associate a specific wind direction with a specific temperature effect.

Tips/Comments for Forecasting Wind Speed (knots):

• NWS outputs wind speed in mph so if you are comparing your forecast value to theirs keep that in mind. Otherwise the models output wind speed (WSP) in knots.
• Look through METAR or surface obs for wind direction and temperature changes. 

Tips/Comments for Forecasting Precipitation (inches):

• Take a look at some higher-resolution models (e.g. WRF, hi-res NAM) or compare a whole bunch at once using a meteogram (ISU)
• The GFS-WRF run by the University of Washington has Redding in their 36-km domain and a list of all of the types of qpf products can be found here:
• http://www.atmos.washington.edu/mm5rt/gfsinit.html
• What does the WPC show? 
• Take a look at some GFS model-derived standardized anomalies of precipitable water (PWAT) to get a handle on any significant movement of the forecast of dry air or very moist air.
• Take a look at some ensemble data (e.g. SREF or for a zoomed-in national look try here. And for a winter-weather specific SREF page then check this out.)
• Most products you will be looking at will output the QPF in inches already so no conversion is necessary. Recall that we are forecasting for the liquid precipitation so if the forecast calls for snow, make sure you aren't forecasting 4 inches-- use the liquid equivalent.

Be sure to check out a previous post found here for a long list of great resources that you should check out! Most of them are also found on Dr. Colle's Coastal Meteorology and Atmospheric Prediction (COMAP) group's website. Please feel free to comment below with any cool sites or tools that you've discovered from your experience!

I don't know much about Redding except that a former boy band singer-turned solo artist Ashley Parker Angel of O-Town fame was born there. If you don't know who he is then A) I'm really old and B) you're better off.




I hope you're excited to forecast for this very different area of the country! Go Team SBU!