City #8: Newark, NJ (KEWR)

The WxChallenge moves on to a city where we all have the chance to shine- Newark, NJ. This is as close as we get to forecasting for near SBU so enjoy it! At least we can rely on the expertise of our friends at our local WFO. We are forecasting for Newark, NJ (KEWR) from 25 February - 7 March for the 24-hour period 06 UTC - 06 UTC which translates to 1 AM EST if you are looking at NWS New York. Forecasts are still due by 00 UTC which is 7 PM local time.

I'm not going to spend too much time describing Newark because (a) it is so close, (b) you may have flown out of it before, and (c) very similar weather should be expected for there as for us so there is nothing varying conceptually. However, if you do have any questions please do not hesitate to comment on this post or email me.


View Larger Map

KEWR is just south of the center of Newark, NJ and just west of Jersey City which is just west of Manhattan. Stalking the airport, we see that it is located close to Newark Bay. So we are dealing with an environment almost identical to ours. I think that forecasting for KEWR will be challenging in the same ways that it is challenging for us especially with the fact that precip depends on track and intensity of cyclones and we look to have an active, progressive pattern on our hands for our first week of forecasting.

Large-scale Pattern:
Just like it will be a challenging forecast for us, so too will it be for Newark. A look at forecast 500-hPa heights according to the GFS shows that after today's ridge moves through, a trough sets up across the Eastern US bringing unsettled weather with each shortwave disturbance that forms. You can see this nicely by looking at a plot of the dynamic tropopause on the 2 PVU surface which shows the trough persisting for this entire first week of forecasting with the low-level vorticity plotted showing the GFS forecast for disturbances that, given enough moisture, may cause some precip. Another way of looking for forcing for ascent is to isolate the Q-vector convergence from the QG-Omega equation. Warm colors represent Q-vector convergence and Tuesday night's system stands out and then there is some weak forcing present other times during the week. So we've got a strong system to deal with Tuesday-Wednesday and general troughiness for the rest of the week.


Tips/Comments for Newark, NJ (KEWR) aka Home Sweet Home-ish:

• Look at more than one deterministic model, especially side-by-side comparisons, toggling between models (Mode: Clickable Map), or even better- ensembles (SREF/GEFS Plumes, SREF Maps, GEFS Maps).
• WxChallenge's wind forecast is for sustained, not gusts. Instead of just looking at plan-view maps at or near the surface, try taking a look at forecast soundings. The measured wind speed is a 2-minute average. Gusts often occur because with heavy precip, higher momentum air can be brought down to the surface, i.e. winds reach the surface via more than just mixing, but unless they persist for about 2-minutes they won't verify. 
• Really read the NWS Area Forecast Discussion (AFD). Some of you may even know the forecaster who wrote the short term  section.

 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 Newark.
• Look at forecast model soundings for the period for KEWR.
• 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 New York, NY WFO forecast discussion for KEWR.

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. 

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)
• What does the HPC show?
• Take a look at some ensemble data (e.g. SREF (if no local option then try SPC's SREF page))
• Most products you will be looking at will output the QPF in inches already so no conversion is necessary.

Alright guys- Team SBU has a distinct advantage here due to us being a stone's throw away from the city! We know and live in this environment, however, Mother Nature is a tricky lady and threw a complicated pattern at us. We can handle it, Fuh-gedda-boud-dit! Go Team SBU!!

City #7: Burbank, CA (KBUR)

The WxChallenge moves on from Austin,TX to a city with a bit less weather. After all of the excitement we experienced personally with "Nemo" maybe forecasting for Southern California can be a way to relax. City #7 is the second city for the spring 2013 semester. We are forecasting for Burbank , CA (KBUR) from 11 February- 21 February for the 24-hour period 06 UTC - 06 UTC which translates to 10 PM local Burbank time (PST = UTC - 8) if you are looking at NWS Las Angeles/Oxnard . Forecasts are still due by 00 UTC which is 7 PM local Long Island time (EST).

Burbank, CA is located just north of Los Angeles and northwest of Hollywood. Imagine having to actually forecast for that area... I wouldn't want to make movie stars cranky, although there isn't much weather so perhaps it is a low-risk forecasting gig. Sorry, I digress.

To familiarize ourselves with the area, it is time to stalk the airport. KBUR is Burbank-Glendale-Pasadena or Bob Hope International Airport. Burbank is located on the eastern edge of the San Fernando Valley. Since it is in a valley, it is surrounded by higher terrain known as the Transverse Range. KBUR is close to the base of the Verdugo Mountains (highest peak = 953 m) to its northeast with the San Gabriel Mountains (highest peak = 3069) farther northeast past the Verdugos. The Santa Monica Mountains (highest peak = 948 m) and Chalk Hills (highest peak = 331 m) are close to the south of the city. A bit west of KBUR is the Simi Hills (highest peak = 652 m). Further from KBUR lies the Santa Susana Mountains (highest peak = 1142 m) to its northwest. Scroll around on the provided Google Map to get a better feel for the terrain.



View Larger Map

So why am I pointing out each small cluster of hills and mountains? Because when there are no synoptic players around to drive the winds, mountain wind systems prevail and will influence temperatures, especially when there is an absence of cloud and the valley and mountain are exposed to full solar insolation and nighttime radiative cooling.

To simplify things, I'll explain things in an idealized sense. Let's say you have a mountain peak and it slopes down into a valley. During the day, the mountain top receives more solar insolation because it is higher so the solar radiation isn't depleted by having to travel through that extra bit of atmosphere like it has to to reach the valley surface. So because the mountain top is receiving extra energy, its surface warms, air above the surface warms and rises freely because the environment at that elevation is cooler than that of the valley due to elevation differences alone. So because air is rising at the top, air rushes in from the valley to fill it. This phenomenon is known as anabatic wind or upslope-flow and occurs during the daytime on calm, sunny days. A similar phenomenon occurs at night, called the katabatic wind or down-slope/drainage flow. Similar physical principles are involved in the fact that at night the top of the mountain will radiatively cool, become more dense and a resulting downslope flow will develop. As the air descends, it will warm.

Unfortunately, KBUR is nestled within 2-50 km of a few hill/mountain ranges of varying altitudes. And these are coastal mountains with the Pacific lying less than 100 km to the southwest. So to summarize my thoughts on what to look for--

• Downslope warming from northeasterly flow. 
• Relatively heavy precip if system brings moist, southeasterly flow (i.e. ahead of a strong low that happens to be anomalously lower in latitude than normal... doubtful for February but we'll see...)
• Dry conditions from any offshore flow pattern

Large-scale Pattern:
A look at forecast 500-hPa heights according to the GFS shows that a ridging pattern will persist throughout our first week of forecasting for KBUR. High pressure dominates with no threat of precip. Easterly and Northeasterly flow could allow for high temps to get a littler higher due to downsloping.


 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 Burbank.
• Look at forecast model soundings for the period for KBUR.
• 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 Las Angeles WFO forecast discussion for KBUR.

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. 
• Downslope flow = warming through adiabatic descent!

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. For example, easterly/northeasterlies can have localized warming effects at Burbank.

 
Tips/Comments for Forecasting Precipitation (inches):

• Take a look at some higher-resolution models (e.g. WRF)
• What does the HPC show?
• Take a look at some ensemble data (e.g. SREF (no local option so try SPC's SREF page))
• Most products you will be looking at will output the QPF in inches already so no conversion is necessary.

Alright guys- time to blast some Katy Perry and Beach Boys, grab your stunna-shades (are those even still a thing?), and demand someone to fetch you two Fiji Waters (one for your tea-cup chihuahua) and forecast for Burbank, CA! Go Team SBU!