Concord, NH was named because it was territory that was disputed between two early settlers and by naming it so they hoped it would create harmony or peace between the opposing people. Let's hope that forecasting for it is filled with peace and harmony and less hair-pulling-out than the uncertain convection that we dealt with for Norman, OK! Concord is located in south-central New Hampshire about 100 km south of the White Mountains. It is located in a flood plain of the Merrimack River at an elevation of around 150 m above sea level.
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Time to stalk KCON! KCON is located across the river from the city and has a WMO ID of 72605 and an elevation of 105 m. There is not too much in the way of complex terrain in the vicinity of Concord so that takes out a bit of mesoscale complexity for forecasting.
Large-scale Pattern:
The forecast upper-level pattern according to the GFS for the start of our first week of forecasting for Concord, NH is leading off with a strong cold frontal passage forecast for Monday evening that may force some showers but will definitely mark the new colder air mass settling into place over the Northeast. No strong synoptic players seem to be emerging for the later part of the week so the forecasting challenge should be getting the temperatures just right. I recommend playing around with BUFKIT in the Met. Lab and paying attenion to any forecast saturated layers indicating cloud cover which would definitely affect the high/low temperatures.
Tips/Comments for Forecasting in General:
- Check out the current weather first via satellite, radar, 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 Concord.
- Look at forecast model soundings for the period for KCON.
- 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.
- 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 Gray/Portland, Maine WFO forecast discussion for the GYX CWA. Keep in mind that they are covering a few diverse landscapes (coastline and higher terrain). These are the experts for that location, after all!
- Other universities have great WxChallenge-specific pages:
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 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 KCON!
- 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.
- e.g. easterly winds should be more moist (coming from the Atlantic) which means a higher dew point which means a higher nighttime temperature and northwesterly winds will advect drier air which means a lower dew point which means the possibility for lower 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.
- Take a look at some higher-resolution models (e.g. WRF)
- What does the WPC show?
- Tropical activity? (Oh my goodness, I hope not... but it is still before 1 December!)
- 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 (South Central option) or for a zoomed-in national look try here.)
- Most products you will be looking at will output the QPF in inches already so no conversion is necessary.
Alright guys- you are all doing really well with the WxChallenge and I hope that you have fun with this second-to-last forecast city for the Fall 2013 semester! It's definitely fun to be back in the Northeast, right? Pay attention to the broad synoptic pattern at hand and use your best judgement to get those diurnal temperature swings just right! If you ever have any questions please feel free to stop by my office in Challenger 121. I still have candy. That is all. Good luck with KCON and let's go Team SBU!!!
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